8.1 Overview of Photosynthesis

• Photosynthesis converts solar energy into chemical energy.

• Organisms that carry on photosynthesis are called autotrophs.

• Heterotrophs are organisms that feed on other organisms.

• Autotrophs and heterotrophs use organic molecules produced by photosynthesis

• Pigments allow photosynthetic organisms to capture solar energy.

8.1 Overview of Photosynthesis

• Flowering Plants as Photosynthesizers– Photosynthesis occurs in the green parts of plants– Leaves contain mesophyll tissue specialized for

photosynthesis– Water is taken up by roots and transported to leaves

by veins– Carbon dioxide enters through openings in the

leaves called stomata– Light energy is absorbed by chlorophyll and other

pigments in thylakoids of chloroplasts

Leaves and Photosynthesis

8.1 Overview of Photosynthesis

• Photosynthetic Reaction

– Solar energy + 6CO2 + 6H2O C6H12O6 + 6O2

• Glucose and oxygen are the products of photosynthesis

• The oxygen given off comes from water

• CO2 gains hydrogen atoms and becomes a

carbohydrate

8.1 Overview of Photosynthesis

• Photosynthesis consists of two sets of reactions– Photo refers to capturing light– Synthesis refers to producing a carbohydrate

• The two sets of reactions are called the:– Light Reactions– Calvin Cycle Reactions

8.5 Photosynthesis Versus Cellular Respiration

• Both plant and animal cells carry out cell respiration

• Only plant cells photosynthesize• Both processes utilize an electron transport

chain and chemiosmosis for ATP production• Photosynthesis reduces CO2 to carbohydrates

and releases O2

• Respiration utilizes O2 and gives off CO2

Photosynthesis and Respiration Compared