1. 5.1 Photosynthesis Overview
Unit 5: Cell Energy
5.1 Photosynthesis Overview

2. The Energy Cycle
Photosynthesis and Cellular Respiration are cyclical of each other.
Photosynthesis is the process to create the energy from sunlight.
The energy is stored in the chemical bonds of sugars.
Cellular respiration is how living organisms use that energy.
Plants and Animals break the bonds to use the energy.

3. Photosynthesis
Uses energy from sunlight to convert water and carbon dioxide (reactants) into high energy sugars and oxygen (products)
This means that sunlight is the ultimate source of energy for all life on Earth.

4. Structure of Carbohydrates
Simple = Monomer
Complex = Polymer
Monosaccharide: simple ring sugars
Ex: glucose and fructose
Formula: CHO in a 1:2:1 ratio
Ex: Glucose- C6H12O6
Disaccharide: two monosaccharides combined.
Ex: sucrose, maltose, and lactose
Polysaccharides: polymers (long chains of repeating units) of monosaccharides
These are energy storing molecules (when you create a bond, it stores energy)
Ex: starch (plants) and glycogen (animals)
Structural: cellulose (found in plants)

5. Function of Carbohydrates
Source of short-term energy
Structural materials in organisms.

6. Adenosine Triphosphate: ATP
ATP is an organic molecule that contains high energy phosphate bonds.
It consists of one adenine, one sugar ribose, and three phosphates.
We can remove a phosphate to release energy. The result is Adenosine Diphosphate or ADP.
We can add a phosphate to ADP to store energy. The result is ATP!

7. Overall Equation
Products
Reactants

8. Reactions in Photosynthesis
Light Dependent Reactions
Light Independent Reactions
Require direct involvement of light
Use sun’s energy to produce ATP
Takes place in the thylakoids
Water is required as a sources of electrons and hydrogen ions
Oxygen is released
No Light is required
ATP and NADPH are used to make sugars
Takes place in the stroma
Carbon dioxide is required

9. Where Photosynthesis Occurs
The Chloroplast is the organelle where photosynthesis occurs
Structure:
Contain an inner and outer membrane
Thylakoid: saclike photosynthetic membranes
Grana: Interconnected stacks of thylakoid
Stroma: Fluid outside the thylakoid

11. Pigments Chloroplasts contain pigments!
Pigments are light-absorbing molecules that gather the sun’s energy
Pigments are located in the thylakoid membranes
Sunlight is a mixture of different wavelengths our eyes perceive as white
Colors include red, orange, yellow, green, blue, indigo, and violet
The sun’s energy travels to Earth as light
The pigments in chloroplasts absorb the different wavelengths of light!

12. Chlorophyll A plant’s principle pigment
Chlorophyll absorbs visible light especially well
Chlorophyll absorbs blue-violet and red wavelengths of light best
Chlorophyll reflects green wavelengths, causing plants to appear green

13. Fall Colors
Plants also contain red and orange pigments, such as carotene, that absorb light in other regions of the spectrum.
As temperatures drop later in the year, chlorophyll pigments break sown first, leaving red and orange pigments to be seen