Photosynthesis How do plants obtain and use the matter and energy they need to live and grow?

Assessing Prior Knowledge (APK) What is the process plants use to create chemical energy? What products do plants need to create chemical energy? What cell organelle is responsible for creating chemical energy in a plant? What waste products do plants create? What types of plant matter can plants make using this process?

Hook: Photosynthesis song Grab a photosynthesis song sheet Put on the left hand side of your notebook

Why is this important? Organisms require energy to grow, reproduce, and perform life processes. Nearly all of the energy used by organisms comes from the Sun. Energy is then transferred from one organisms to another via trophic interactions One organism eats the parts or products of another organism

Pathways of Energy Flow At the molecular level, two biochemical pathways lie at the center of energy flow: Photosynthesis – energy from the sun enters the ecosystem Cellular respiration – process of turning the products of photosynthesis into energy that cells can use to perform work

Photosynthesis Chemical Reaction Photosynthesis and cellular respiration are chemical reactions. Each chemical reaction has reactants and products. Reactants are the starting materials for a reaction and products are the materials created by the reaction. Does not destroy or create energy or matter… they rearrange it by transferring energy from one state to another.

Where chlorophyll is, which converts light into energy Photosynthesis Plants, algae, and some bacteria perform photosynthesis. They also don’t depend on other organisms for energy Animals, fungi, and archaea do not. Two major components: Light dependent reaction Light independent reaction Where chlorophyll is, which converts light into energy

Step 1: Light Dependent Reactions Within each chloroplast is a set of light-capturing proteins that are folded into disc-shaped stacks called thylakoids. Light particle (photon) strikes a chlorophyll molecule, energy is transferred, and electrons are absorbed. NADP+ (electron carrier) binds with hydrogen to form NADPH. NADPH transfers electrons to stroma.

Step 2: Light Independent Reaction The Calvin Cycle Named after Melvin Calvin, discoverer of this awesomeness  Occurs in the stroma Does not require light, but it does require products of previous reaction Uses energy to convert carbon from CO2 into sugars.

ATP – Useable Energy All cells use a common and versatile chemical energy currency: adenosine triphosphate (ATP). Nucleotide attached to 3 phosphate groups Bonds between the phosphate groups store the usable energy in ATP. Breaking off a single phosphate group releases energy and transforms ATP to adenosine diphosphate (ADP). Photosynthesis produces a small amount of ATP by phosphorylating ADP.

Cellular Respiration: (2 kinds—Aerobic and Anaerobic) Cellular respiration is the process by which the energy of glucose is released in the cell to be used for life processes (movement, breathing, blood circulation, etc…)

Aerobic Respiration: requires oxygen Occurs in the mitochondria of the cell Total of 36 ATP molecules produced General formula for aerobic respiration: C6H12O6 + 6O2 6 CO2 + 6H2O + 36 ATP glucose + oxygen carbon dioxide + water + energy Human cells contain a specialized structure – the mitochondrion – that generates energy.

Electron Transport Chain Electrons carried in NADH Mitochondria In Cytoplasm Electrons carried in NADH and FADH2 Krebs Cycle Electron Transport Chain Glucose Glycolysis 2 2 32

Summary: 3 steps: 1st glycolysis 2nd Krebs cycle 3rd Electron Transport Chain (ETC)

Anaerobic Respiration: occurs when no oxygen is available to the cell (2 kinds: Alcoholic and Lactic Acid) Much less ATP produced than in aerobic respiration

Steps of Anaerobic Respiration First step in anaerobic respiration is also glycolysis Anaerobic Respiration Cytoplasm Alcoholic fermentation Bacteria, Yeast 2 ATP C6H12O6 glucose glycolysis Lactic acid fermentation Muscle cells 2 ATP ETC Mitochondria Krebs Cycle Aerobic Respiration 36 ATP

Alcoholic fermentation—occurs in bacteria and yeast Process used in the baking and brewing industry—yeast produces CO2 gas during fermentation to make dough rise and give bread its holes glucose ethyl alcohol + carbon dioxide + 2 ATP

Lactic acid fermentation—occurs in muscle cells Lactic acid is produced in the muscles during rapid exercise when the body cannot supply enough oxygen to the tissues—causes burning sensation in muscles glucose lactic acid + carbon dioxide + 2 ATP

Cellular Respiration Photosynthesis Kind of energy? Where do these reactions occur? Outcome of the reaction?