Chapter 8: Photosynthesis Overview and Processes

Photosynthesis

Process converting solar energy into chemical energy.

Autotrophs

Organisms producing their own food from inorganic substances.

Photoautotrophs

Use sunlight to synthesize food from CO2 and water.

Chemoautotrophs

Obtain energy from inorganic compounds, not sunlight.

Heterotrophs

Organisms relying on others for food and energy.

Glucose

Simple sugar produced during photosynthesis.

Oxygen

Byproduct released during photosynthesis.

Carbon dioxide

Gas absorbed by plants during photosynthesis.

Water

Essential reactant absorbed by roots for photosynthesis.

Stomata

Pores on leaves for gas exchange.

Chloroplasts

Organelles where photosynthesis occurs in plant cells.

Mesophyll cells

Leaf cells containing high densities of chloroplasts.

Light-dependent reactions

Convert light energy into chemical energy (ATP, NADPH).

Calvin cycle

Uses ATP and NADPH to synthesize sugars.

Thylakoid membranes

Site of light-dependent reactions in chloroplasts.

Stroma

Fluid inside chloroplasts where Calvin cycle occurs.

Chlorophyll a

Primary pigment absorbing light for photosynthesis.

Chlorophyll b

Accessory pigment assisting in light absorption.

β-carotene

Carotenoid pigment protecting photosystems from excess energy.

Photosystems

Complexes of proteins and pigments capturing light energy.

Electron Transport Chain (ETC)

Series of proteins transferring electrons during light reactions.

NADP reductase

Enzyme converting NADP+ to NADPH in light reactions.

ATP synthase

Enzyme synthesizing ATP using H+ gradient.

Carbon fixation

Process of converting CO2 into organic compounds.

Rubisco

Enzyme catalyzing CO2 fixation in Calvin cycle.

3-PGA

Intermediate product formed during Calvin cycle.

G3P

Sugar produced in Calvin cycle, precursor to glucose.

Chemiosmosis

Process generating ATP using H+ gradient.

Visible light

Electromagnetic radiation visible to the human eye.

Wavelength

Distance between successive peaks of a wave.

Light energy

Electromagnetic energy from photons.

Guard cells

Cells regulating the opening and closing of stomata.