BIOL214 Lecture Notes - Lecture 11: C4 Carbon Fixation, Carbon Fixation, Light-Independent Reactions

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salmoncrocodile477

6 Aug 2018

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Describe the role of rubisco and how its actvity is regulated. Explain what photorespiration is and why it occurs. Chloroplasts: role of chloroplasts in plants is to capture light energy and onvert it to chemical energy. Co2 assimilation (the calvin cycle: 1xc per cycle, but need 3 cycles to produced glyceraldehyde 3 phosphate, therefore, therefore 9x atp and 6x nadp. Stage 1: carbon fixation: ru15bp 2x pga. 2-carboxyarabinitol 1 phosphate: noctural inhibitor of rubisco, produced during darkness in some plants, transition state analogue that binds to rubisco and inhibits activity, when light returns, it is either broken down or expelled by rubisco activase. Rubisco activase activates rubisco: co2 is a substrate of rubisco, rubisco also required a bound co2 for catalytic activity, binding of ribulose 1,5 bisphophate and 2 carboxyarabinitol 1 phosphate prevents rubisco activation, rubisco activase overcomes this. In some species rubisco activase is activated by light via a redox mechanism.

Related Questions

Question 1 The membrane structures inside the chloroplast are called the ______, while the fluid surrounding the stacks of membrane is called the ______.
a. stroma; thylakoid
b. thylakoid; cytosol
c. thylakoid; stroma
d. thylakoid; matrix
e. matrix; thylakoid

Question 2 What is considered the ultimate source of energy for living things on Earth?
a. the sun
b. electrons
c. green plants
d. oxygen
e. ATP

Question 3 Why do most plant leaves appear green?
a. They contain a lot of starch which has a green color.
b. They have chloroplasts which absorb green light for photosynthesis.
c. During the light reaction phase carbon dioxide is converted to oxygen which emits green light.
d. They have chloroplasts which absorb all colors of light except for green, which is reflected.
e. During the dark reaction phase water is converted to oxygen which emits green light.

Question 4 Plants perform only photosynthesis, not respiration. True False

Question 5 What is the primary purpose of the light reactions of photosynthesis?
a. to create oxygen gas
b. to produce glucose
c. to convert solar energy to chemical energy (in the form of ATP and NADPH) to power the dark reactions
d. to remove carbon dioxide gas from the atmosphere
e. to create water

Question 6 The light dependent reactions occur in the:
a. mitochondrial membrane.
b. mitochondrial matrix.
c. stroma.
d. thylakoid membrane.
e. cytosol.

Question 7 The energy to run the dark reactions of photosynthesis is produced _________.
a. by the CO2 initially used in the dark reactions.
b. during glycolysis
c. during the light reaction phase
d. during the Krebs cycle
e. during anaerobic respiration

Question 8 Which of the following substances could be totally eliminated and not interfere with the process of photosynthesis?
a. O2
b. H2O
c. light
d. CO2

Question 9 What product(s) do plants produce during photosynthesis that is/are used by humans and other animals?
a. carbon dioxide
b. carbon dioxide and water
c. glucose and oxygen
d. glucose
e. oxygen

Question 10 Only plants can carry out photosynthesis. True False

Question 11 During the light reactions of photosynthesis, ...
a. oxygen is produced from H2O.
b. glycolysis occurs.
c. the Krebs cycle occurs.
d. CO2 is combined into glucose.
e. ATP is broken down to ADP + P

Question 12 The reactants of photosynthesis are:
a. sugar.
b. sugar and water.
c. O2 and CO2
d. O2 and sugar.
e. CO2 and water.

Question 13 During the dark reaction phase of photosynthesis in plants...
a. ATP is created.
b. H+ ions are moved into the stroma from the matrix.
c. molecules of CO2 are combined into sugar.
d. H2O is split into oxygen and H+.
e. solar energy is converted to chemical energy.

coffeelion96

5: chloroplast kept in the dark can continue to make sugar is provided with

A: NADPH, CO2, and ADP

B: CO2, and ATP

C: NADPH, ATP, and CO2

D: NADPH and ATP

E: water and ATP

7: C3 plants are more susceptible to photorespiration than either C4 or CAM plants. Why do most plants lack the C4 pathway??

A: Switching between C3, C4, and CAM photosynthesis is very difficult for most plants

B: ?Rubisco is more efficient in C3 plants when compared to rubisco of C4 and CAM plants

C: Most plant species do not have vacuoles in their cells to store the malate generated from CO2 taken in during the night.

D; : Photorespiration is not a serious problem for most plants.?

E: There is an energetic cost to C4 and CAM pathways that only makes them advantageous in very hot and/or arid environments.?

8: In Engelmann's classic experiment, why were the oxygen-requiring bacteria clustered around the regions of Spirogyra algae that were bathed in red, blue, and violet light?

A; The bacteria were immobile and that is where Engelmann happened to place them

.?B; The most energy-rich wavelengths of light are found at the edges of visible and nonvisible light (ultra

violet and infrared)

C; Photosynthesis is most active in those wavelengths of light and thus more oxygen is consumed by the algae in those regions.

D: Photosynthesis is most active in those wavelengths of light and thus more oxygen is produced by the algae in those regions.?

E: : Chlorophyll is green and thus reflects green light.

9: In any experiment, changes to the dependent variable based on the manipulations of the independent variable are measured. When determining the action spectrum of a given plant, what is the independent variable and what is the dependent variable?

A: independent = rate of O2 release in photosynthesis; dependent = wavelength?

B: ?independent = absorption of light; dependent = wavelength

C: independent = wavelength; dependent = rate of O2 release in photosynthesis?

D: independent = wavelength; dependent = absorption of light?

E: independent = rate of O2 release in photosynthesis; dependent = absorption of light

11: In order to elucidate the Calvin cycle, Calvin and his colleagues used two-dimensional paper chromatography to analyze the presence of different molecules under different conditions. What did they conclude from the accumulation of RuBP when CO2 levels were low??

A: CO2 serves as a non-competitive inhibitor of rubisco.

B: RuBP is the last substrate to react in the Calvin cycle.

C: RuBP only reacts with CO2 when concentrations of ATP are low

D: RuBP is the first substrate to react with CO2

E: RuBP only reacts with CO2 in the sunlight

12: Why isn't oxygen produced by organisms that perform anoxygenic photosynthesis?

A; their membranes lack ATP synthase?

B; They use a different enzyme for the initial reactions of the calvin cycle

C: they use electrons donors other than water

D: their photosystem do not utilize the calvin cycle

E: their chorophyll contains an iron rather than magnesium

tanelk218

Review question its 1-12 sorry for the xtra questions in the bottom

1:2D chromatography is so named because ____

A: there are two steps: labeling with a radioactive marker and separation via chromatography

B: two different solutions are used in the paper chromatography

C: the molecules are separated into a linear arrangement, meaning two dimension

D: two different types of radioactive markers must be used

E: the process separates the molecules in two direction, first along the X and then along the Y axis

2: :Which molecule(s) regulate(s) photosynthesis by sensing the metabolic status of the chloroplast and regulating proton flow out of the thylakoid lumen??

A: ATP synthase

B: antenna complex

C: Chrolophyll B

D: carotenoids

E: chlorphyll A

3: When does A CAM plant take in atmospheric CO2?

A: daytime only

B: Summer day

C: winter day

D: nighttime only

E: anytime the calvin cycle is happening

4: Where can you find ATP synthase in a plant cell ?
A; in the thylakoid membrane only

B: in the mitochondial inner membrane

C: both thylakid and inner mitochondria membrane

D: only in the nucleus

E: embedded in the plasma membrane

5: chloroplast kept in the daek can continue to make sugar is provided with