Photosynthesis I

Question 1

Photosynthesis

Answer 1

Process of converting solar energy to biochemical energy.

Question 2

Thylakoid

Answer 2

A membrane-bound structure in chloroplasts where light-dependent reactions of photosynthesis occur

Question 3

Grana

Answer 3

Stacks of thylakoids in chloroplasts that increase the surface area for photosynthesis. 40-60 grana linked together by arms

Question 4

Lumen

Answer 4

The inner space of a thylakoid, where protons accumulate during photosynthesis

Question 5

Stroma

Answer 5

The fluid-filled space surrounding the grana in a chloroplast, where the Calvin cycle takes place

Question 6

Photosynthesis equation

Answer 6

6CO2 + 6H2O + light ——> C6H12O6 + 6O2

Question 7

Light-dependent reactions

Answer 7

• The reaction happens in the grana of the inner membrane
• Reactions of photosynthesis that use energy from light to produce ATP, NADPH and O2

Question 8

Light-independent reactions (Calvin Cycle)

Answer 8

• The reaction takes place outside the grana
• Reactions in photosynthesis that do not require light
• Energy from ATP and NADPH is used to build high-energy compounds such as sugar

Question 9

Biochemical energy

Answer 9

Energy stored in chemical bonds of molecules.

Question 10

Photosynthesis by-product

Answer 10

O2 released during photosynthesis

Question 11

For photosynthesis to happen what needs to happen as well?

Answer 11

Respiration also has to happen

Question 12

Respiration

Answer 12

Respiration occurs in mitochondria where the stored energy (glucose, organic molecules) are converted into ATP

Question 13

Visible light

Answer 13

• Is what drives and powers photosynthesis
• About 40% of solar energy received on earth is in form of visible light
• Leaves absorb 80% of visible light reaching them

Question 14

Chlorophyll absorbs which light?

Answer 14

light in the blue (430 nm) and red (680 nm) regions of
the visible spectrum (400-700 nm)

Question 15

Chlorophyll reflects which light?

Answer 15

Green light is reflected

Question 16

Chlorophyll a

Answer 16

Primary pigment in photosynthesis, absorbs blue/red light.

Question 17

Chlorophyll b

Answer 17

• Accessory pigment, transfers energy to chlorophyll a
• Does not directly take part in the light reactions

Question 18

Accessary Pigments

Answer 18

• Pigments aiding photosynthesis by capturing light
• Carotenoids (yellow and orange),
• Phycobilins (red or blue)
• Accessory pigments are not visible until chlorophyll a breaks down (fall colours)

Question 19

Carotenoids

Answer 19

Yellow/orange pigments that absorb blue-green light.

Question 20

Phycobilins

Answer 20

Pigments found in cyanobacteria and red algae.

Question 21

Calvin cycle

Answer 21

Converts CO2 and RuBP in glucose

Question 22

Photosystems

Answer 22

Groups of pigment molecules in thylakoids

Question 23

Photosystem I

Answer 23

Contains P700, uses light energy for electron transfer

Question 24

P700

Answer 24

Chlorophyll a in PSI, absorbs light at 700 nm

Question 25

Photosystem II

Answer 25

Contains P680, absorbs light at 680 nm

Question 26

Light Reaction Centre

Answer 26

Has the proteins - Light harvesting (LHCII) - Reaction Centers (PSI & PSII) - Proteins with 2 electron transport chains (Cytochrome) - ATP Synthase Complex

Question 27

Antenna pigments

Answer 27

Gather and transfer light energy to reaction center

Question 28

Z-scheme

Answer 28

Electron flow pathway linking PSI and PSII

Question 29

Pheophytin (Pheo)

Answer 29

Primary electron acceptor in PSII

Question 30

Photolysis

Answer 30

Water splitting process producing electrons and oxygen

Question 31

Plastoquinone

Answer 31

Mobile electron carrier in thylakoid membrane

Question 32

Photophosphorylation

Answer 32

ATP synthesis powered by electron transport energy

Question 33

Chemiosmosis

Answer 33

Proton gradient used to produce ATP in thylakoids

Question 34

Cyclic electron flow

Answer 34

- Only uses PSI, so no oxygen is produced - Nothing is getting sent to the Calvin cycle - Creates ATP by using the electron transport chain

Question 35

Noncyclic electron flow

Answer 35

Electrons flow from water to NADPH, generating O2

Question 36

Photoinhibition

Answer 36

Photoinhibition happens when plants get too much light, the light damages PSII. As a result, the plant can't photosynthesize as efficiently, which means it makes less food

Question 37

Photooxidation

Answer 37

Bleaching of chlorophyll due to light exposure

Question 38

Kranz anatomy

Answer 38

C4 plants leaf anatomy - Mesophyll - Bundle sheath cell