Topic 4 (LINKED)

Question 1

Factors that affect photosynthesis

Answer 1

Temperature
Light
CO2 concentration
Chlorophyll

Question 2

How does Temp affect:

Answer 2

This affects how much kinetic energy particles have
=> affects speed at which carbon dioxide and water move through plant

At higher temperatures; enzymes can be denatured (active site no longer complementary to substrate)

Question 3

How does Light affect

Answer 3

More light a plant receives; faster rate of photo.

This will continue until some other factor is required for photo. Prevents the rate as it is now in short supply

Question 4

How does Co2 affect:

Answer 4

More carbon dioxide; the faster the reaction can occur

This will continue until some other factor is required for photo. Prevents the rate as it is now in short supply

Question 5

How does Number of Chlorophyll

Answer 5

More chloroplasts; faster rate of photosynthesis

Affected by:
Disease (TMV)
Lack of nutrients (magnesium- chlorosis) (Nitrate- stunted growth)

Question 6

What is inverse square law and what does it show us

Answer 6

Shows relationship between light intensity and distance

As distance increases; light intensity decreases (inversely proportional)

Question 7

Uses of Glucose:

Answer 7

Used in respiration (aerobic and anaerobic)
Converted into insoluble starch for storage in leaves
Produce fat or oil for storage
Produce cellulose- strengthen cell wall
Used to produce amino acids

Question 8

Conditions and products of Aerobic respiration

Answer 8

Oxygen

glucose + oxygen=> carbon dioxide + water

Oxidation of glucose complete
=> more energy

Question 9

Conditions and products of Anaerobic respiration

Answer 9

No Oxygen

glucose => lactic acid

Incomplete oxidation of glucose
=> less energy

Fermentation in yeast
Glucose => alcohol + Co2

Question 10

Effect of exercise

Answer 10

Body reacts to increased demand for oxygen in many different ways

Breathing rate and breath volume increases amount of oxygen absorbed into blood by diffusion; and the amount of Co2 removed
Heart rate increases

If exercising vigorously- body may not be able to supply sufficient oxygen to muscles to meet the demand for energy

An ‘oxygen debt’ is created after exercising in this way
=> ‘extra’ oxygen needed to react with lactic acid
The body can deal with this in 2 different ways:

Can be oxidised to form Co2 and water (from anaerobic to aerobic respiration)
Blood flowing through the muscles transports the lactic acid to liver where it is converted back into glucose