Photosynthesis

Question 1

Balanced Chemical Equation for Photosynthesis

Answer 1

6Co2 + 6 H2O = C6H1206 + 6O2

Question 2

Explain the benefits of a leaf having a large surface area.

Answer 2

The larger surface area the more chance of exposure to sunlight that it has.

Question 3

What is the cuticle in a plant.

Answer 3

A waxy layer on outer surface of epidermal cells which prevents the leaf from loosing water.

Question 4

Define Photosynthesis

Answer 4

Photosynthesis is the process where light energy is transformed into chemical energy and is stored as sugars.

Question 5

What is the role of the stomata in a plant?

Answer 5

Provides access into the leaf for carbon dioxide.

Question 6

What is the role f the xylem vessels?

Answer 6

Supply water form the roots to the cells of the leaf.

Question 7

Where does photosynthesis occur?

Answer 7

Chloroplast

Question 8

Define chlorophyll

Answer 8

Chlorophyll is a photosynthetic pigment which absorbs blue and red light. They reflect green, hence the colour of plants.

Question 9

Which form of chlorophyll has direct involvement with photosynthesis?

Answer 9

Chlorophyll A

Question 10

Why is it a benefit to have other pigments?

Answer 10

Other pigments such as chlorophyll b absorb light and transfer it to chlorophyll a, thus broadening the range of different wavelengths that can drive photosynthesis.

Question 11

Where does the light-dependent stage occur?

Answer 11

Thylakoid Membrane

Question 12

List inputs for the light dependent stage

Answer 12

• Sunlight
• Chlorophyll
• NADP
• ADP + Pi
• H20

Question 13

List outputs for the light dependent stage

Answer 13

• ATP
• Oxygen (waste product)
• NADPH

Question 14

Explain briefly what happens in the light dependent stage

Answer 14

1. Light energy is trapped in the chlorophyll causing electrons to become excited.
2. The electrons drive photolysis: The splitting of a water molecule into hydrogen ions, oxygen gas and electrons are also relased
3. NADP joins with a hydrogen ion to for NADPH
4. ADP+ Pi forms ATP

Question 15

What drives the second stage of photosythesis

Answer 15

The NADPH AND ATP from the first stage/

Question 16

What is the light independent stage also known as?

Answer 16

The Calvin Cycle

Question 17

Inputs of the Calvin Cycle

Answer 17

NADPH
ATP
CO2

Question 18

Outputs of the calvin cycle

Answer 18

Glucose
NADP
ADP + Pi

Question 19

Briefly explain the steps of the calvin cycle

Answer 19

1. Co2 molecues in the stroma combine with a 5C compound called RuBP. The enzyme that joins these two is called RiBisCo. This is called carbon fixation
2. A 6C compound splits in 2 3C compounds
3. ATP and NADPH are used to rearrange the structre of the molecules in a number of steps to form 2 triosphosphate molecules.
4. A 3C sugar compound is released to form glucose.
5. The remaingin molecules reform RuBP

Question 20

What are the main factors that affect the photosynthetic Rate?

Answer 20

• Light Intensity
• Temperature
• Co2 Concentration

Question 21

What are the main parts in a chloroplast?

Answer 21

Thylakoid
Granum
Grana
Intermembrane Space
Outer Membrane
Inner Membrane
Stroma
Stroma Lamella
Starch Molecule
DNA

Question 22

Word equation for photosynthesis

Answer 22

Carbon dioxide + water ——-> (in the presecence of light (energy) and chlorophyll)) yields glucose and oxygen1

Question 23

Define autotrophs

Answer 23

Self feeding organisms that synthesis their own organic molecules

Question 24

Define hetertrphs

Answer 24

Animals receiving their energy from other organisms

Question 25

Where does the LD stage occur?

Answer 25

Grana

Question 26

Where does the LID occur

Answer 26

stroma

Question 27

Photosynthesis is an

Answer 27

endergonic reaction