Photosynthesis and Respiration

The Basics

How do organisms obtain energy?

• Plants get their energy from the sun!• Plants are called autotrophs

Auto = Self Troph = Nourish

• Animals eat food to get energy!• Animals are called heterotrophs

Hetero = Different Troph = Nourish

Heterotrophs = Animals

Autotrophs = Plants

Definitions

• Photosynthesis – the process of converting light energy into stored energy (glucose)– Takes place in the chloroplast

• Respiration – the process of converting food energy (glucose) into chemical energy (ATP)– Takes place in the mitochondria

Light Energy

• A molecule in chloroplasts, called chlorophyll, can capture energy from the sun.

• Light comes in many colors and each color has a different amount of energy.

Cellular Energy

• Cellular energy is ATP (adenosine triphosphate)

• Used by all cells as their energy source (cellular currency).

• It easily gains and loses a third phosphate group– 3 phosphates = Fully Charged (ATP)– 2 phosphates = Partially charged (ADP)

Energy is stored in chemical bonds. It is released when bonds are broken.

Equations

• Photosynthesis:6H2O + 6CO2 + Light → C6H12O6 + 6O2

• Respiration:C6H12O6 + 6O2 → 6H2O + 6CO2 + Energy

Answer these questions at the end of your notes in your logbooks

1. How do plants and animals obtain energy?2. In what organelle does the process of Photosynthesis

occur?3. In what organelle does the process of Respiration occur?4. In what type of cells do Photosynthesis and Respiration

take place? For each process describe if it is: Plant, Animal, Both, Neither

5. Why are animal cells not capable of carrying out Photosynthesis?

6. Photosynthesis and Respiration can be summarized into equations. Write the equations and how do they relate to one another.

7. Analyze why leaves change color in autumn.8. Identify the parts of the plant involved in Photosynthesis.