Topic 4//Photosynthesis/Respiration/Metabolism/Aerobic/Anaerobic/Exercise

Question 1

What is word equation for photosynthesis

Answer 1

carbon dioxide + water =
glucose + oxygen

Question 2

What are the 5 ways plants use glucose

Answer 2

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

Question 3

How do plants use glucose for respiration

Answer 3

Respiration transfers energy from glucose which enables plants to convert rest of glucose into various useful substances

Question 4

How do plants use glucose for Making cellulose

Answer 4

Glucose is converted into cellulose for making strong plant cell walls

Question 5

How do plants use glucose for Making amino acids

Answer 5

Glucose is combined with nitrate ions to make amino acids which are then made into proteins

Question 6

How do plants use glucose for storing as fats or oil

Answer 6

Glucose is turned into lipids for storing in seeds

Question 7

How do plants use glucose for storing as starch

Answer 7

Glucose is turned into starch and stored in roots, stems and leaves ready for use when photosynthesis isnt happening like in winter.
Starch is insoluble which makes it better than storing as glucose

Question 8

What main 2 factors limits rate of photosynthesis depending on environmental conditions

Answer 8

At night - Light is limiting factor
In winter - Temperature is limiting factor

Question 9

How does light slow down rate if photosynthesis

Answer 9

Light provides energy needed for photosynthesis. As light level is raised, rate of photosynthesis increases steadily only to a certain point. Beyond that as light intensity increases, rate will no longer increase as either CO2 or temp is limiting factor

Question 10

How does CO2 affect rate of photosynthesis

Answer 10

Amount of CO2 will only increase rate of photosynthesis up to a point. Beyond that point, the limiting facot must be either temperature or light

Question 11

How does Temperature affect rate of reaction

Answer 11

Usually if temperature is limiting factor its because its too low and enzymes needed for photosynthesis work more slowly . If plant gets too hot, the enzymes needed for photosynthesis will get damaged

Question 12

What are the 6 steps of Measuring rate of photosynthesis

Answer 12

1. source of light placed at specific distance from pondweed
2. then left to photosynthesise for set amount of time whilst O2 will be collected in capillary tube
3. syringe is used to draw gas bubbles in tube alongside ruler and length is measured
4. experiment is repeated twice with same distance and mean volume of O2 calculated
5. whole experiment repeated with light source at different distance

Question 13

Define respiration

Answer 13

process of transferring energy from glucose which goes in every cell

Question 14

Is respiration endo or exothermic

Answer 14

Exothermic - transfers energy to environment

Question 15

What are the three examples of how organisms use energy transferred by respiration

Answer 15

1. Build up larger molecules from smaller ones
2. In animals, used to allow muscles to contract so can move about
3. In mammals and birds, energy is used to keep their body temperature steady in colder surroundings

Question 16

Define Metabolism

Answer 16

The sum of all of the reactions that happens in a cell or the body

Question 17

What is aerobic respiration

Answer 17

Respiration using oxygen and is most efficient way to transfer energy from glucose in plants and animals. Most reactions happens in mitochondria.

Question 18

What is formula for aerobic respiration

Answer 18

glucose + oxygen=carbon dioxide + water

Question 19

What is anaerobic respiration

Answer 19

incomplete breakdown of glucose making lactic acid and it doesnt transfer as much energy as aerobic respiration because oxygen is not fully oxidised.

Question 20

What is formula for anaerobic respiration in humans

Answer 20

Glucose = lactic acid

Question 21

Describe Anaerobic respiration in yeast cells

Answer 21

They can respire without oxygen and in yeast cells is called fermentation which is used to make bread ( its the Co2 that makes the bread rise) and alcoholic drinks

Question 22

What is work equation if Anaerobic respiration in plants and yeast cells

Answer 22

Glucose = ethanol + carbon dioxide

Question 23

How does Anaerobic respiration lead to an Oxygen Debt

Answer 23

When you stop exercising, you will have to repay the oxygen that you didnt get to your muscles in time because your heart, lungs and blood couldnt keep up with the demand earlier so you have to keep breathing hard to get more oxygen into your blood.

Question 24

How does your body cope with high levels of lactic acid

Answer 24

the blood that enters your muscles transport lactic acid to the liver when it is converted back to glucose

Question 25

Define oxygen debt

Answer 25

Amount of oxygen your body needs to react with the build up of lactic acid and remove it from cells.
So oxygen reacts with lactic acid to form harmless carbon dioxide and water