wk 6 4 Biochem of liver

Question 1

where is the first destination of majority of nutrients and xenobiotics absorbed from GI tract

Answer 1

liver

before entering systemic circulation

Question 2

4 other functions of liver

Answer 2

bile production
elimination of unwanted molecules (metabolism, excretion)
secretion of pproteins (albumin)
storage of important molecules

Question 3

hepato insuffiency may be indicated in

Answer 3

stool colour change

-end stage liver disease= white poo

Question 4

what aspect colours stool/urine

Answer 4

bilirubin

Question 5

liver may also be considered a regulator of metabolism, how

Answer 5

carbo and lipid metabolism (stores fuels)

amino acid metabolism (urea cycle)

Question 6

define electrophoressi

Answer 6

allows separation of proteins by size

Question 7

blood plasma is composed of

Answer 7

albumin

globulins - alpha,beta, gamma

Question 8

5 functions of plasma proteins

Answer 8

maintenance of oncotic/colloid osmotic pressure (dont exit via interstitial fluid, prevents loss of plasma)
transport of hydrophobic substances (steroids, fatty acids, bilirubin, cholesterol)
pH buffering
Enzymatic function (clotting)
Immunity

Question 9

which globulin transports lipoproteins, lipid hormones and bilirubin

Answer 9

alpha globulin

transports vitA also

Question 10

2 examples of beta globulins

Answer 10

transferrin (transfers Fe3+) (iron defiency)

fibrinogen (clots)

Question 11

what hormone stimulates production of albumin

Answer 11

insulin

Question 12

what decreases the level of albumin 3

Answer 12

starvation
low protein diet
liver disease

Question 13

t/f albumin is negatively charged

Answer 13

true

Question 14

if albumin has a low affinity for binding hydrophobic molecules, how is it able to transport them

Answer 14

high conc. of molecules

Question 15

3 processes which iron is required

Answer 15

haemoglobin
myoglobin
cytochromes

Question 16

what globulin transports copper

Answer 16

ceruloplasmin

Question 17

what is copper requirred for? defiency indicated what disease

Answer 17

essential for regulation of redox reaction and use of iron

wilsons disease

Question 18

what is steroid hormones derived from

Answer 18

cholesterol

Question 19

t/f without transport proteins, hormones would be eliminated rapidly by liver/kidney

Answer 19

true

thyroxine bound to thyroid-binding globulin
cortisol bound to cortisol-binding globulin

Question 20

t/f liver is only organ capable of metabolising and excreting cholesterol

Answer 20

true

Question 21

when cholesterol is transported back to liver, what is it excreted by

Answer 21

bile salts via biliary system/faeces

Question 22

3 vitamins stored in liver

Answer 22

vit A, D, and B12

Question 23

what is iron stored as

Answer 23

ferritin

Question 24

what is a major component of gall stones

Answer 24

cholesterol

Question 25

t/f cholesterol is incorporated into lipoproteins and solubilised

Answer 25

true

located in core of molecule

Question 26

cholesterol synthesis requires 3

Answer 26

acetyl-CoA (c atoms)
NADPH (reducing power))
ATP (energy)

Question 27

what is the key rate limiting enzyme in cholesterol synthesis

Answer 27

HMG-CoA reductase

(target for controlling synthesis of cholesterol)`

Question 28

mevalonic acid

Answer 28

rate limiting enzyme

unique to cholesterol synthesis

Question 29

what is targeted in statins

Answer 29

HHMG-CoA reductase

Question 30

products from cholesterol synthesis

Answer 30

Vit D (regulates calcium)
Hormones - Corticosteroids
Androgens
Estrogens 
Bile salts (main)

Question 31

cholestyramine is an anion exchange resin, what does it do

Answer 31

bind to bile salts

inhibits reabsorption in enterohepatic circulation