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
