Cholesterol

Question 0

What are the four main functions of cholesterol

Answer 0

Precursor for bile salts
Component of membranes
Precursor for steroids
Precursor for vitamin d

Question 1

What are the three ways the liver receives cholesterol

Answer 1

Synthesizes it de novo
Diet
HDLs

Question 2

What are the two key points of the structure of cholesterol

Answer 2

Very hydrophobic

Has a steroid nucleus

Question 3

When does the synthesis of cholesterol occur

Answer 3

Well fed state

When cholesterol is low

Question 4

Where does cholesterol synthesis occur

Answer 4

Cytoplasm

Question 5

What is the 1st step of cholesterol synthesis

Answer 5

Formation of HMG CoA from 3 Acetyl CoA

Question 6

What is the rate limiting step of cholesterol synthesis

Answer 6

HMG CoA to mevalonate by HMG CoA reductase

Question 7

What is the cofactor required for HMG CoA reductase

Answer 7

NADPH

Question 8

How many molecules of mevalonate are required to make one cholesterol

Answer 8

6

Question 9

How many Acetyl CoA are required to make one mevalonate

Answer 9

3

Question 10

True or false: Energy is required in the form of ATP and NADPH to make cholesterol

Answer 10

True

Question 11

At what point in the formation of cholesterol does the molecule need a carrier protein

Answer 11

Squalene

Question 12

Smith-lemli-Optiz syndrome is a defect in what part of the cascade

Answer 12

Enzymes involved in the conversion of lanosterol to cholesterol

Question 13

What are some of the symptoms of smith-lemli-Optiz syndrome

Answer 13

Ambiguous genitalia
Limb abnormalities
Mental retardation

Question 14

What two compounds/complex enhance transcription of the HMG CoA reductase gene

Answer 14

SCAP- SREBP complex

Question 15

What do high sterol levels mean for HMG CoA reductase

Answer 15

No more sterols needed
HMG CoA reductase to be ubiquinated
Destroyed by proteaosomes

Question 16

How do statins work

Answer 16

Competes for the active site on the HMG CoA reductase enzyme

Question 17

How is cholesterol transported in the serum

Answer 17

Micelles

Question 18

What do chylomicrons transport

Answer 18

Dietary lipids

Question 19

What do VLDLs transport

Answer 19

Newly synthesized lipids

Question 20

What do LDLs transport

Answer 20

Transport cholesterol away from the liver

Question 21

What do HDLs transport

Answer 21

Cholesterol to the liver

Question 22

LDLs have the highest percentage of _______ of the cholesterol carriers

Answer 22

Cholesterol

Question 23

HDLs have the highest percentage of ________ of the cholesterol carriers

Answer 23

Protein

Question 24

Chylomicrons have the highest percentage of ________ of the cholesterol carriers

Answer 24

Fat

Question 25

Which lipoproteins would you expect to be raised based on a pt recently eating a meal

Answer 25

Chylomicrons | VLDLs

Question 26

What is the scaffolding protein used in chylomicron formation

Answer 26

Apo B-48

Question 27

What is Apo C-11 needed for in chylomicrons

Answer 27

Activate lipoprotein lipase

Question 28

What is Apo E needed for in chylomicrons

Answer 28

Ligand that will clear chylomicron remnants from the blood

Question 29

What is the scaffolding protein in forming VLDLs

Answer 29

Apo B-100

Question 30

Cells that are low on cholesterol will synthesize what to remove cholesterol from the blood

Answer 30

LDL receptors (Apo b-100 )

Question 31

What enzyme converts cholesterol into its storage form

Answer 31

ACAT

Question 32

What is the scavenger receptor macrophages use to find damaged LDLs

Answer 32

SR-A

Question 33

What are three things that can cause damage to LDLs

Answer 33

Oxidative stress High blood sugar Chemicals

Question 34

What enzyme allows the HDL particle to take up free cholesterol from peripheral tissues

Answer 34

ABCA1

Question 35

What esterifies the free cholesterol from peripheral tissues

Answer 35

LCAT

Question 36

What protein allows HDLs to transfer cholesterol to the liver and tissues

Answer 36

SR-B1

Question 37

Tangier disease is a defect in what?

Answer 37

Genetic defect of ABCA1 protein | Needed in HDL synthesis

Question 38

Type 1 hyperlipoproteinemia is a defect in what

Answer 38

Deficiency in Apo c-II

Question 39

What is the defect in familial hypercholesterolemia

Answer 39

Defect in LDL receptor (Apo b-100 )

Question 40

What is the defect in type three hyperlipoproteinemia

Answer 40

Apo E protein

Question 41

What is the only significant way cholesterol leaves the body

Answer 41

Bile

Question 42

Bile is ________ soluble than cholesterol

Answer 42

More

Question 43

How do bile acid sequesterants reduce serum cholesterol?

Answer 43

Reduce enterohepatic circulation of bile salts Cholesterol is used to replace what is lost Serum cholesterol is lowered

Question 44

What is the term for gall stones

Answer 44

Cholelithiasis

Question 45

What would cause cholesterol gallstones

Answer 45

Too little bile salts | Too much cholesterol