(a) Define enzymes.
(b) State six characteristics of enzymes.
(c) Describe the role of pancreatic juice in the digestion of carbohydrates and proteins in a mammal.
(d) In what form is carbohydrate stored in (i) animals (ii) plants
(e) Describe the saprophytic nutrition of Rhizopus.
Explanation
(a) Definition of enzymes: Enzymes are organic catalyst substance that speed up/slow down the rate of biochemical reactions, they are made of proteins, and produced by living cells.
(b) Characteristics of enzymes are:
(1) Remain chemically unchanged at the end of a reaction
(2) Are specific in action/one or a group of enzymes will act on specific substrates
(3) Required in small quantities
(4) Act best over a specific range of temperature/between 35o — 40°C
(5) They are denature/destroyed at high temperature/inactivated at very low temperature
(6) Act best at specific Ph (either acidic or alkaline)
(7) Their action is reversible
(8) Enzyme action is retarded by poison or inhibitors
(9) Some are inactive and require a co-enzyme/agent to activate them
(10) They can function outside the body of the organism that produces them
(11) Enzymes are protein in nature
(c) Role of Pancreatic juice in carbohydrate and Protein digestion are:
(1) Pancreatic juice provides an alkaline medium for the action of the enzymes involved; Which operate in the small intestine/duodenum
(2) Pancreatic juice contains Amylase/Amylopsin, which converts starch to maltose sugar, it also contains trypsin, which converts proteins to peptone / peptide/ polypeptides /amino acids
(3) Carboxypeptidase, converts polypeptides to amino acids.
(d) Storage of excess carbohydrate takes this form:
(i) In Animals : Glycogen /fat
(ii) In plants: Starch /Sucrose/ Sugar
(e) The saprophytic nutrition of reproduction goes like this: - Rhizopus grows on organic matter e.g. damp/moist food/ bread / decaying mater substrate; its hyphae penetrate the food / substrate and secrete hydrolyzing enzymes, Which digest the food / substrate / results in extracellular digestion; the hyphae absorb the digested food / soluble products for metabolic activity.