Photosynthesis

Question 1

What is photosynthesis?

Answer 1

• the process by which plants trap and convert solar energy to useable energy

Question 2

Name the two major energy storage molecules in biological systems.

Answer 2

• Glucose
• ATP

Question 3

What is ATP?

Answer 3

• Adenosine tri-phosphate
• stores and releases energy
• ADP + P = ATP
• directly fuels organelle activity
• the creation of the bond stores energy
• breaking the bond liberates energy

Question 4

What organelles do photosynthesis occur in?

Answer 4

Chloroplasts

Question 5

List the sub-structures of a chloroplast.

Answer 5

• 2 outer membranes ( inner, outer )
• Thylakoids
• Granum (grana)
• Stroma
• Lamella (lamellae)
• Chlorophyll

Question 6

What are the two phases of photosynthesis?

Answer 6

• Phase 1: Light reactions
• Phase 2: Dark reactions

Question 7

What is produced as an output of light reactions?

Answer 7

• ATP ( used as energy source in next stage )
• NADPH ( used as energy source in next stage )
• O2

Question 8

Where do dark reactions occur?

Answer 8

• stroma

Question 9

What process occurs during the dark reactions?

Answer 9

Calvin Cycle

Question 10

What are the inputs for dark reactions?

Answer 10

• ATP (from light reactions)
• NADPH (from light reactions)
• CO2 ( from the atmosphere )

Question 11

What is the equation for photosynthesis?

Answer 11

6CO2 + 6H2O →( sunlight energy ) C6H12O6 + 6O2

Question 12

What light colours are the most efficient increasing the rate of photosynthesis?

Answer 12

• Blue ( 1st )
• Red ( 2nd )

Question 13

Why do plants look green?

Answer 13

They reflect green and yellow light

Question 14

Which type of light is absorbed most by chlorophyll?

Answer 14

red and blue wavelengths

Question 15

What is stroma?

Answer 15

• empty space in chloroplast
• where light independent reaction occur

Question 16

What is thylakoids?

Answer 16

• stack of granum

Question 17

What is granum/ gran?

Answer 17

• stacks of thylakoids -> where light dependent reactions occur

Question 18

What is lamella?

Answer 18

• connect thylakoids

Question 19

What is the purpose of inner membrane?

Answer 19

• maintain the internal environment

Question 20

What is the purpose of outer membrane?

Answer 20

• act as a protective barrier, regulating what enters and leaves the chloroplast

Question 21

what is the purpose of stroma lamellae?

Answer 21

• connects grana

Question 22

Where do light reactions occur?

Answer 22

• thylakoids of grana
• require solar energy

Question 23

What are the inputs of light reactions

Answer 23

• light energy ( energises chlorophyll )
• H2O -> split into H+ and OH-

Question 24

What are the outputs of dark reaction

Answer 24

• PGAL -> glucose: C6H12O6
• O2

Question 25

what is chlorophyll?

Answer 25

- The green pigment in chloroplasts that absorbs light energy

Question 26

What factors affect photosynthesis?

Answer 26

- light intensity - carbon dioxide concentration - temperature

Question 27

How does temperature affect photosynthesis?

Answer 27

- as temperature increases, enzymes also increase, therefore photosynthesis occur faster

Question 28

what is the role of light dependent reactions?

Answer 28

- to produce ATP and NADPH for further use in dark reactions

Question 29

What is the role of dark reactions?

Answer 29

- produce glucose for energy and growth