Photosynthesis

Question 1

How is the structure of the leaf adapted for effcient photosynthesis?

Answer 1

• large surface area
• thin
• many chloroplasts
• airspaces in mesophyll
• network of xylem and phloem numerous stomata
• transparent cuticle

Question 2

What are the 3 stages of photosynthesis?

Answer 2

1. Capturing of light energy by chlorophyll
2. Conversion of light energy into chemical energy
3. Reduction of CO2 to produce organic molecules

Question 3

What is a limiting factor?

Answer 3

A factor that is at its least favourable value; limits the rate of process

Question 4

How is the rate of photosynthesis measured?

Answer 4

• rate of O2 given out

- rate of CO2 taken in

Question 5

What is the light compensation point?

Answer 5

Point at which volume of CO2 given out by respiration and taken in by photosynthesis is equal; there is no net movement of gases

Question 6

What is the effect of CO2 concentration on the rate of photosynthesis?

Answer 6

• directly proportional to rate

- affects enzyme activity, especially rubisco in LIR

Question 7

Where does the LDR take place and how is this region adapted?

Answer 7

• thylakoid membrane;
• provides large SA for attachment of chlorophyll, electron carriers and enzymes
• chloroplasts contain DNA and ribosomes, can quickly synthesise proteins/enzymes required for reaction

Question 8

Name the products of the LDR

Answer 8

• O2 gas
• NADPH
• ATP

Question 9

How is ATP produced in LDR?

Answer 9

As electrons pass down electron transport chain, the move down energy levels, ATP is synthesised from ADP + Pi

Question 10

Where does the LIR take place and how is this region adapted?

Answer 10

• stroma
• surrounds grana, so products of LDR can directly diffuse into stroma
• contains all enzymes needed for reaction
• contains DNA and ribosomes

Question 11

Name the products of the LIR

Answer 11

• organic molecules (glucose)
• NADP
• ADP + Pi

Question 12

What is carboxylation?

Answer 12

Addition of carbon to compound