Biochemical Aspects of Liver Metabolism Flashcards Preview

JL Gastrointestinal > Biochemical Aspects of Liver Metabolism > Flashcards

Flashcards in Biochemical Aspects of Liver Metabolism Deck (77)
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1

Where is the first destination of most nutrients and xenobiotics absorbed from the GI tract?

Liver

2

What does the liver produce?

Bile

3

Name a plasma protein excreted from the liver?

Albumin

4

What two roles does the liver have in regulation of metabolism?

1. Carbohydrate and lipid metabolism - fuel storage
2. Amino acid metabolism - urea cycle

5

What allows seperation of proteins by size?

Electrophoresis

6

What 4 plasma proteins can be seperated by electrophoresis?

1. Albumin
2. Alpha globulins
3. Beta-globulins
4. Gamma globulins

7

What substances maintan oncotic or colloid osmotic pressure?

Plasma proteins

8

What transports hydrophobic substances like steroid hormones, free fatty acids, bilirubin and cholesterol?

Plasma proteins

9

How can plasma proteins be involved with pH buffering?

Amino-acid side chains can carry net charges

10

What plasma proteins transport lipoproteins, lipids, hormones and bilirubin?

Alpha-globulins such as ceruloplasmin

11

What alpha-globulin, other than ceruloplasmin, transports vitamin A?

Retinol binding protein

12

What does deficiency of vitamin A cause?

Visual impairment

13

What is vitamin A converted to?

Retinaldehyde, part of rhodopsin, a visual pigment

14

Name two beta-globulins?

Transferrin and fibrinogen

15

What two things does transferrin do?

Transports Fe3+
Indicator of iron deficiency

16

What is an inactive form of fibrin and is involved in clotting of blood?

Fibrinogen

17

What is the most abundant plasma protein?

Albumin

18

How would you describe albumin?

Small, negatively charged, water-soluble

19

What is the main determinant of plasma oncotic pressure?

Albumin

20

What stimulates production of albumin in the liver?

Insulin

21

What are levels of albumin like in liver disease?

Low

22

What two factors can lead to low levels of albumin?

Starvation and low protein diets

23

What does albumin have multiple binding sites for?

Hydrophobic molecules

24

What is the affinity and capacity like for albumin?

Low affinity, but high capacity because of high concentration

25

Name three endogenous lipophilic substances that albumin transports?

Fatty acids
Bilirubin
Thyroid hormones

26

What important exogenous substances does albumin carry?

Aspirin

27

What special structural feature of albumin allows it to carry hydrophobic molecules?

Hydrophilic clefts in globular domains

28

What do haemoglobin, myoglobin and cytochromes all haev which is a key component?

Iron

29

How is iron transported?

As ferric ion Fe3+ bound ti transferrin

30

How is iron stored?

In cells bound to ferritin