Topic 4 - Bioenergetics

Question 1

What is photosynthesis?

Answer 1

It is the process by which a plant uses energy to transfer carbon dioxide and water into glucose and oxygen.
Energy is transferred to chloroplasts through light.

Question 2

Is photosynthesis endothermic or exothermic?

Answer 2

Endothermic - Energy is gained since its transferred from the environment.

Question 3

What is the word and symbol equation for photosynthesis?

Answer 3

Carbon dioxide + water —–(light)—–> Glucose + Oxygen

6CO2 + 6H2O ——(light)—–> C6H12O6 + 6O2

Question 4

What is glucose in plants used for?

Answer 4

Respiration
Making cellulose
Making amino acids
Stored as oil or fats
Stored as starch

Question 5

What are limiting factors of the rate of photosynthesis?

Answer 5

Light intensity (night)
Concentration of CO2
Temperature(winter)
Amount of chlorophyll(disease)

Question 6

What does the inverse square law show and what is the equation for it?

Answer 6

It shows that light intensity is proportional to 1/d^2

Light intensity (proportion symbol) 1/d^2

Question 7

How can you artificially create an ideal environment for your plants?

Answer 7

Grow them in a greenhouse.

Question 8

How are greenhouses helpful?

Answer 8

Trap suns heat so temperature doesnt become limiting.
You could put a heater if too cold or shades and ventilation if too hot.

Use artificial light after sun gone down.

Increase CO2 in greenhouse with paraffin heater.

Keep pests away

Question 9

What is respiration?

Answer 9

Respiration is the process of transferring energy from the breakdown of glucose and it goes on in every cell in your body continuously.

Question 10

What are some examples of how organisms use energy from respiration?

Answer 10

Build up larger molecules from smaller ones eg proteins from amino acids.

Used to allow muscles to contract.

Keep body temperature steady

Question 11

What is metabolism?

Answer 11

The sum of all reactions that happen in a cell or the body is cal.ed its metabolism.

Question 12

Whats the difference between aerobic and anaerobic respiration?

Answer 12

Aerobic respiration uses oxygen and glucose to produce carbon dioxide and water.
Anaerobic respiration uses only glucose and is the incomplete breakdown of glucose, making lactic acid.

Question 13

When is anaerobic respiration useful?

Answer 13

In emergencies like during exercise and you dont have enough oxygen for aerobic respiration it allows you to keep on using your muscles for a while longer.

Question 14

What is the word and symbol equation for aerobic respiration?

Answer 14

Opposite of photosynthesis

Glucose + oxygen ——> carbon dioxide + water

C6H12O6 + 6O2 ——> 6CO2 + 6H2O

Question 15

What is the word equation for anaerobic respiration?

Answer 15

Glucose —-> lactic acid

Question 16

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

Answer 16

Glucose ——> ethanol + carbon dioxide

Question 17

What is anaerobic respiration in yeast called and when is yeast helpful?

Answer 17

Fermentation.

In bread-making carbon dioxide from fermentation of yeast is what makes the bread rise.

In beer and wine making, the fermentation process produces alcohol.

Question 18

What happens when you exercise? (In terms of respiration)

Answer 18

Muscles need energy from respiration to contract. When you exercise your muscles contract more so you need more energy. Energy comes from increased respiration.

Your breathing rate and breath volume increase (get more oxygen into the blood)
Heart rate increase (pump oxygenated blood round body quicker).

Vigorous exercise (sprinting) your body cant supply enough oxygen so anaerobic respiration takes place.

Question 19

What happens after anaerobic respiration?

Answer 19

You have an oxygen debt.
This is the amount of extra oxygen your body needs to react with the build up of lactic acid and remove it from your cells.
Oxygen reacts with lactic acid to form CO2 and water.

Question 20

What does your body do whilst your in oxygen debt?

Answer 20

Breathing hard after a while after youve stopped exercise.
Pulse and breathing rate stay high.
Blood transports lactic acid to liver where its converted back to glucose.

Question 21

How can you investigate effect of exercise on the body?

Answer 21

1) Measure breathing rate by counting breaths and heart rate by taking the pulse.
2) Record these 5 mins after walking, running, sitting etc.
3) Pulse rate will increase, the more intense the exercise is.
4) To reduce effect of random errors, do it as a group and record the average.