paper 1 bioenergetics ✅ topic 4

Question 1

Give two uses of the energy released in respiration

Answer 1

muscle contraction
keeping warm
building larger molecules

Question 2

What are the two products of anaerobic respiration in plant cells

Answer 2

carbon dioxide and ETHANOL

Question 3

When plants take in energy what types of reaction is it

Answer 3

endothermic

Question 4

What is the equation for photosynthesis

Answer 4

6co2 + 6H20 > c6h12o6 > 602

Question 5

What happens to the rate of photosynthesis when light intensity increases (3)

Answer 5

If we increase the light intensity, rate of photosynthesis also increases, that tells us the light intensity was limiting

Question 6

What are the limiting factors of photosynthesis

Answer 6

• Temperature
• Light intensity
• Co2 concentration
• The amount of chlorophyll in the leaf

Question 7

What are two uses of glucose

Answer 7

• release energy on respiration
• produce strach

Question 8

REQUIRED PRACTICAL : effect of light intensity on the rate of photosynthesis

Answer 8

• Start by taking a boiling tube and placing it 10cm away from an LED light source

• Fill boiling tube with sodium hydrogen carbonate solution, this releases carbon dioxide which is needed for photosynthesis

• Put a piece of pondweed into the boiling tube

• leave for 5 minutes to acclimatise to the conditions in the boiling tube

• bubbles of gas should be produced (oxygen)

• Start a stop watch and count number of bubbles produced in one minute

• repeat two more times calculate men’s number

• Next do experiment again BUT with 20cm away from LED

• then 30, 40

Question 9

Why do we use a LED source

Answer 9

don’t produce too much heat which will affect the experiment

Question 10

What are the two problems with this practical

Answer 10

• The number of bubbles can be too fast to count accurately

• Bubbles are not always the same size

Question 11

HOWNTO SOLVE PROBLEM OF INACCURATE RESULTS BY COUNTING BUBBLES

Answer 11

Measuring volume of oxygen produced

Question 12

How do you measure volume do oxygen produced

Answer 12

Place the pondweed under a funnel and catch the bubbles in a measuring cylinder

use it to measure of volume of oxygen produced

Question 13

explain inverse square law

Answer 13

If you double the distance then the number of bubbles per minute falls by a factor of four

Question 14

Why does aerobic respiration produce a lot of energy

Answer 14

Glucose molecule has been fully oxidised

Question 15

What happens in anaerobic respiration in muscles

Answer 15

Glucose to Lactic acid

Question 16

What is Fermentation

Answer 16

Anaerobic Respiration in yeast cells

Question 17

How does the body provide extra oxygen during exercise

Answer 17

breathing rate and volume increases

Question 18

Explain why the death of the snail caused the concentration of carbon dioxide to increase

Answer 18

The snail is being decayed (1)
By decomposers (1)
Therefore respiration releases CO2(1)

Question 19

How is energy gained for plants to carry out photosynthesis

Answer 19

light is absorbed by chlorophyll

Question 20

Describe how glucose from the small intestine is moved to a muscle cell

Answer 20

glucose is absorbed by diffusion into the bloodstream
the blood delivers glucose to muscles in capillaries

Question 21

Explain how the changes on blood flow to the the athletes muscle helps him to run

Answer 21

vasoconstriction to working muscles supplies more oxygen and glucose for more respiration so it can release more energy for muscle contraction

Question 22

Why would a damaged alveoli male exercising difficult

Answer 22

less oxygen taken in

Question 23

What is the substance stored in the muscles and used during exercise

Answer 23

glycogen