Lipid Metabolism II

Question 1

Four major steps of Beta-oxidation.

Answer 1

1. Oxidation
2. Hydration
3. Oxidation
4. Thiolysis
   - Repeated until COMPLETELY degraded to Acyl CoA

Question 2

1 Beta-hydroxybutyrate yields how many ATP

Answer 2

26

Question 3

HSL

Answer 3

Hormonally sensitive Lipase

Question 4

What major enzyme is used in the beta-Oxidation of FA?

Answer 4

Acyl CoA Dehydrogenase

ACAD

Question 5

Within the intestinal cell, the ____ and the ____ are condensed to form ____?

Answer 5

FFA and MAGs

TAG

Question 6

Transport of Lipids in Blood

Answer 6

• Nascent Chylomicrons secreted by Exocytosis
• Secreted into the LYMPH system
• Enter the blood via thoracic duct
• Accepts proteins from HDL to form Mature Chylomicrons
• ApoE and ApoCII are important

Question 7

What digests TAGs?

Where are they located?

Answer 7

Lipases

Located in the intestine

Question 8

3 acidic compounds of ACoA

Answer 8

1. Acetoacetate
2. Beta-hydroxybutarate
3. Acetone

Question 9

Apolipoprotien-CII functions?

Answer 9

• Activates Lipoprotein Lipase present on CAPILLARY endothelial cells
• Present in Muscle and Adipose tissue
• Breaks Down Chylomicrons

Question 10

ATGL

Answer 10

Adipose triglyceride lipase

Question 11

Total ATP generated from FA Oxidation?

Total ATP Used?

Net ATP?

Answer 11

108

2

106

Question 12

Contents of Chylomicrons

Answer 12

• Apoproteins
• Phospholipids
• Cholesterol
• Vitamins (Fat soluble)

“ V CAP”

Question 13

Purpose of Isomerase

Answer 13

To move the DISRUPTIVE bond

Question 14

What is responsible for shuttling the FA into the Mitochondria?

Answer 14

Carnitine Shuttle

Question 15

1 acetoacetate can yield hoe many ATP

Answer 15

23

Question 16

What is the major Apoprotein in the synthesis of Chylomicrons?

Answer 16

Apo B48

Question 17

Ketone bodies are formed primarily from what?

Answer 17

The breakdown of FA

Question 18

What membrane in NOT permeable to FA?

Answer 18

Outer Mitochondrial membrane

Question 19

Ketone Body Characteristics

1. Where is it produced?
2. What does it provide?

Answer 19

1. Produced in the LIVER only
2. Provides energy to the peripheral tissues

And

Provides energy during fasting and starvation

Question 20

ATP generation from NADH

Answer 20

• Delivers e- to Complex I of ETC
• Generates 2.5 ATP per cycle
• Generates 17.5 ATP total

Question 21

Fate of GLYCEROL after the breakdown of TAG?

Answer 21

• Goes to the LIVER cell
  1. Can go through GLYCOLYSIS to produce Pyruvate

OR

2. Can go through GLUCONEOGENESIS to produce Glucose

Question 22

Stoichiometry of FA Oxidation

Answer 22

Palmitoyl CoA + 7FAD + 7NAD+ + 7CoA + 7H2O

————>

8ACoA + 7FADH2 + 7NADH + 7H+

Question 23

Apolipoprotein-E (ApoE) function

Answer 23

• Recognized by receptors on surface of LIVER cells

- Allowing for uptake via ENDOCYTOSIS

Question 24

Physiological Ketosis

Answer 24

• Mild/Mod increase in Ketone bodies

Question 25

Phase I of FA Oxidation and where does it occur?

Answer 25

- FA Activation | - Occurs in the CYTOSOL

Question 26

ATP generation from ACoA

Answer 26

- Enters the TCA cycle - Generates 10 ATP per cycle - Generates 80 ATP total

Question 27

Purpose of Reductase

Answer 27

REDUCES the Double Bond

Question 28

What membrane is NOT permeable to FA CoA?

Answer 28

Inner-Mitochondrial Membrane

Question 29

ATP generation from FADH2

Answer 29

- Delivers e- to CoQ/ubiquinone of ETC - Generates 1.5 ATP per cycle - Generates 10.5 ATP total

Question 30

Physio Ketosis occurs during what?

Answer 30

4 things 1. Fasting 2. Pregnancy 3. Prolonged exercise 4. Ketogenic diet

Question 31

TAGs breakdown to form ___ and ___? Where does this occur?

Answer 31

FFA and 2 Monoacylglycerols (MAG) Happens in the lumen of the SMALL intestine

Question 32

Lingual and Gastric lipases digest __ and __ FA in TAG. Maximum amount of carbons

Answer 32

Short and Medium Less than or equal to 11

Question 33

Pathological Ketoacidosis

Answer 33

Occurs when Glucagon/Insulin ratio is increased - favors FA breakdown - Increased 1. ACoA in Liver Mitochondria 2. GNG 3. KB 4. Excretion of Acetoacetate and Beta-hydroxybutyrate in urine o

Question 34

Glucagon vs Epinephrine

Answer 34

Both are involve in the mobilization of FA from adipocytes - Glucagon is used in times of HUNGER - Epinephrine is used in times of EXERCISE

Question 35

Fate of FA after the breakdown of TAG?

Answer 35

- Goes to - Can go to form ACoA via FA OXIDATION - Enter the TCA cycle - Produces CO2 and H2O

Question 36

Purpose of emulsification of fats

Answer 36

Increase Surface Area

Question 37

Unsaturated and EVEN Chain FA degradation require?

Answer 37

2 additional enzymes 1. Isomerase 2. Reductase

Question 38

Phase II of the FA Oxidation sand where does it occur?

Answer 38

- Beta Oxidation | - Occurs primarily in the Mitochondrial Matrix (actual degradation)

Question 39

Odd numbered DB are handled by ____.

Answer 39

Isomerase