Petri Guide

Question 1

What kind of bond hols the fatty acid onto sphingolipids?

Answer 1

Amide only (note the initial acyl group is reduced, so no acyl groups in this molecule)

Question 2

What 3 lipids are typically found on the outer leaflet?

Answer 2

1. Sphingomyelin
2. Phophatidylcholine
3. Glycolipids (A,B,O bloodtype)

Question 3

What 3 phospholipids can be make by headgroup activation and what is special about this group of phospholipids?

Answer 3

1. PC
2. PS
3. PE

*They can be interconverted
PE –> PC, via 3 SAM
PE –> PS, via simple exchange
PS –> PE, via decarboxylation

Question 4

What do you get when you use phospholipase A1 on a phospholipid?

Answer 4

• Saturated fatty acid

- glycerol + C2 UNsaturated FA + C3 phosphate and headgroup

Question 5

What do you get when you use phospholipase A2 on a phospholipid?

Answer 5

• UNaturated fatty acid

- glycerol + C1 Saturated FA + C3 phosphate and headgroup

Question 6

What do you get when you use Phospholipase C on a phospholipid?

Answer 6

• DAG

- phosphate-Headgroup

Question 7

What do you get when you used phospholipase D on a phospholipid?

Answer 7

• Phosphatidic Acid

- Headgroup

Question 8

What phospholipase turns phosphatidylcholine into arachnidonic acid?

Answer 8

Phospholipase A2

** This reaction is used in Eicosonoid Synthesis for prostagladins, leukotrienes etc.

Question 9

What two precursors can be reacted to get cardiolipin?

Answer 9

• CDP-DAG

- Phosphatidylglycerol

Question 10

Where are p450 proteins located?

Answer 10

1. Cytosolic Side of ER

2. Inner Mitochondrial Membrane

Question 11

What protein works with the p450s on the cytosolic side of the ER?

Answer 11

• NAPH Cytochrome p450 Reductase (FAD and FMN)

Question 12

What proteins work with p450s on the inner mitochondrial membrane?

Answer 12

1. Ferrodoxin Reductase (FAD)

2. Ferrodoxin (Fe/S)

Question 13

What is cytochrom b5?

Answer 13

small membrane bound heme-containing protein that gets electrons from NADH and gives them to p450s

Question 14

What phase of drug metabolism are p450s involved in?

Answer 14

Phase I

Question 15

What does ACTH do to p450s?

Answer 15

-Induces Steriod Biosynthetic p450s by cAMP cascade

Question 16

What does clofibrate do to p450s?

Answer 16

• peroxisome proliferator, CYP4A1 induced

Question 17

What p450 is induced by Aromatic Hydrocarbons?

Answer 17

CYP2E1

Question 18

What CYP is induced by Alcohol?

Answer 18

CYP2E

Question 19

How would you monitor CYP activity in someone?

Answer 19

• measure the amount of byproduct being excreted as a result of the CYP doing detoxification

Question 20

Where is CYP3A4 found and what does it do?

Answer 20

Found in liver, detoxifies ~120 drugs

*NOT prone to polymorphisms

Question 21

What does CYP2A6 do?

Answer 21

detoxifies 1/4 of the drugs we take in

*PRONE to polymorphisms

Question 22

What p450 works on cholesterol biosynthesis?

Answer 22

CYP51

Question 23

T or F: triazole affects mostly CYP51 in fungi but it also acts on human CYP3A4 to an extent.

Answer 23

True

Question 24

Does glucagon affect muscle and fat?

If so How?

Answer 24

• ONLY affects fat

- Turns on HORMONE SENSITIVE LIPASE

Question 25

When you run out of glycogen what is the next source for gluconeogensis?

Answer 25

AMINO acids from protein breakdown

Question 26

What enzymes are present in the liver that allow it to make ketone bodies?

Answer 26

HMG CoA synthase | HMG lyase

Question 27

What enzyme is lacking in the liver that prevents it from doing ketone body synthesis?

Answer 27

Succinyl CoA - AOA CoA transferase

Question 28

Why does high NADH keep cause shunting of Acetyl CoA to ketone body synthesis?

Answer 28

- High NADH leads to OAA getting converted to malate via malate dehydrogenase - without OAA to react with Acetyl CoA is transferred to Ketone body production

Question 29

What is responsible for aiding in the addition of ApoE and ApoCII to the nascent chylomicron

Answer 29

HDLs

Question 30

What are the 3 fates of FACoA?

Answer 30

Energy - beta oxidation and ketogenesis Membrane lipid formation - phospholipids and sphingolipids Storage- TAGs

Question 31

What are the 4 steps in fatty acid oxidation and what enzymes catalyze these reactions?

Answer 31

1. oxidation: FACoA dehydrogenase 2. Hydration: Fatty enoyl CoA Hydratase 3. oxidaiton: ß-hydroxy acyl CoA dehydrogenase 4. Cleavage: ß-ketoacyl thiolase **Think about whats happening...

Question 32

What enzyme is involved anytime there is a double bond that needs to be fixed so ß-oxidation can proceed?

Answer 32

enoyl CoA isomerase

Question 33

For conjugated double bonds what enzymes are needed to allow ß-oxidation to proceed?

Answer 33

2,4 dienoyl CoA Reductase - REQUIRES NADPH enoyl CoA isomerase to move the bond back between alpha and beta

Question 34

What reaction allows for oxidation of odd chain and branch chain fatty acid oxidation?

Answer 34

Propionyl CoA carboxylase - Adds HCO3- using ATP energy - Has biotin as a cofactor ***Note succinyl CoA mutase actually ends up making the succinate

Question 35

What does the presence of dicarboxylic acids in the urine indicate?

Answer 35

- Omega oxidation is taking place | - MCFA's are building up (most likely there is an associated pathology)

Question 36

What enzyme turns pyruvate to OAA?

Answer 36

Pyruvate carboxylase

Question 37

What are the 4 regulators of acetyl CoA carboxylase?

Answer 37

1. Insulin (+) 2. Citrate (+) 3. Palmitoyl CoA (-) 4. AMP-activated PK (-)

Question 38

Where are FAs sent in order to get longer?

Answer 38

ER