Question

What is the difference between photosystem 1 and photosystem 2?

Answer 1

Photosystems:

1. Photosystems are functional units for photosynthesis that are defined by specific pigment organization and association patterns.
2. Their task is the absorption and transfer of light energy, which implies electron transfer.
3. Photosystems are physically located in thylakoid membranes.
4. Although all photosystem pigments may absorb photons needed in photosynthetic activities, only a few pigment molecules are actually engaged in the conversion of photon light energy to electrochemical energy.
5. The photosystem is primarily composed of two types of pigments: chlorophyll and accessory pigments.
6. Types of photosystems are Photosystem 1 and photosystem 2.

Photosystem 1: These are located on the outer surface of the thylakoid membrane, which synthesizes ATP and NADPH.

Photosystem 2: These are located on the inner surface of the thylakoid membrane, which Synthesizes ATP.

Difference between photosystem 1 and photosystem 2:

Photosystem 1	Photosystem 2
1). Photocenter is P700.	1). Photocenter is P680.
2). Pigments absorb longer wavelength of light i.e., greater than 680 nm.	2). Pigments absorb shorter wavelength of light i.e., less than 680 nm.
3). Uses light energy to convert NADP to NADPH2.	3). Uses light energy to dissociate water molecules.
4). Has less number of proteins in the core complex.	4). Has multi-subunit complex in the core complex.
5). Is the center for iron-sulfur type reaction.	5). Is the center for quinone-type reaction.
6). Has more chlorophyll a than chlorophyll b.	6). Has more chlorophyll b than chlorophyll a.
7). Not involved in the photolysis of water.	7). Involved in the photolysis of water.
8). Participates in cyclic and non-cyclic photophosphorylation.	8). Participates in non-cyclic photophosphorylation.
9). Contains Chlorophyll A-695, Chlorophyll A-670, Chlorophyll A-680, Chlorophyll A-700, Chlorophyll B, carotenoids.	9). Contains Chlorophyll A-670, Chlorophyll A-660, Chlorophyll A-695, Chlorophyll A-680, Chlorophyll A-700, Chlorophyll B, phycobilin, xanthophylls.