organisation biology

Question 1

what are enzymes made of

Answer 1

amino acids(proteins)

Question 2

explain the lock and key model

Answer 2

substrate (reactant)has a complementary shape like a key fits into area of enzyme called active site joins together with the key allowing the reaction to occur

Question 3

what are the 2 products it can form

Answer 3

it can join together to make a larger product or break down into a smaller products detaching from the enzyme and diffusing away leaving the enzyme to catalyze another substrate

Question 4

why do enzymes denature if the temp is too hot and why is the reaction slow if the temp is cold

Answer 4

the forces that hold the enzyme together are broken and the substrate no longer fits as the active site shape has been distorted/ at lower temps the enzyme and substrate that move around do so with less energy and therefore collide with less energy and at a lower rate(less number of successful colisions

Question 5

what indicator do we use to see if starch is broken down

Answer 5

iodine

Question 6

what colour does it turn if starch is present and what colour does it stay id no starch is present

Answer 6

turns blue black/stays orange

Question 7

where is amylase produced and what does it break down

Answer 7

salivary glands pancreas and small intestine and breaks down starch into maltose

Question 8

where is protease produced and what does it break down

Answer 8

it is made in the stomach , pancreas and small intestine and breaks down proteins into amino acids

Question 9

where are lipases produced and what do they break down

Answer 9

they are made in the pancreas and secreted into the duodenum and they break sown lipids into fatty acids and glycerol

Question 10

how does bile help in digestion

Answer 10

-neutralises hcl from stomach as enzymes in small intestine cant work well in acidic conditions
-Bile salts emulsify large fat droplets into smaller one to increase sa for lipase to break them down

Question 11

what is glucose tested with

Answer 11

benedicts solution which goes from blue to brick red. it requires heating(water bath

Question 12

what reagent is used for proteins

Answer 12

biuret solutions which goes from blu to purple

Question 13

lipids

Answer 13

ethanol. goes from colourless to a cloudy milky white emulsion

Question 14

good gas exchange surfaces have features in common

Answer 14

large sa
thin walls
good ventilation
good blood supply

Question 15

alveoli in lungs have

Answer 15

large surface area

Question 16

thin walls

Answer 16

alveoli walls are only 1 cell thick(short diffusion pathway

Question 17

good ventilation

Answer 17

lots of air so air is replenished which means there is always high o2 conc inside alveoli ready to diffuse into the blood where it is at a low o2 conc. performed by breathing and creates a steep conc gradient

Question 18

good blood supply

Answer 18

ensure