bioenergetics

Question 1

is photosynthesis and endothermic or exothermic reaction?

Answer 1

endothermic

Question 2

what is the photosynthesis reaction equation?

Answer 2

carbon dioxide + water -> glucose + oxygen

Question 3

what is the chemical formula for the photosynthesis reaction equation?

Answer 3

6CO2 + 6H2O -> C6H12O6 + 6O2

Question 4

what is needed for a plant to photosynthesise?

Answer 4

carbon dioxide, water, sunlight, chlorophyll

Question 5

what do you need for the pondweed practical?

Answer 5

beaker, lamp, timer, ruler, pondweed

Question 6

what is the independent variable in the pondweed practical?

Answer 6

distance of desk lamp form pondweed

Question 7

what is dependent variable in the pondweed practical?

Answer 7

number of bubbles of oxygen in one minute

Question 8

what does a plant need to do to create proteins?

Answer 8

they need to absorb nitrate ions from the soil by using their root hair cells and active transport

Question 9

what is a limiting factor?

Answer 9

something that is in ‘short supply’

Question 10

what is photosynthesis in plants and algae limited by?

Answer 10

carbon dioxide, light intensity, temperature and the amount of chlorophyll in chloroplasts

Question 11

on a graph for limiting factors, when the curve is slowly going up what could be limiting that x?

Answer 11

light intensity

Question 12

at the plateau on the graph of limiting factors what could be limiting at y?

Answer 12

co2, temperature, chlorophyll levels

Question 13

farmers eliminate limiting factors but what must they consider?

Answer 13

the cost of adding extra co2, profit made from crop sales, if cost exceeds profit made

Question 14

what could a farmer use to increase temperature in their greenhouse for the colder months?

Answer 14

paraffin heater

Question 15

how could a farmer adapt their greenhouse to enrich the co2?

Answer 15

co2 from cylinders can be added to enrich co2

Question 16

in the summer, what could farmers do to control temperature levels?

Answer 16

ventilator flaps can be opened on the greenhouse to reduce temperature levels in the greenhouse

Question 17

is aerobic respiration an exothermic or endothermic reaction?

Answer 17

exothermic

Question 18

what is the equation of aerobic respiration?

Answer 18

glucose + oxygen -> carbon dioxide + water + heat

Question 19

what is the chemical equation of the aerobic respiration equation?

Answer 19

C6H12O6 + 6O2 -> 6CO2 + 6H2O + heat

Question 20

how does oxygen reach our cells?

Answer 20

oxygen moves via diffusion from the bloodstream into the cell through the cell membrane

Question 21

how does glucose reach our cells?

Answer 21

glucose is absorbed from the small intestine into the bloodstream via diffusion, the bloodstream then delivers the glucose to the cells through the capillaries

Question 22

when does anaerobic respiration occur in the muscles?

Answer 22

when there isn’t enough oxygen reaching the muscles

Question 23

what is the equation for anaerobic respiration?

Answer 23

glucose -> lactic acid + smaller amounts of energy

Question 24

why is there smaller amounts of energy produced in anaerobic respiration?

Answer 24

it is because the glucose is not fully oxidised

Question 25

what is the equation for the production of lactic acid in the muscle cells?

Answer 25

lactic acid + oxygen debt -> carbon dioxide + water

Question 26

what happens to the lactic acid produced in the muscle cells?

Answer 26

lactic acid in the muscles are transported to the liver where it's converted to glucose, lactic acid in cells reacts with oxygen to form co2 and water

Question 27

what is the equation for anaerobic respiration in plants?

Answer 27

glucose -> ethanol + carbon dioxide + smaller amounts of energy

Question 28

what are some of the uses of energy transferred in aerobic respiration?

Answer 28

to build larger molecules from smaller ones, enable muscles to contract, maintain steady body temperature in colder surroundings

Question 29

how does the body respond to exercise? - breathing rate

Answer 29

to take in more oxygen, this supplies muscles with more oxygenated blood

Question 30

how does the body respond to exercise? - heart rate increased

Answer 30

deliver more blood containing larger amounts of oxygen and glucose to the muscles and remove lactic acid

Question 31

how does the body respond to exercise? - body temperature increases

Answer 31

respiration is an exothermic reaction and releases energy in our muscles as heat

Question 32

how does the body respond to exercise? - sweating

Answer 32

sweat can evaporate from the surface of the skin, this transfers heat energy from the blood, cooling the skin