M1-C1-L78 --> Lipids

Front 1

In terms of metabolism, what is insulin responsible for in a fed state?

Back 1

1. Uptake of carbohydrates
2. Metabolism of lipolipids

Front 2

Where do you find fatty acid synthase?

Back 2

In the cytoplasm

Front 3

What the @#$% is going on here?

Back 3

Answer

Front 4

Fatty acid synthesis takes many steps with how many enzymes?

Back 4

Just one

Front 5

How do you elongate fatty acids with how many added carbons each time?

Back 5

Sequential additions of malonyl CoA, and release of CO2. Thus 2 carbons added each time.

Front 6

Fatty acid synthesis ends with formation of what? How many carbons is this molecule?

Back 6

Palmitate (16 carbons)

Front 7

What enzyme is responsible for forming malonyl-CoA and what special molecule is on it?

Back 7

Acetyl CoA Carboxylase containing biotin.

Front 8

How does malonyl-CoA get formed?

Back 8

Acetyl-CoA carboxylase adds a carbon on to acetyl-CoA from HCO3-

Front 9

During a fed state, what molecule does what to the regulation of malonyl-CoA formation?

Back 9

Insulin activates formation of citrate to acetyl-CoA

Front 10

During a fasting state, what molecules signal what to the regulation of malonyl-CoA formation?

Back 10

Glucagon and epinephrine inhibit Acetyl-CoA carboxylase

Front 11

Give an example of feed-forward activation for malonly-CoA formation.

Back 11

High levels of citrate will activate Acetyl-CoA carboxylase.

Front 12

Give an example of feedback inhibition for malonly-CoA formation.

Back 12

Palimate inhibits Acetyl-CoA carboxylase

Front 13

What are all the activators of malonyl-CoA formation?

Back 13

1. Citrate
2. Insulin

Front 14

What are all the inhibitors of malonly-CoA formation?

Back 14

Palmitate, Epinephrine, and Glucagon.

Front 15

Palmitate elongation occurs where?

Back 15

Smooth ER

Front 16

T/F - Palmitate elongation and fatty acid synthesis occurs using the same enzymes.

Back 16

False - although both use malonyl CoA to contribute the carbons, the enzymes are different

Front 17

Acetyl-CoA is formed in mitochondria and fatty acid syntheisis occurs in the cytoplasm. What allows acetyl-CoA to get to cytoplasm?

Back 17

Acetate shuttle
or
Citrate cleavage pathway

Front 18

In the acetate shuttle, what does citrate break down into?

Back 18

Acetyl-CoA and oxaloacetate

Front 19

How does oxaloacetate re-enter the mitochondria?

Back 19

Must be reduced to malate or pyruvate to enter the mitochondria

Front 20

Conversion of oxaloacetate to malate yields what?

Back 20

NADH

Front 21

Conversion of oxaloacetate to pyruvate yields what?

Back 21

NADH and NADPH

Front 22

Conversion of malate to pyruvate yields what?

Back 22

NADPH

Front 23

What is the enzyme responsible for forming NADPH from malate to pyruvate?

Back 23

malic enzyme

Front 24

Is cholesterol required in the diet?

Back 24

No. All cells can synthesize it from simple precursors

Front 25

What is the enzyme catalyzing the final step in cholesterol synthesis?

Back 25

7-dehydrocholesterol D7 Reductase

Front 26

What is the disorder associated with a defect or absence of 7-dehydrocholestrol D7 Reductase?

Back 26

Smith-Lemli-Opitz syndrome (SLOS)

Front 27

What is the beginning precursor of cholesterol?

Back 27

Acetyl-CoA

Front 28

General description of stage 1 of cholesterol synthesis.

Back 28

3 Acetyl CoA form Mevalonate

Front 29

General description of stage 2 of cholesterol synthesis.

Back 29

Mevalonate conversion to Isoprolene

Front 30

General description of stage 3 of cholesterol synthesis.

Back 30

6 Isoprolene (5C) forms Squalene

Front 31

General description of stage 4 of cholesterol synthesis.

Back 31

Squalene goes through cyclization and subsequent modifications to form cholesterol.

Front 32

What is the first committed step in cholesterol synthesis?

Back 32

HMG-CoA (3 acetyl CoA condensed together) will be reduced to mevalonate with the help of HMG CoA reductase

Front 33

What three things regulate the biosynthesis of cholesterol?

Back 33

1. Intracellular cholesterol concentration.
2. Insulin
3. Glucagon

Front 34

How does cholesterol take part in it's own feedback inhibition?

Back 34

Cholesterol (or one of it's derivative) will inhibit GENE TRANSCRIPTION or activate DEGRADATION of HMG CoA Reductase

Front 35

What phosphorylates HMG-CoA Reductase, and what does this do?

Back 35

Glucagon phosphorylates it to inactivate HMG CoA Reductase.

Front 36

What dephosphorylates HMG-CoA Reductase, and what does this do?

Back 36

Insulin dephosphorylates it to activate HMG-CoA Reductase.

Front 37

Cholesterol is primarily made where?

Back 37

Liver

Front 38

What are the two forms that cholesterol is exported in from the liver?

Back 38

1. Bile salts
2. Cholestryl esters (lipoproteins)