Question

Photosynthesis has two main parts (light-independent and light dependent). Which descriptions can BEST be used to explain photosystem I and photosystem II? I. Light-independent reaction II. Light-dependent reaction III. Products are ATP and NADPH. IV. Occurs in the thylakoid membranes V. Occurs in the stroma VI. Photolysis of water occurs during this stage. A) I, V, and VI B) I, IV, V, and VI C) I, II, III, and V D) II, III, IV, and VI

Answer 1

Answer:

D

Explanation:

In photosystems, the reactive center gives of an electrons that are conveyed along a chain of pigments that harness the energy of the electrons to pump H+ ions from the stroma into the thylakoid – hence creating a proton motive force that will be used to generate ATPs by ATP synthase enzyme. Eventually the electrons are passed to NADP+ that is reduced to NADPH (2 electrons per molecule). The photolysis of a water molecule by sunlight gives H+ and O- and 2 free electrons used to replace the lost electrons in the photosystems reactive center. This whole process is referred to as photophosphorylation.

Answer 2

Answer:

Option D explain the photo system I

Explanation:

In a light independent reaction, light energy from sun is essential to carry out photosynthesis and produce energy molecules such as ATP and NADH. These reactions take place within the thylakoid membrane of chloroplasts. When the sunlight from the sun is taken by the green leaves of the plant it is initially used to break down the water molecules that releases free electron  

Hence, option D is correct