Photosynthesis & Respiration Chapters 6 & 7 Photosynthesis & Respiration 1

I. Energy: the ability to do work Why do cells need energy? Active transport Cell division, growth, & development To make macromolecules (carbs, proteins, etc.) To build cell parts (membranes, mitochondria, etc.) 2

I. Energy B. Two classifications of organisms based on how they obtain energy: 1. Autotrophs: organisms that can make their own food (Ex: plants) 2. Heterotrophs: organisms that obtain food from other sources (Ex: animals, fungi) 3

I. Energy C. Pathway of energy: 4

I. Energy D. Cellular Energy = ATP : Adenosine Tri-phosphate ATP ADP ADP 5

I. Energy E. Overview of Photosynthesis & Cellular Respiration 6

II. Photosynthesis: Photo = light Synthesis = to make Process by which autotrophs convert solar energy to cellular energy (ATP) and stored food (glucose) Overall reaction: Occurs in the chloroplasts of plant cells Solar E is converted by the use of pigment, molecules that absorb certain wavelengths of light and reflect (what we see) others. 7

II. Photosynthesis Photosynthesis consists of two phases Light reactions: the “photo” part Solar energy converted to cellular energy (ATP) Chlorophyll “captures” (absorbs) light H2O is split, releasing O2 gas (as a waste product) Occurs in the thylakoid membrane of chloroplasts 8

II. Photosynthesis Primary photosynthetic pigment: Chlorophyll: main photosynthetic pigment, absorbs blue & red light, reflects green Accessory pigments Carotenes: absorb blue & green, reflect yellow and orange. In fall, chlorophyll is broken down and we see the colors of the accessory pigments 9

II. Photosynthesis Calvin Cycle: the synthesis part Energy from light reactions used to “fix” CO2 (gas) into glucose (solid) Occurs in the stroma of chloroplast 10

II. Photosynthesis 11

Cool Down Questions What are the reactants needed for photosynthesis to occur? What products are produced by photosynthesis? What are the 2 reactions of photosynthesis? Where does the light dependent reaction take place?

Cool Down Questions What are the reactants and products of the light dependent reaction? Where does the light independent reaction take place? 7. What are the reactants and products of the light independent reaction?