B3 quick questions

Question 1

name the five levels of organisation

Answer 1

cells, tissues, organs, organ systems, organisms

Question 2

what is a tissue

Answer 2

a group of cells with similar structures and functions

Question 3

what is an organ

Answer 3

a group of tissues working together to perform a speciific function

Question 4

what is the function of the liver in digestion

Answer 4

produces bile, which neutralises hydochloric acid from the stomach and emulsifiess fat to form small droplets with a large sa

Question 5

what is the function of salive in digestion

Answer 5

lubrication to help swallowing and contains amylase to break down starch

Question 6

name three enzymes produced in the pancreas

Answer 6

protease lipase and amylase

Question 7

what are enzymes

Answer 7

a protein made of amino acids that can be used as a bilogical catalyst to speed up a reaction without being used up itself

Question 8

why are enzymes described as specific

Answer 8

each enzyme only catalyses a specific reaction, because the active site only fits together with certain substrates

Question 9

what is the lock and key analogy

Answer 9

• each enzyme has a specific shaped active site
• the substrate fits into and binds to the enzymes active site
• this forms an enzyme substrate complex
• the activation energy is reduced
• the reaction is catalysed and products released

Question 10

describe the function of amylase

Answer 10

to brek down starch into glucose

Question 11

where is amlyse made

Answer 11

salivary glands pancreas and small intestine

Question 12

describe function of proteases

Answer 12

to break down proteins into amino acids

Question 13

where are proteases made

Answer 13

stomach pancreas and small intestine

Question 14

function of lipase

Answer 14

to break down lipids into glycerol and fatty acids

Question 15

where is lipase prouced

Answer 15

pancreas and small intestine

Question 16

what are two factors that affect the rate of activity of an enzyme

Answer 16

temp and pH

Question 17

what does denatured mean

Answer 17

shape of an enzymes active site is disformed by an extreme ph or very high temp so it can no longer bind with the substrate

Question 18

describe the effect of temp on enzyme activity

Answer 18

as temp increases, rate of reaction increases untill it reaches optimum for enzyme activity, above this temp enzyme activity decreases and eventually stops

Question 19

describe the effect of pH of enzyme activity

Answer 19

different enzymes have a different optimum pH at which their activity is greatest, a pH much lower or higher than this enzyme activity deraeses and stops

Question 20

why do different digestive enzymes have different optimum pH

Answer 20

different pats of the digestive system have very different pHs, the stomach is strongly acidic whereas the pH of the small intestine is close to neutral