Chapter 10 (Photosynthesis)

Question 1

Is photosynthesis exergonic or endergonic?

Answer 1

endergonic because it is absorbing energy

Question 2

In photosynthesis, what does light energy turn into?

Answer 2

chemical energy

Question 3

Why does photosynthesis break down water?

Answer 3

to grab electrons to put them back into organic molecules and have oxygen as a waste product

Question 4

Where does photosynthesis take place?

Answer 4

chlorophyll

Question 5

Where is the granum located?

Answer 5

inside the chloroplast (oval shapes stacked on top of one another)

Question 6

What is a granum?

Answer 6

a stack of thylakoids (those oval shapes)

Question 7

What is a chlorophyll?

Answer 7

a photoreceptor that captures light energy

Question 8

Where is the chlorophyll located?

Answer 8

dots located on thylakoid membrane (anchored in)

Question 9

What is the thylakoid membrane?

Answer 9

the membrane around the thylakoid

Question 10

What type of ring does chlorophyll have?

Answer 10

porphyrin ring (Mg in the middle)

Question 11

Where does the reaction happen in chlorophyll on the porphyrin ring?

Answer 11

at the R group, also has a hydrocarbon tail to anchor

Question 12

How do the electrons get energized in photosynthesis as the chlorophyll ring gets to a higher energy structure?

Answer 12

by light energy

Question 13

What is the energy transfer in chlorophylls called?

Answer 13

resonance energy transfer

Question 14

What forms does chlorophyll come in?

Answer 14

chlorophyll a and chlorophyll b

Question 15

What is the differences between chlorophyll a and chlorophyll b?

Answer 15

chlorophyll a R group is CH3

chlorophyll b R group is CHO

Question 16

What color is chlorophyll good at absorbing?

Answer 16

violet to blue and yellow to red, NOT GREEN

Question 17

What are accessory pigments?

Answer 17

helping chlorophyll absorbing light, recognized by colors

Question 18

Where are accessory pigments located?

Answer 18

on the thylakoid membranes

Question 19

What are carotenoids?

Answer 19

accessory pigments (beta carotene), orange color

Question 20

What are another type of catenoid?

Answer 20

accessory pigments, xanthophyll, comes as lutein and expressed as yellow

Question 21

What vitamin do we get beta-carotenes from?

Answer 21

vitamin A

Question 22

Why is vitamin A so important for humans?

Answer 22

beta carotenes help with bringing retinoic acid to the retina so that the retina can capture the light energy with photoreceptors on the membrane and generate membrane potential for a neuron signal

Question 23

What energy do we see as the accessory pigments absorb light energy?

Answer 23

You see the energy it does NOT absorb

Question 24

What are anthocyanins?

Answer 24

accessory pigments manufactured from sugar rings sometimes, expressed as purple/red

Question 25

When the leaf starts dying and the chlorophyll starts dying rapidly, what happens?

Answer 25

the leftover is the changing of colors since the accessory pigments take longer to degrade

Question 26

What are tannins?

Answer 26

leave the brown color after the rest of the pigments die

Question 27

What is carbon fixation?

Answer 27

taking carbon in the gaseous form fixing it into G3P phosphate

Question 28

What are the stages of photosynthesis?

Answer 28

light-dependent reactions aka photophosphorylation | Calvin cycle

Question 29

What is the stroma?

Answer 29

fluid inside the chloroplast (where Calvin cycle takes place)

Question 30

What does the thylakoid membrane act like in regards to cellular respiration?

Answer 30

the electron transport chain

Question 31

In the thylakoid membrane, what is the first photosystem?

Answer 31

photosystem II w/ p680

Question 32

In the thylakoid membrane, what is the second photosystem?

Answer 32

photosystem I w/ p700

Question 33

What is in between photosystem II and I?

Answer 33

complex (etc)

Question 34

What happens during the light dependent reaction?

Answer 34

photons electrons excite chlorophyll molecules to get into a high energy stage, as the energy stage lowers the H+ get pumped into the thylakoid space to create a gradient for ATP synthase to generate ATP

Question 35

What is located after photosystem I?

Answer 35

ATP synthase

Question 36

What are the light dependent reactions called?

Answer 36

photophosphorylation

Question 37

What is the final electron accepter for photophosphorylation?

Answer 37

NADP+

Question 38

Where does H2O split and become O2?

Answer 38

near photosystem II, called oxygen-evolving complex

Question 39

Why does H2O get split?

Answer 39

donate electrons and hydrogens to replace the ones that got excited and left from photosystem II

Question 40

What does photophosphorylation produce?

Answer 40

ATP and NADPH

Question 41

What are reaction centers?

Answer 41

the chlorophyll molecules at the "center" that get excited after electrons keep hitting it and after absorbing light

Question 42

What part of photophosphorylation is noncyclic?

Answer 42

photosystem II, ETC

Question 43

What part of the photophosphorylation is cyclic?

Answer 43

photosystem I

Question 44

What is the first step in photophosphorylation?

Answer 44

photons absorbed in photosystem II, energy excites electrons and gets to the reaction enter P680 to boost electrons to highest level

Question 45

What is the second step in photophosphorylation?

Answer 45

excited electrons passed to electron acceptor (PQ) and waters gets split to H and O2 to replaces the lost electron in photosystem II

Question 46

What is the third step in photophosphorylation?

Answer 46

electron acceptor brings excited electron to etc, etc denergizes the molecules and pump out 4 H+

Question 47

What is the fourth step in photophosphorylation?

Answer 47

PC (electron acceptor) brings de-eergized electron to photosystem I, photons hit photosystem I and energizes electron to get to P700

Question 48

What is the fifth step in photophosphorylation?

Answer 48

electrons travels down another short etc via PC and NADP+ goes to NADPH and the protons go through ATP synthase to make ATP

Question 49

Where does the Calvin Cycle take place?

Answer 49

the stroma

Question 50

What is the purpose of the Calvin cycle?

Answer 50

to fix carbon and make 3-carbon sugars

Question 51

What fuels the Calvin Cycle?

Answer 51

NADPH and ATP

Question 52

What is the first step in the Calvin Cycle?

Answer 52

CO2 + ribulose 1, 5 bisphosphate (RuBP, 5 carbon sugar ring) to make 2 molecules of 3-phosphoglycerate

Question 53

What is the second step in the Calvin Cycle?

Answer 53

phosphoglycerate kinase breaks ATP to ADP + P -----> 1,3 diphosphoglycerate

Question 54

What is the third step in the Calvin Cycle?

Answer 54

G3P dehydrogenase breaks NADPH to NADP+ -----> G3P (3, carbon sugar)

Question 55

What is the fourth step in the Calvin Cycle?

Answer 55

1 G3P go to glucose and 5 G3P get converted into ribulose 1,5 bisphosphate via kinase (ATP to ADP +P)

Question 56

How many CO2 need to go through the calvin cycle for one G3P to get out?

Answer 56

3 CO2

Question 57

When three CO2 molecules enter, how many G3P molecules made?

Answer 57

6 G3P (1 goes to glucose, 5 get converted to 1,5 ribulose bisphosphate)

Question 58

mnemonic for Calvin cycle

Answer 58

``` rick (rubisco) please (3 - phosphate) bake (1,3 bisphosphate) good (G3P) raisins (ribulose 1,5 bisphosphate) ```

Question 59

What does the Calvin Cycle produce?

Answer 59

sugar from CO2, using ATP and NADPH

Question 60

What does the Calvin cycle begin with?

Answer 60

carbon fixation, incorporating CO2 into organic molecules

Question 61

Does the Calvin cycle depend on the light directly?

Answer 61

no they are considered light-independent because they indirectly use light