Download Notes: Chapter 8 Photosynthesis

Notes: Chapter 8 Photosynthesis
8-1 Energy and Life
I. All living organisms require energy
A. Autotrophs – get energy from sun
a. Example - plants
B. Heterotrophs – get energy from eating food
a. animals, fungi, most bacteria
II. Chemical Energy
A. ATP (Adenosine Tri-Phosphate) – energy molecule
a. The Adenosine part of ATP is made of adenine and a
ribose sugar
b. Tri – phosphate part of ATP is made of 3 phosphate
groups linked together
c. Energy is released when a bond is broken between the
phosphates
d. Label the ATP molecule below:
A = adenine
B = ribose sugar
C = diphosphate
D = phosphate
B. ADP (Adenosine Di-Phosphate) – ADP forms ATP when a
phosphate group is added
a. Identical to ATP, EXCEPT, ADP contains 2 phosphate
groups instead of 3
C. What are some ways that a cell uses energy (ATP)?
a. active transport
b. movement within the cell
c. making proteins
d. responding to cell signals
8-2 Photosynthesis: An Overview
A. Discovery of Photosynthesis
a. Van Helmont – mass gain in plants comes from water;
water is a reactant in photosynthesis
b. Priestly –a closed container with a plant causes a candle
to continue to burn; closed container without a plant causes
candle to burn out; plants produce oxygen
c. Ingenhousz – water plants produce oxygen bubbles in the
light, but not in the dark; light is required for plants to
make oxygen
B. Photosynthesis Equation
a. Carbon dioxide + water ---------> sugars + oxygen
b.
CO2
+ H2O ----------> C6H12O6 + O2
C. Light and Pigments
a. Photosynthesis requires light; visible light is a mixture of
different wavelengths of light that allows us to see color
b. Pigments are molecules that absorb certain
wavelengths of light
1. Example: Chlorophyll is the main pigment in the
chloroplasts of plants
D. Photosynthesis: The process can be divided into 2 parts:
a. The light-dependent reactions – light is required
b. The light-independent reactions (also called “dark
reactions” or “The Calvin Cycle” – light is not required
c. Label the process of photosynthesis on the following page...
Inside a Chloroplast
Stroma
Granum (stack of
thykaloids)
Summary of Photosynthesis
E. Factors Affecting Photosynthesis:
a. a water shortage can slow or stop photosynthesis
b. Temperature should be between 00 C and 35 0C
c. The more light, the more photosynthesis...to a certain
point