Plants of the C4 family lack the enzyme RuBisCo. Bundle-sheath cells surround vascular bundles rather than contain this protein. As a result, in plants with C4 cells, Calvin cycles do not take place in bundle-sheath cells. CO2 is mainly accepted into cells of the mesophyll by phosphoenol pyruvate, which is a three - carbon compound. In this reaction, it is transformed into oxaloacetic acid (OAA), a four-carbon compound. Further conversion of OAA to malic acid occurs. The Calvin cycle links malic acid to CO2 by decarboxylation in bundle-sheath cells. RuBisCo can no longer function as an oxygenase because of this.
Answered by Abhisek | 1 year agoGive a comparison between the following:
(a) C3 and C4 pathways
(b) Cyclic and non-cyclic photophosphorylation
(c) Anatomy of leaf in C3 and C4 plants
Figure shows the effect of light on the rate of photosynthesis. Based on the graph, answer the following questions:
(a) At which point/s (A, B or C) in the curve is light a limiting factor?
(b) What could be the limiting factor/s in region A?
(c) What do C and D represent on the curve?
Look at leaves of the same plant on the shady side and compare it with the leaves on the sunny side. Or, compare the potted plants kept in the sunlight with those in the shade. Which of them has leaves that are darker green? Why?
Why is the colour of a leaf kept in the dark frequently yellow, or pale green? Which pigment do you think is more stable?
Suppose there were plants that had a high concentration of Chlorophyll b, but lacked chlorophyll a, would it carry out photosynthesis? Then why do plants have chlorophyll b and other accessory pigments?