CFTRI M.Sc. (Food Technology) Zoology Syllabus

Name the male and female sex hormones and their primary endocrine sources.

Testosterone from the testes (Leydig cells); estrogen and progesterone from the ovaries.

What is digestion?

The process of breaking down complex, insoluble food molecules into simple, soluble, absorbable forms by mechanical and chemical means.

Which enzyme in saliva begins starch digestion and what does it produce?

Salivary amylase (ptyalin), which breaks starch into maltose.

Name the gastric enzyme that digests proteins and the form it is secreted in.

Pepsin, secreted as the inactive zymogen pepsinogen and activated by HCl.

What are the three functions of hydrochloric acid in the stomach?

It activates pepsinogen to pepsin, provides an acidic medium for enzyme action, and kills ingested microorganisms.

What is the role of bile in digestion and where is it produced and stored?

Bile emulsifies fats into small droplets to aid lipase action; it is produced by the liver and stored in the gall bladder.

Name the three major pancreatic enzymes and their substrates.

Trypsin (proteins), pancreatic amylase (starch), and lipase (fats/triglycerides).

Which enzyme activates trypsinogen to trypsin in the small intestine?

Enterokinase (enteropeptidase) secreted by the intestinal mucosa.

Into what end products are carbohydrates, proteins, and fats finally digested?

Carbohydrates to monosaccharides (e.g., glucose), proteins to amino acids, and fats to fatty acids and glycerol.

What is the optimum pH for the action of pepsin and pancreatic enzymes?

Pepsin acts best in an acidic pH (about 1.5-2); pancreatic enzymes act best in an alkaline pH (about 7.5-8.5).

What enzyme digests milk protein and is especially important in infants?

Rennin, which curdles milk protein (casein) for easier digestion.

What is absorption in the context of the digestive system?

The passage of digested food molecules from the intestinal lumen through the mucosa into the blood or lymph.

Which part of the alimentary canal is the main site of nutrient absorption?

The small intestine, especially the ileum.

What structural features increase the absorptive surface area of the small intestine?

Circular folds, villi, and microvilli (brush border) on the epithelial cells.

What is the lacteal and what does it absorb?

A lacteal is the central lymphatic capillary inside each villus that absorbs digested fats (chylomicrons).

By which mechanisms are glucose and amino acids absorbed in the intestine?

Mainly by active transport (often sodium-coupled secondary active transport) and some facilitated diffusion.

What is mainly absorbed in the large intestine?

Water, electrolytes, and some vitamins (such as vitamin K produced by gut bacteria).

What is assimilation as distinguished from absorption?

Assimilation is the incorporation of absorbed nutrients into body tissues and their use in growth, repair, and energy; absorption is merely their uptake into blood/lymph.

How are fat-soluble vitamins absorbed?

Along with dietary fats, in association with bile salts forming micelles, then into the lacteals of the lymphatic system.

What is respiration in living organisms?

The biochemical process of oxidizing food (mainly glucose) to release energy in the form of ATP, often accompanied by gas exchange.

Differentiate between external and internal (cellular) respiration.

External respiration is the exchange of O2 and CO2 between the organism and environment; internal respiration is the oxidation of nutrients within cells to release energy.

Write the overall equation for aerobic respiration of glucose.

C6H12O6 + 6O2 -> 6CO2 + 6H2O + energy (about 38 ATP).

What are the three main stages of aerobic respiration and where do they occur?

Glycolysis (cytoplasm), Krebs cycle (mitochondrial matrix), and electron transport chain/oxidative phosphorylation (inner mitochondrial membrane).

What is the net ATP yield of glycolysis?

A net gain of 2 ATP (and 2 NADH) per glucose molecule.

What are the end products of anaerobic respiration in muscle cells and in yeast?

Lactic acid in muscle cells; ethanol and carbon dioxide in yeast (fermentation).

Why is aerobic respiration more efficient than anaerobic respiration?

Because complete oxidation of glucose yields about 38 ATP, whereas anaerobic respiration yields only 2 ATP per glucose.

What respiratory pigment carries oxygen in human blood and where is it located?

Haemoglobin, located in the red blood cells (erythrocytes).

What is the respiratory quotient (RQ)?

The ratio of the volume of CO2 produced to the volume of O2 consumed during respiration (RQ = CO2 released / O2 consumed).

What is homeostasis in animal physiology?

The maintenance of a constant internal environment (temperature, pH, water, solute balance) despite changes in external conditions.

Distinguish between poikilothermic and homeothermic animals.

Poikilothermic (cold-blooded) animals have body temperature varying with the environment; homeothermic (warm-blooded) animals maintain a constant body temperature.

What is the basic structural and functional unit of the nervous system, and how do nerve impulses cross between neurons?

The neuron; impulses cross from one neuron to the next at a synapse via chemical neurotransmitters.

What is osmoregulation and which organ is chiefly responsible for it in mammals?

Osmoregulation is the control of water and salt balance in body fluids; the kidney is chiefly responsible in mammals.