Photosynthesis

Question 1

What is an organic compound?

Answer 1

A compound that contains a carbon atom

Question 2

What is an inorganic compound?

Answer 2

One that doesn’t contain carbon

Question 3

What is oxidation?

Answer 3

O I L R I G Oxidation is loss of hydrogen or gaining oxygen

Question 4

What is a co enzyme?

Answer 4

Non protein molecule that help enzymes to function eg) NAD

Question 5

What is phosphorylation?

Answer 5

Adding a phosphate eg) ADP + Pi

Question 6

What is photophosphorylation?

Answer 6

Using light to add a phosphate.

Question 7

What uses light to split a molecule?

Answer 7

Photolysis

Question 8

What is an ETC?

Answer 8

Where electrons flow through proteins in a membrane

Question 9

What is a proton?

Answer 9

A positive charge eg) H+

Question 10

What is a chloroplast?

Answer 10

An organelle that absorbs light energy to be used for photosynthesis, to make useful organic compounds

Question 11

What is a thylakoid?

Answer 11

Membrane is the site of the light dependant reaction, high SA, contains photosynthetic pigments. Eg) chlorophyll A+B and carotene

Question 12

Why is photosynthesis important?

Answer 12

It converts light energy into chemical energy (stored in carbs) This allows the energy to be transferred to other organisms by consumption

Question 13

What is the chemical equation of photosynthesis?

Answer 13

6CO2 + 6H2O ———> 6O2 + C6H12O6

Question 14

Where does the light dependant reaction take place?

Answer 14

Chlorophyll (thylakoid membrane)

Question 15

Describe the light dependant reaction. (5 steps)

Answer 15

The light energy is absorbed by photosynthetic pigments in the chlorophyll

This excites the electrons they leave the chloroplasts which is then photoionised

The electrons are transferred through5 a carrier molecule in the thylakoid membrane

as electrons move down the ECT they use energy to pump protons from the stroma into the thylakoid creating a proton gradient

The protons diffuse out via the ATP synthase enzyme releasing energy for the Phosphorylation of ADP +Pi to ATP. ( chemiosmosis)

Question 16

name 3 photosynthetic pigments

Answer 16

chlorophyll A, chlorophyll B, carotene

Question 17

What are the products of the light dependent reaction?

Answer 17

ATP + NADPH

Question 18

What is the role of the Calvin Cycle?

Answer 18

uses products of LDR to make useful organic products from CO2

Question 19

What is the first stage of the calvin cycle?

Answer 19

CO2 (1C) combines with RUBP (5C) catalysed by the enzyme rubisco to make 2 molecules of GP (3C each)

Question 20

What is stage 2 of the calvin cycle?

Answer 20

Both molecules of GP (3C each) are reduced by LDP products (ATP —-> ADP and NADPH—–> NADP) to form 2 TP (3C each)

Question 21

what is stage 3 of the calvin cycle?

Answer 21

most TP is regenerated to form RUBP, some TP is used to make useful organic compounds eg) glucose

Question 22

How many extra carbons are there per spin of the calvin cycle?

Answer 22

1

Question 23

Name 3 limiting factors of photosynthesis

Answer 23

Temperature, CO2 conc, light intensity

Question 24

Light intensity as a limiting factor

Answer 24

higher the light intensity the more energy there is for the LDR so the faster the rate of photosynthesis

light needs to be of teh right WL

Question 25

CO2 conc as a limiting factor

Answer 25

optimum CO2 is 0.4% atmosphere is 0.04% in atmosphere limiting factor during the day

Question 26

Temperature as a limiting factor

Answer 26

Increases KE increasing Enzyme action can increase transpiration --- stomata close

Question 27

How can farmers use light intensity to increase yield?

Answer 27

use a green house use light of correct wavelength

Question 28

How can farmers use CO2 to increase yield?

Answer 28

fossil fuel burner increases CO2 conc

Question 29

How can farmers use temperature to increase yield?

Answer 29

burner increases temp greenhouse traps warm air maintain optimum temperature using thermostat