function of the liver

Question 1

what are some functions of the liver

Answer 1

synthesise bile

detoxifying harmful substances

control blood glucose levels

control amino acid and lipid levels

stores glycogen

Question 2

liver stores sugar in the form of what?

Answer 2

Glycogen

Question 3

what percentage of the weight of the liver is glycogen

Answer 3

8% of the weight

Question 4

how many grams of glycogen can the liver store

Answer 4

120g

Question 5

how does the storage of glycogen contribute to the control of blood glucose levels

Answer 5

glycogen can be broken down into glucose when required

Question 6

what is detoxification

Answer 6

rendering a harmful substance/ toxin harmless

Question 7

what are harmful substances which the liver can detoxify

Answer 7

Hydrogen peroxide
alcohol/ethanol
drugs

Question 8

what are the two enzymes used in detoxification

Answer 8

Cytochrome p450
Catalase

Question 9

what is Cytochrome p450

Answer 9

An enzyme used in the detoxification of the liver, can breakdown cocaine or medicinal drugs.

Question 10

what does catalase do

Answer 10

Breakdown hydrogen peroxide into oxygen and h20

Question 11

is catalase intracellular

Answer 11

yes

Question 12

Catalase has a high turnover number what does this mean

Answer 12

it can catalase a lot of hydrogen peroxide in 1 second

Question 13

what is the turnover number of catalase to hydrogen peroxide

Answer 13

5 million

Question 14

what are the effects of alcohol in the liver

Answer 14

depresses nerve activity
contains chemical potential energy for respiration

Question 15

what are the effects of alcohol/ ethanol in the body

Answer 15

depresses nerve activity

Question 16

how is alcohol detoxified in liver

Answer 16

ethanol is broken down and dehydrogenated by enzyme ethanol dehydrogenase, to produce ETHANAL
this produces 2H which is used to reduce NAD

ETHANAL is then dehydrogenated by ethanal dehydrogenase to produce ethanoate and 2H which again reduces an NAD

ethanoate is then combined with a coenzyme A which produces acetyl coenzyme A which is used in respiration

Question 17

what two enzymes are used in detoxification of alcohol

Answer 17

ethanol dehydrogenase

ethanal dehydrogenase

Question 18

what is fatty liver and how is it caused

Answer 18

NAD is also used to break down fatty acids in liver for respiration. therefore a sufficient amount of NAD is needed for both detoxification and fatty acid breakdown

however, if too much alcohol is consumes it uses up the store of NAD, so there isnt enough to breakdown fatty acids..

fatty acids then covert back to lipids and are stored as fat in the liver causing “fatty liver”.

Question 19

what are the two processes to remove and excrete an amino component

Answer 19

deamination

orthinine cycle

Question 20

what is deamination

Answer 20

removes amino group from an amino acid to produce ammonia
and a keto acid

Question 21

what are the products of deamination

Answer 21

keto acid and ammonia

Question 22

why is it important that ammonia doesnt accumulate

Answer 22

highlt toxic molecule

Question 23

what does the orthinine cycle do

Answer 23

a cycle made to convert ammonia into urea. as ammonia is very soluble and highly toxic

Question 24

why is urea better than ammonia

Answer 24

it is less soluble and less toxic therefore can be circulated

Question 25

summarise the orthenine cycle

Answer 25

ammonia + co2 = urea + water.

Question 26

why is it important that excess amino acids are excreted

Answer 26

because the amine group on amino acids is toxic when accumulated