Nat5 Biology Unit Three Life On Earth Key Area 3 Photosynthesis

Question 1

What are the two stages of photosynthesis?

Answer 1

Light Reactions

Carbon Fixation

Question 2

What happens During the Light Reactions?

Answer 2

The light energy from the sun is trapped
by chlorophyll in the chloroplasts and is converted into chemical energy which is used to generate ATP.
○ Water is split to produce hydrogen and oxygen.
○ Oxygen diffuses from the cell.

Question 3

What happens during Carbon Fixation?

Answer 3

A series of enzyme-controlled
reactions, which use hydrogen and ATP (produced by the
light reactions) with carbon dioxide to produce sugar.

Question 4

What is the word process of Photosynthesis?

Answer 4

Light
CO2 + Water ——> Sugar + O2
Chlorophyll

Question 5

The ______ in sugar is available for ____ or the sugar can be converted into other substances, such as _____ and ____

Answer 5

The CHEMICAL ENERGY in sugar is available for RESPIRATION or the sugar can be converted into other substances, such as STARCH (STORAGE) and CELLULOSE (STRUCTURAL)

Question 6

What are Limiting Factors?

Answer 6

A factor that is in short supply.

If the quantity is increased, then the rate of Photosynthesis will increase

Question 7

What are the Limiting Factors of Photosynthesis?

Answer 7

Carbon Dioxide Concentration - One of the raw materials - if there a lot of it, the rate of Photosynthesis will be high
Light Intensity - the higher it is the faster the rate of Photosynthesis
Temperature - the enzymes will denature once they get past their optimum temperature

Question 8

What are the limiting factors at X and Y?

                                            Y
                                            /
                    \_\_\_\_\_\_\_\_\_\_\_\_\_\_ 30°
                   /\_\_\_\_\_\_\_\_\_\_\_\_\_\_ 20°
                  /                                               ^
                 /                                                |
                /                                             ROP
               /         -X                                    |
              /                                                   ^ \_\_\_\_\_\_\_/

Light Intensity

Answer 8

X - Light Intensity
Y - Temperature

                                              Y
                                              /
                    \_\_\_\_\_\_\_\_\_\_\_\_\_\_ 30°
                   /\_\_\_\_\_\_\_\_\_\_\_\_\_\_ 20°
                  /                                               ^
                 /                                                |
                /                                             ROP
               /         -X                                    |
              /                                                   ^ \_\_\_\_\_\_\_/

Light Intensity