Lipid metabolism

Question 1

The 4 types of phospholipids are?

Answer 1

1. PhosphatidylCholine
2. PhosphatidylSerine
3. Phosphatidylinositol
4. Phosphatidylethanolamine

Question 2

Explain ketogenesis?

Answer 2

Ketogenesis refers to the biochemical synthesis of ketone bodies by breaking down fatty acids and ketogenic amino acids

Question 3

Explain Ketosis?

Answer 3

Ketosis is a metabolic state where the body burns fat for energy rather than glucose

Question 4

Mention the functions of ketone bodies you know?

Answer 4

1. They serve to keep organs like brain & heart in constant supply of energy.
   2.ketone bodies help to maintain energy homeostasis
2. Ketone bodies production saves muscle protein.

Question 5

Briefly explain Lipids?

Answer 5

Lipids constitute a heterogenous group of compound which includes fats, oil, steroids, wax and other related compounds

Question 6

Lipids are classified into 3; name them?

Answer 6

1. Simply Lipids
2. Complex lipids
3. Derived lipids

Question 7

Mention some Diseases associated with lipid metabolism?

Answer 7

1. Obesity
2. Diabetes mellitus
3. Hypertriglyceridema
4. Ketone acidosis

Question 8

In details, explain the digestion of TriAcylGlycerol(TAG)?

Answer 8

Triacylglycerol digestion begins in the mouth by mechanical mastication to increase surface area and action of Lingual lipase, but this digestion is limited.
Digestion in the mouth and stomach(gastric lipase) is limited due to solubility of substrate and the chain length of fatty acids. Thus lipases preferentially hydrolyse shirt and medium chain fatty acids with 12carbon or less.
Main digestion occurs in the lumen of the intestine due to pancreatic lipase.
When partially digested food leaves the stomach and enters the intestine, the hormone Cholecystokinin, is secreted to cause contraction of the gall bladder to release bile salt and pancreas to release digestive enzyme. Bile salt act to emulsify fats, followed by hydrolysis from the pancreatic enzymes (pancreatic lipase and coenzyme colipase), along with

Question 9

Bile salt are synthesized in?

Answer 9

The bile canalliculi of the liver

Question 10

The major enzyme that digest Triacylglycerol are?

Answer 10

Pancreatic lipase

Question 11

Pancreatic lipase is secreted along side with another protein called?

Answer 11

Colipase

Question 12

Food coming from the stomach is acidic but Action of pancreatic enzymes is made possible because of?

Answer 12

Bicarbonate secretions released to neutralise the pH, and provide optimal conditions for action.

Question 13

What is the function of colipase in the digestion of TAG?

Answer 13

Colipase binds to dietary fats and increase the lipase activity of pancreatic lipase.
Pancreatic lipase hydrolyse fatty acids of all chain length to produce free fatty acids and 2mono acyl glycerol

Question 14

What is the role of phospholipase A2 in digestion

Answer 14

They digest phospholipid to a free fatty acids and a lysophospholipid

Question 15

Explain the process of absorption an transport of dietary lipids?

Answer 15

The fatty acid and 2monoacylglycerol produced by digestion are packaged into micelles(a small aggregate of mixed lipids and bile salt). Micelles have a fatty acids view with water soluble exterior. This allows efficient transportation to the microvilli(intestinal epithelial cells).
While the fatty acid and 2 mono acyl glycerol are absorbed, bile Salts are left behind in the intestinal lumen

Question 16

At what point are the bile extensively reabsorbed?

Answer 16

When they reach the ileum.

Question 17

_______ and________ do not require bile salts for their absorption?

Answer 17

Short and medium chain fatty acids

Question 18

Mention functions of cholesterol?

Answer 18

1. Major component of cell membrane
2. Modulates membrane fluidity
3. Stabilizes membrane structure
4. Increase permeability of cell membrane
5. Increases cell signaling

Question 19

Enumerate the functions of phospholipids

Answer 19

1. Helps maintain membrane integrity and fluidity
2. Participates in lipid metabolism and signaling pathways.
3. Plays a role in cell signaling, apoptosis, and blood clotting.
4. Regulates the activity of enzymes and transporters in mitochondria.
5. Plays a critical role in maintaining mitochondrial structure and function

Question 20

What is kenogenesis?

Answer 20

Ketogenesis is the biological process through which organisms produce ketone bodies by breakdown of fatty acids and ketogenic amino acids

Question 21

What is ketoacidosis?

Answer 21

Ketoacidosis is the excess secretion of ketone bodies

Question 22

What is ketonemia?

Answer 22

Ketonemia is when the rate of production of ketone bodies exceed the rate of utilization.

Question 23

What is a ketourea test?

Answer 23

It is used to monitor or measure amount of ketone bodies through the urine

Question 24

Function of ketone bodies?

Answer 24

1. They serve to keep organs like the brain and hear in constant supply of energy even in absence of glucose
2. Ketone bodies help to maintain energy homeostasis
3. Ketone bodies except acetone are water soluble
4. Production of ketone bodies save muscle protein

Question 25

What are the fat soluble vitamins?

Answer 25

Vitamin A,D,E,K

Question 26

Chylomicrons are transported in the lymphatic system but enter into the blood at?

Answer 26

The Thoracic duct

Question 27

Give one example of short and medium chain fatty acid

Answer 27

Breast milk