Unit 8: Photosynthesis

Question 1

Photosynthesis

Answer 1

A biochemical process for building carbohydrates from sunlight and carbon dioxide

Question 2

Reduction

Answer 2

Reactions in which a molecule acquires electrons and gains energy

Question 3

Oxidation

Answer 3

Reactions in which a molecule loses electrons and releases energy

Question 4

Electron Donor

Answer 4

Molecules that donate electrons

Question 5

Photosynthetic Electron Transport Chain

Answer 5

A series of redox reactions in which electrons are passed from one compound to another

Question 6

Photosystems

Answer 6

Protein-pigment complexes that absorb light

Question 7

Calvin Cycle

Answer 7

The process in which carbohydrates are synthesized using CO2

Question 8

Photic Zone

Answer 8

A surface layer about 100 m deep in the ocean where photosynthesis occurs

Question 9

Horizontal Gene Transfer

Answer 9

The transfer of genetic material between organisms that are not parent and offering

Question 10

Thylakoid Membrane

Answer 10

A highly folded membrane where the photosynthetic electron transport chain is located

Question 11

Grana

Answer 11

Flattened sacs connected to one another by membrane bridges so that the thylakoid forms a single continuous membrane

Question 12

Lumen

Answer 12

A fluid-filled interior compartment in the thylakoid membrane

Question 13

Stroma

Answer 13

The region surrounding the thylakoid membrane

Question 14

Steps of the Calvin Cycle

Answer 14

1. Carboxylation
2. Reduction
3. Regeneration

Question 15

Carboxylation

Answer 15

CO2 absorbed from the air is added to a 5-carbon molecule

Question 16

Regeneration

Answer 16

The 5-carbon molecule needed for carboxylation gets regenerated

Question 17

Ribulose 1,5 Bisphosphate (RuBP)

Answer 17

A 5-carbon sugar that CO2 gets added too

Question 18

Ribulose Bisphosphate Carboxylase Oxygenase (Rubisco)

Answer 18

The enzyme that catalyzes the carboxylation reaction

Question 19

3-Phosphoglycerate (3-PGA)

Answer 19

The first stage products of the Calvin cycle

Question 20

Nicotinamide Adenine Dinucleotide Phosphate (NADPH)

Answer 20

The reducing agent used in the Calvin cycle

Question 21

Reduction of 3-PGA Steps

Answer 21

1. ATP is used to phosphorylate 3-PGA
2. NADPH transfers two high-energy electrons to the phosphorylated compound

Question 22

Triose Phosphates

Answer 22

3-carbon carbohydrate molecules that are exported from the chloroplast

Question 23

Visible Light

Answer 23

The portion of the electromagnetic spectrum that is visible to our eyes and used in photosynthesis

Question 24

Chlorophyll

Answer 24

A major photosynthetic pigment

Question 25

Accessory Pigments

Answer 25

Allows photosynthetic cells to absorb a broader range of visible light then would be possible with chlorophyll alone

Question 26

Reaction Centre

Answer 26

A configured pair of chlorophyll molecules that receives absorbed light energy

Question 27

Z Scheme

Answer 27

The overall energy trajectory in the photosynthetic electron transport chain in which energy increases by absorption of light in PS II, decreases, then a second input of light energy at PS I before decreasing again as NADPH is reduced

Question 28

Photosystem II

Answer 28

Supplies electrons to the beginning of the electron transport chain where it loses an electron and pulls electrons from water

Question 29

Photosystem I

Answer 29

Energizes electrons with a second input of light energy so it has enough energy to reduce NADP+

Question 30

Cytochrome b6f Complex

Answer 30

A protein complex in which electrons pass between photosystem II and photosystem I

Question 31

Cyclic Electron Transport

Answer 31

An alternative pathway for electrons in which electrons re-enter the photosynthetic electron transit chain upstream of the cytochrome-b6f proton pump

Question 32

Reactive Oxygen Species

Answer 32

Reactive oxygen species that are generated when excess light energy and electrons are transferred into oxygen

Question 33

Xantophylls

Answer 33

Yellow-orange pigments that slow the formation of reactive oxygen species by reducing excess light energy and converting it to heat