Liver Biochemistry Flashcards

1
Q

What protein made by the liver is a inflammatory marker and a marker for heart disease?

A

C reactive protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What liver cells protect against viruses and tumors?

A

Pit cells (Lymphocytes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What comes together to form IPP?

A

3 acetyl CoA’s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the sources of acetyl CoA?

A
  • oxidative decarboxylation of pyruvate
  • Beta oxidation of fatty acids
  • Breakdown of amino acids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Acetyl CoA is transported into the cytoplasm via what?

A

Citrate shuttle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How many units of IPP form the tetracyclic (4 ring) sterane backbone of most steroids?

A

6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What carbon on cholesterol has a hydroxyl group?

A

C3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Where is the double bond on cholesterol?

A

Between C5 and C6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The liver packages cholesterol into what?

A

VLDL molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Enzyme from Acetyl CoA –> Acetoacetyl CoA

A

Acetyl CoA acetyltransferase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Enzyme for Acetoacetyl CoA –> HMG CoA

A

HMG CoA synthase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Enzyme for HMG CoA –> Mevalonate

A

HMG CoA reductase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What step is the rate limiting step in cholesterol biosynthesis?

A

HMG CoA –> Mevalonate using HMG CoA reductase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Name all the intermediates in cholesterol biosynthesis in order

A

Acetyl CoA –>Acetoacetyl CoA –> HMG CoA –> Mevalonate –> IPP –> Squalene –> Lanosterol –> Cholesterol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What 2 things accelerate or promote the reaction of HMG CoA to Mevalonate?

A

Insulin and thyroxine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What things inhibit or slow down the reaction of HMG CoA to Mevalonate?

A

Glucagon, Sterols, high AMP, Vitamin E, and statins

17
Q

What inhibits conversion of Lanosterol to cholesterol?

A

Antifungal agents

18
Q

What things are formed from side reactions from intermediates of cholesterol synthesis?

A

Ubiquitous and Heme A (in cytochromes)

19
Q

Long term statin use for cholesterol regulation will inhibit the formation of what?

A

Ubiquinone which will mess up TCA cycle

20
Q

Local centers for signal transduction processes and sites for abnormal processing of proteins in neurodegenerative disorders?

A

Lipid rafts

21
Q

Where are the ubiquitination sites on HMG CoA reductase?

A

Lysine 89 and Lysine 248

22
Q

What membrane is HMG reductase on?

23
Q

The catalytic domain of HMG CoA reductase faces what?

A

The cytosol

24
Q

HMG CoA reductase is directly inhibited by what?

A

Free Fatty acids, Bile Acids, and oxysterols

25
These are pharmacological molecules that are competitive inhibitors and sit in the active site of HMG CoA reductase
Statins
26
Referring to covalent modifications, HMG CoA reductase is Active in what form?
Dephosphorylated
27
Low energy state does what to HMG CoA reductase?
Causes phosphorylation thus inactivation
28
Translation of HMG CoA reductase is reduced by what?
Gamma-tocotrienol (vitamin E family) and oxylanosterols
29
In the presence of high cholesterol, HMG CoA interacts with INSIG which causes what?
Polyubiquitination of HMG CoA reductase
30
Polyubiquitination of HMG CoA reductase leads to removal from the ER and degradation by what?
26S protea some
31
While synthesized cholesterol is packaged into VLDLs, dietary cholesterol is delivered to the liver via what?
Chylomicron remnants
32
In the synthesis of Bile Acids, cholesterol is converted to ________ by the enzyme ________.
7-alpha- hydroxycholesterol; 7-alpha-hydroxylase
33
Name the intermediates in bile acid synthesis in order.
Cholesterol --> 7-alpha-hydroxycholesterol --> chenocholic acid --> cholinergic acid