Govt Exams
Simple carbohydrates include monosaccharides (glucose, fructose, galactose) and oligosaccharides (2-10 units like sucrose, maltose, lactose). Complex carbohydrates are polysaccharides with >10 units (starch, glycogen, cellulose).
Sucrose (table sugar) is a disaccharide composed of one glucose and one fructose unit linked by an α(1→2) glycosidic bond. It is a non-reducing sugar.
Phosphoglucose isomerase (PGI) catalyzes the reversible conversion of glucose-6-phosphate to fructose-6-phosphate in glycolysis, step 2.
Maltose consists of two glucose units linked by an α(1→4) glycosidic bond. This is a reducing disaccharide formed during starch digestion.
Glycogen, the storage polysaccharide in animals, is primarily stored in the liver (100-120g) and skeletal muscles (400-500g). The liver glycogen maintains blood glucose, while muscle glycogen is used locally.
Ribose is a pentose sugar (5-carbon sugar) that is a component of RNA. Deoxyribose is found in DNA, while glucose and fructose are hexose sugars.
Peptide bonds form through a condensation reaction between the carboxyl group (-COOH) of one amino acid and the amino group (-NH2) of another, releasing H2O. They are covalent and stable.
ER chaperones like BiP (heat shock protein 70) assist in protein folding, prevent aggregation, and aid in proper disulfide bond formation during synthesis.
LDH catalyzes the interconversion of lactate and pyruvate using NAD+ as an electron acceptor and NADH as an electron donor in the coupled redox reaction.
Collagen triple helix is stabilized by hydrogen bonds between the three polypeptide chains and covalent cross-links (lysine and hydroxylysine residues) between molecules, providing mechanical strength.