Topic 4 - Bioenergetics

Question 1

What is the word and symbol equation for photosynthesis?

Answer 1

Word equation:
— Carbon dioxide + water —> glucose + oxygen

Symbol equation:
— 6CO2 + 6H2O —> C6H12O6 + 6O2

Question 2

What are five uses of glucose from photosynthesis?

Answer 2

• – Respiration
• – Making cellulose to strengthen cell wall
• – Making amino acids
• – Stored as starch
• – Stored as fats and oils

Question 3

What four factors affect the rate of photosynthesis?

Answer 3

• – Temperature
• – Carbon dioxide concentration
• – Light intensity
• – Amount of chlorophyll

Question 4

When a graph levels off, what is it implying?

Answer 4

There is a limiting factor.

REMEMBER: PLEASE GO AND REFER TO THIS IN MORE DETAIL USING CGP BOOK

Question 5

What is the inverse square law that links light intensity and distance?

Answer 5

light intensity = 1 / d^2

Question 6

How do organisms use the energy transferred by respiration?

Answer 6

• – Movement by muscle contraction
• – Keeping warm
• – Chemical reactions to build up larger molecules

Question 7

What is the word equation for:

• – aerobic respiration?
• – anaerobic respiration?
• – anaerobic respiration in plants and yeast?

Answer 7

Aerobic respiration:
— Glucose + oxygen —> carbon dioxide + water

Anaerobic respiration in muscles:
— Glucose —> lactic acid

Anaerobic respiration in yeast:
— Glucose —> carbon dioxide + ethanol

Question 8

What happens when you exercise?

Answer 8

The body respires more. This is due to the increased use of energy required for muscle contraction. Also the body requires more oxygen as the heart rate, breathing rate and breathing volume increases. If exercise is more vigorous then the body begins to respire anaerobically. This can cause a build up of lactic acid in the muscles.

Question 9

What is oxygen debt? How else can the body cope with high levels of lactic acid after exercise?

Answer 9

Oxygen debt:
— The amount of extra oxygen the body requires after exercise to react with the build up of lactic acid and remove it from the cells

Another way the body copes is when blood reaches the muscles it transports lactic acid to the liver where it can be converted back into glucose

Question 10

What is the definition of metabolism?

Answer 10

Metabolism:

— The sum of all the reactions in a cell or the body.