Exam 3

Question 1

Chylomicrons

Answer 1

Made by the small intestines in the fed state. Absorbed into the lymph vessels then moves into the blood. Rich in TG’s. Carry triglycerides (fat) from the intestines to the liver, to skeletal muscle, and to adipose tissue.

Question 2

VLDL

Answer 2

Made in the liver from excess dietary carbohydrate and protein along with the chylomicron remnant. Secreted in the bloodstream. Rich in TG’s. Function is to carry (newly synthesised) triglycerides from the liver to adipose tissue. Contains apo B100. Similar to Chylomicrons, but made by different tissues.

Question 3

LDL

Answer 3

Made in the liver as VLDL. Comes from VLDL once it has lost a lot of its TG’s. Secreted into the bloodstream from liver. Rich in Cholesterol. Function is to deliver cholesterol to all body cells.

Question 4

HDL

Answer 4

Made in the liver and small intestine. Secreted into the bloodstream. The function is to pick up cholesterol from body cells and take it back to the liver (reverse cholesterol transport). Potential to help reverse heart disease.

Question 5

Oxidation of LDL

Answer 5

PUFA’s are oxidized and trigger oxidation of apoB100 –> oxLDL

Question 6

Lingual Lipase

Answer 6

Produced in serous gland lying beneath tongue. Involved in lipid digestion. Important for fat digestion in infants. Relies on mechanical emulsification. Does not need bile - able to penetrate fat globule and is stable at low pH. Undigested fat in stomach delays emptying (via hormone GIP & secretin)

Question 7

Pancreatic Lipase

Answer 7

Involved in lipid digestion

Question 8

Phospholipase

Answer 8

Breaks Phospholipids, involved in lipid digestion

Question 9

Cholesterol Esterase

Answer 9

Breaks Cholesterol Esterase, involved in lipid digestion

Question 10

How do you generate ATP from Fatty Acids?

Answer 10

B-Oxidation

Question 11

List the transporter and transporter enzymes that move fatty acids from the cytosol to the mitochondria

Answer 11

carnitine, carnitine acyl transferase I & II (CAT I & II)

Question 12

How are fatty acids released from triglycerides in the blood?

Answer 12

Hydrolyzed by lipoprotein lipase

Question 13

How are fatty acids released from triglycerides in the tissue?

Answer 13

hydrolyzed by tissue lipases or hormone sensitive lipases

Question 14

How are fatty acids released from triglycerides in the intestinal lumen?

Answer 14

hydrolysis by pancreatic lipase, assisted by colipase

Question 15

Rate limiting enzyme for cholesterol synthesis

Answer 15

HMG CoA reductase

Question 16

Rate limiting enzyme in fatty acid synthesis

Answer 16

ACoA Carboxylase

Question 17

What are the binding sites on fatty acid synthase complex

Answer 17

condensing enzyme (CE) and Acyl Carrier Protein (ACP)

Question 18

Is actyl CoA the product or the substrate of ketone synthesis / ketogenesis?

Answer 18

Substrate

Question 19

Is actyl CoA the product or the substrate of the TCA cycle?

Answer 19

Substrate

Question 20

Is actyl CoA the product or the substrate of pyruvate to pyruvate dehydrogenase?

Answer 20

Product

Question 21

Is actyl CoA the product or the substrate of Citrate to Citrate Lyase?

Answer 21

Product

Question 22

Is actyl CoA the product or the substrate of fatty acid synthesis?

Answer 22

Substrate

Question 23

Is actyl CoA the product or the substrate of Beta-Oxidation?

Answer 23

Product

Question 24

Is actyl CoA the product or the substrate of Cholesterol synthesis?

Answer 24

Substrate

Question 25

Does ketone synthesis occur in the cytosol or mitochondria?

Answer 25

Mitochondria

Question 26

Does the hexose monophosphate shunt occur in the cytosol or mitochondria?

Answer 26

Cytosol

Question 27

Does fatty acid breakdown occur in the cytosol or mitochondria?

Answer 27

Mitochondria

Question 28

Does fatty acid synthesis occur in the cytosol or mitochondria?

Answer 28

Cytosol

Question 29

Short chain fatty acids are carried on what?

Answer 29

Albumin

Question 30

What catalyzes the condensation of oxacloactetate, water, and ACoA, forming water?

Answer 30

Condensing Enzyme

Question 31

LCAT

Answer 31

Converts free cholesterol to cholesterol esters. Bound to HDL and LDLs

Question 32

ACAT

Answer 32

Converts free cholesterol to cholesterol esters.

Question 33

Inhibits the use of fat as an energy source.

Answer 33

Insulin (inhibits release of glucagon). Stored sugar is used instead, glycogenolysis