topic 4

Question 1

what is respiration

Answer 1

an exothermic reaction because it releases energy from glucose

Question 2

in aerobic respiration what is glucose reacted with

Answer 2

oxygen which produces carbon dioxide and water + energy

Question 3

aerobic respiration equation

Answer 3

glucose + oxygen —–> carbon dioxide and water

Question 4

what does aerobic respiration release and why

Answer 4

lots of energy because the glucose molecule has been fully oxidised

Question 5

when do muscle cells respire anaerobically

Answer 5

when there is a shortage of oxygen

Question 6

what is the equation for anaerobic respiration

Answer 6

glucose ——-> lactic acid + energy

Question 7

anaerobic respiration does not require …

Answer 7

oxygen

Question 8

what does anaerobic respiration do compared to aerobic respiration

Answer 8

it releases much less energy

Question 9

why in anaerobic respiration is less energy released

Answer 9

because the oxidation of glucose is incomplete

Question 10

anaerobic respiration in plants and yeast equation

Answer 10

glucose ——-. ethanol + carbon dioxide + energy

Question 11

what is anaerobic respiration in yeast cells called

Answer 11

fermentation

Question 12

what causes bread to rise

Answer 12

carbon dioxide produced by fermentation creates bubbles in the bread causing the bread to rise

Question 13

during exercise, why does the body need energy

Answer 13

for muscle contraction

Question 14

because the body needs more energy what increases

Answer 14

aerobic respiration increases

Question 15

what does the “aerobic respiration increases” mean for the body

Answer 15

the body cells require more oxygen

Question 16

to provide extra oxygen what 3 things increase

Answer 16

breathing rate

• breathing volume
• heart rate

Question 17

what does breathing more frequently and taking deeper breathes get into the body

Answer 17

it gets more oxygen into the blood stream

Question 18

why does heart rate increase

Answer 18

to get oxygenated blood around the body

Question 19

where in the body does anaerobic respiration happen during exercise

Answer 19

in the muscles

Question 20

what does the oxidation of incomplete glucose lead to

Answer 20

it leads to a build up lactic acid

Question 21

during long periods of vigorous exercise what does the lactic acid do to muscles

Answer 21

it causes the muscles to become fatigued

Question 22

what does the muscles becoming fatigue mean

Answer 22

the muscles stop contracting efficiently

Question 23

what creates oxygen debt

Answer 23

when the body has to remove lactic acid from the muscles

Question 24

how is the lactic acid transported out of the muscles

Answer 24

by the blood

Question 25

what happens after lactic acid is transported out of the muscles THEN taken to the LIVER

Answer 25

the lactic acid is converted back to glucose in a series of chemical reactions

Question 26

what does reacting with the accumulated lactic acid and removing it from the cells require

Answer 26

oxygen

Question 27

what is oxygen debt

Answer 27

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

Question 28

what is the energy released by respiration used by

Answer 28

enzymes

Question 29

why is the energy released by respiration used by enzymes

Answer 29

to synthesise new molecules in the cell

Question 30

what is metabolism

Answer 30

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

Question 31

in plants what is glucose converted into

Answer 31

cellulose or starch

Question 32

what does glucose react with to make amino acids

Answer 32

nitrate ions

Question 33

what are amino acids used to do in plants

Answer 33

synthesise proteins

Question 34

glucose + nitrate ions —–>

Answer 34

amino acids

Question 35

what is glucose in humans converted into

Answer 35

glycogen

Question 36

what makes a lipid molecule

Answer 36

1 glycerol molecule + 3 fatty acid molecules

Question 37

where is lipid found in the body

Answer 37

found in the cell membrane

Question 38

excess protein is broken down into the chemical called …

Answer 38

urea

Question 39

what is the urea excreted by

Answer 39

the kidneys