b2

Question 1

why does too much sugar make you overweight

Answer 1

provides more energy than is used

Question 2

what are the lung adaptions that help the rapid absorption of oxygen into the blood

Answer 2

• many alveoli
• large surface / area
• thin (exchange) surface
• good blood supply

Question 3

what happens to glucose in the small intestine

Answer 3

• carbohydrates broken down by carbohydrase/ amylase
• absorption of glucose into blood by active transport

Question 4

how does closing a stomata help a plant

Answer 4

reduces water loss - prevents wilting

Question 5

what is the function of the stomata

Answer 5

carbon dioxide in
oxygen out
controls water loss

Question 6

water is transported from the roots to the stem of a plant through the…

Answer 6

xylem

Question 7

dissolved sugars are transported through the plant through the …

Answer 7

phloem

Question 8

what substances are transported in blood plasma

Answer 8

water
co2
glucose
lactic acid
amino acids

Question 9

why is having a greater conc of red blood cells advantageous

Answer 9

more haemoglobin
more oxygen can be transported
more aerobic respiration

Question 10

how to determine concentation inside an object in water

Answer 10

• use five different
  concentrations of salt / sugar
  solution in beakers
• plot percentage change
  (in mass / volume) on graph
• determine the concentration
  where the curve crosses
  the zero percentage change (in mass / volume)

Question 11

how does bile effect lipase

Answer 11

• bile emulsifies fats
• creates larger sa of fats
• lipase can break down fats more effectively

Question 12

what does a stent do

Answer 12

opens / widens (artery)
so (more) blood can flow through

Question 13

what parts of the body produce amylase

Answer 13

salivary glands
pancreas
small intestine

Question 14

describe lock and key enzyme theory

Answer 14

• substrate binds to active site (of enzyme)
• (because) shape of active site and substrate are complementary
• bonds between the molecules are broken to produce smaller
  molecules

Question 15

why would one have difficulty absorbing fat is tube from gall bladder to small intestine is blocked

Answer 15

• less bile reaches the small intestine
• less emulsification of fat
• smaller surface area for lipase to break down fat
• pH of small intestine is not neutralised
• lipase is not at its optimum pH to break down fat

Question 16

why dont red blood cells have nuclei

Answer 16

more room for haemoglobin