Chapter 10 - photosynthesis

Question 1

What is the key process to life in plants?

Answer 1

PhOtOsYnThEsIs :D

Question 2

PSN converts light to…?

Answer 2

Chemical energy

Question 3

PREFIXES:
What does cata mean?

Answer 3

down

Question 4

PREFIXES:
What does ana mean?

Answer 4

Up

Question 5

What are the 2 prokaryotes he named?

Answer 5

cyanobacteria (blue/green algae) and purple sulfur bacteria

Question 6

What are the two eukaryotes he named?

Answer 6

plants and algae

Question 7

What do all green plants contain?

Answer 7

Chloroplasts

Question 8

What cells are the majority of chloroplasts found in?

Answer 8

Mesophyll cells

Question 9

What are parts of the structure of chloroplasts?

Answer 9

o Surrounded by double membrane
o Central aqueous fluid called stroma
o Contain system connected sacs called thylakoid

Question 10

What do thykaloids form and contain?

Answer 10

o Thylakoids form stacks called grana
o Thylakoids contain green pigment called chlorophyll

Question 11

What are the two types of chlorophyll?

Answer 11

Chlorophyll alpha
Chlorophyll beta

Question 12

What are the relations between chlorophyll and light/colors?

Answer 12

 Absorb strongly in blues and reds
 Absorb poorly in green and near green

Question 13

Which chlorophyll is the dominant one?

Answer 13

Alpha

Question 14

Which chlorophyll absorbs violet-blue & orange-red?

Answer 14

Alpha

Question 15

Which chlorophyll primarily absorbs blues

Answer 15

Beta (alpha absorbs blue, but a violet-blue).

Question 16

Which photosystem?
* Center contains chl P700
* Absorbance peaks at 700nm

Answer 16

Photosystem 1

Question 17

Which photosystem?
* Center contains chl P680
* Absorbance peaks at 680nm

Answer 17

Photosystem 2

Question 18

what is the chemical reaction/formula for photosynthesis?

Answer 18

6CO2 + 6H2O —–> C6H12O6 + 6O2

Question 19

What is a biproduct of photosynthesis?

Answer 19

Oxygen

Question 20

Which is the real chemical reaction for photosynthesis?
A) C6H12O6 + 6O2 —–> 6CO2 + 6H2O
B) 6CO2 + 6H2O —–> C6H12O6 + 6O2
C) 6C2H4O + 6H2O —–> C6H14O6 + 6O2
D) C6H14O6 + 6O2—–> 6C2H4O + 6H2O

Answer 20

B

Question 21

Is photosynthesis ender or exer gonic

Answer 21

Endergonic

Question 22

On what do light dependent reactions occur?

Answer 22

Thylakoids

Question 23

What do light dependent reactions produce?

Answer 23

ATP and NADP-H

Question 24

What are the other names for light independent reactions?

Answer 24

Calvin cycle or dark reactions

Question 25

In what do light independent reactions occur?

Answer 25

Stroma

Question 26

What are the material and product of the light dependent reactions?

Answer 26

H2O is raw material CO2 is biproduct

Question 27

What are the material and product of light independent reactions?

Answer 27

CO2 is raw material Sugar is product

Question 28

What is photolysis of water?

Answer 28

Water split by an enzyme in oxygen-evolving complex

Question 29

What are the steps in photolysis of water?

Answer 29

* 2 electrons (source needed for elec trans chain) * Replace e- lost by p680 * 2 protons * Some H+ used to form NADP-H * Oxygen atom * Combines with second to form O2

Question 30

in PS2, what accumulates in the stroma?

Answer 30

ATP

Question 31

in PS1, what accumulates in the stroma?

Answer 31

NADP-H

Question 32

What are the steps in photosystem 2? (copy paste)

Answer 32

o P680 transfers e- to a primary electron acceptor o Lost e- replaced by those from water o Acceptor shuttles e- to elec trans chain o E- move down elec trans chain & release free energy o Energy powers H+ pumps which move H+ into thylakoid lumen o Concentration of H+ creates membrane potential o H+ return to stroma through ATP synthase via chemosmosis o This flow of H+ regenerates ADP>ATP called photophosphorylation

Question 33

What are the steps in photosystem 1? (copy paste)

Answer 33

o P700 transfers e- to a primary electron acceptor o Lost e- replaced with those from PS-2 o Acceptor shttles electrons to a second elec trans ch o Elec trans ch does not pump H+ o NADP+ reduced to NADP-H o Reduced by receipt of 2e- + 1H+ o By enzyme NADP+ reductase

Question 34

What does linear electron flow create and which PS does it use?

Answer 34

* Uses both photosystems * Makes ATP, NADPH, and O2

Question 35

What does cyclic electron flow create and which PS does it use? (plus some other info)

Answer 35

* Only uses PS1 * Makes only atp. No NADPH or O2 * Excited E- can take a different path * Excited e- are cycled to the first elec tr ch rather than 2nd * Cp shifts to cyclic path when atp drops and NADPH rises * More ATP than NADPH is needed in calvin cycle

Question 36

What is the calvin cycles job?

Answer 36

To complete the synthesis of sugar

Question 37

What are the key players of the calvin cycle?

Answer 37

o NADP-H (Nicotinamide adenine dinucleotide) o RuBisCO (Ribulose-1,5-bisphosphate carboxylase/oxygenase) o RuBP (Ribulose bisphosphate) o 3-PGA (Phosphoglyceria acid) o G3P (Glyceraldehyde 3 phosphate)

Question 38

What is the most abundant enzyme on earth?

Answer 38

Rubisco

Question 39

What are the 3 stages of the calvin cycle?

Answer 39

o Carbon fixation o Reduction phase o Regeneration phase

Question 40

What are the steps in carbon fixation?

Answer 40

 A co2 molecule enters cycle  Combines with RuBP to form 6 carbon molecule  Reaction catalyzed by RuBisCO  Molecule quickly breaks into two 3-PGA

Question 41

What are the steps in the reduction phase?

Answer 41

 Reduction is gain  3-PGA mols converted to G3P  Reaction uses ATP + NADP-H  NADP-H is e- donor: a reducing agent

Question 42

What are the steps in the regeneration phase?

Answer 42

 Some G3P exit cycle from glucose  Others recycled to regenerate RuBP acceptor  Requires ATP + complex network of reactions

Question 43

Summarize the calvin cycle

Answer 43

o 3 turns of cycle to make 1 G3P o Key molecules for three turns:  3CO2 + 3RuBP make 6 G3P  1 G3P mol exits cycle & makes glucose  5 G3P mols regenerated to 3RuBP  2ATP * 9 ATP hydrolyzed to 9 ADP * 6 needed during reduction, 3 for regeneration  3 NADPH * Reducing agent * NADPH oxidized to 6 NADP+ * All during reduction step

Question 44

Advantages and disadvantages of C3 photosynthesis?

Answer 44

 RUBISCO inefficient  Fixation slow  Stomata open fir co2 so water can escape  H2O gradient >> CO2 gradient  H2O losses can be high  Inefficient except where water is plentiful

Question 45

What are the taxa, fixation, and fixation reaction for C3 photosynthesis?

Answer 45

o Taxa (class)  Most vascular plants o Fixation + Calvin cycle  Both occur in mesophyll during the day o Fixation reaction  Co2 + rubp + rubisco - PGA  PGA enters calvin cycle

Question 46

What are the taxa, fixation, and fixation reaction for C4 photosynthesis?

Answer 46

o Taxa  Angiosperms, mostly monocots grasses, corn, and sugar cane o Fixation & Calvin cycle  Fix in mesophyll cells  CC in bundle sheath cells  Both during day o Fixation reaction  CO2 + PEP + PEP carboxylase -> 4-C acid  Acid enters sheath cells + releases CO2  CO2 then combines with RuBP

Question 47

Advantages and disadvantages of C4 photosynthesis?

Answer 47

 PEP carboxylase has high affinity for CO2  Fewer stomates open  less h2o loss  Better than C3 in high temps + low atmospheric CO2

Question 48

What are the taxa, fixation, and fixation reaction for CAM photosynthesis?

Answer 48

o Taxa  Crassulaceae (succulents, cacti, and pineapple) o Fixation + calvin cycle  Both occur in mesophyll cells  Fix during night  Calvin cycle during day o Fixation reaction  CO2 + PEP + PEP carboxylase  4 carbon acid  Acid accumulates at night  Used in calvin cycle during the day

Question 49

Advantages and disadvantages of CAM photosynthesis?

Answer 49

 Stomata open at night when cooler  Low PSN rates but conserves H2O