PHOTOSYNTHESIS & RESPIRATION

What is ATP? ATP = Adenosine TriPhosphate Adenine + Ribose + 3 Phosphates Adenine Ribose ADENOSINE Phosphate Triphosphate

Why ATP? Phosphates have a large amount of chemical energy. Whenever a bond holding a phosphate is broken, a large amount of usable cellular energy is released. ADENOSINE PP P PPP ENERGY

ATP CYCLE Occurs continuously in cells About 10 million new ATP molecules are made in every cell every second!!! ADP 1.Stored Energy Energy stored in chemical bonds. 2. Releasing Energy Energy released by breaking bonds – used to power cells 3. Energy Depleted ADP has less chemical energy than ATP 4. Making ATP Energy released by other chemical reactions and processes can be used to bond a phosphate to ADP to make ATP + P

PHOTOSYNTHESIS Series of complex chemical processes that convert light energy into carbohydrates Overall Equation light + H 2 O + CO 2 C 6 H 12 O 6 + O 2 Occurs in Chloroplasts Two types of reactions – Light Dependent Light Independent (aka. Calvin Cycle, Dark rxn)

Reactants & Products of Photosynthesis ReactantsProducts Carbon DioxideGlucose (sugar) WaterOxygen Light Energy

Light Dependent Reaction Occurs in the thylakoid Water is absorbed through roots. Sunlight enters the chloroplast, causing H 2 O molecules to split. O 2 leaves as a waste product through the stomata. NADP + picks up the H + ions (becoming NADPH) and moves them to the stroma for the light independent reaction (Calvin cycle).

Light Independent Reaction – Calvin Cycle Carbon dioxide from the atmosphere enters H + breaks off from NADPH NADP + returns to the Light Dependent Reaction Carbon dioxide becomes “fixed” with the H + producing the glucose molecule C 6 H 12 O 6

Cellular Respiration Where does the Glucose (C 6 H 12 O 6 ) & O 2 from photosynthesis go? Used by both plant & animal cells to create ATP!!!  Releases energy  Makes cell energy  Close to the reverse of photosynthesis ! Cellular Respiration Equation O 2 + C 6 H 12 O 6 → CO 2 + H 2 O + ATP

Cellular Respiration 3 step process  Glycolysis  Krebs Cycle/Citric Acid Cycle  Electron Transport Chain

Step 1: GLYCOLYSIS 2 ATP2 ADP4 ADP4 ATP 2 NAD 2 NADH Glucose 2 - PGAL 2 - Pyruvate Occurs in Cytoplasm of cell Anaerobic process (no O 2 required) Net production of 2 ATP (make 4 but use 2) Releases only 2% of chemical energy that is stored in Glucose

Step 2: Krebs Cycle/Citric Acid Cycle Occurs in Mitochondria Matrix Requires presence of O 2 2 Pyruvate from Glycolysis transformed into Acetyl CoA & enters cycle Net production of:  2 ATP  2 FADH  6 NADH

Step 3 – Electron Transport Chain Remaining energy of glucose in electrons carried by NADH & FADH NADH & FADH enter electron transport chain in mitochondria cristae Produce 32 more ATP From Krebs Cycle From Alteration of Pyruvate to Acetyl CoA

Summary of Cellular Respiration H2OH2O CO 2 In Matrix In Cristae

What if there is not enough or no O 2 present? Alcoholic Fermentation (Yeast) Pyruvate + NADH → Ethanol + NAD + CO 2 Used in baking, beer & wine production Lactic Acid Fermentation Pyruvate + NADH → Lactic Acid + NAD Strenuous exercise = can’t get all the O 2 your cells need so use lactic acid fermentation = Sore muscles!!!

Chemosynthesis Chemosynthesis uses energy released from chemical reactions to produce food for organisms. Organisms that carry out chemosynthesis are microbes (bacteria) that live far from the Sun, such as deep on the ocean floor.