Fats, Protein And DNA Metabolism

Question 1

Digestion of Dietary Fats

Answer 1

1. Begins in the small intestine with bile salts and pancreatic lipase
2. Breakdown of triglycerides into monoglycerides and free fatty acids
3. Emulsification by bile salts increases surface area from enzyme action

Question 2

Absorption of Dietary Fats

Answer 2

1. Fatty acids and monoglycerides absorbed by intestinal epithelial cells
2. Re-esterified into triglycerides and packaged into chylomicrons
3. Transported via lymphatic system to circulation

Question 3

Emulsification

Answer 3

Bile salts secreted by the lover and stored in the gallbladder, mixes with dietary fats in the small intestine, breaking them down into smaller droplets = larger SA for enzyme action

Question 4

Michelle formation

Answer 4

Bile salts surround the digested lipid products, forming tiny structures (micelles) which facilitate transport to the intestinal epithelial cells.

Question 5

Lymphatic transport

Answer 5

Chylomicrons are released into the lymphatic system via lacteals (specialised lymphatic capillaries in the intestinal villi) and enter the bloodstream

Question 6

Lingual lipase

Answer 6

A small amount of fat digestion begins in the mouth due to lingual lipase secreted by the tongue glands

Question 7

Colipase

Answer 7

This protein is crucial for the proper function of pancreatic lipase, helping it to bind to the surface of lipid droplets

Question 8

Oxidation of Fatty Acids

Answer 8

The process where energy is produced by degradation of fatty acids by.

Question 9

Types of fatty acids oxidation

Answer 9

1. B-oxidation of fatty acid
2. The a-oxidation
3. W-oxidation of fatty acids

Question 10

B - oxidation of fatty acid

Answer 10

Beta oxidation is the process by which fatty acids, in the form of Acyl-CoA molecules, are broken down in mitochondria and/or in peroxisomes to generate Acetyl-CoA -enters TCA cycle.

Occurs in many tissues e.g, liver,kidney and heart

Cannot occur in brain as fatty acids cannot be taken up by it

Question 11

Stages of beta oxidation

Answer 11

1) beta-oxidation in the mitochondria breaks down fatty acids into acetyl-CoA units, producing NADH and FADH2.

2) The acetyl-CoA enters the citric acid cycle

3) Electrons from NADH and FADH2 are used to power ATP synthesis via oxidative phosphorylation

Question 12

Transport of acyl CoA into the mitochondria

Answer 12

1. Acyl groups from acyl CoA is transferred to carnitine to form acyl carnitine catalysed by carnitine acyltransferase 1, in the outer mitochondrial membrane .
2. Acylcarnitine is shuttled across the inner mitochondrial membrane by a translocation enzyme