Week 9

Question 1

What are the 4 ways fat can be metabolised?

Answer 1

1. Digest fat and store it in the adipose
2. Digest fat and use the energy (beta oxidation)
3. mobilise fat from the adipose and use the energy (beta oxidation and ketone body formation)
4. Excess carbohydrates can be transferred into fat and stored (liver; lipogenesis)

Question 2

What helps to emulsify fat droplets?

Answer 2

Bile salts

Question 3

Where are triglycerides and phospholipids resynthesized?

Answer 3

In epithelial cells

Question 4

What are chylomicrons made up of?

Answer 4

• Triglycerides
• Phospholipids
• Cholesterol
• Proteins

Question 5

What is lipoprotein lipase? (LPL)

Answer 5

an enzyme on the endothelial surface

Question 6

What stimulates and inhibits the expression of LPL?

Answer 6

The insulin in the adipocytes will stimulate it but insulin will inhibit the secretion of LPL in skeletal muscle

LPL in skeletal muscle is activated by glucagon and epinephrine

Question 7

How are fatty acids made?

Answer 7

Through the hydrolysis of triglycerides

Question 8

What is Beta-oxidation?

Answer 8

The cleaving of fatty acids

Question 9

Where does beta-oxidation occur?

Answer 9

in the outer and inner mitochondrial membrane

Question 10

How are fatty acids transported?

Answer 10

Attached to a CoA from the Acyl CoA synthase creating Fatty Acyl CoA

Question 11

As fatty acyl CoA cant pass the mitochondria membrane what is it converted into so It can pass?

Answer 11

It is turned into fatty acylcarnitine by carotene palmitoyl transferase 1

Question 12

What are the 4 reactions in beta oxidation?

Answer 12

1. Oxidation reaction
2. Hydration Step
3. Oxidation step
4. Cleavage of beta alpha bond

Question 13

What are the 4 enzymes in beta-oxidation?

Answer 13

1. Acyl-CoA dehydrogenase
2. Enoyl-CoA hydratase
3. Beta hydroxyacyl CoA dehydrogenase
4. Thiolase

Question 14

What are the products of beta oxidation?

Answer 14

• Fatty acyl CoA

- Acetyl CoA

Question 15

How does beta oxidation change when a double bond is present?

Answer 15

The first reaction (the oxidation step) is skipped

Question 16

What is the equation for the number of acetyl CoA that will be produced?

Answer 16

Number of carbons/2

the 2 is for the number of carbons in acetyl CoA

Question 17

What is the equation for the number of NADH produced?

Answer 17

of acetyl CoA - 1

Question 18

What is the equation for the number of FADH produced?

Answer 18

of NADH - how many double bonds

Question 19

What vitamin is essential for fatty acid breakdown?

Answer 19

Vitamin B12

Question 20

What is medium chain acyl CoA dehydrogenase deficiency?

Answer 20

An inherited defect in beta oxidation

Question 21

If diagnosed, how is medium chain acyl CoA dehydrogenase deficiency managed?

Answer 21

By avoiding prolonged fasting

Question 22

What substrates are required for fatty acid synthesis?

Answer 22

Malonyl CoA and 2 NADPH

Question 23

What regulates acetyl CoA carboxylase?

Answer 23

• AMPK can act as a regulator
• insulin will stimulate
• glucagon will limit it

Question 24

When does ketone body synthesis occur?

Answer 24

When the body is out of OAA and Acetyl CoA levels are high

Question 25

What are the two enzymes for ketosis?

Answer 25

Beta hydrobutyrate dehydrogenase and thiolase

Question 26

What are the problems of ketosis?

Answer 26

• reduces the use of glucose
• increased acetyl CoA
• Increased blood acidity
• tissues without mitochondria’s cannot use them