4.3.1 Photosynthesis

Question 1

define the terms autotroph and heterotroph;

Question 2

state that light energy is used during photosynthesis to produce complex organic molecules;

Question 3

explain how respiration in plants and animals depends upon the products of photosynthesis

Question 4

state that in plants photosynthesis is a two-stage process taking place in chloroplasts

Question 5

explain, with the aid of diagrams and electron micrographs, how the structure of chloroplasts enables them to carry out their functions

Question 6

define the term photosynthetic pigment

Question 7

explain the importance of photosynthetic pigments in photosynthesis;

Question 8

state that the light-dependent stage takes place in thylakoid membranes and that the light-independent stage takes place in the stroma;

Question 9

outline how light energy is converted to chemical energy (ATP and reduced NADP) in the light-dependent stage (reference should be made to cyclic and non-cyclic photophosphorylation, but no biochemical detail is required

Question 10

explain the role of water in the light-dependent stage;

Question 11

outline how the products of the light-dependent stage are used in the light-independent stage (Calvin cycle) to produce triose phosphate (TP) (reference should be made to ribulose bisphosphate (RuBP), ribulose bisphosphate carboxylase (rubisco) and glycerate 3-phosphate (GP), but no other biochemical detail is required);

Question 12

**explain the role of carbon dioxide in the light-independent stage (Calvin cycle); **

Question 13

state that TP can be used to make carbohydrates, lipids and amino acids;

Question 14

state that most TP is recycled to RuBP

Question 15

describe the effect on the rate of photosynthesis, and on levels of GP, RuBP and TP, of changing carbon dioxide concentration, light intensity and temperature;

Question 16

discuss limiting factors in photosynthesis with reference to carbon dioxide concentration, light intensity and temperature;

Question 17

describe how to investigate experimentally the factors that affect the rate of photosynthesis (HSW3).