Bio Molecule And Bio Medical Techniques

About Bio Molecule And Bio Medical Techniques

Living organisms are made of a limited number of types of atoms that combine to form molecules, the building blocks of life. Protoplasm is a complex mixture of both organic & inorganic compounds. Molecules found in protoplasm of cells are called biomolecules. The structure & function of different cell constituents are interplay of their constituent chemicals, their arrangement & properties. The aggregation of various elements present in the form of inorganic & organic molecules in a cell, constitutes the cellular pool. It provides all the necessary materials for the structure & functions of different types of cells. The constancy of the pool is maintained by the intake & elimination of specific molecules.

Elements found in living organisms

Chief elements of organic molecules	Ions	Trace elements
O (Oxygen) 65%	K+(Potassium)0.30%	Cu (Copper)	Mo (Molybdenum)
C (Carbon) 20%	Mg++(Magnesium)	Fe (Iron)	Si (Silicon)
H (Hydrogen) 10%	Na+ (Sodium) 0.10%	Mn (Manganese)	Al (Aluminum)
N (Nitrogen) 3%	Cl− (Chlorine)	Co (Cobalt)	V (Vanadium)
P (Phosphorus) 1.5%	Ca++ (Calcium) 2%	Zn (Zinc)	I (Iodine)
S (Sulphur) 0.20%		B (Boron)

S. No.	Monosaccharide	Aldose	Ketose
1.	Trioses	Glyceraldehyde	Dihydroxyacetone
2.	Tetroses	Erythrose, Threose	Erythrulose
3.	Pentoses	Ribose, Deoxyribose, Xylose, Arabinose	Ribulose
4.	Hexoses	Glucose, Galactose, Mannose	Fructose
5.	Heptoses	Glycoheptose, Galactoheptose	Sedoheptulose

Difference between reducing and non-reducing sugars

S. No.	Reducing sugar	Non-reducing sugar
1.	It is sugar which has a free aldehyde or ketonic group, e.g., Glucose, Fructose, Maltose.	The sugar does not have a free aldehyde or ketonic group, e.g., Sucrose.
2.	It reduces cupric ions of blue copper sulphate in Benedict's or Fehling's solution to cuprous ions of reddish copper oxide.	It does not change cupric ions to cuprous ions.

classifications of proteins

According to structure

Type of proteins

Nature

Functions

Fibrous proteins

Secondary structure most important

Insoluble in water, physically tough, long parallel polypeptide chains cross-linked at intervals forming long fibres or sheets

Structural component of cell.

Examples : Collagen (Tendons, bone, connective tissues) Myosin (muscles) Silk (spider, web) Keratin (hair, horn, nails, feathers)

Globular proteins

Tertiary structure most important, Polypeptide chains tightly folded to form spherical shape. Easily soluble

Form enzymes, antibodies and some hormones e.g., Insulin

According to function

Types

Examples

Occurrence/Function

Structural

Collagen

Keratin

Elastin

Viral coat proteins

Component of connective tissue, bone, tendons, cartilage.

Skin, feathers, nails, hairs, horns.

Elastic connective tissue (ligaments)

Wraps up nucleic acid of virus.

Enzymes

Trypsin

Ribulose biphosphate

Carboxylase

Glutamine synthetase

Catalyses hydrolysis of proteins.

Catalyses carboxylation (addition of CO₂) of ribulose

biphosphate in photosynthesis.

Catalyses synthesis of the amino acid glutamine from

glutamic acid + ammonia.

Hormones

Insulin

Glucagon

ACTH

Help to regulate glucose metabolism

Stimulates growth and activity of the adrenal cortex

Respiratory pigment or Transport

Haemoglobin

Myoglobin

Serum albumin

Transport of O₂ in vertebrate blood

Stores O₂ in muscles.

Transport of fatty acids and lipids in blood.

Protective

Antibodies

Fibrinogen

Thrombin

Form complexes with foreign proteins.

Forms fibrin during blood clotting.

Convert fibrinogen in to fibrin

Contractile

Myosin

Actin

Help in muscle contraction

Moving filaments in myofibrils of muscles

Storage

Ova albumin

Casein

Egg white protein

Milk protein

Toxins

Snake venom

Diphtheria toxin

Toxin made by diphtheria bacteria.

According to composition

Simple protein -The proteins are made of amino acids only. They are

S. No.	Protein	Occurrence
1.	Albumins	Leucosin (cereal grains), legumelin (Legume seeds), serum albumin (blood), ovalbumin (egg), lactalbumin (milk).
2.	Globulins	Legumin (legume seeds), tuberin (potato), serum globulin (blood), Vitellogenin (egg yolk).
3.	Polamines	Zein (Maize grains), hordein (barley grains), gliadin (wheat grains)
4.	Glutelins	Glutelin (maize grains), glutenin (wheat grains), oryzenin (rice grains).
5.	Histones	In nucleoproteins.
6.	Protamines	In nucleoproteins offish sperms.
7.	Scleroproteins	Keratin, Elastin, Collagen.

Conjugated proteins - Besides being made of polypeptides, the conjugated proteins possess additional groups, metals or ions and other non-proteinous substances (prosthetic group).

S. No.	Protein	Prosthetic group	Occurrence
1.	Nucleoproteins	Nucleic acid	Proteins associated with nucleic acids. e.g. histone, non histone
2.	Mucoproteins	Carbohydrate	Mucin, Ovomucoid (egg white), other mucoid structures.
3.	Glycoproteins	Carbohydrate	Membrane surface.
4.	Lipoprotein	Lipid	Chylomicrons, HDL, LDL, VLDL membrane.
5.	Phosphoproteins	Phosphoric acid	Caesinogen (milk), Ovovitellin (egg yolk).
6.	Metalloproteins	Metal	Ferritin (Fe), Siderophitin (Fe), Ceroplasmin (Cu).
7.	Chromoproteins	Pigment	Erythrocytes, Muscles, Blood of some invertebrates, Red Algae, (pigment) Blue green Algae, Electron carries, Enzymes, Chloroplasts, Retina, Plant Photomorphogenetic reactions.

Derived proteins - They are formed from proteins, generally as intermediates of their breakdown or as end product of an irreversible reaction. They are

S. No.	Protein	Occurrence
1.	Proteans	Fibrin (from Fibrinogen)
2.	Coagulated protein	Cooked proteins
3.	Metaproteins	First fraction
4.	Proteoses	Intermediate fraction
5.	Peptones	Polypeptides
6.	Peptides	Fraction with a few amino acid residues.

classification of fatty acids

Fatty acids are of two types. These are saturated fatty acids and unsaturated fatty acids.

S. No.	Saturated fatty acids	Unsaturated fatty acid
1.	These fatty acids do not have any double bond.	They have one or more double bonds.
2.	They increase blood cholesterol.	Unsaturated fatty acids decrease cholesterol level of blood.
3.	Saturated fatty acid combine with cholesterol to increase its precipitation in blood vessels.	They combine with cholesterol to help it in its incorporation into lipoprotein for passage into liver.
4.	These fatty acids have higher melting points.	These fatty acids have lower melting points.
5.	They are solid at room temperature.	They are liquid at room temperature.
6.	Saturated fatty acids are more abundant in animal fats.	These fatty acids are more abundant in plant fats.
7.	They occur mostly in storage cells.	In animals, they occur mostly in non storage cells.
8.	They do not undergo hydrogenation as a double bond is absent.	They can undergo hydrogenation, which changes unsaturated fatty acids into saturated fatty acids.
9.	Example: butyric acid, stearic acid, palmitic acid etc.	Example : oleic acid, linoleic acid, linolenic acid, arachidonic acid.

Types of DNA

S. No.	Characters	A-DNA	B-DNA	C-DNA	D-DNA	Z-DNA
1.	Helix coiling or orientation	Right Handed	Right Handed	Right Handed	Right handed	Left handed
2.	Course of helix	−	Regular	−	−	Zigzag
3.	Base pair per helix	11	10 (5 dimmers)	9	8	12 (6 dimmers)
4.	Helix diameter	2.6 Å	34 Å	−	−	45 Å
5.	Distance between two base pairs	−	3.4 Å	3.3 Å	3.03 Å	3.7 Å
6.	Diameter of DNA molecule	−	20 Å	−	−

Differences between Eukaryotic and prokaryotic DNA.

S. No.	Eukaryotic DNA	Prokaryotic DNA
1.	It occurs inside the nucleus and semi-autonomous organelles.	It does not occur inside organelle or subcellular structure.
2.	Eukaryotic DNA does not occur on direct contact with cytoplasm.	Prokaryotic DNA is directly embedded in cytoplasm.
3.	It is of two types, nuclear DNA and organelle DNA.	It is also two types, genophoric and extrachromosomal.
4.	Nuclear DNA has two or more duplexes.	Genophoric DNA has only one duplex.
5.	Cistrons contain noncoding regions or introns.	Cistrons do not have introns.
6.	Main part or nuclear DNA of eukaryotes is linear. Organelle DNA is circular.	Prokaryotic DNA is commonly circular.
7.	Nuclear DNA is associated with histone protein.	Prokaryotic DNA is without association with histones and DNA is naked.
8.	Plasmids are absent.	Plasmids or small circular segments of DNA are present in many prokaryotes.

Comparison between DNA and RNA

Characters	DNA	RNA
Location	Primarily in nucleus but also in mitochondria and chloroplasts	Cytoplasm, nucleus, nucleolus
Pyrimidine bases	Cytosine [C], Thymine [T]	Cytosine [C], Uracil [U]
Pentose sugar	Deoxyribose sugar	Ribose sugar
Polynucleotide strands	Mostly double stranded but single stranded DNA is also found in φ x 174 bacteriophages and other bacteriophages like M13, fd, f, etc.	Mostly single stranded but double stranded RNA is also found in wound tumour viruses, reovirus, cauliflower mosaic virus, cyanophages etc.
Cyto chemical reaction	Feulgen	Basophilic dyes with ribonuclease treatment or pyronin Y.
Hydrolyzing enzymes	Deoxyribonuclease (DNase)	Ribonulease (RNase)
Role	Always act as genetic material	Responsible for the protein synthesis and sometimes act as genetic material.

Differences between competitive inhibition and allosteric inhibition

S. No.	Competitive inhibition	Allosteric inhibition
1.It is caused by a chemical, which has structural similarity with the substrate.		It is due to hemical, which has not much. structural similarity with the substrate.
2.The inhibitor binds to the active site of the enzyme.		The inhibitor attaches to a specific inhibitor site of enzyme other than active site.
3.The active site is blocked by the inhibitor.		The active site become non-receptive due to allosteric modulation of negative type.
4.Substance fails to reach the active site as the latter is occupied by competitive inhibitor.		Substrate fails to bind with the active site as the. latter is not conformationally receptive.
5.There is no change in the structure of enzyme.		The enzyme is conformationally changed by the attachment of inhibitor.
6.Inhibitor is not connected with metabolic pathway of which the inhibited enzyme is a component.		Inhibitor is intermediate or end product of metabolic pathway of which the inhibited enzymes is a component.
7.It has no regulatory function.		Allosteric inhibition prevents excess formation of a product. It, therefore, had a regulatory function.

HUMAN Hormone

Gland			Hormone	Functions			Secretion control mechanism
Hypothalamus			Releasing and inhibiting hormones and factors, seven identified, possible number unknown. Posterior pituitary hormones produced here	Control of specific anterior pituitary hormones.			Feedbackmechanisms involving metabolite and hormone levels.
Posterior pituitary gland			No hormones synthesized here, stores and secretes the following: Oxytocin	Ejection of milk from mammary gland, contraction of uterus during birth			Feedbackmechanisms involving hormones and nervous system.
			Antidiuretic hormone (ADH) (vassopresin)	Reduction of urine secretion by kidney			Blood osmotic potential
.	Follicle stimulating hormone (FSH)			In male, stimulates spermatogenesis. In female, growth of ovarian follicles			Plasma estrogen and testosterone via hypothalamus
	Luteinising hormone (LH)			In male, testosterone secretion			Plasma testosterone via hypothalamus
				In female, secretion of estrogen and progesterone, ovulation and maintenance of corpus luteum			Plasma estrogen level via hypothalamus
Anterior pituitary gland	Prolactin					Stimulatesmilk production and secretion		Hypothalamic hormones
	Thyroid stimulating hormone (TSH)					Synthesisand secretion of thyroid hormones, growth of thyroid glands		Plasma T3 and T4 levels via hypothalamus
	Adrenocorticotrophic hormone (ACTH) or corticotrophin)					Synthesisand secretion of adrenal cortex hormones, growth of gland		Plasma ACTH via hypothalamus
	Growth hormone (GH)					Protein synthesis, growth, especially of bones of limbs.		Hypothalamic hormones
Parathyroid gland		Parathormone				Increases blood calcium level. Decreases blood phosphate level		Plasma Ca2+ level, and plasma PO43- level
Thyroid gland		Triiodothyroxine (T3) and thyroxin (T4)				Regulation ofbasal metabolicrate, growthand development		TSH
		Calcitonin				Decreasesblood phosphate level		Plasma Ca2+ level
Adrenal cortex		Glucocorticoids (cortisol)				Protein breakdown, glucose and glycogen synthesis, adaptation to stress, anti-inflamma-tory, allergy effects		ACTH
Adrenal cortex		Mineralocorticoid (aldosterone)				Na+ retention in kidney, Na+ and K+ratios in extra cellular and intracellular fluids, raises blood pressure		Plasma Na+ and K+levels and low blood pressure
		Sex steroid				Development of sex organ in foetus
Adrenal medulla		Adrenaline (epinephrine)				Increases rate and force of heartbeat, constriction of skin andvisceral capillaries Dilation of arterioles of heart and skeletal muscles, raises blood glucose level		Sympathetic nervous system .
		Nor adrenaline (nor-epinephrine)				General constriction of small arteries, elevation of blood pressure		Nervous system
Islets of Langerhans		Insulin (beta cells)		Decreases bloodglucose level, increases glucose and amino acid uptake and utilization of cells				Plasma glucose and amino acid levels.
		Glucagon (alpha cells)		Increases blood glucoselevel, breakdown of glycogen to glucose in_liver				Plasma glucose level.
Stomach		Gastrin		Secretion of gastric juices				Food in stomach
Duodenum		Secretin		Secretion of pancreatic juice Inhibits gastric secretion				Acidic food in duodenum.
		Cholecystokinin (Pancreozymin)			Emptying of gall bladder and liberation of pancreatic juice into duodenum			Fatty acids and amino acids in duodenum.
Kidney		Renin			Conversion of angiotensinogen into angiotensin			Plasma Na+ level, decreased blood pressure
Ovarian follicle		Oestrogens (1 7β-estradiol)			Female secondary sex characteristics, estrous cycle			FSH and LH
Corpus luteum .		Progesterone			Gestation, inhibition of ovulation			LH
					Uterine growth and foetal development.			LH
		Relaxin			child birth
Placenta		Chorionic gonadotrophin			Maintenance of corpus luteum			Developing foetus
		Human placental lactogen			Stimulates mammary growth			Developing foetus
Testis		Testosterone			Male secondary sexual characteristics			LH and FSH

Plant hormone

Name		Function	Distribution	Function
1.	Auxin/Indole Acetic Acid	Acidic Auxinonitriolic acid Auxenolonic acid Indole 3–acetic acid Tryptophan is precursor of Auxins.	Throughout the plant body but their greate amount is found in actively growing region	Cell elongation. Callus formation. Apical dominance. Parthenocarpy. Prevention from abscission. Root initiation. Removal of weeds. Stimulation of respiration. Sex expression. Phototropism and geotropism
2.	2. Gibberellins or Plant growth hormones	Acidic the precursor is a 5C–compound, iso pentenyl pyrophosphate.	Throughout the plant body.	Stem elongation. Light induced stem growth. Genetic dwarfism. Promotion of flowering. Increase in flower and fruit size. Parthenocarpy. Breaking dormancy.
3.	3. Cytokinins or Kinetins	6–furfuryl aminopurine is derivative of adenine	The synthesis of sytokinins occurs in root tips, transported to different parts of the plant through xylem elements	Cell division. Delay of senescence. Breaking dormany of seeds. Induction of parthenocarpy. Resistance of high temperature. Sex expression, Apical dominance, Morphogenesis.
4.	4. Abscisic acid or Stress hormone	Mevalonic acid	Synthesize in mature leaves and translocated to shoot apex.	Ageing and abscission of leaves. Closure of stomata under condition of water stress. Act as antitranspirant and is also known as stress hormone. It regulates the dormancy of seeds & buds by inhibiting the growth activates on account of this antagonistic behavior, It is called as antigibberelin. It induces flowering during long days.
	5. Ethylene or Plant–Gas hormone	Methionine is precurosor of Ethylene.	All seed plants are known to produce ethylene. The site of production of production is shoot apex.	Help in ripening of fruit. It causes petal discolouration. Stimulates germination of seeds. Inhibits root and stem elongation. Induces root hair formation.

Most abundant mineral in body fluids is Na⁺ followed Cl^–
Most abundant mineral in cellular pool is K⁺ followed by phosphate.
Human milk contains maximum amount of Lactose (milk sugar).
F. A. Lipmann is called as father of ATP cycle.
Sweetest protein is moinellin and sugar is fructose (fruit sugar).
Amino acid glycine does not posses asymmetrical carbon atom.
Essential fatty acids are Lionoleic acid, Linolenic acid and Arachidonic acid.
Glucose is universal sugar. Also called Blood sugar and gives instant energy.
Raffinose is a trisaccharide with one moiety each of glucose, galactose and fructose.
Refined oils are saturated fatty acids.
Unripe grapes are rich in tartaric acid while tomato is rich in citric acid.
Asafoetida is gum resin.
Canada balsam (Abies balsamia) is oleoresin.
Oxalic acid is the most common type of organic acid.
Galactose is called brain sugar.
Inborn or acquired disorder of lipid metabolism is called Lipidosis.
Paraffin wax is not a wax but a petroleum product. Bee wax contain palmitic acid and myaicly alcohol.
Glycolipids are also known as cerebrolipids because of their presence in brain. They are sweet.
Butyric acid is found in butter and is the smallest fatty acid.
Ergasterol is phytosterol (plants). Stigmosterol is found in Coconut and Soyabean, cytosterol in cereals and cholesterol in potato.
Prostaglandins are hormones present in semen.
Natural silk is a polyamide showing pleated sheet secondary structure.
Rayon or artificial silk is derived cellulose.
Aspartame is an artificial sweetener. This is a synthetic peptide.
Bradykinin is a nonpeptide pain stimulant and encephalins are natural short lived pain killer peptides.
Pulses are deficient in Methionine and tryptophan.
Most abundant protein is Rubisco in plants
There are approximately 3000 enzymes present in a cell.
Enzymes are thermolabile, amphoteric, colloidal and substrate specific.
Specificity of an enzyme is due to apoenzyme position.
Tertiary structure of enzymatic protein is folded in such a way as to create a region called active site that has correct molecular dimension and topology to accomodate and bind with a specific substance.
Enzymes useful in hydrolyzing fats and lipids known as Esterases.
Ribonucleic acid has catalytic and synthetic functions.
Ribozyme was the name given to ribonucleic acid of Tetrahymena thermophila (Protozoan). It is a non-protein enzyme.
Thomas Cech and Sydney Altmann were awarded nobel prize for the discovery of enzymatic activity of Ribozyme.
Riboenzyme is the intervening sequence of Tetrahymena ribosomal RNA. This RNA can be spliced in the of protein. Zang and Cech (1986) have shown that this molecule can also catalyze the cleavage region and deletion of added polycytidylic acid, in the artificial aligonucleotide. Starting with poly C that is 5 nucleotides long, poly C upto 30 nucleotides long. Each ribozyme molecule can generate hundreds of elongated substrate molecules and is thus a classic enzyme. The reaction has hyperbolic kinetics and is specific for RNA, for deoxy poly C acts as a classic competitive inhibitor in reciprocal plots.
Ribonuclease P This enzyme is involved in the maturation of RNA precursors. Ribonuclease P cuts off 5' extension precisely at the start of the mature molecule. Once purified the enzyme was found to consist of an RNA molecule and a protein molecule. One molecule of RNA is competent in itself in absence of protein to cut many tRNA precursors (Guerrier - Takadad and Altman, 1984).
Some nuclear RNPs contain RNS of U₁ and U₂ also are type of ribozymes involved in the splicing of mRNA precursors but the details of its functioning are not yet known.
It was known that in origin of life, RNA was found first, is capable of self replication e.g., one ribozyme can elongate poly C molecules; from which protein and later on DNA may have been evolved.
If product is accumulated in the reaction and acts as inhibitor, it is called feed back inhibition.
The enzyme Urease was crystallized by Sumner.
Turnover number is the number of moles of substrate converted to product per minute per unit of enzyme. Related quantities are the catalytic center activity which is the turn over number per active site of the enzyme protein, for enzymes with more than one active site. It is also called as catalytic rate constant Kcat.

Turn over number

36 million for carbonic anhydrase.
5 million for catalase.
10,000 for sucrase.
50 for Flavoprotein.
30 for Lysozyme.

Amount of enzyme catalyzing the transformation of l μ. mole of substrate per unit as called enzyme unit.
70% enzymes are found in mitochondria.
Zymogens are precursors of enzymes.
Certain diseases are the result of enzyme deficiency, e.g., Phenylketonuria, where persons are deficient in phenylalanine hydroxylase enzyme necessary to break down phenylalanine.
The other enzyme deficient diseases are Galactosemia (galactose 1-P uridyl transferase), Albinism (Tyrosinase) and Methemoglobinemia (methemoglobin reductase) etc.
Antibodies binds with specific ligands may be generated to catalyze specific reactions just like enzymes. Such antibodies are termed as abzymes e.g., abzymes in acyl transfer reactions, C−C bond formation, C−C bond cleavage.
Rennet tablets (containing rennin from calf s stomach) are used for coagulating milk protein to obtain casein (cheese from milk).

Bio Medical Technologies
A modern hospital can make use of variety of sophisticated instruments and equipment of accurate diagnosis and treatment of diseases. Three main categories of instruments and equipment used are diagnostic, imaging, and therapeutic.
Diagnostic Instruments
Bio Medical Technologies

Imaging Instruments
(i) X-rays

Following their discovery by Wilhelm Roentgen, a German physicist in 1895, X-ray became an important tool for medical diagnosis.
X-ray are a form of electromagnetic radiation of extremely short wavelength.
When a beam of X-rays is directed at a part of the body such as chest, the rays are absorbed more by dense structures such as the ribs or heart muscles than by less dense structures such as the skin or lungs.
This causes shadows of variable intensity to be cast on a photographic film.
X-rays cause no sensation when passed through body tissues.
Large or frequent radiation doses may damage the skin and internal organs and may cause cancer in later life.
The study of X-rays for detection and treatment of disease is called radiology.
X-ray imaging in the simplest form is commonly employed for diagnosing diseases of the heart, lungs and detection of bone and joint injuries.
Nowadays, the risk involved in having X-rays is extremely small; radiation doses are kept to a minimum.

(ii) Computed Tomographic Scanning (CT)
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