bioenergetics (p1)

Question 1

What is photosynthesis?

Answer 1

A reaction in plants where carbon dioxide and water react to form glucose and oxygen

Question 2

Where does photosynthesis take place?

Answer 2

In chloroplasts in green plant cells

Question 3

Where is the energy for photosynthesis taken from?

Answer 3

light radiation from the Sun

Question 4

What type of reaction is photosynthesis?

Answer 4

Endothermic (energy is taken in from the surroundings)

Question 5

What is the word equation for photosynthesis?

Answer 5

Carbon dioxide + water → glucose + oxygen

Question 6

What is the symbol equation for photosynthesis?

Answer 6

6 CO₂ + 6 H₂O → C₆H₁₂O₆ + 6 O₂

Question 7

What are the three main things that affect photosynthesis?

Answer 7

1) Light
2) CO₂ concentration
3) Temperature

Question 8

How does temperature affect the rate of photosynthesis?

Answer 8

• If the temperature is low, the enzymes needed for photosynthesis work more slowly.
• If the plant gets too hot (around 45°C), the enzymes become damaged.

Question 9

How do plants use glucose?

Answer 9

• used for respiration
• to produce important molecules

Question 10

What is cellulose used for in plants?

Answer 10

Making strong cell walls.

Question 11

Why do plants store starch?

Answer 11

It is a source of stored energy ready for when photosynthesis isn’t happening

Question 12

What is respiration?

Answer 12

a reaction which is always occurring in living cells to provide energy

Question 13

Is respiration exothermic or endothermic?

Answer 13

Exothermic

Question 14

How do organisms use energy from respiration?

Answer 14

• chemical reactions to build larger molecules * movement
• keeping warm

Question 15

What is aerobic respiration?

Answer 15

Respiration using oxygen

Question 16

What is anaerobic respiration?

Answer 16

respiration without oxygen

Question 17

Where does aerobic respiration happen?

Answer 17

in the mitochondria

Question 18

Where does anaerobic respiration happen?

Answer 18

in the cytoplasm

Question 19

What is the word equation for respiration?

Answer 19

Glucose + oxygen → carbon dioxide + water

Question 20

What is the symbol equation for respiration?

Answer 20

C₆H₁₂O₆ + 6 O₂ → 6 CO₂ + 6 H₂O

Question 21

What is the word equation for anaerobic respiration in humans?

Answer 21

Glucose → lactic acid

Question 22

What is the word equation for anaerobic respiration in plants and yeast cells?

Answer 22

Glucose → ethanol + carbon dioxide

Question 23

What is the name given to anaerobic respiration in yeast cells?

Answer 23

Fermentation

Question 24

When do human body cells start to respire anaerobically?

Answer 24

During exercise when your body can’t supply enough oxygen to your muscles

Question 25

Why is anaerobic respiration less good than aerobic respiration?

Answer 25

• It doesn’t transfer as much energy as aerobic respiration
• It causes lactic acid to build up in the muscles, which is painful.

Question 26

How is fermentation used in industry?

Answer 26

• Bread making
• Making alcoholic drinks

Question 27

How does your body increase the amount of oxygen that gets to your cells when you exercise?

Answer 27

• Breathing rate and depth increases (to get more oxygenated blood to cells)
• Heart rate increases (to get oxygenated blood to cells quicker, and to remove CO₂ quicker)

Question 28

What happens to muscles after long periods of exercise?

Answer 28

Muscles get tired and stop contracting efficiently

Question 29

What is metabolism?

Answer 29

The sum of all the chemical reactions occuring in an organism.