Lecture 2 & 3 Photosynthesis I & II

Question 1

Autotrophs

Answer 1

Produce organic molecules from co2 and other raw inorganic materials (primary producers of biosphere)

Question 2

Photoautotrophs

Answer 2

Use light as energy

Question 3

Chemoautotrophs

Answer 3

harvest energy from oxidizing inorganic substances aka sulfur/ammonia (unique to bacteria)

Question 4

Heterotrophs

Answer 4

consumers, live off organic compounds produced by others

Question 5

Where are chloroplasts mainly found

Answer 5

Mesophyll cells, forming tissues in interior of leaf

Question 6

What is stomata

Answer 6

Place where CO2 enters and 02 exits leaf

Question 7

Veins

Answer 7

Deliver water from roots/ carry off sugar from mesophyll

Question 8

Stroma

Answer 8

Contains membrous sacs (Thylakoids) which contain chlorophyll
Thylakoids stacked in columns called grana

Question 9

Net process of photosynthesis

Answer 9

6CO2 + 6H2O + light energy —>

C6H12O6 +6O2

Question 10

What is Photosynthesis

Answer 10

Redox Reaction, water split and electrons transferred with H+ from water to CO2, reducing it to sugar.
Polar covalent bonds converted to non polar

Question 11

Two processes of photosynthesis

Answer 11

Light Reaction

Calvin Cycle

Question 12

What is the light reaction process in photosynthesis

Answer 12

concerts solar energy to chemical energy

Question 13

What is calvin cycle in photosynthesis

Answer 13

Turns CO2 into organic molecules and uses energy from light reaction to reduce new carbon piece to sugar

Question 14

What’s happens in light reaction?

Answer 14

light enerygy absorbed by chlorophyll transfers electrons and hyrdrogen from water to NADP+, forming NADPH

also generates ATP by photophosphorylation for calvin cycle

Question 15

Visible light

Answer 15

Most important segment for life, 380 to 750 nm

Question 16

Chlorophyll a

Answer 16

dominant, absorbs red and blue wave lengths best, least in green

Question 17

Chlorophyll b

Answer 17

slightly diff then chlorophyll a, funnels energy from wavelengths to chlorophyll a

Question 18

Carotenoids

Answer 18

funnel energy from other wavelengths to chlorophyll a, and photoprotect against excessive light

Question 19

What is energy of photon concerted to?

Answer 19

Potential energy of an electron raised from ground state to an excited state

Question 20

Photosystem

Answer 20

light gathering antenna complex for chlorophyll and carotenoids molecules

Question 21

Reaction center

Answer 21

contains primary electron acceptor which removes an excited electrons and starts light reactions

Question 22

Absorbing light energy results in splitting of water then…

Answer 22

2 e- are realeased and flow to reaction center

Question 23

Photosystem I

Answer 23

reaction centre with absorption peak at 700nm (P700 center)

Question 24

Photosystem II

Answer 24

reaction center peak 680nm (diff proteins than other photosystem)

Question 25

Both photosystem swirl together to generate….

Answer 25

ATP and NADPH using light energy

Question 26

Noncyclic electron flow

Answer 26

1. Reaction center oxidized when photosystem II absorbs light
2. enzyme extracts electrons from water and gives to reaction center
3. photoexcited elctrons pass long electron transport chain until arriving at Photosystem I reaction center
4. ATP produced along transport chain by electrons
5. At bottom of chain, electrons fill “hole” in P700 center
6. Hole causeed by electrons passed from chain to NADP+ creating NADPH

Question 27

Both photosystems use solar power to provide…

Answer 27

Chemical energy, ATP

Reducing power, NADPH

Question 28

Cyclic Electron Flow

Answer 28

Pathway can be taken by photosystem I elctrons only

generate ATP by Cylclic Photophosphorylation along electron chain

Generates surplus of ATP

Question 29

Chemiosmosis

Answer 29

elctron transport chain pumps protons across membrane while electrons pass

builds H+ gradient = Proton motive force

Atp synthase generate ATP from proton motive force

Question 30

Mitochondria generate energy from….

Answer 30

Food molecules to ATP (Respiration)

Question 31

Co2 enters The calvin cycle and it uses ATP and NADPH to make…

Answer 31

G3P

Question 32

Each turn of calvin cycle fixes…

Answer 32

1 Carbon

Question 33

Synthesis of G3P requires…

Answer 33

3 cycles and fixes 3CO2

Question 34

Synthesis of one glucose requires…

Answer 34

6 cycles

Question 35

3 Calvin Cycle Phases:

Answer 35

1. Carbon Fixation
2. Reduction
3. Regeneration of the CO2 acceptor

Question 36

Phase 1: Carbon Fixation phase of calvin cycle

Answer 36

Co2 attaches to 5 carbon sugar (RuBP) and catalyze day Rubisco. Splits in half and makes 2 molecules of Phosphoglycerate per co2

Question 37

Phase 2: Reduction (Calvin Cycle)

Answer 37

2 3-phosphoglycerate molecules joined in atp reaction to for 1,3 Bisophoglycerate which is reduced by NADPH to form G3P

Question 38

Phase 3: Regeneration of the Co2 (Calvin Cycle)

Answer 38

5 G3P molecules form 3 RuBP molecules, 3 ATP molecules needed to complete cycle and prepare for next

Question 39

Net synthesis of 1 G3P molecule

Answer 39

Consumes 9 ATP and 6 NAPDH

3 ATP and 2 NADPH per CO2