29 In noncyclic photosynthesis select all that apply 30 A ph

29.

In noncyclic photosynthesis, (select all that apply)

30.

A photosystem (select all that apply)

31.

Steps of the Calvin Cycle include (select all that apply)

32.

C4 photosynthesis (select all that apply)

35.

Structures associated with the chloroplast include (select all that apply)

36.

During the light dependent reactions of photosythesis,

39.

Endergonic reactions

40.

ATP (select all that apply)

44.

Factors that influence the rate of enzyme activity include (select all that apply)

46.

Functions of membrane proteins include

Solution

29. The phosphorylation of ADP to ATP in the presence of sunlight is called photophosphorylation. Non-cyclic photophosphorylation, occurs in the frets or stroma lamellae. The electron obtained from the photolysis of water moves in non cyclic manner. The electron is accepted by NADP. In this reaction both ATP and NADPH are produced. Oxygen is evolved as a bye product.

30. Photosystems are functional units involved in photosynthesis. They are found in the thylakoid membranes of plants. There are two types of photosystems-PS-I and II. PS-I consist largely of chlorophyll-a, molecules. Photosystem II contains both chlorophyll a and b. At the centre of a photosystem is the reaction center, which absorbs light to reduce molecules. This centre is a complex of several proteins, pigments (carotenoids) and other co-factors which in coordination perform the photosynthesis reactions.

31. The Calvin cycle reactions consist of three main stages

a. Carbon fixation- Carbon dioxide combines with a five-carbon acceptor molecule, ribulose-1,5-bisphosphate (RuBP), the reaction is catalyzed by the enzyme RuBP carboxylase/oxygenase, (rubisco) to form 3-phosphoglyceric acid (3-PGA).

b. Reduction. 3-PGA is reduced into glyceraldehyde-3-phosphate (G3P) by ATP and NADPH, which donates electrons.

c. Regeneration. G3P is converted into glucose, while some molecules of G3P is recycled to regenerate the RuBP molecule.

32. C₄ photosynthesis or the Hatch-Slack pathway is one of three known processes for carbon fixation. C₄ fixation is believed to have evolved lately. In C4 plants PEP carboxylase fixes CO₂ to make oxaloacetic acid (OAA) in the mesophyll cells. The OAA then makes malate (4 carbons), which enters bundle sheath cells and releases the CO₂. The extra energy, required for the additonal step is provided by ATP. So C₄ plants are able to fix carbon more efficiently under stress conditions like drought, high temperatures, and limited CO₂.In C3 plants, where Rubisco is the CO₂ acceptor, due to its dual carboxylase and oxygenase activity, loss of substrate and energy by photorespiration, can occur. But in C4 plants such loss is avoided. Hence photorespiration is avoided.

33.Chloroplast is the cell organelle responsible for photosynthesis. It has an inner and outer membrane, with an intermediate space in between. Inside are stacks of thylakoids, called grana, suspended in stroma, the dense fluid inside of the chloroplast. These thylakoids contain the chlorophyll necessary for photosynthesis. The space inside the the thylakoid is called the thylakoid space.