Which organisms perform oxygenic photosynthesis?

Which organisms perform oxygenic photosynthesis?

• A. Plants and cyanobacteria
• B. Some bacteria only
• C. Animals
• D. Fungi

Answer: (A)

Oxygenic photosynthesis is the process that releases oxygen while converting light energy into chemical energy by using water as the electron donor. Plants and cyanobacteria perform this because they carry out the light reactions in which water is split to oxygen, with electrons flowing through photosystems to generate NADPH and ATP for the carbon-fixing steps. Cyanobacteria are photosynthetic bacteria that share the same two-photosystem machinery as plants, so they release oxygen as a byproduct. Animals and fungi don’t photosynthesize at all, so they don’t produce oxygen in this way. Some bacteria do photosynthesis, but many use different electron donors and do not generate oxygen, which is why they’re not described as performing oxygenic photosynthesis.

Oxygenic photosynthesis is the process that releases oxygen while converting light energy into chemical energy by using water as the electron donor. Plants and cyanobacteria perform this because they carry out the light reactions in which water is split to oxygen, with electrons flowing through photosystems to generate NADPH and ATP for the carbon-fixing steps. Cyanobacteria are photosynthetic bacteria that share the same two-photosystem machinery as plants, so they release oxygen as a byproduct. Animals and fungi don’t photosynthesize at all, so they don’t produce oxygen in this way. Some bacteria do photosynthesis, but many use different electron donors and do not generate oxygen, which is why they’re not described as performing oxygenic photosynthesis.