Biomolecules

NCERT

Biomolecules

All the organic compounds/molecules that can be obtained from a living cell/tissue/organism

The relative abundance of Carbon and Hydrogen is…

higher in living beings than in Earth’s crust

Chemical composition analysis in living tissue

Grind the trichloroacetic acid with the living tissue and strain through a cloth to form 2 compounds: a filtrate(acid-soluble) and a retentate(acid-insoluble)

Micromolecules and what they include

Molecules weighed less than 1000 daltons and present in acid-soluble pools. Include amino acids, N bases, and monosacharides

Macromolecules

Molecules weighing more than 1000 daltons and present in acid-insoluble pools. Include proteins, nucleic acids, polysacharides

“Ash” analysis technique

Drying a living tissue and burning it too be left with inorganic compounds to study the chemical analysis of living tissue

Abundance of elements from greatest to lowest in the human body

O > C > H > N

Abundance of elements from greatest to lowest in the Earth’s crust

O > Si > Ca > Na

Metabolites

intermediate products of metabolism

Primary metabolites

metabolites required for basic or primary metabolic processes

Secondary metabolites

metabolites not involved in primary metabolism and have no direct function in growth and development.

Examples of secondary pigment metabolites

Carotenoids & Anthocyanins

Examples of secondary alkaloid metabolites

Morphine & Codeine

Examples of secondary terpenoid metabolites

Monoterpenoid & Diterpenoid

Examples of secondary essential oil metabolites

lemon grass oil, rosemary oil

Examples of secondary toxin metabolites

Abrin & Ricin

Examples of secondary lectin metabolites

Concanavalin A

Examples of secondary drug metabolites

Vinblastin & Circumin

Examples of secondary polymeric metabolites

Rubber, Gums, cellulose

The four micromolecules are…

Proteins, Nucleic Acids, Carbohydrates, and Lipids

Polymeric substances

Any substances which are in the form of a polymer or are found as a polymer

Water is the…

most abundant chemical in all living organisms

What are carbohydrates?

They are the main source of energy and the cell’s first choice of energy made of monosachhcarides.

Carbohydrate ratio

Carbon, hydrogen, and oxygen in a 1:2:1 ratio

Polyhydroxy aldehydes or ketones

Chemical compostion of carbohydrates

Monosaccharides

The simplest sugars which cannot be furthur broken down, all occur in both the D & L form except Dihydroxyacetone, and in either a ring or straight chain.

All monosaccharides are…

poly-hydroxy aldehydes or ketones

Chiral Carbon

A carbon atom that is attached to four different types of atoms or group of atoms

Pyranose

6-carbon ring

Furanose

5-carbon ring

Anomers

type of monosaccharides that have the -H and -OH groups changing at the anomeric carbon in only cyclic forms.

Anomeric carbon

aldehyde or ketone carbon which connects the linear form to the cyclic form

Epimers

isomers formed as a result of intechange of the -OH and -H groups on just one carbon atoms. Exist in both linear and cyclic forms.

Aldoses

monosaccharides with free aldehyde groups

Ketones

monosaccharides with free ketone groups

Trioses

3-carbon monosaccharide (C3H603) - Dihydroxyacetone, glyceraldehyde

Tetroses

4-carbon monosaccharides (C4H8O4) - Erythrose and Erythrulose

Pentoses

5-carbon monosaccharides (C5H10O5) - xylose, xylulose, deoxyribose, aribonose, ribose, ribulose

Hexoses

6-carbon monosaccharides (C6H12O6) - glucose, fructose, galactose, mannose

Heptoses

7-carbon monosaccharides (C7H14O7) - seduheptulose

Glucose

Main respiratory substance also known as grape sugar, blood sugar, and dextrose

Fructose

Sweetest carbohydrate and also known as fruit sugar and laevulose

Galactose

most abundant carbohydrate found in brain and nervous tissue so its also called brain sugar

Mannose

Carbohydrate present in hemicellulose

Oligosaccharides

Carbohydrates made of 2-10 monosaccharides linked when an aldehyde or ketone group fo one monosaccharide reacts with an alcoholic group of another monosaccharide to form a glycosidic linkage from 1’ to 4’

Disaccharides

Carbohydrates composed of 2 monosaccharide units that are water soluble and sweet in taste.

Maltose

disaccharide which is in intermediate compound in starch digestion and abundant in germinating starchy seeds (malt sugar)

Lactose

Disaccharide also known as “milk sugar”

Sucrose

Naturally non-reducing disaccharide which is used to transport sugars in plants. A.k.a invert sugar, cane sugar, or commercial sugar

Trehalose

Naturally non-reducing disaccharides present in the haemolymph(insect blood) cof insects

Polysaccharides

carbohydrates composed of a large number of monosaccharides that are insoluble in water and do not taste sweet

Right end of polysacchardes

reducing end

Left end of polysacchardes

non-reducing end

Nutritive polysaccharides

carbohydrates present as stored food such as starch and glycogen

Structural polysaccharides

carbohydrates used in structure formation

Homopolysaccharides

polysaccharides composed of the same monomer

Cellulose

Most abundant organic unbranched, linear homopolysaccharide of ß-d-glucose units at a ß 1’-4” linkage which is used as the main component of plant cell walls and to form Rayon fibre.

Starch

Homopolysaccharides made of ⍺-D-glucose units used and composed of 20% amylose and 80% amylopectin to store food in plants and gives a blue colour with iodine solution

Amylose

unbranched homopolysaccharides made up of less ⍺-D-glucose units at a 1’-4” linkage

Amylopectin

branched homopolysaccharide made up of more ⍺-D-glucose units.

Amylopecting branching occurs approx. …

every 20-30 ⍺-D-glucose units at 1’-4” & and 1’-6”

Glycogen

highly branched homopolysaccharide of approx. 6 lakh ⍺-D-glucose units used as a storage form of carbohydrate in the liver and muscles of animals at

Chitin

homopolysaccharide which is the linear polymer of N-acetyl-D-glucosamine and an important component of the exoskeleton of Arthropods and cell wall of fungi

Inulin

smallest storage water-soluble homopolysaccharide of 25-35 fructose units linked by ß-1’-2” bonds found in the roots of Dahlia and Artichokes.

Dextrin

intermediate homopolysaccharide obtained by the digestion of glycogen and starch and hydrolyzed to from maltose and glucose

Heteropolysaccharides

polysaccharides composed of different monosaccharides

Hyaluronic acid

heteropolysaccharides made of D-glucuronic acid and N-acetyl-D-glucosamine arranged alternately to form a binding material (animal cement)found in the extracellular matrix of connective tissue for its toughness and flexibility of cartilage and tendons

Chondroitin

heteropolysaccharide which occurs in connective tissue

Heparin

heteropolysaccharide which is an anticoagulant of blood

Pectins

heteropolysaccharide found in cell walls where it binds cellulose fibres in bundles

Hemicellulose

heteropolysaccharide present in cell wall

Agar

mucopolysaccharide obtained from red algae to be used as a culture medium in laboratory

Lipids

hydrophobic micromolecules that do not form polymers and provide more energy than carbohydrates stored as fats and its derivatives

Simple Lipids

three long chain fatty acids and a glycerol bonded by an ester bond to form a tryglycerol

Glycerol

a trihydroxy sugar alcohol or trihydroxy propane in tryglycerides

Fatty acids

long chains with a carboxyl group and an R group which could be a methyl, ethyl, or a higher number of CH2 groups

Triglycerides

simple lipid made by 3 fatty acid chains and a glycerol

Saturated Fatty acid chains

Non-essential and less reactive fatty acids that are present in solid form due to the presence of only C-C single bonds and found in mostly in animals except fish.

Unsaturated fatty acid chains

Essential highly reactive fatty acids that are present in a liquid form due to the presence of C-C double AND single bonds and are found in mostly plants and fish

MUFA

monounsaturated fatty acid chains composed of 18-C Oleic acid

PUFA

polyunsaturated fatty acid chains composed of 18-C Linoleic or 20-C Arachidonic acid

Waxes

Monoesters with only one molecule of fatty acid attached to a monohydroxy alcohol

Compound Lipids

lipids composed of phospholipids

Phospholipids

Amphipathic lipids in the cell membrane composed of 2 molecules of fatty acid chains, 1 glycerol, H3PO4, and a nitrogenous compound.

Amphipathic

Having hydrophobic tails and a hydrophilic tail

Lecithin or Phosphatidyl choline

phospholipid attached to a nitrogeneous choline located in the cell membrane

Cephalin

phospholipid attached to a nitrogenous Ethanolamine in nervous tissues, egg yolk, and blood platelets

Sphingolipids

Phospholipids with an amino alcohol sphingosine instead of a glycerol at the myelin sheath of nerves

Glycolipids

A compound lipid with one fatty acid, one sphingosine, and one galactose

Gangliosides

these occur in nerve ganglia and spleen

Derived Lipids

complex lipids derived from simple or compound lipids that are insoluble in water and soluble in organic solvents

Steroids

derived lipids that exhibit tetracyclic structure and regulate organismal processes

Sterols

Also known as cholesterol, it acts as the parent steroid and transforms into Cholecalciferol (Vitamin D0) when exposed to UV radiation

Sterones

Ketonic steroids used as sex hormones such as testosterone and progesterone

Chromolipid

most complex lipid in plasma membrane composed of repeated isoprene units

Proteins

Macromolecules made from C, H, O, N, S and the heteropolymers to amino acids

Structure of amino acid

Side group, one carboxyl, one hydrogen, and one alkaline compound bonded to a central carbon atom

Amino acids

organic amphoteric compounds containing an amino group and an acidic group on the same carbon with substituted methanes

Isoelectric point

point of pH where amino acids have both positive and negative charges in equal amounts

Threonine

essential amino acids