Biochemistry week 2

Question 1

How are fatty acids stored

Answer 1

• They are stored in WAT as TAG( triacylglycerol)

Question 2

Explain the process how fatty acids are broken doen

Answer 2

ATGL (Adipose triglyceride lipase):
Breaks TAG into diacylglycerol.

HSL (Hormone-sensitive lipase):
Breaks diacylglycerol into monoacylglycerol.

MAG lipase:
Breaks monoacylglycerol into free fatty acids (FFA) and glycerol.

Question 3

What does TAG stand for

Answer 3

triacylglycerol

Question 4

Explain how fatty acids are transported

Answer 4

• Travel in the blood and bind to albumin

Question 5

Free Fatty acids are activated intio fatty acylCoA using what?

Answer 5

• Fatty acyl - CoA synthetase ( thiokinase)
• Uses 2 ATP

Question 6

Where does fatty acid oxidation happen

Answer 6

IN the mItochodnria

Question 7

What is the purpose of the carnitine shuttle

Answer 7

• Helps the long chain fatty acids to get inside the mitochondria

Question 8

Where does the actication of fatty acids tske place(2)

Answer 8

• Endoplasmic reticulum
• outer mitochondrial membrane

Question 9

What does the beta oxidation step produce

Answer 9

• 7 FADH2
• 7 NADH
• 8acetyl CoA

Question 10

Name the 3 special cases during the beta oxidation step

Answer 10

-Oxidation of fatty acids with an odd number of carbons
- Oxidation of unsaturated fatty acids
-Peroxisome b oxidation for VLCFAs

Question 11

What is the unique feature of the special case + what is the end product:
- The oxidation of fatty acids with odd chain FA

Answer 11

• Propionyl CoA
• Succinyl coA, which goes to the TCA cycle

Question 12

What is the unique feature of the :oxidation of unsaturated fatty acids as a special case

Answer 12

• The double bonds interrupt the cycle

Question 13

What is the unique feature of VLCFAs as a special case + end product

Answer 13

• Too long for mitochondria so its processed in the peroxisomes
  -Shortened fatty acids

Question 14

explain what regulates b oxidation

Answer 14

Increases:
-Glucagon, epinephrine
- Exercise which decreases malonyl coA , which therfore increases B oxidation

Decreases:
-Insulin
-HighATP /NADH
- Low ATP
-Fed state, which increases malonyl coA which decresses b oxidation

Question 15

Where are ketone bodies made

Answer 15

• Liver mitochondria during fasting , diabetes

Question 16

In ketone bodies/ketogensis what does the liver use FA to make

Answer 16

• acetycl coA

Question 17

What happens in ketolysis

Answer 17

• Tissues convert acetoacetate into aceto acety coA via thiophrase

Question 18

Name the 4 steps in b oxidation

Answer 18

1. Oxidation (dehydration) by FAD Linked acyl dehydrogenase
2. Hydration by hydratase
3. Oxidation by NAD linked dehydrogenase
4. Thiolytic cleavage by thiolase

Question 19

What is Zellweger syndrome

Answer 19

• Defective peroxisome formation which leads to impaired fatty acid oxidation
• • the buildup of VLCFA

Question 20

What is symptoms of Zellweger syndrome

Answer 20

• Hypotonia
  -Seizures
  -Developmental delay
  -Jaundice

Question 21

What is Ketonuria

Answer 21

The presence of ketone bodies in urine

Question 22

What causes Ketonuria

Answer 22

• Fasting, Diabetes type 1