Biology PT3

Question 1

photosynthesis

Answer 1

converts light energy into chemical energy as glucose

Question 2

Equation for photosynthesis

Answer 2

light, excess water, chlorophyll

6CO2 + 6H2O —-> C6H12O6 + 6O2

Question 3

Two stages of photosynthesis and their location

Answer 3

Light dependent —> Granum

Light independent —-> Stroma

Question 4

Light trapping pigments in grana

Answer 4

• chlorophylls

- carotenoids

Question 5

Inputs of light dependent (LDR)

Answer 5

light energy
H2O
co-enzymes:
ADP+Pi
NADP+

Question 6

Outputs of light dependent (LDR)

Answer 6

O2
co-enzymes:
ATP
NADPH

Question 7

Inputs of light independent (LIR)

Answer 7

CO2
co-enzymes:
ATP
NADPH

Question 8

Outputs of light independent (LIR)

Answer 8

C6H12O6 (glucose)
co-enzymes:
ADP+Pi
NADP+

Question 9

NADPH/NADP+

Answer 9

NADP+ carries hydrogen ions and electrons by forming NADPH and moves from the light dependent reaction to the light independent reaction in a cyclical manner.

Question 10

ATP/ADP+Pi

Answer 10

ADP carries energy by forming ATP and moves from the light dependent reaction to the light independent reaction in a cyclical manner.

Question 11

Photosynthetic pathways

Answer 11

C3 , C4 and CAM (crassulacean acid metabolism)

Question 12

C3 plants (vegetables)

Answer 12

• 3 carbon compound in carbon fixation
• both LIR and LDR in spongey mesophyll cells
• use Rubisco enzyme
• stoma open during day
• cool wet climate

Question 13

Rubisco

Answer 13

an enzyme believed to be most abundant on earth!
used in carbon fixation
can be competitively inhibited by O2

Question 14

O2 and Rubisco

Answer 14

O2 = competitive inhibitor for rubisco which causes photorespiration

Question 15

Photorespiration

Answer 15

O2 acts as a competitive inhibitor to rubisco = photorespiration instead of the independent reaction of fixing CO2. (more photoresp. plants in hot dry envir.)

Question 16

C4 plants (australian natives)

Answer 16

• 4 carbon compound in carbon fixation
• both LDR in spongey mesophyll cells with LIR also in bundle sheath
• use Rubisco enzyme and PEPCase
• hot dry climate

Question 17

CAM plants (cacti)

Answer 17

• LDR in day and LIR in day and night
• use Rubisco enzyme
• very hot dry climate

Question 18

State the role of Rubisco in all plants

Answer 18

Catalyse reducing carbon dioxide to form glucose in the light independent reaction in the stroma of a chloroplast.

Question 19

Role of the chloroplast

Answer 19

Site of photosynthesis

Question 20

Location of Light dependent reaction within the chloroplast

Answer 20

Grana

Question 21

Location of light independent reaction within the chloroplast

Answer 21

Stroma

Question 22

Coenzymes

Answer 22

Molecules that are used as loaded or unloaded forms to move energy (ATP), protons and electrons (NADPH and NAD) between reactions in the cell in a cyclical manner

Question 23

Endosymbiotic theory

Answer 23

Chloroplast and mitochondria originated when a prokaryote engulfed another prokaryote cell speciliased in photosynthesis or energy conversion from glucose to ATP

Question 24

Evidence to support the endosymbiotic theory

Answer 24

• Double membrane
• Bacterial ribosomal material (70s ribosomes)
• own DNA (single circular)

Question 25

Stroma

Answer 25

Fluid, enzyme dense, part of chloroplast where light independent reactions take place.

Question 26

Granum

Answer 26

Stack of folded thylakoid membranes where the light dependent reactions occur.

Question 27

Photolysis

Answer 27

Water is split by light energy to make oxygen, hydrogen ions and electrons in the light dependent reaction.