Unit 2 Review

Question 1

Cholesterol is a precursor to whichhormones?

Answer 1

Progesterone, aldosterone, cortisol, estradiol, testosterone (PACET)

Question 2

How much of human cholesterol is synthesized?

Answer 2

80%

Question 3

What do bile salts do?

Answer 3

Solubilize fat globules in the small intestine by dispersing them into micelles (synthesized by liver).

Question 4

What do lipases do?

Answer 4

Break down intestinal triglycerides for absorption by the intestinal enterocytes

Question 5

What do chylomicrons do?

Answer 5

Transfer exogenous lipids through the bloodstream.

Question 6

What do VLDL, IDL, and LDL do?

Answer 6

Transfer endogenous lipids from the liver to the tissues.

Question 7

What does HDL do?

Answer 7

Transports cholesterol and other lipids from tissues back to liver.

Question 8

What apolipoproteins do chylomicrons have?

Answer 8

ApoB48, ApoCII, ApoE

Question 9

What apolipoproteins do VLDL and IDL have?

Answer 9

ApoB100, ApoCII, ApoE

Question 10

What does ApoCII do?

Answer 10

Activates lipoprotein lipase (frees fatty acids from triglycerides)

Question 11

What apolipoproteins does LDL have?

Answer 11

ApoB100

Question 12

What apolipoproteins does HDL have?

Answer 12

ApoCII, ApoE

Question 13

What tissues have the highest need for fatty acids?

Answer 13

MMAAG - Muscle, mammary, adrenal, adipose, gonads

Question 14

Which lipoprotein has the highest triglyceride content?

Answer 14

Chylomicrons

Question 15

Which lipoprotein has the highest cholesterol content?

Answer 15

LDL

Question 16

Which lipoprotein has the highest protein content?

Answer 16

HDL

Question 17

Of VLDL and IDL, which has less triglycerides?

Answer 17

IDL

Question 18

Where does ketone body synthesis occur?

Answer 18

Mitochondria of liver cells

Question 19

What are ketone bodies made from?

Answer 19

Acetyl CoA

Question 20

Where does cholesterol synthesis occur?

Answer 20

Cytosol of liver cells

Question 21

Which tissues create their own cholesterol?

Answer 21

BOLIT - Brain, ovaries, liver, intestine, testes

Question 22

What are notable molecules assc with cholesterol synthesis?

Answer 22

HMG CoA, mevalonate, DMAPP/IPP, prenyl transferase, squalene

Question 23

What is the committed step of cholesterol synthesis?

Answer 23

HMG CoA –> Mevalonate

Question 24

What enzyme do statins target?

Answer 24

HMG CoA reductase

Question 25

How is cholesterol metabolized?

Answer 25

The ring structure can't be broken down; it has to be recycled or turned into bile acid and excreted

Question 26

What regulates cholesterol synthesis?

Answer 26

Sterol response element/SREBP

Question 27

What are the three types of ketone bodies?

Answer 27

Acetoacetate, acetone, D-B-hydroxybutyrate

Question 28

What are key molecules associated with ketogenesis?

Answer 28

HMG CoA --> Acetoacetate --> Acetone/DBHB (NADH-dependent)

Question 29

What do CPT-I and CPT-II do?

Answer 29

Move fatty acyl CoA into matrix for beta oxidation

Question 30

Where does beta oxidation take place?

Answer 30

Mitochondrial matrix

Question 31

Which tissues oxidize FAs?

Answer 31

Heart, muscle, kidneys

Question 32

What is the order in which the body breaks down its stored energy?

Answer 32

Glucose --> Glycogen --> Fats --> Proteins

Question 33

Where are triglycerides stored?

Answer 33

Adipose tissue, between muscle fibers, within muscle cells

Question 34

Which hormones signal for release of glucose, glycogen breakdown, and HSL activation?

Answer 34

Glucagon and Epi

Question 35

What does HSL activation do?

Answer 35

Frees fatty acids from TG storage and gives them to albumin for transport to the blood

Question 36

What happens to glycerol after its separated from stored triglycerides?

Answer 36

Pyruvate or gluconeogenesis

Question 37

What 2 enzymes are needed to oxidize unsaturated fatty acids?

Answer 37

Isomerase, reductase (Polyunsaturated)

Question 38

What is needed to oxidized branched and very long chain fatty acids?

Answer 38

Transport to peroxisome

Question 39

What happens during oxidation of odd-chain fatty acids?

Answer 39

Produces propionyl CoA, which has to be converted to succinyl CoA

Question 40

Where are fatty acids synthesized?

Answer 40

Cytosol

Question 41

What process involves excess of citrate?

Answer 41

Fatty acid biosynthesis

Question 42

What is the relationship between fatty acid synthesis and the citric acid cycle?

Answer 42

In FA synthesis, body uses OAA to create citrate, stopping the citric acid cycle.

Question 43

What happens to the citrate in the cytosol?

Answer 43

Converted to OAA, then back to pyruvate to generate NADPH (needed for fatty acid synthesis)

Question 44

What is the other source of NADPH for fatty acid synthesis?

Answer 44

PPP

Question 45

There is a high _____ in the cytosol, and a high _____ in the mitochondria.

Answer 45

High NADPH in cytosol, high NADH in mitochondria.

Question 46

What notable molecules are associated with FAS?

Answer 46

Malonyl CoA, -ACP molecules

Question 47

What does acetyl CoA carboxylase do?

Answer 47

Converts acetyl CoA to malonyl CoA for FAS

Question 48

What enzymes are used to modify palmitate?

Answer 48

Elongase and desaturase

Question 49

Where is palmitate modified?

Answer 49

Smooth ER

Question 50

Linoleate ratio

Answer 50

18:2

Question 51

Linolenate ratio

Answer 51

18:3

Question 52

What is the precursor made by the COX pathway?

Answer 52

PGH2 (then thromboxanes, prostaglandins, prostacyclins)

Question 53

What is the molecular mechanism associated with aspirin?

Answer 53

Binds to Ser residue in COX, preventing arachidonic acid from binding and being converted to PGH2

Question 54

What is the "activation product" associated with triglyceride and phospholipid biosynthesis?

Answer 54

Phosphatidic acid

Question 55

"Mechanism" for TG synthesis

Answer 55

PA --> DAG + Fatty Acyl CoA --> TAG

Question 56

"Mechanism" for PL synthesis

Answer 56

DAG + CDP --> GPL (DAG or head group -OH)