CFTRI M.Sc. (Food Technology) Food Biotechnology, Biochemistry & Nutrition Syllabus

What is the function of the pentose phosphate pathway?

It generates NADPH for biosynthesis (e.g., fatty acid synthesis) and ribose-5-phosphate for nucleotide synthesis, operating in the cytoplasm parallel to glycolysis.

What is beta-oxidation and where does it occur?

Beta-oxidation is the mitochondrial breakdown of fatty acids into acetyl-CoA units, each cycle removing 2 carbons and yielding 1 FADH2, 1 NADH, and 1 acetyl-CoA.

Why do fats yield more energy per gram than carbohydrates?

Fatty acids are more highly reduced (more C-H bonds) and contain less oxygen, so their oxidation releases more energy; fat gives about 9 kcal/g versus 4 kcal/g for carbohydrate.

What are ketone bodies, when are they formed, and name them.

Ketone bodies (acetoacetate, beta-hydroxybutyrate, acetone) are made in the liver from excess acetyl-CoA during starvation, fasting, or uncontrolled diabetes, and serve as fuel for brain and muscle.

Where does fatty acid synthesis occur and what is the key precursor and reducing agent?

Fatty acid synthesis occurs in the cytoplasm using acetyl-CoA (via malonyl-CoA) as building blocks and NADPH as the reducing agent, catalyzed by fatty acid synthase.

Distinguish saturated, monounsaturated, and polyunsaturated fatty acids.

Saturated fatty acids have no C=C double bonds; monounsaturated have one double bond; polyunsaturated have two or more double bonds (e.g., omega-3, omega-6).

What are essential fatty acids and give examples?

Fatty acids the body cannot synthesize and must obtain from diet: linoleic acid (omega-6) and alpha-linolenic acid (omega-3).

What is transamination in protein metabolism?

The transfer of an amino group from an amino acid to a keto acid (usually alpha-ketoglutarate), catalyzed by transaminases using pyridoxal phosphate (vitamin B6) as coenzyme.

What is the urea cycle and why is it important?

It is the liver pathway that converts toxic ammonia (from amino acid catabolism) into urea for excretion; it detoxifies nitrogenous waste and occurs partly in mitochondria and partly in the cytoplasm.

Distinguish essential from non-essential amino acids and give examples.

Essential amino acids must come from the diet (e.g., lysine, leucine, valine, methionine, tryptophan); non-essential amino acids can be synthesized by the body (e.g., alanine, glutamate, glycine).

What does nitrogen balance indicate in protein nutrition?

It compares nitrogen intake to excretion: positive balance (growth, pregnancy) means intake exceeds loss; negative balance (starvation, illness) means loss exceeds intake; zero balance is maintenance in healthy adults.

Write the overall balanced equation for photosynthesis.

6 CO2 + 6 H2O + light energy -> C6H12O6 + 6 O2 (carbon dioxide and water converted to glucose and oxygen using light energy).

What are the two stages of photosynthesis and where does each occur?

The light-dependent reactions occur in the thylakoid membranes (produce ATP, NADPH, O2); the light-independent reactions (Calvin cycle) occur in the stroma (fix CO2 into glucose).

What is the role of chlorophyll in photosynthesis?

Chlorophyll is the green pigment in chloroplasts that absorbs light energy (mainly red and blue, reflecting green) to drive the light reactions; chlorophyll-a is the primary pigment.

What enzyme catalyzes CO2 fixation in the Calvin cycle and what is the first stable product in C3 plants?

RuBisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase) fixes CO2; the first stable product in C3 plants is 3-phosphoglycerate (3-PGA), a 3-carbon compound.

Classify vitamins into the two solubility groups with examples.

Fat-soluble vitamins: A, D, E, K (stored in body fat). Water-soluble vitamins: B-complex and C (not stored, needed regularly).

Match these deficiency diseases to their vitamins: scurvy, rickets, beriberi, pellagra.

Scurvy - vitamin C; rickets - vitamin D; beriberi - thiamine (B1); pellagra - niacin (B3).

What is the main function of vitamin A and what deficiency does it cause?

Vitamin A (retinol) is essential for vision (forms rhodopsin), epithelial integrity, and immunity; deficiency causes night blindness and xerophthalmia.

What is the function of vitamin K and vitamin D in the body?

Vitamin K is required for blood clotting (synthesis of clotting factors); vitamin D promotes intestinal calcium and phosphorus absorption for bone mineralization.

Which vitamin functions as a major water-soluble antioxidant and aids iron absorption?

Vitamin C (ascorbic acid); it is also required for collagen synthesis and enhances absorption of non-heme iron.

What deficiency disease is caused by lack of vitamin B12 and folate?

Megaloblastic (pernicious) anemia; both are needed for DNA synthesis and red blood cell maturation, and B12 deficiency also causes neurological damage.

Distinguish macrominerals from microminerals (trace elements) with examples.

Macrominerals are needed in larger amounts (calcium, phosphorus, sodium, potassium, magnesium); microminerals/trace elements are needed in tiny amounts (iron, zinc, iodine, copper, selenium).

What are the main functions of calcium and iron in the body?

Calcium: bone and teeth formation, blood clotting, muscle contraction, nerve function. Iron: component of hemoglobin and myoglobin for oxygen transport; deficiency causes anemia.

What is the role of sodium and potassium in the body?

They are the major electrolytes maintaining fluid balance, osmotic pressure, and nerve/muscle excitability; sodium is mainly extracellular and potassium mainly intracellular (sodium-potassium pump).

Which mineral is essential for thyroid hormones and which deficiency disease results?

Iodine is required for thyroxine (T4) and T3; deficiency causes goiter and, in children, cretinism.

What is the structural difference between DNA and RNA?

DNA has deoxyribose sugar, the base thymine, and is usually double-stranded; RNA has ribose sugar, the base uracil, and is usually single-stranded.

Name the three main types of RNA and their functions.

mRNA carries the genetic code from DNA to ribosomes; tRNA brings amino acids to the ribosome during translation; rRNA forms the structural and catalytic core of ribosomes.

What are nucleotides composed of?

Each nucleotide has three parts: a nitrogenous base (purine or pyrimidine), a pentose sugar (ribose or deoxyribose), and one or more phosphate groups.

Besides heredity, name two important roles of nucleotides in metabolism.

ATP/GTP serve as energy currency; nucleotides also form coenzymes (NAD, FAD, coenzyme A) and act as signaling molecules (cyclic AMP).

What is the physiological caloric value (Atwater factors) of carbohydrates, proteins, and fats?

Carbohydrates and proteins yield about 4 kcal/g each; fats yield about 9 kcal/g; (alcohol yields about 7 kcal/g).

What is Basal Metabolic Rate (BMR) and how is Body Mass Index (BMI) calculated?

BMR is the energy expended at complete rest to maintain vital functions; BMI = weight(kg) / height(m)^2, used to classify underweight, normal, overweight, and obese.

What is dietary fiber and why is it important for health?

Dietary fiber is indigestible plant carbohydrate (cellulose, pectin, etc.); it aids bowel movement, lowers cholesterol, controls blood sugar, and gives satiety though it provides little energy.

Define a balanced diet.

A diet that provides all nutrients (carbohydrates, proteins, fats, vitamins, minerals, water, and fiber) in correct proportions and adequate amounts to meet the body's needs for energy, growth, and maintenance.