6. Respiration

Question 1

Can energy be created

Answer 1

Energy cannot be created or destroyed, and exists in a number of forms

Question 2

Name the 8 forms of energy

Answer 2

Potential, kinetic, heat, electrical, light, sound, chemical, atomic

Question 3

What do all cells need

Answer 3

Energy, life cannot be sustained without energy

Question 4

What is the source of energy

Answer 4

The sun is the source of energy in all living things

Question 5

How can food be discovered to have energy

Answer 5

If we burn food its energy is released as heat, like fuel

All food contains energy

Question 6

What is a more effective way of finding if food contains energy

Answer 6

By using a calorimeter, increased surface area on the coiled copper wire, heatproof platform keeps heat in, stirrer disperses heated water

Question 7

Which contains more energy, carbohydrates, protein or lipids (fat)

Answer 7

LIPID - 32kj/g
Protein - 17kj/g
Carbohydrate - 16kj/g

Question 8

How can energy be released

Answer 8

Respiration

Question 9

What is the breakdown of glucose with oxygen present called

Answer 9

Aerobic respiration

Question 10

Explain the dry mass experiment

Answer 10

Peas in vacuum flask, temps recorded at start and after being left for a few days

Question 11

What does a respirometer do

Answer 11

A respirometer measures the rate at which an organism respired

Question 12

How does a respirometer work

Answer 12

Liquid is sucked up tube by disappearance of oxygen

Rate water moves = rate of respiration

Question 13

What do respiring organisms produce

Answer 13

Water and carbon dioxide

Question 14

What is ATP

Answer 14

Vitally important, as it is a source of immediate energy

which all cells can access

Question 15

How are the three Phosphates joined

Answer 15

By high energy bonds, which store the energy

Question 16

What is the ATP equation

Answer 16

ADP + P(i) + energy ATP

Question 17

What are the roles of ATP

Answer 17

To store and release energy

To provide a link between energy releasing reactions and energy consuming reactions

Question 18

What is aerobic respiration

Answer 18

Takes place in all cells and is essential to life

Series of enzyme controlled reactions released in a controlled fashion

Glucose + Oxygen > Carbon dioxide + Water + Energy

Question 19

Describe glycolysis

Answer 19

Breakdown of glucose in the cytoplasm

Anaerobic

Breaks down to 2x pyruvate and 2 ATP are produced

Question 20

Describe aerobic stage

Answer 20

Further breakdown of glucose in mitochondrion

Oxygen required

Kreb’s cycle - as pyruvate goes into cycle and through it, it loses 3x carbon dioxide

Breaks down to 2x 18 (36) ATP, carbon dioxide, and water

Question 21

What is the total ATP production

Answer 21

Glycolysis = 2 ATP
Aerobic stage = 36 ATP

TOTAL = 38 ATP

Question 22

Describe fermentation

Answer 22

Less efficient, produces toxic waste

Animal - In cytoplasm, anaerobic, 2 ATP produced

        - Pyruvate > Lactate
        - Reversible process, when oxygen is available
        - Oxygen debt, repaid by rapid breathing

Plant - In cytoplasm, anaerobic, 2 ATP produced

     - Pyruvate > Ethanol + carbon dioxide
     - Irreversible process
       - Carbon dioxide is given off leaving only 2, when pyruvate needs 3