the liver and dietary requirements

Question 1

what is the hepatic portal vein

Answer 1

from the intestines, supplying blood with high concentrations of digested food products (e.g. glucose, amino acids) to the liver

Question 2

what is the hepatic artery

Answer 2

from the aorta, supplying oxygenated blood to the liver

Question 3

what is the hepatic vein

Answer 3

transports deoxygenated blood to the vena cava from the liver

Question 4

what are the cells of the liver called

Answer 4

hepatocytes

Question 5

describe what happens when the blood glucose concentration increases

Answer 5

the pancreas releases insulin from beta cells,
Insulin binds to the liver
Liver converts glucose to glycogen by the process glycogenesis
Increased uptake of glucose

Question 6

Alcohol can also be metabolised in the liver in 2 stages. Name the two enzymes involved in each stage and the product produced

Answer 6

Enzyme 1: alcohol dehydrogenase
Product: acetaldehyde
Enzyme 2: aldehyde dehydrogenase
Product: acetate

Question 7

Cirrhosis is a liver disease caused by excessive drinking. Describe how cirrhosis can kill someone

Answer 7

healthy tissue replaced with scar tissue. So liver fails

Question 8

Explain how insulin lowers the concentration of blood glucose in a non diabetic person

Answer 8

-insulin binds to the receptor on the target cell (liver/muscle cells)
-causes more transport/channel/carrier proteins to become activated and move into the plasma membrane
-glucose diffuses into the cell and lowers the blood glucose levels
-glucose is converted into glycogen
-stimulates fatty acids/lipids from glucose
-raises rate of respiration in cells, using more glucose

Question 9

During a glucose tolerance test the person remains at rest.why is it important that the person remains at rest

Answer 9

-movement uses muscles which increases rate of respiration
-respiration requires glucose

Question 10

name and explain two lipoproteins and their function

Answer 10

LDL: delivers cholesterol to the body cells
HDL: removes cholestrol from body cells

Question 11

what are the substances that are metabolised in the liver

Answer 11

-fats
-alcohol
-drugs
-haemoglobin
-proteins

Question 12

name another hormorne involved in glucose regulation which works in the same way as glucagon

Answer 12

adrenaline

Question 13

what else can cause cirrohis

Answer 13

hepatisis c

Question 14

during alcohol metabolism what ar ethe two molecules that come out of acetate

Answer 14

-h2o
-co2

Question 15

in order for alcohol metabolism to occur what must be reduced

Answer 15

NAD

Question 16

name the process that
-creates urea
-removes ammonia from an amino acid
-produces amino acids not found in diet

Answer 16

-ornithine cycle or detoxification
-deamination
-transamination

Question 17

describe how the liver converts haemoglobin inot bilirubin

Answer 17

-haemaglobin split into haem and globin
-globin broken down into amino acids
-the iron is removed from the haem
-haem group forms a green pigment called billverdin
-which is then converted into billirubin