What is the Difference Between Photosystem 1 and Photosystem 2?
🆚 Go to Comparative Table 🆚Photosystem 1 (PS1) and Photosystem 2 (PS2) are multi-protein complexes involved in oxygenic photosynthesis. They contain pigments that help collect light energy and play a crucial role in the light-dependent reactions of photosynthesis. The key differences between PS1 and PS2 are:
- Location: PS1 is located on the outer surface of the thylakoid membrane, while PS2 is located on the inner surface of the thylakoid membrane.
- Photocenter: The photocenter of PS1 is called P700, while the photocenter of PS2 is called P680.
- Light Absorption: PS1 absorbs light of longer wavelengths (> 680 nm), while PS2 absorbs light of shorter wavelengths (< 680 nm).
- Reaction: PS1 uses light energy to convert NADP+ to NADPH2, while PS2 uses light energy to dissociate water molecules.
- Protein Complex: PS1 has a comparatively smaller number of proteins (about 15 subunits) in its core complex, while PS2 has a multi-subunit complex in its core complex.
- Pigment Composition: PS1 comprises chlorophyll A-695, chlorophyll A-670, chlorophyll A-680, chlorophyll A-700, chlorophyll B, and carotenoids, while PS2 comprises chlorophyll A-670, chlorophyll A-660, chlorophyll A-695, chlorophyll A-680, chlorophyll A-700, chlorophyll B, phycobilins, and xanthophylls.
- Involvement in Photolysis: PS1 is not involved in the photolysis of water, while PS2 is involved in the photolysis of water.
- Photophosphorylation: PS1 participates in both cyclic and non-cyclic photophosphorylation, while PS2 participates in non-cyclic photophosphorylation.
In summary, Photosystem 1 and Photosystem 2 have distinct roles, locations, and compositions in the light-dependent reactions of photosynthesis.
Comparative Table: Photosystem 1 vs Photosystem 2
The key differences between Photosystem 1 (PS I) and Photosystem 2 (PS II) are their absorption wavelengths and the pigments involved in their reaction centers:
Feature | Photosystem 1 | Photosystem 2 |
---|---|---|
Wavelength of light absorbed | Greater than 680 nm (longer wavelengths) | Less than 680 nm (shorter wavelengths) |
Reaction center | P700 (about 680 nm) | P680 (approximately 680 nm) |
Pigments | Consists of various chlorophyll types and carotenoids | Contains different types of chlorophyll, phycobilins, and xanthophylls |
Location | Outer surface of the grana thylakoid membrane | Inner surface of the grana thylakoid membrane |
Protein Complex | Approximately 700 nm | Approximately 680 nm |
Both photosystems are multi-subunit membrane-protein complexes involved in oxygenic photosynthesis. They play crucial roles in converting light energy into chemical energy during the light reaction of photosynthesis.
- Oxidative phosphorylation vs Photophosphorylation
- Photosynthesis vs Chemosynthesis
- ATP vs NADPH
- Photodissociation vs Photoionization
- Thylakoid vs Stroma
- Oxygenic vs Anoxygenic Photosynthesis
- Photochemical vs Electrochemical Reaction
- Chlorophyll vs Chloroplast
- Photosynthesis vs Photorespiration
- Photoelectric Effect vs Photovoltaic Effect
- Photosynthesis vs Cellular Respiration
- Photoionization vs Photoelectric Emission
- Light Reaction vs Calvin Cycle
- NAD+ NADH vs NADPH
- Chemiosmosis in Mitochondria vs Chloroplast
- Cytochrome vs Phytochrome
- Photocatalysis vs Electrocatalysis
- Telophase 1 vs 2
- Photochemical vs Thermal Reaction