Chapter 8 Photosynthesis 8.1 Energy and Life 10/27/2005

What is Energy? Ability to do work

Autotrophs vs. Heterotrophs Makes their own food Use the energy of the sun Ex. Plants Obtains energy from the foods they consume

ATP Adenosine TriPhosphate Made up of: Adenine 5 Carbon sugar (ribose) Three phosphate groups KEY TO STORE & RELEASE ENERGY

Storing Energy ADP (Adenosine DiPhosphate) Similar to ATP 2 phosphate groups Key to the way in which living things store energy Add on available energy with a phosphate to ADP to create ATP Analogy --> Battery

Releasing Energy How is the energy stored in ATP released? Breaking the chemical bond between the second and third phosphate group Basic energy source of all cells

What is energy used for? Carry out active transport protein synthesis Responses to chemical signals

ATP can only pack small amounts of energy

Adenine P Phosphate Ribose ADP

Adenine Phosphate P P P Ribose ATP

8.2 Photosynthesis: An Overview

Photosynthesis key cellular process identified with energy production Who goes through photosynthesis? PLANTS

Photosynthesis Equation REACTANTS LIGHT 6CO2 6H2O + Carbon dioxide Water

Photosynthesis Equation PRODUCTS Sugar Oxygen LIGHT C6H12O6 + 6O2

Photosynthesis Equation LIGHT 6CO2 + 6H2O C6H12O6 + 6O2 DESCRIBE WHAT IS HAPPENING IN THE REACTION. In photosynthesis, plants use the energy of sunlight to change water and carbon dioxide into high-energy sugars and oxygen.

Lights and Pigments Plants need Light Form of energy Pigment light absorbing molecule Chlorophyl Principal pigment in plants

8.3 The Reactions of Photosynthesis

Chloroplast where photosynthesis takes place thylakoid membranes = saclike photosynthetic materials found in chloroplast

Chloroplast Granum = stack of thylakoid photosystems = organization of chlorophyll and other pigments light collecting units of the chloroplast

Photosystems 2 part process Light dependent In the thylakoid membranes Light independent (Calvin cycle) In the stroma Region outside the thylakoid membranes

Electron Carriers Sunlight excites electrons in chlorophyll electrons gain tons of energy high energy electrons need special carriers from chlorophyll to other molecules

Light Dependent Reactions requires lights uses energy from light to produce ATP and NADPH

Light Dependent Reactions Products OXYGEN GAS (02) 2 energy carriers ADP -- > ATP NADP+ --> NADPH

Light Dependent Reaction 5. ATP Formation ATP Synthase = protein on cell membrane Allows H+ to pass through membrane ATP Synthase binds ADP + P+, creating ATP

Light Dependent Reactions Products OXYGEN GAS (02) 2 energy carriers ADP -- > ATP NADP+ --> NADPH