Microbes in Human Welfare

Microbes in Human Welfare

Bacteria

(1) Study of bacteria is called bacteriology.

(2) Linnaeous placed them under genus vermes.

(3) Nageli classified bacteria under schizomycetes.

(4) Bacteria are unicellular, microscopic organisms.

(5) These are the smallest cell wall having prokaryotic cell.

(6) They differ from animals in having a rigid cell wall and being capable to synthesize vitamins.

Size:

(i) Bacteria are the smallest of all known cellular organisms which are visible only with the aid of microscope.

(ii) They are 3 to 5 microns (1 m = 1/1000 millimetre or about 1/25,000 inch) in length.

(iii) A few species of bacteria are approximately 15m in diameter.

Shape:

(i) The shape bacteria usually remain constant.

(ii) Some of them are able to change their shape and size with changes in environmental conditions. Such bacteria, which change their shape, are called pleomorphic.

(iii) The bacteria possess the following forms.

(a) Cocci: (GK. Kokkos = Berry) They are oval or spherical in shape. They are called micrococcus when occur singly as in Micrococcus, diplococcus when found in pairs as in Diplococcus pneumoniae, tetracoccus in fours, streptococcus when found in chains as in Streptococcus lactis, staphylococcus when occurring in grape like clusters as in Staphylococcus aureus and sarcine, when found in cubical packets of 8 or 64 as in Sarcina.

(b) Bacilli: They are rod–shaped bacteria with or without flagella. They may occur singly (bacillus), in pairs (diplobacillus) or in chain (streptobacillus).

(c) Vibrios: These are small and ‘comma like, kidney like. They have a flagellum at one end and are motile, vibrio bacteria has curve in its cell e.g., Vibrio cholerae.

(d) Spirillum (Spira = Coil): The spirillum bacteria (plural-spirilla). They are spiral or coiled like a cork-screw. The spirillar forms are usually rigid and bear two or more flagella at one or both the ends e.g. spirillum, spirochaete, etc.

(e) Filament: The body of bacterium is filamentous like a fungal mycelia. The filaments are very small e.g. Beggiota, Thiothrix etc.

(f) Stalked: The body of bacterium posses a stalk e.g. Caulobacter.

(g) Budded: The body of bacterium is swollen at places e.g. Retrodomicrobiom.

Role of Bacteria in nitrogen cycle:

Nitrogen cycle existing in nature, comprises of –

Nitrogen fixation:

(1) Many free-living soil inhabiting bacteria such as, Azotobacter (aerobic), Clostridium (anaerobic), etc. have ability to fix atmospheric nitrogen into ammonia.

(2) The other group of nitrogen fixing bacteria lives in symbiotic association with other plants.

(3) The most important symbiotic nitrogen fixing bacteria is Rhizobium spp.

(4) The various species of Rhizobium inhabit different leguminous plants. For example, R. leguminosarium infects soyabeans, etc.

(5) They develop root nodules and fix atmospheric nitrogen into ammonia in symbiotic association with leguminous plants.

(6) The fixed nitrogen is partly taken up by the leguminous plants and metabolised.

(7) A part of fixed nitrogen is diffused out into the surrounding soil.

Ammonification:

(1) The nitrogenous compounds of the dead remains of plants, animals and their excretory products are decomposed into ammonia by a number of bacteria and other microorganisms.

(2) The conversion of nitrogenous organic compounds into ammonia is termed as ammonification.

(3) It is carried by many ammonifying bacteria such as Bacillus ramosus, B. vulgaris, B. mycoides, etc.

Nitrification:

(1) Many bacteria enhance the nitrogen fertility of soil by converting ammonium compounds to nitrites (e.g., Nitrosomonas) and nitrites into nitrates (e.g., Nitrobacter).

Denitrification:

The nitrates and ammonia are converted to nitrous oxide and finally to nitrogen gas by several denitrifying bacteria, e.g., Pseudomonas fluorescence, P. denitrificans, Bacillus subtilis, Thiobacillus denitirficans, etc.

Useful activities

(i) Decay of organic wastes: Many saprotrophic bacteria act as natural scavengers by continuously removing the harmful organic wastes (i.e., dead remains of animals and plants) from man's environment. They decompose the organic matter by putrifaction and decay. The simple compounds produced as a result of decomposition and decay (viz., carbon dioxide, carbon monoxide, nitrates, sulphates, phosphates, ammonia, etc.) are either released back into the environment for recycling or absorbed by the plants as food. Thus, the bacteria play duel role by disposing of the dead bodies and wastes of organisms and by increasing the fertility of soil.

(ii) Role in improving soil fertility: Saprotrophic bacteria present in soil perform various activities for their survival. Some of these activities improve the fertility of soil by formation of humus, manure, etc.

(a) Humus: The microbial decomposition of organic matter and mineralization results in the formation of complex amorphous substance called humus. The humus improves the aeration, water holding capacity, solubility of soil minerals, oxidation-reduction potential and buffering capacity of the soil.

(b) Composting: It is conversion of farm refuse, dung and other organic wastes into manure by the activity of saprotrophic bacteria (e.g., Bacillus stearothermophilus, Clostridium thermocellum, Thermomonospora spp, etc.)

(c) Adding sulphates: A few sulphur bacteria (e.g., Beggiatoa) add sulphur into the soil by converting H2S into sulphates.

(iii) Sewage, disposal: Ability of anaerobic bacteria to purify the organic matter is used in the the sewage disposal system of cities. The faeces are stored in covered reservoirs and allowed to purify. The solid matter is decomposed into liquidy sludge which is passed through coarse filters. The effluent is finally purified and drained out into the river or used as fertilizer in the fields. The common bacteria involved in sewage disposal are – Coliforms (E. coli), Streptococci, Clostridium, Micrococcus, Proteus, Pseudomonas, Lactobacillus, etc.

(iv) Role in Industry: Useful activities of various bacteria are employed in the production of a number of industrial products. Some of these are given below–

(a) Lactic acid: Lactic acid is commercially produced from pasteurized whey (the watery part of milk) through fermentation caused by Lactobacilus bulgaricus and L. delbrueckii.

(b) Curd: Curd is prepared from pasteurized milk by the process called curdling. It is initiated by adding a starter culture of Lactobacillus bulgaricus and Streptococcus thermophillus, into the milk at 40°C. Lactobacillus converts lactose to lactic acid whereas Streptococcus causes coagulation of casein due to acidity.

(c) Cheese: Preparation of cheese from the milk involves two main steps – first curdling of milk, and second the subsequent ripening of solid curd by the use of different bacterial strains.

(d) Butter: It is prepared by churning of sweet or sour cream. The microorganisms responsible for preparation of butter cream are – Streptococcus lactis and Leuconostoc citrivorumare. The characteristic butter aroma develops due to a volatile substance – diacetyl. It is produced by the action of streptococcus on pasteurized milk.

(e) Retting process: Fibres of flax, hemp and jute are separated by the process called retting. During this process the stems of the plants are submerged in water, where the bacterial activity results in the rotting of softer parts. The tough bast fibres become loosened and easily separated from each other. These fibres are spun and woven into various articles.

Lipids

Lipids

(1) Term lipid was coined by Bloor.

(2) These are esters of fatty acids and alcohol.

(3) They are hydrophobic insoluble in water but soluble in benzene, ether and chloroform.

(4) Lipids are classified into three groups:–

(A) Simple lipids: These are the esters of fatty acids and glycerol. Again they are typed as:–

(a) Fats and Oils: (Natural lipids or true fats). These are triglycerides of fatty acid and glycerol. Fats which are liquid at room temperature are called oils. Oils with polyunsaturated fatty acids are called polyunsaturated e.g. sunflower oil, lower blood cholesterol.

(b) Fatty acids: Obtained by hydrolysis of fats. Formic acid is simplest fatty acid (HCOOH). These are of 2 types:–

(i) Saturated fatty acids: The fatty acids which do not have double bond in between carbon atoms.e.g. butyric acid, palmitic acid,hexanoic acid, etc. They have high melting points, solid at room temperature and increase blood cholesterol.

(ii) Unsaturated fatty acids: The fatty acids which have double bonds in carbon atoms. e.g. 8 hexadecanoic acid, 9 octadecanoic acid etc. They have lower melting points mostly found in plant fats, liquid at room temperature and lower the blood cholesterol.

(c) Waxes: These are simple lipids composed of one molecule of long chain fatty acid and long chain monohydric alcohol. Waxes have high melting point, insoluble in water, resistant to atmospheric oxidation, chemically inert and not digested by enzymes. They reduce rate of transpiration by making plant tissue water proof and work as excellent lubricant.

(B) Compound lipids: They contain some additional or element. Group with fatty acid and alcohol on the basis of group they may be of following types:

(a) Phospholipids: These contain phosphoric acid. It helps in transport, metabolism, blood clotting and permeability of cell membrane. It is a bipolar molecule i.e. phosphate containing end is hydrophilic whereas fatty acid molecules represent hydrophobic (non-polar tail).

(b) Glycolipids: These contain nitrogen and carbohydrate beside fatty acids. Generally found in white matter of nervous system. e.g. sesocine frenocin.

(c) Chromolipids : It includes pigmented lipids e.g. carotene.

(d) Aminolipids : Also known as sulpholipids. It contains sulphur and amino acids with fatty acid and glycerol. Cutin and suberin are also compound lipids resistant to water and also provide mechanical support in plants.

(iii) Derived lipids: These are obtained by hydrolysis of simple and compound lipids.

(5) Functions of lipids

(a) Oxidation of lipids yields comparatively more energy in the cell than protein and carbohydrates. 1gm of lipids accounts for 39.1 KJ.

(b) The oil seeds such as groundnut, mustard, coconut store fats to provide nourishment to embryo during germination.

(c) They function as structural constituent i.e. all the membrane systems of the cell are made up of lipoproteins.

(d) Amphipathic lipids are emulsifier.

(e) It works as heat insulator.

(f) Used in synthesis of hormones.

(g) Fats provide solubility to vitamins A, D, E, and K.

Amino Acids

Amino Acids

(1) Amino acids are normal components of cell proteins (called amino acid).

(2) They are 20 in number specified in genetic code and universal in viruses, prokaryotes and eukaryotes.

(3) Structure and Composition : Amino acids are basic units of protein and made up of C, H, O, N and sometimes S. Amino acids are organic acids with a carboxyl group (–COOH) and one amino group(-NH2) on the a -carbon atom. Carboxyl group attributes acidic properties and amino group gives basic ones. In solution, they serve as buffers and help to maintain pH. General formula is R-CHNH2.COOH.

(4) Classification

Based on R-group of amino acids

(a) Simple amino acids: These have no functional group in the side chain. e.g. glycine, alanine , leucine, valine etc.

(b) Hydroxy amino acids: They have alcohol group in side chain. e.g. threonine, serine, etc.

(c) Sulphur containing amino acids: They have sulphur atom in side chain. e.g. methionine, cystenine.

(d) Basic amino acids: They have basic group (-NH2) in side chain. e.g. lysine, arginine.

(e) Acidic amino acids: They have carboxyl group in side chain. e.g. aspartic acid, glutamic acid.

(f) Acid amide amino acids: These are the derivatives of acidic amino acids. In this group, one of the carboxyl group has been converted to amide (-CONH2). e.g. asparagine, glutamine.

(g) Heterocyclic amino acids: These are the amino acids in which the side chain includes a ring involving at least one atom other than carbon. e.g. tryptophan, histidine.

(h) Aromatic amino acids: They have aromatic group (benzene ring) in the side chain. e.g. phenylalanine, tyrosine, etc.

Biomolecules

Biomolecules

Ptroteins

(1) The word protein was coined by Berzelius in 1838 and was used by G. J. Mulder first time 1840.  

(2) 15% of protoplasm is made up of protein. Average proteins contain 16% nitrogen, 50–55% carbon, oxygen 20–24%, hydrogen 7% and sulphur 0.3 – 0.5%. Iron, phosphorous, copper, calcium, and iodine are also present in small quantity.

(3) Structure of proteins: It is due to different rearrangement of amino acids. When carboxyl group of one amino acid binded with amino group (– NH2) of another amino acid the bond is called peptide bond. A peptide may be dipeptide, tripeptide and polypeptide. The simplest protein is Insulin. According to Sanger (1953) insulin consists of 51 amino acids. A protein can have up to four level of conformation.

(i) Primary structure: The primary structure is the covalent connections of a protein. It refers to linear sequence, number and nature of amino acids bonded together with peptide bonds only. e.g. ribonuclease, insulin, haemoglobin, etc.

(ii) Secondary structure: The folding of a linear polypeptide chain into specific coiled structure (α - helix) is called secondary structure and if it is with intermolecular hydrogen bonds the structure is known as ß - pleated sheet. α - helical structure is found in protein of fur, keratin of hair claws, and feathers. ß - pleated structure is found in silk fibres.

(iii) Tertiary structure: The arrangement and interconnection of proteins into specific loops and bends is called tertiary structure of proteins. It is stabilized by hydrogen bond, ionic bond, hydrophobic bond and disulphide bonds. It is found in myoglobin (globular proteins).

(iv) Quaternary structure: It is shown by protein containing more than one peptide chain. The protein consists of identical units. It is known as homologous quaternary structure e.g. lactic dehydrogenase. If the units are dissimilar, it is called as heterogeneous quaternary structure e.g. hemoglobin which consists of two α - chains and two ß - chains.

Nucleic Acid

 (1) Definition: Nucleic acids are the polymers of nucleotide made up of carbon, hydrogen, oxygen, nitrogen and phosphorus and which controls the basic functions of the cell.

(2) These were first reported by Friedrich Miescher (1871) from the nucleus of pus cell.

(3) Altmann called it first time as nucleic acid.

(4) They are found in nucleus. They help in transfer of genetic information.

(5) Types of nucleic acids : On the basis of nucleotides i.e. sugars, phosphates and nitrogenous bases, nucleic acids are of two types which are further subdivided. These are DNA (Deoxyribonucleic acid) and RNA (Ribonucleic acid).

(A) DNA (Deoxyribonucleic acids) 

(i) Types of DNA: It may be linear or circular in eukaryotes and prokaryotes respectively.

(a) Palindromic DNA: The DNA helical bears nucleotide in a serial arrangement but opposite in two strands.

                              -T-T-A-A-C-G-T-T-A-A….

                              -A-A-T-T-G-C-A-A-T-T….

(b) Repetitive DNA: This type of arrangement is found near centromere of chromosome and is inert in RNA synthesis. The sequence of nitrogenous bases is repeated several times.

(c) Satellite DNA: It may have base pairs up to 11 – 60bp and are repetitive in nature. They are used in DNA matching or finger printing (Jefferey). In eukaryotes, DNA is deutrorotatory and sugars have pyranose configuration.

(B) RNA or Ribonucleic acid: RNA is second type of nucleic acid which is found in nucleus as well as in cytoplasm i.e. mitochondria, plastids, ribosomes etc. They carry the genetic information in some viruses. They are widely distributed in the cell.

The trachea, also called the windpipe.

The trachea, also called the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air-breathing animals with lungs. The trachea extends from the larynx and branches into the two primary bronchi. At the top of the trachea the cricoid cartilage attaches it to the larynx. The trachea is formed by a number of horseshoe-shaped rings, joined together vertically by overlying ligaments, and by the trachealis muscle at their ends. The epiglottis closes the opening to the larynx during swallowing.

The trachea begins to form in the second month of embryo development, becoming longer and more fixed in its position over time. It is epithelium lined with column-shaped cells that have hair-like extensions called cilia, with scattered goblet cells that produce protective mucins. The trachea can be affected by inflammation or infection, usually as a result of a viral illness affecting other parts of the respiratory tract, such as the larynx and bronchi, called croup, that can result in a barking cough. Infection with bacteria usually affects the trachea only and can cause narrowing or even obstruction. As a major part of the respiratory tract, when obstructed the trachea prevents air entering the lungs and so a tracheostomy may be required if the trachea is obstructed. Additionally, during surgery if mechanical ventilation is required when a person is sedated, a tube is inserted into the trachea, called intubation.

Structure-

An adult's trachea has an inner diameter of about 1.5 to 2 centimetres (0.59 to 0.79 in) and a length of about 10 to 11 centimetres (3.9 to 4.3 in); wider in males than females.[2] It begins at the bottom of the larynx, and ends at the carina, the point where the trachea branches into left and right main bronchi.[2] The trachea is surrounded by 16 - 20 rings of hyaline cartilage; these 'rings' are 4mm high in the adult, incomplete and C-shaped.[2] Ligaments connect the rings.[3] The trachealis muscle connects the ends of the incomplete rings and runs along the back wall of the trachea.

Function-The trachea is one part of the respiratory tree, that is a conduit for air to pass through on its way to or from the alveoli of the lungs. This transmits oxygen to the body and removes carbon dioxide

Molecular Basis of Inheritance

Molecular Basis of Inheritance

DNA

(1) DNA is a long polymer of deoxyribonucleotides.

(2) The length of the DNA depends on the number of nucleotide pairs present in it.

(3) Bacteriophage lambda has 48,502 base pairs.

Central dogma of molecular biology

(1) Crick proposed the Central dogma in molecular biology

(2) It states that the genetic information flows from DNA à RNA à Protein. 

(3) In some viruses like retroviruses, the flow of information is in reverse direction, which is from RNA à DNA à mRNA à Protein.

Structure of polynucleotide chain:

(1) A nucleotide has three components-

(a) A nitrogen base

(b) A pentose sugar (ribose in RNA and deoxyribose in DNA)

(c) A phosphoric acid.

(2) There are two types of nitrogen bases:

(a) Purines (Adenine and Guanine)

(b) Pyrimidines (Cytosine, Uracil and Thymine)

(3) Adenine, Guanine and Cytosine are common in RNA and DNA.

(4) Uracil is present in RNA and in DNA in place of Uracil, Thymine is present.

(5) In RNA, Pentose sugar is ribose and in DNA, it is Deoxyribose.

(6) Based on the nature of pentose sugar, two types of nucleosides are formed - ribonucleoside and deoxyribonucleotides.

(7) Two nucleotides are joined by 3’-5’ Phosphodiester linkage to form dinucleotide.

(8) More than two nucleotides join to form polynucleotide chain.

(9) The two strands of DNA (called DNA duplex) are antiparallel and complementary, i.i., one in 5’->3’ direction and the other in 3”->5” direction.

History of DNA

(1) DNA is an acidic substance in the nucleus.

(2) It was first identified by Friedrich Meischer in 1869. He named it as ‘Nuclein”

(3) In 1953 double helix structure of DNA was given by James Watson and Francis Crick, based on X-ray diffraction data produced Maurice Wilkins and Rosalind Franklin.

Packaging of DNA Helix

(1) The basic unit into which DNA is packed in the chromatin of eukaryotes.

(2) Nucleosome is the basic repeating structural (and functional) unit of chromatin, which contains nine histone proteins.

(3) Distance between two conjugative base pairs is 0.34nm

(4) The length of the DNA in a typical mammalian cell will be 6.6 X109 bp X 0.34 X10-9 /bp, it comes about 2.2 meters.

(5) The length of DNA is more than the dimension of a typical nucleus (10-6m)

DNA Replication

(1) DNA is the only molecule capable of self duplication so it is termed as a living molecule.

(2) All living beings have the capacity to reproduce because of DNA.

(3) DNA replication takes place in S-phase of the cell cycle. At the time of cell division, it divides in equal parts in the daughter cells.

(4) Delbruck suggested three methods of DNA replication i.e.

(i) Dispersive

(ii) Conservative

(iii) Semi-conservative

(5) The process of DNA replication takes a few minutes in prokaryotes and a few hours in eukaryotes.

RNA

(1) RNA is the first genetic material.

(2) RNA is a non hereditary nucleic acid except in some viruses (retroviruses).

(3) RNA used to act as a genetic material as well as catalyst.

(4) It is a polymer of ribonucleotide and is made up of pentose ribose sugar, phosphoric acid and nitrogenous base (A,U,G,C).

(5) RNA may be of two types – genetic and non-genetic.

DNA finger printing

DNA finger printing

(1) Alec Jeffreys et al (1985) developed the procedure of genetic analysis and forensic medicine, called DNA finger printing.

(2) It is individual specific DNA identification which is made possible by the finding that no two people are likely to have the same number of copies of repetitive DNA sequences of the regions.

(3) It is also known as DNA profiling.

(4) The chromosomes of every human cell contain scattered through their DNA short, highly repeated 15 nucleotide segments called “mini-satellites” or variable-number Tandem Repeat (VNTR).

Technique for DNA fingerprinting

(1) Only a small amount of tissues like blood or semen or skin cells or the hair root follicle is needed for DNA fingerprinting.

(2) Typically DNA content of about 100,000 cells or about 1 microgram is sufficient.

(3) The procedure of DNA fingerprinting involves the following major steps:

(i) DNA is isolated from the cells in a high-speed refrigerated centrifuge.

(ii) If the sample of DNA is very small, DNA can be amplified by Polymerase Chain Reaction (PCR).

(iii) DNA is then cut up into fragments of different length using restriction enzymes.

(iv) The fragments are separated according to size using gel electrophoresis through an agarose gel. The smaller fragments move faster down the gel than the larger ones.

(v) Double stranded DNA is then split into single stranded DNA using alkaline chemicals.

(vi) These separated DNA sequences are transferred to a nylon or nitrocellulose sheet placed over the gel. This is called ‘Southern Blotting’ (after Edward Southern, who first developed this method in 1975).

(vii) The nylon sheet is then immersed in a bath and probes or makers that are radioactive synthetic DNA segments of known sequences are added. The probes target a specific nucleotide sequence which is complementary to VNTR sequences and hybridizes them.

(viii) Finally, X-ray film is exposed to the nylon sheet containing radioactive probes. Dark bands develop at the probe sites which resemble the bar codes used by grocery store scanners to identify items.

Applications of DNA fingerprinting

This technique is now used to:

(i) Identify criminals in forensic laboratories.

(ii) Settle paternity disputes.

(iii) Verify whether a hopeful immigrant is, as he or she claims, really a close relative of already an established resident.

(iv) Identify racial groups to rewrite biological evolution.

Genomics and Human Genome

Genomics and Human Genome project:

(1) The term genome has been introduced by Winkler in 1920 and the genomics is relatively new, coined by Thomas Rodericks in 1986.

(2) Genomics is the subdiscipline of genetics devoted to the mapping, sequencing and functional analysis of genomes. Genomics is subdivided into following types:

(a) Structural genomics: It is the study of genome structure deals with the complete nucleotide sequences of the organisms.

(b) Functional genomics: It is the study of genome function which includes transcriptome and proteome. Transcriptome is a complete set of RNAs transcribed from a genome while proteome is a complete set of proteins encoded by a genome and aims the determination of the structure and function of all the proteins in living organisms.

(3) The human genome project, sometimes called “biology’s moon shot”, was launched on october 1, 1990 for sequencing the entire human genome of 2.75 billion (2.75 ´ 109 or 2750000 bp or 2750000 kilobase pairs or 2750 megabase pairs) nucleotide pairs.

(4) Two important scientist associated with human genome are Francis Collins, director of the Human Genome Project and J. Craig Venter, founding president of Celera genomics.

(5) The complete sequencing of the first human chromosome, small chromosome 22, was published in December 1999.

Prospects and implications of human genome:

(1) The genome project is being compared to the discovery of antibiotics.

(2) Efforts are in progress to determine genes that will revert cancerous cells to normal.

(3) The human genome sequencing not only holds promise for a healthier living. It also holds the prospects of vast database of knowledge about designer drugs, genetically modified diets and finally our genetic identity.

Somatic Cells

Somatic Cells

Somatic cells account for all the cells of the body except reproductive cells. Other than gametes, stem cells and germs cells, all the cells of a multicellular organism are known as somatic cells.

Diploid somatic cells undergo mitosis and are responsible for growth, repair and regeneration.

Somatic terms originate from the word ‘Soma’, which means ‘body’. They make up the entire organism other than cells, which have a reproductive function or are undifferentiated, e.g. stem cells.

🔹Somatic Cells Characteristics

➖Somatic cells are responsible for the growth and development of an organism

➖They are required for repair and regeneration

➖Somatic cells undergo mitosis and contain the same set of chromosomes as the organism

➖Somatic cells have a diploid set of chromosomes as compared to gametes, which are produced by meiosis (reduction division) and have a haploid set of chromosomes

➖Many species like wheat have a varied set of chromosomes in their somatic cells, e.g. hexaploid, triploid, tetraploid, etc.

➖Somatic cells undergo mutation more frequently as compared to germ cells

➖Somatic cells are used for cloning by which identical clone of an individual is produced

➖“Somatic cell nuclear transfer” is one such process where the nucleus of a somatic cell is transferred to an ovum cell. It is then implanted into the uterus and we get the identical clone. “Dolly the sheep” was cloned from an adult somatic cell

➖Somatic cells are used to conserve genetic information of animals

➖Genetic engineering and manipulation of somatic cells is controversial but of great importance to research and biotechnology

🔹Somatic Cells Types and Examples

There are numerous types of somatic cells. In our body, there are 220 types of somatic cells. Many cells are differentiated to perform various specific functions.

Some of the specialised somatic cells are:

➖Skin Cells: They have a unique quality of regeneration.

➖Nerve Cells: Neurons are specialised cells, which receive and propagate signals to and from the brain and spinal cord to other parts of the body. They are responsible for the control and coordination of bodily functions.

➖Muscle Cells: Myocytes are specialised cells to perform different functions. There are three main types of muscles:

       Smooth muscle – Internal lining of internal organs, digestive tract and urinary tract

       Cardiac muscle – Present in heart and helps in the pumping of blood

       Skeletal muscle – Attached to bones and helps in body movement

➖Blood Cells: Blood is composed of many differentiated cells:

         Erythrocytes – Red blood cells (RBCs) carry oxygen to different tissues. In humans, RBCs are biconcave and anucleated

         Leucocytes – White blood cells (WBCs) provide protection against foreign antigens and infections. There are five main types of WBCs

         Platelets – Thrombocytes are responsible for blood clotting

Significance of fertilization

Human Reproduction- Significance of fertilization

(a) It provides stimulus for the egg to complete its maturation.

(b) It activates the ovum to develop into a new individual by repeated mitotic division.

(c) Fertilization restores the diploid number of chromosomes (46 in man) in the zygote by adding male’s haploid set of chromosomes.

(d) It makes the egg more active metabolically.

(e) It combines the character of two parents and introduces variations. So help in evolution.

(f) Sex chromosomes of sperm is either X or Y and helps in sex determination.

(g) Fertilization membrane formed after sperm entry, checks the entry of additional sperms.

(h) Copulation path sets the axis of division.

Menstrual Cycle

(1) Menstruation occurs in human, apes and old world monkeys.

(2) Menstruation is bleeding from the uterus of adult females at intervals of one lunar month.

(3) Beginning of menstruation or first menstruation is called menarche.

(4) The beginning of menstruation varies. It usually occurs between 12 and 15 years.

(5) The cycle of events starting from one menstruation till the next one is called Menstrual Cycle.

(6) In human females, menstruation is repeated at an average interval of about 28/29 days.

(7) One ovum is released (ovulation) during the middle of each menstrual cycle.

(8) It is regulated by certain hormones, some of which are secreted by the pituitary gland.

(9) The pituitary gland is stimulated by releasing factors produced in the hypothalamus.

(10) The hormones produced by the pituitary gland influence the ovaries. The hormones secreted by the ovaries affect the walls of the uterus.

Phases of Menstrual Cycle

The menstrual cycle consists of following four phases:

(1) Menstrual Phase:

(i) In a 28 days menstrual cycle,the menses takes place on cycle days 3-5.

(ii) The production of LH from the anterior lobe of the pituitary gland is reduced.

(iii) The withdrawal of this hormone causes degeneration of the corpus luteum and, therefore progestrone production is reduced.

(iv) Production of oestrogen is also reduced in this phase.

(v) The endometrium of uterus breaks down & menstruation begins.

(vi) The cells of endometrium secretions, blood & unfertilised ovum constitutes the menstrual flow.

(2) Follicular Phase:

(i) This phase usually includes cycle days 6-13 or 14 in a 28 days cycle.

(ii) The follicle stimulating hormone (FSH) secreted by the anterior lobe of the pituitary gland stimulates the ovarian follicle to secrete oestrogens.

(iii) Oestrogen stimulates the proliferation of the endometrium of the uterine wall.

(iv) The endometrium becomes thicker by rapid cell multiplication and this is accompanied by an increase in uterine glands & blood vessels.

(3) Ovulatory Phase:

(i) Both LH & FSH attain a peak level in the middle of cycle (about 14th day).

(ii) Oestrogen concentration in blood increases.

(iii) Rapid secretion of LH induces rupturing of graffian follicle and thereby the release of ovum.

(iv) In fact LH causes ovulation.

(4) Luteal Phase:

(i) Includes cycle days 15 to 28.

(ii) Corpus luteum secretes progestrone.

(iii) Endometrium thickens.

(iv) Uterine glands become secretory.

Hormonal Control of MC

(i) FSH stimulates the ovarian follicles to produce oestrogens.

(ii) LH stimulates corpus luteum to secrete progestrone.

(iii) Menstrual phase is caused by the increased production of oestrogens.

(iv) LH causes ovulation

(v) Proliferative phase is caused by the increased production of oestrogens.

(vi) Secretory phase is caused by increased production of progestrone.

What are heart valves?

What are heart valves?

The heart has 4 chambers, 2 upper chambers (atria) and 2 lower chambers (ventricles). Blood passes through a valve before leaving each chamber of the heart. The valves prevent the backward flow of blood. Valves are actually flaps (leaflets) that act as one-way inlets for blood coming into a ventricle and one-way outlets for blood leaving a ventricle. Normal valves have 3 flaps (leaflets), except the mitral valve. It only has 2 flaps. The 4 heart valves are:

Tricuspid valve. This valve is located between the right atrium and the right ventricle.

Pulmonary valve. The pulmonary valve is located between the right ventricle and the pulmonary artery.

Mitral valve. This valve is located between the left atrium and the left ventricle. It has only 2 leaflets.

Aortic valve. The aortic valve is located between the left ventricle and the aorta.

How do the heart valves work?

As the heart muscle contracts and relaxes, the valves open and shut. This lets blood flow into the ventricles and atria at alternate times. Here is a step-by-step description of how the valves work normally in the left ventricle:

When the left ventricle relaxes, the aortic valve closes and the mitral valve opens. This lets blood flow from the left atrium into the left ventricle.

The left atrium contracts. This lets even more blood to flow into the left ventricle.

When the left ventricle contracts, the mitral valve closes and the aortic valve opens. This is so blood flows into the aorta and out to the rest of the body.

While the left ventricle is relaxing, the right ventricle also relaxes. This causes the pulmonary valve to close and the tricuspid valve to open. This lets blood flow into the right ventricle that was returned to the right atrium from the body.

When the left ventricle contracts, the right ventricle also contracts. This causes the pulmonary valve to open and the tricuspid valve to close. Blood flows out from the right ventricle to the lungs before it is returned to the left atrium as fresh, oxygenated blood.

What is heart valve disease?

Heart valves can have several problems. These include:

Regurgitation is a leaky valve. This means the valve doesn't fully close and the blood flows backward through the valve. This results in leakage of blood back into the atria from the ventricles in the case of the mitral and tricuspid valves. Or it leaks back into the ventricles in the case of the aortic and pulmonary valves. This can cause the chambers to be overworked because they have repump the extra blood that was returned. Over time, this can cause structural and functional changes in the heart chambers. These changes prevent the chambers from pumping blood normally.

Stenosis is a narrowed valve. With stenosis, the valve opening is narrowed and the valve doesn't open correctly. This makes it harder for the heart to pump blood across the narrowed valve. The heart must use more force to pump blood through the stiff (stenotic) valve or valves. This can also cause structural and functional changes to the different chambers of the heart. These changes prevent the heart from pumping blood normally.

Atresia. This means the valve opening doesn't develop normally during childhood. This prevents blood from passing from an atria to a ventricle, or from a ventricle to the pulmonary artery or aorta. Blood must find another route. This is usually through a problem present at birth (congenital). This might be an atrial septal defect or a ventricular septal defect. This acts as another route for the blood to move through the heart

When heart valves fail to open and close correctly, the damage to the heart can be serious. The harm can affect the heart's ability to pump blood through the body.

Father of Surgery (early): *Sushruta*

★Father of Biology: *Aristotle*

★Father of Physics: *Albert Einstein*

★Father of Chemistry: *Jabir Bin Hayan*

★Father of Statistics: *Ronald Fisher*

★Father of Zoology: *Aristotle*

★Father of History: *Herodotus*

★Father of Microbiology: *Louis Pasteur*

★Father of Botany: *Theophrastus*

★Father of Algebra: *Diophantus*

★Father of Blood groups: *Landsteiner*

★Father of Electricity: *Benjamin Franklin*

★Father of Trigonometry: *Hipparchus*

★Father of Geometry: *Euclid*

★Father of Modern Chemistry: *Antoine Lavoisier*

★Father of Robotics: *Nikola Tesla*

★Father of Electronics: *Ray Tomlinson*

★Father of Internet: *Vinton Cerf*

★Father of Economics: *Adam Smith*

★Father of Video game: *Thomas T. Goldsmith, Jr.*

★Father of Architecture: *Imhotep*

★Father of Genetics: *Gregor Johann Mendel*

★Father of Nanotechnology: *Richard Smalley*

★Father of Robotics: *Al-Jazari*

★Father of C language: *Dennis Ritchie*

★Father of World Wide Web: *Tim Berners-Lee*

★Father of Search engine: *Alan Emtage*

★Father of Periodic table: *Dmitri Mendeleev*

★Father of Taxonomy: *Carolus Linnaeus*

★Father of Surgery (early): *Sushruta*

★Father of Mathematics: *Archimedes*

★Father of Medicine: *Hippocrates*

★Father of Homeopathy: *Samuel Hahnemann*

★Father of Law: *Cicer*

TEA

TEA 

Synonym: Camellia thea. 

 Biological source: Tea contains prepared leaves and leaf buds of Thea sinensis Linn. 

Family: Theaceae. 

 Geographical source: Tea is cultivated in India, Srilanka, Indonesia, China and Japan. In India it is cultivated in North-Eastern India (mainly in Assam and Bengal), South India (in Nilgiri, Palni, Annamalai hills in Tamilnadu, Kerala and Karnataka states) and North West India (in Dehradun, Almora and Garhwal district of Uttaranchal, Kangra valley and Mandi district of Himanchal Pradesh). 

Cultivation and Collection: 

The tea is available in two forms: 

1. Black tea 

2. Green tea 

             Black tea is available from India and Srilanka whereas green tea is available from China and Japan. Black tea is obtained by fermentation of fresh tea leaves which further dried artificially. 

              Green tea is obtained by keeping tea leaves in copper vessel and then dried artificially. 

              Tea is a dried leaf of bush which contains theine which gives cheap and stimulation drink upon addition of boiling water with sugar and milk. So tea is most important beverage crop of India. The basic requirement for the cultivation of tea leaves are deep, light, well drained acidic soil (pH 5.8 to 5.4 or less), humid climate with annual rainfall (100 cm), altitude (2100 meter above sea level), temperature is in the range of 21°C to 29°C is ideal for its cultivation. Tea is shade loving plant and it develops more vigorously when planted along with shady trees. 

Healthy lungs are pink lungs

Healthy lungs are pink lungs

Healthy lungs look pink and rubbery on the outside. The more you smoke though, the more tarry and black they become. This can have a serious effect on quality of life, and can even cause bubbles (called blebs) rupturing in your lungs (a condition called spontaneous pneumothorax)

The average human adult has 2000-4000 taste buds

The average human adult has 2000-4000 taste buds

They aren’t only located on the tongue. These tiny sense organs that give us the ability to taste are also located in the back of your throat, your nose, and your esophagus. That’s right, your nose doesn’t just smell — it can taste too! The sense of smell is a very important component of tasting.

HEART

We all know that the heart of a healthy person beats 72 times in 1 minute. We also know that the heart of a man flows blood throughout his body. The question is how much blood our heart pumps in 1 minute

1. Your heart keeps beating even after the body breaks apart as long as it gets enough oxygen because it has its own electrical impulse.

2. A human heart pumps 70 ml of heartbeat once and 4.7 liters in 1 minute and about 7570 liters throughout the day and about 16 million liters of blood throughout life. This is equivalent to a tap being open for 45 years.

3. Which side is the heart: Your heart is not in the left or right side, but in the middle of the chest.

4. After four weeks of pregnancy, the baby's heart starts beating.

5. So far, the lowest 26 beats per minute of a human being and the highest 480 beats per minute has been recorded.

6. Your heartbeat also changes according to the song you are listening to.

7. Every day your heart generates so much energy that a truck can be driven up to 32 km and equal to the movement of the moon throughout life.

8. New born baby has the fastest heartbeat (70-160 beat / minute) and in old age heartbeat is slowest (30-40 beat / minute).

9. The weight of your heart is 250 to 350 grams, it is 12 cm long, 8 cm wide and 6 cm thick i.e. the size of the fist of your two hands.

10. Your heart beats 72 times in a minute and about 1 lakh times throughout the day and about 2.5 billion times in whole life.

11. Chances of arrival of Heart Attack are most frequent on Monday morning and most days of Christmas in the year.

12. Heart attack symptoms are different in both men and women. A broken heart also feels like a heart attack.

13. Your heart sends blood to all 75 trillion cells of the body except the cornea cells found in the eye.

14. The sound of 'thump-thump' when the heart beats is due to the opening and closing of the 4 valves found in the heart.

15. Heart disease has also been found in 3,000 year old mummies.

16. Heart cancer is rare because heart cells stop spreading over time.

17. The heart rate of women is 8 more every minute than the beat of men.

18. The thickness of our body's largest artery, the 'Aorta' found in the heart, is equal to the pipe found in the garden.

19. Your left lung is smaller in size than the right lung because it has to give place to the heart.

20. The heart of a man who is addicted to cocaine drugs can still beat for 25 minutes after taking him out of the body.

21. If our heart pumps blood out of the body, then it makes the blood 30 ft. Can bounce up

22. "Heart Symbol" has been in use since 1250 to denote love. But no one knows why this is happening.

23. Most people die of heart diseases in 'Turkmenistan', 712 out of 1 lakh people every year.

24. The electric current (ECG) measuring machine of the heart was invented in 1903 by 'Willem Einthoven'.

25. Heart attack while having sex is very rare, 75% of these have also come when a man is cheating on his wife.

26. History: The first successful heart surgery was done in 1893, the first successful prosthetic valve was inserted in 1950, the first human heart was inserted into another human in 1967 (this person lived for 18 days) and the first permanent artificial heart in 1982. Fitted.

27. Octopus has three hearts.

28. The dog's heart is the largest according to the size of the body.

29. Blue whale has a heart as big as a car and weighs 590 kg. It is the largest of all organisms.

30. The smallest heart in animals is of 'Fairy Fly' (wasp-like) with a length of only 0.02 centimeter.

31. The heart of 'Etruscan Shrew' (a species of rat in Malaysia and some other countries) recorded the highest 1511 beats per minute and the heart of 'Hibernating Groundhog' (a type of squirrel of North America) recorded the lowest 5 beats per minute. has gone.

32. The heart size of 'Python' (snake) gets bigger while eating.

What is the relationship between gonorrhea and chlamydia?

What is the relationship between gonorrhea and chlamydia?

Ans-Gonorrhea and chlamydia are both bacteria that cause STDs. The risk factors are the same for both infections, and both cause similar symptoms. The complications of chlamydia are very similar to gonorrhea except chlamydia is much less likely to affect sites other than the reproductive tract. Diagnosis and treatment are virtually the same as well. If you think you may have an STD, you should see a healthcare professional. They can determine what type it is by testing you as described above, and then start proper treatment.  

What are the differences between macrocytic anemia and microcytic anemia?

What are the differences between macrocytic anemia and microcytic anemia? 

Anemia is a term for low hemoglobin or red blood cells. Anemia can be divided into different types based on the volume of the red blood cells. Macrocytic anemia means that the red blood cells are larger than normal. In microcytic anemia, the cells are smaller than normal. We use this classification because it helps us to determine the cause of the anemia.

The most common causes of macrocytic anemia are vitamin B-12 and folate deficiency. Pernicious anemia is a type of macrocytic anemia due to the body not being able to absorb vitamin B-12. Elderly, vegans, and alcoholics are more susceptible to developing macrocytic anemia.

The most common cause of microcytic anemia is iron-deficiency anemia, usually due to poor dietary intake or blood loss, such as menstrual blood loss or through the gastrointestinal tract. Pregnancy, menstruating women, infants, and those with a diet low in iron may have an increased chance of developing microcytic anemia. Other causes of microcytic anemia include defects in hemoglobin production such as sickle cell disease, thalassemia, and sideroblastic anemia.

Gall bladder

About Gall bladder ___

In vertebrates, the gallbladder is a small hollow organ where bile is stored and concentrated before it is released into the small intestine. In humans, the pear-shaped gallbladder lies beneath the liver, although the structure and position of the gallbladder can vary significantly among animal species.

What is cancer ?

What is cancer ?

Cancer is not a type of disease, but it occurs in many forms. There are more than 100 types of cancer. Most cancers are named after the organ or cells in which they begin - for example, cancer that starts in the colon is called colon cancer, a cancer that starts in the basal cells of the skin. Is called carcinoma.

The term cancer is used for diseases in which abnormal cells divide without control and are able to invade other tissues. Cancer cells can spread to other parts of the body through the blood and lymphatic system.

Main categories of cancer

Carcinoma: A cancer that occurs in the skin or in the tissues that make up or cover the levels of internal organs.

Sarcoma: A cancer that starts in bone, cartilage, fat, muscle, blood vessels or other connective tissue or accessory.

Leukemia: Cancer that begins in tissues such as the blood-forming bone marrow and causes the production of abnormal blood cells in large amounts and entry into the blood.

Lymphoma and myeloma: A cancer that starts in the cells of the immune system.

Central nervous system cancer: Cancer that starts in the brain and spinal cord tissues.

Origin of cancer

All types of cancer begin in cells, which are the basic unit of life in the body. To understand cancer, it is useful to find out what happens when normal cells turn into cancer cells.

Benign tumors: These are not cancerous tumors. Often they can be removed from the body and in most cases, they do not come back again. Cells in benign tumors do not spread to other parts of the body.

Malignant tumors: These are cancerous tumors, and the cells of these tumors can invade surrounding tissue and spread to other parts of the body. The spread of cancer from one part of the body to another is called metastasis.

Leukemia: It is a cancer of the bone marrow and blood, not a tumor.

Some symptoms of cancer

Tightness or lump in the breast or any other part of the body.

A new mole or a change to an existing mole.

Any soreness that cannot be cured.

Hoarseness or coughing.

Changes in bowel or bladder habits.

Feeling discomfort after meals.

Difficulty swallowing.

Increase or decrease in weight without any reason.

Abnormal bleeding or discharge.

Feeling weak or feeling very tired.

Usually, these symptoms do not occur due to cancer. These can be caused by benign tumors or other problems. Only doctors can tell them exactly. Whoever has these symptoms or other health changes, should be seen by a doctor to find out immediately. Usually, early cancer does not hurt. If you have symptoms of cancer, do not wait to see a pain to see a doctor.

Cancer prevention ?

Some ways to reduce the risk of getting cancer are:

Do not use tobacco products.

Eat less fat and use more vegetables, fruits and whole grains.

Do regular exercise.

Laboratory test

With the help of blood, urine, or other fluids the doctor may examine it. These tests can detect how well the organs are functioning. In addition, heavy amounts of some substances also indicate cancer. These substances are often called tumor markers. However, abnormal laboratory results are not definitive signs of cancer. One should not rely only on laboratory tests to check for cancer.

Imaging process

It photographs the areas inside the body, or helps the doctor know if a tumor is present in the body. These imaging can be done in several ways:

X-rays: X-rays are the most common way of looking at the organs and bones inside the body.

CT scan: In this method an X-ray machine is attached to a computer, which makes a series of detailed images of organs (such as a dye) with a contrast material. These pictures are easy to read.

Radionuclide scan: It involves imaging by injecting a small amount of radioactive material. It flows through blood and gets deposited in some bones or organs. A machine called a scanner measures and detects radioactivity. The scanner makes images of bones or organs on a computer screen or on film. Soon radioactive material is released from the body.

Ultrasound: An ultrasound device transmits sound waves that people cannot hear. The waves hit the tissues inside the body like echoes and return. The computer uses these echoes to create images called sonograms.

MRI: It is used to make detailed images of body parts from a computer connected to a strong magnet. Doctors can view these pictures on a monitor and print them on film.

PET scan: After injecting a small amount of radioactive material, a special machine makes drawings to show chemical activities in the body. Cancer cells sometimes appear as areas of high activity.

In most cases, doctors are required to perform a biopsy to check for cancer. For biopsy, a sample of tissue is taken from the identified tumor and sent to the laboratory for examination. The pathologist looks at those tissues with the help of a microscope.

Cancer treatment process ?

Cancer therapy includes surgery, radiation therapy, chemotherapy, bacterial therapy and biological therapy. Depending on the type of cancer condition, the doctor may adopt a single or combined procedure. How much the disease has spread, the age of the patient and general health and other elements also have to be taken into consideration.

Biopsy

Sampling can be taken in several ways:

By needle: The doctor uses a needle to remove tissue or fluid.

Through an endoscope: The doctor uses a thin, lighted tube (endoscope) to view the areas inside the body. Doctors can receive tissue or cells through a tube.

Through surgery : Surgery may involve cutting or incision.

In a biopsy to be cut, the surgeon removes the entire tumor. Often some of the normal tissue surrounding the tumor is removed.

In an incised biopsy, the surgeon removes only part of the tumor. If the symptom or test result indicates cancer, the doctor finds out whether it is due to cancer or some other reason.

18F sodium fluoride bone scan

blood cancer

 

Overactive hepatitis (leukemia) is a cancer of the blood or bone marrow. Blood cells start to grow abnormally, especially white blood cells.

Symptoms:

Excessive bleeding.

Anemia (anemia).

Other symptoms like fever, inertia, night sweats and flu

Weakness and fatigue.

Loss of appetite and / / weight loss.

Swollen gums or bleeding from them.

Nervous Symptoms (Headache).

Enlarged liver and spleen.

Easily scratched and frequent infection.

Joint pain.

Swollen glands (tonsils).

Breast Cancer