Chapter 10 Parts 3 & 4

Question 1

What do the stoma control?

Answer 1

They can open and close to allow for the diffusion of gas into and out of the cell.

Question 2

How is carbon involved in the Calvin cycle.

Answer 2

CO2 enters the cell via the stoma and then is reduced to make sugars.

Question 3

Where is the Calvin cycle taking place?

Answer 3

• The stroma of the chloroplast.

- the liquid matrix of the chloroplast

Question 4

What are the phases of the Calvin cycle?

Answer 4

1. ) Fixation
2. ) Reduction
3. ) Regeneration

Question 5

Describe the fixation phase of the Calvin cycle?

Answer 5

• grab gases from the atmosphere ( CO2) and stick them to organic molecules within the cell.
• .) 3RuBP + 3CO2 —–> 6 3PGA

Question 6

Where does the energy from the reduction phase of the Calvin Cycle come from?

Answer 6

• Products of the light dependent reactions, these occur prior to the Calvin Cycle.
• Chemical energy in the form ATP and NADPH

Question 7

Describe the reduction phase of the Calvin Cycle?

Answer 7

• The product from fixation: ( 2 3PGA) is put into a reaction with the products from the light dependent reactions (ATP & NADPH).
• To form two organic molecules ( 5G3P & 1 G3P)
• 2 3PGA + 6ATP & 6NADPH —-> 5G3P & 1 G3P

Question 8

What did Dr.Reedy say the ATP and NADPH were created for via the light dependent reactions?

Answer 8

• Motha
• Fuckin
• CARBON REDUCTION

Question 9

t/f : all steps of the Calvin Cycle occur in the same place?

Answer 9

True, they all occur in the stroma.

Question 10

What takes place in the regeneration phase of the Calvin Cycle?

Answer 10

• Some products of the previous steps are used to regenerate RuBP.
• 5G3P + 3ATP —-> 3RuBP

Question 11

What do the 3CO2 that we begin the Calvin Cycle with tell us?

Answer 11

• Since the product is G3P, which is a carbon compound, we known that serves to build other organic molecules.
• Therefore, if you bring 3 carbons into the system you are able to pull out three to get back to where you started.

Question 12

T/F: Rubisco is the most abundant enzyme on the planet?

Answer 12

True

Question 13

What does Rubisco do?

Answer 13

• It is a massive enzyme used to catalyze the fixation phase of the Calvin Cycle.
• Grabs a CO2 and binds it to the end of a 5 carbon compound RuBP.

Question 14

In the fixation phase of the Calvin Cycle what happens after the RuBP has a CO2 bound to its end?

Answer 14

• Forms a 6 carbon complex that is cut in half to form 2

3PGA.

Question 15

How many active sites does the enzyme, Rubisco, contain?

- What does this mean in terms of its effectiveness?

Answer 15

• 8
• 2.) It can potentially catalyze 8 of these reactions at one time, thus “ making it an absolute fucking Pablo Escobar”- Marcus Reedy PhD.

Question 16

What provides the energy in the first step of the Reduction phase?
i.e. the 3PGA needs what to move to the second step?

Answer 16

• 6 ATP

Question 17

What provides the energy in the second step of the Reduction phase allowing for the reduction of carbon to form G3P?

Answer 17

Energy from 6NADPH

Question 18

Out of the 6 G3P that are produced from the reduction phase, how many are pulled out to make other organic molecules?
- What are examples of those other molecules that are being made from G3P + only Jesus knowns?

Answer 18

1. ) 1 is removed.

2. ) Fructose, glucose, etc.

Question 19

Where do the 5 remaining G3P go?

Answer 19

• They enter the regeneration phase of the Calvin Cycle.

- This plus in addition to ATP is used to regenerate RuBP.

Question 20

What is the purpose of the regeneration step to the Calvin Cycle?

Answer 20

• Regenerate RuBP so the cycle may continue.

Question 21

How many times does the Calvin Cycle have to occur?

- Why

Answer 21

1. ) 3 cycles per influx of 3 CO2
2. ) this is because we only remove one G3P per cycle and we need to remove 3 G3P to create a full one.
   - A full one allows for the creation of other organic molecules.

Question 22

What was Marcus’s PR Bench Press?

- With a greater concentration of mitochondria located in his pec’s and tri’s what did this equate to?

Answer 22

• A shear minimum of 675 pounds

- Thor’s strength and an absurd amount of dates from women in the biology department

Question 23

What do the sugars made from the Calvin cycle do?

Answer 23

• They are used to make sucrose or starches

Question 24

What is the chemical equation if Rubisco is in the presence of lots of O2 molecules?
i.e. what reaction is taking place in the fixation step of the Calvin Cycle?

Answer 24

RuBP + O2 —-> 3-phosphoglycerate( used in Calvin Cycle) + 2-phosphoglycolate (when processed CO2 is released and ATP is used)

Question 25

When does oxygen bind to the Rubisco?

Answer 25

During photorespiration

Question 26

What is the problem with the 2-phospohglycolate produced when O2 + RuBP occurs?

Answer 26

- it requires a fair amount of energy ( ATP) to break it down, and it isn't very useful in the cell. - Further it hinders the effectiveness of the photosynthetic ability of the plant.

Question 27

If their is a massive influx of oxygen what will likely be carried out?

Answer 27

- Photorespiration:

Question 28

Why is photorespiration a problem for plants that live in prolonged extremely dry conditions?

Answer 28

- Yes, when their stomata open CO2 can diffuse in and O2/H2O out, but plants also loose water vaper. - Water vapor loss is significant: since it is a prolonged period of dryness the plant can begin to desiccate.

Question 29

How do plants in extremely dry conditions keep from desiccating? - What does their counteraction do?

Answer 29

- They close their stomata for long periods of time. 2. ) because the stomata are closed no more CO2 can diffuse in and O2/H2O can't get out - This leads to photorespiration.

Question 30

What is the alternative pathway that plants in prolonged dry conditions use instead of photorespiration?

Answer 30

The C4 pathway: - There is use of an alternate enzyme PEP carboxylase. - This takes CO2 from the atmosphere and places it on a 3-Carbon compound generating a four carbon acid. - -----------------------------------------------------------

Question 31

What is the chemical equation of the C4 pathway in plants?

Answer 31

- C4 plants: 3-Carbon + CO2 -------------------------------> 4-carbon organic compound PEP carboxylase acid

Question 32

What is the chemical equation of the C3 pathway in plants?

Answer 32

- C3 plants: RuBP + CO2 -------------------------->2 3-phosphoglycerate Rubisco ( 3-carbon organic acid)

Question 33

What are the two broad categories of plants that use the C-4 pathway of carbon fixation? - Also, describe the differences between the two.

Answer 33

C4 plants: mesophyll cells that contain PEP Carboxylase carry out these reactions. - The product, a four carbon compound is eventually broken down, and the CO2 is re-released to diffuse into the adjacent bundle sheath cells. - These cells carry out normal photosynthesis, as light independent reactions occur here and meaning there is no excess of O2. -------------------------------------------------------------------- CAM plants: They open up their stomata at night using PEP Carboxylase, when it is safe ( sun involves water vapor loss). - At night they open the Stomata and CO2 enters the cell. - PEP Carboxylase fixes the CO2 and generates a 4-C compound. - It does through the duration of the night and builds up large quantities of the 4-C compound. - Then, during the day the 4-C compound is broken down to CO2 and the Calvin cycle can occur. ------------------------------------------------------------------- Commonalties: Both contain rubisco, but carry out C4 pathway first.

Question 34

Which cells near the leaf surface contain the PEP carboxylase? In these cells what other type of reaction occurs here?

Answer 34

- The mesophyll cells. | - The light dependent reactions.

Question 35

Which cell near the leaf surface contains rubisco? | In these cells what other type of reaction occurs here?

Answer 35

bundle sheath cells. They carry out light independent reactions, therefore they lack oxygen and they can continue to carry out photosynthesis.

Question 36

CAM plants vs C4 plants? | examples?

Answer 36

``` CAM = desert shit C4 = shit in Omaha- Dr. Sneedy ```