Photosynthesis Overview

Study Notes

Overview of Photosynthesis

Photosynthesis is the process by which plants, algae, and some bacteria convert light energy from the sun into chemical energy in the form of organic compounds, such as glucose.
This process occurs in specialized organelles called chloroplasts, which are present in plant cells.

Light-Dependent Reactions

Light energy is absorbed by pigments such as chlorophyll and converted into ATP and NADPH.
These reactions occur in the thylakoid membranes of the chloroplast and involve the following steps:
1. Light absorption by pigments
2. Excitation of electrons
3. Transfer of electrons to electron acceptors
4. Formation of ATP and NADPH

Light-Independent Reactions (Calvin Cycle)

The energy from ATP and NADPH is used to convert CO2 into glucose.
These reactions occur in the stroma of the chloroplast and involve the following steps:
1. Carbon fixation (CO2 is fixed into a 3-carbon molecule)
2. Reduction of 3-carbon molecules to form glyceraldehyde 3-phosphate (G3P)
3. Regeneration of RuBP (the 5-carbon molecule that binds to CO2)
4. Production of glucose from G3P

Importance of Photosynthesis

Provides energy and organic compounds for plants to grow and develop
Supports life on Earth by producing oxygen and food for heterotrophic organisms
Plays a critical role in the Earth's carbon cycle and climate regulation

Factors Affecting Photosynthesis

Light intensity and quality
Temperature
Water availability
CO2 concentration
pH and nutrient availability

Description

Learn about the process of photosynthesis, including light-dependent and light-independent reactions, and its importance in supporting life on Earth. Understand the factors that affect photosynthesis and its role in the Earth's carbon cycle and climate regulation.