Bioenergetics

Question 1

what kind of reaction is photosynthesis?

Answer 1

• an endothermic reaction

Question 2

the word equation for photosynthesis:

Answer 2

carbon dioxide + water&raquo_space;» glucose + oxygen

Question 3

what is the formula equation for photosynthesis?

Answer 3

CO2 + H2O&raquo_space;»» C6H12O6 + O2

Question 4

what are the five uses of the glucose that is a product of photosynthesis?

Answer 4

1. release energy in respiration
2. produces starch as a storage molecule; it can be converted back to glucose when needed
3. converted to fats and oils; used by the plant as a storage form of energy
4. make cellulose; helps strengthen the cell
5. produces amino acids

Question 5

what are the four limiting factors of photosynthesis?

Answer 5

• light intensity
• carbon dioxide
• temperature
• the amount of chlorophyll in the leaf

Question 6

how can farmers increase the rate of photosynthesis of their plants in a greenhouse?

Answer 6

• they light the greenhouse
• they heat the greenhouse
• they add extra carbon dioxide to the greenhouse

Question 7

what type of reaction is respiration?

Answer 7

• an exothermic reaction

Question 8

what is the word equation for aerobic respiration?

Answer 8

glucose + oxygen&raquo_space;»> carbon dioxide + water

Question 9

in what case would muscle cells respire anaerobically?

Answer 9

when there is a shortage of oxygen

Question 10

word equation for anaerobic respiration:

Answer 10

glucose&raquo_space;»> lactic acid

Question 11

why does aerobic respiration require energy?

Answer 11

because the glucose molecule is fully oxidised

Question 12

why does anaerobic respiration not require a great deal of energy?

Answer 12

the glucose molecule isn’t fully oxidised

Question 13

what is fermentation?

Answer 13

anaerobic respiration in yeast cells

Question 14

what product is produced by fermentation?

Answer 14

ethanol (alcohol to make alcoholic drinks)

Question 15

what happens during exercise? (4)

Answer 15

• the body needs a great deal of energy for muscle contractions
• aerobic respiration increases
• to provide for the increase of aerobic respiration, breathing rate and breathing volume increases
• heart rate increases to pump oxygenated blood around the body

Question 16

what is the oxygen debt process? (3)

Answer 16

• where the body has to remove the lactic acid from the muscles
• lactic acid is transported out of the muscles by the blood and is then taken back to the liver
• it’s converted back to glucose in a series of chemical reactions

Question 17

define oxygen debt

Answer 17

the amount of extra oxygen the body needs after exercise to deal with the lactic acid

Question 18

define metabolism

Answer 18

the sum of all chemical reactions in a cell or the body

Question 19

what is glucose converted to in humans?

Answer 19

glycogen

Question 20

how is a lipid molecule formed?

Answer 20

1 glycerol molecule + 3 fatty acid molecules