Photosynthesis Quiz

Site of Photosynthesis

• Photosynthesis occurs mainly in the leaves of green plants.
• Mesophyll cells, located within leaves, harbor chloroplasts which facilitate photosynthesis.
• Optimal temperature range for photosynthesis activity is between 120-40°C.

Chloroplast Structure

• Composed of an outer membrane and an inner membrane.
• The inter-membrane space is present between the two membranes.
• Grana, stacks of thylakoids, are essential for light-dependent reactions.
• Stroma, the fluid surrounding the thylakoids, is where the light-independent reactions occur.

Types of Pigments

• Chlorophyll a (Chla) - bright blue-green, serves as the chief pigment in photosynthesis.
• Chlorophyll b (Chlb) - yellow-green, functions as an accessory pigment to broaden light absorption.
• Xanthophyll - yellow pigment, also an accessory pigment.
• Carotenoids - yellow-orange pigments, serve as additional accessory pigments.

Photosystems

• Two types of photosystems are crucial for capturing light energy during photosynthesis.
• Photosystem I (PS-I)
  • The reaction center is designated as P700.
  • Light harvesting complex (LHC) acts as an antenna to gather light.
  • Absorbs maximum light at a wavelength of 700nm.
• Photosystem II (PS-II)
  • The reaction center is referred to as P680.
  • Contains hundreds of pigments and proteins.
  • Absorbs maximum light at a wavelength of 680nm.

Steps in Light-Dependent Reactions

• Initial step involves the absorption of light energy.
• Water molecules are split, resulting in the release of oxygen.
• During these reactions, ATP and NADPH are produced, essential for subsequent processes.

Photophosphorylation Types

• Non-cyclic photophosphorylation
  • Responsible for ATP formation during light-dependent reactions.
• Cyclic photophosphorylation
  • Produces ATP in light-independent reactions, operating in a cycle.

Test your knowledge on the process of photosynthesis, focusing on the site and structures involved, such as chloroplasts and their membranes. Explore the different types of pigments and their roles in capturing light energy for plant growth.