Photosynthesis

Question 1

Co enzyme definition and examples

Answer 1

Non protein molecules that help enzymes to work by transferring other molecules around

Question 2

Photophosphorylation

Answer 2

Using light energy to add a phosphate

Question 3

Photolysis

Answer 3

Using light energy to split a molecule

Question 4

Summary of the light dependent reaction

Answer 4

Uses light energy to make ATP and NADPH (reduced NADP)
takes place on the thylakoid membrane (large surface area)
Sometimes called photophosphorylation

Question 5

Summary of light independent reaction

Answer 5

Uses products of light dependent reaction to make useful organic compounds
Takes place in the stroma
Calvin cycle

Question 6

Light dependent reaction

Answer 6

Photosynthetic pigments absorb light energy
Causes excitation of electrons which leave the chlorophyll in photo system 2 (photoionisation)
Electrons move along electron transport chain, releasing energy
This energy is used to join ADP and Pi to make ATP
NADP is reduced to form NADPH
Photolysis of water makes protons electrons and oxygen

Question 7

Light independent reaction

Answer 7

CO2 combines with RuBP catalysed by the enzyme rubisco
Makes 2 molecules of GP
Both GP molecules are reduced to form 2 TP using 2 NADPH and 2 ATP
Most TP is regenerated to form RuBP using energy from ATP
some of the TP is converted into useful organic compounds (eg lipids, amino acids and glucose)

Question 8

Light independent reaction mark scheme

Answer 8

Carbon dioxide combined with RuBP
Produces two GP using rubisco
GP reduced to triose phosphate
Using reduced NADP
Using energy from ATP
triose phosphate converted to glucose/ RuBP