CELL RESPIRATION Chapter 6

RESPIRATION Main goal = make ATP Cellular respiration is the reverse of the photosynthesis reaction Cell Respiration Chemical Equation: C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O

WHO? WHERE? WHEN? Who? ALL living things Where? Mitochondria When? If food is available and energy is required

TWO MAIN TYPES Aerobic - requires oxygen Anaerobic - does not require oxygen Glycolysis is the first step of both

GLYCOLYSIS Occurs in the cytoplasm Function = Breaks glucose down into 2 pyruvate (pyruvic acid) molecules

GLYCOLYSIS Needs –2 ATP & 2 NAD Creates –4 ATP (Net=2) –2 NADH + 2H + molecules –2 molecules of pyruvate Happens with or without O 2

NO OXYGEN OXYGEN NO OXYGEN OXYGEN Anaerobic Respiration –Step 1: Glycolysis –Step 2: Fermentation Aerobic Respiration –Step 1: Glycolysis –Step 2: Krebs Cycle –Stage 3: ETC

AEROBIC RESPIRATION Where = Cytoplasm & Mitochondria When = Oxygen is present 1. Glycolysis 2. Kreb’s Cycle 3. ETC

KREB’S CYCLE Where = Mitchondrial matrix Function = To completely break down glucose Needs = Acetyl Co-A enzyme Makes –Citric Acid (also called citric acid cycle) –CO 2 released –2 ATP, 10 NADH & 2 FADH 2

ETC Where = Occurs mitochondrial cristae Function = Passing of H+/e- Needs= ATP Synthase enzyme Makes = water & most energy

AEROBIC RESPIRATION IN TOTAL 2 ATP made from glycolysis 2 ATP made from Kreb’s Cycle ~28 ATP made from ETC ~32 ATP total

Aerobic Respiration Aerobic Respiration

ANAEROBIC FERMENTATION Where = Occurs in cytoplasm When = No Oxygen present Makes = No ATP –Regenerates NAD+ for glycolysis

ANAEROBIC FERMENTATION Products depend on organism –Muscles (animal) = lactic acid –Yeast = ethyl alcohol

RESPIRATION REVIEW Anaerobic –No oxygen –Starts w/ glycolysis –Fermentation –Makes 2 ATP –Waste: lactic acid, ethyl alcohol Aerobic –Has oxygen –Starts w/ glycolysis –Krebs & ETC –Makes ~34 ATP –Waste: CO 2, H 2 0