Respiration

Question 1

Aerobic respiration

Answer 1

The complete break down of glucose molecules using oxygen in order to give us energy.

Question 2

Symbol equation for aerobic respiration

Answer 2

C₆H₁₂O₆ + 6O2 ——> 6CO₂ + 6H₂O

Question 3

Word equation for aerobic respiration

Answer 3

Glucose + oxygen ——> carbon dioxide + water (+energy)

Question 4

Where does aerobic respiration occur?

Answer 4

In the cytoplasm of cells in early stages, but releases energy into the mitochondria.

Question 5

Anaerobic respiration

Answer 5

The incomplete breakdown of glucose molecules without oxygen to release energy.

Question 6

Symbol equation for anaerobic respiration

Answer 6

C₆H₁₂O₆ ——> 2C₃H₆O₃

Question 7

Word equation for anaerobic respiration

Answer 7

Glucose ——> lactic acid (+energy)

Question 8

Where does anaerobic respiration take place?

Answer 8

Only the cytoplasm in cells

Question 9

Oxygen debt

Answer 9

The amount of oxygen required remove lactic acid from the body, as it is a poison

Question 10

How does oxygen remove lactic acid?

Answer 10

Takes it to the liver via blood and:
- oxidises it to carbon dioxide and water
- converted to glucose then glycogen

Question 11

Metabolism

Answer 11

Term used for the rate of reactions in an organisms body, controlled by enzymes

Question 12

Why do we need energy?

Answer 12

• growth
• cell division
• muscle contraction
• protein synthesis
• active transport
• nerve impulses
• maintaining body temperature

Question 13

How are cells adapted for this?

Answer 13

Lots of mitochondria in order to respire more.
Mitochondria has a folded inner membrane to make a larger surface area for enzymes involved.

Question 14

Muscle fatigue

Answer 14

Using muscle fibres too vigorously for a while stops them contracting efficiently, could be from a build up of lactic acid.

Question 15

Anaerobic respiration in yeast

Answer 15

Forms ethanol and carbon dioxide, important for making bread and alcohol.

Question 16

Metabolic reactions examples using glucose

Answer 16

Forming lipid molecules
Synthesis of proteins
Converting to glycogen
(In plants) converting to starch, amino acids and cellulose

Question 17

What type of reaction is respiration?

Answer 17

Exothermic because it releases energy

Question 18

Why is anaerobic respiration ‘incomplete breakdown’?

Answer 18

Because the glucose molecules haven’t been fully oxidised: not in the present of oxygen

Question 19

Why would muscle cells respire anaerobically?

Answer 19

If it’s in certain conditions such as exercising where not enough oxygen is present

Question 20

Why does anaerobic respiration release less energy?

Answer 20

The oxidation of glucose is incomplete

Question 21

Fermentation

Answer 21

Anaerobic respiration in yeast to form ethanol and carbon dioxide

Question 22

Why is fermentation needed for alcoholic drinks?

Answer 22

Makes ethanol, which is used in the drinks such as beer

Question 23

Why is fermentation needed in bread making?

Answer 23

Makes CO2, as it produces bubbles so the bread rises

Question 24

Effects of exercise on the body

Answer 24

Needs more energy for muscle contraction
Increase in aerobic respiration = needs more oxygen
Rate of breathing rises
Heart rate increases to pump oxygenated blood to muscles
If not enough O2, increased anaerobic respiration
So lactic acid builds up = muscles fatigued and stop contracting efficiently
Condition known as oxygen debt entered

Question 25

Storage form of glucose in humans?

Answer 25

Glycogen

Question 26

Forming a lipid

Answer 26

Using the molecules of glycerol (from converted fat molecules)
+ 3 fatty acid molecules
Forms cell membranes and stores energy

Question 27

Metabolic reaction for protein

Answer 27

Break down of protein forms urea