BIOL 2905 Chapter Notes - Chapter 9.2: Oxaloacetic Acid, Cytosol, Photorespiration

32 views2 pages

lavendershark790

23 Oct 2017

School

York University

Department

Biology

Course

BIOL 2905

Professor

Dasantila Golemi- Kotra

For unlimited access to Textbook Notes, a Class+ subscription is required.

Document Summary

C4 plants pathway: plants in hot climates have evolved mode of carbon fixation that minimizes, co2 initially binds to pep (3-c) producing oxaloacetate (4-c), which is reduced to malate. Malate is transported to site of calvin cycle where its converted to pyruvate (3-c), releasing co2. Levels of are higher, which inhibits oxygenation reactions. Thus, minimizing photorespiration: c4 process occurs in mesophyll cells. Malate intermediate from c4 cycle diffuses from mesophyll cells to bundle sheath cells, located deeper in tissue where 02 conc: for each turn in c4 pathway, additional atp is required to regenerate pep. More atp requirement is met by extra sunlight c4 metabolism is found in: called c4 b/c 1st product is a 4-carbond molecule rather than 3-carbon. During day, the malate diffuses from vacuoles into cytosol where its oxidized to pyruvate & co2 is released in high concentration.

Related Questions

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