Photosynthesis Defined: process by which light energy is converted to chemical energy. Is this an example of metabolism? Is this a chemical reaction? Autotrophs: self feeding Energy: ATP

Light- Absorbing Structures Pigments: molecule that contains a light- absorbing structure Chlorophyll: primary pigment involved with photosynthesis Carotenoids: secondary pigments in photosynthesis http://pubs.acs.org/doi/full/10.1021/ol400327j

Color- absorption vs. reflection What visible light colors (wavelength) does chlorophyll A and B absorb? Reflect? If a color is absorbed, can it be reflected?

Discuss class graphs and why we only had small peaks.

Infrared (IR) light Invisible to human eye “Night Vision” “Thermographic” cameras http://www.physicscentral.com/explore/action/images/turtles.jpg;

Cyanobacteria Photosynthetic Bacteria Prokaryotes Lack organelles Single celled

Who came first?

Endosymbiosis Video

Recap Story of Life Atoms  Molecules Molecules  Organic compounds: monomers Monomers  Polymers Amino acids  protein and enzymes Glycerol & fatty acids  lipids Phospholipids  selective permeability Maintain Homeostasis Photosynthesis- Carry out Metabolic Reactions

Photosynthesis Stages 6CO2 + 6H2O + light energy  C6H12O6 + 6O2 Stages of Photosynthesis: Absorb light energy (via pigments) Convert light energy  chemical energy Convert chemical energy  organic compounds

Photosynthesis Calvin Cycle (Light- Independent) Light Reaction Steps Occurs in the Thylakoid Membrane  Chloroplast Light energy is absorbed Water molecules are split into H+ ions, O- and e-. O- combine to form O2 that diffuses out of thylakoid membrane H+ ions travel down concentration gradient through the transport protein ATP synthase via facilitated diffusion. ATP synthase uses energy from H+ gradient to combine ADP + Pi  ATP (chemical energy) Light energy excites electrons, which bounce through the Electron Transport Chain (ETC) and land on NADP+ reductase, enzyme. NADP+ reductase combines e- + NADP+  NADPH Inputs: H2O + light energy Intermediates: H+ ions, Oxygen and Electrons Outputs: ATP and NADPH Occurs in the stroma  chloroplast CO2 is added to a 5-C compound via enzyme RuBisCO to make a 6-C compound. The resulting 6-C compound splits into two 3- C compounds; phosphates from ATP and electrons from NADPH are added. One of the 3-C compounds is used to make C6H12O6, a sugar to store energy for plant. The other 3-C compound gets recycled back into the mix to keep cycle going. Inputs: ATP, NADPH and CO2 Intermediates: 3- carbon sugar Outputs: C6H12O6

6. 7. 6. 2. 3. 4. 5.

organic compounds: sucrose, starch Unstable 6 carbon compound 3 carbon simple sugar (recycled) organic compounds: sucrose, starch Unstable 6 carbon compound RuBisCO + 5 carbon compound