CELLULAR RESPIRATION Chapter 7

ORGANELLE OF FOCUS

OVERALL EQUATION C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + energy(ATP) Glucose + Oxygen  Carbon Dioxide + Water + ATP Adenosine triphosphate

VOCABULARY Autotrophs Organisms that are able to produce their own chemical energy (food), ex. plants Heterotrophs –Organisms that obtain their chemical energy from other sources, by eating ex. animals Cellular Respiration –Breaking down organic molecules to produce energy Aerobic Respiration –Oxygen present for pathway of breaking down food Anaerobic Respiration –No Oxygen present - causes an alternative pathway

Focus on Aerobic Pathway for Cellular Respiration STEPS –1. Glycolysis – splits the glucose in half (6C to 3C), occurs in cytoplasm of cell –2. Pyruvic acid conversion – loss of CO 2 produces a product ready for the next step, occurs in mitochondria –3. Kreb Cycle – breaks down the remaining carbons from what’s left of the glucose molecule, produces high energy products NADH and FADH 2,, occurs in matrix of mitochondria

Steps continued -4. Electron Transport Chain – a series of proteins along the inner membrane of mitochondria that pass e- * OXYGEN is the final acceptor of electrons * H+ build up powers ATP synthase (sound familiar)

Glycolysis

Pyruvic Acid Conversion Why twice?

Kreb Cycle Where does CO 2 go? Where do NADH and FADH 2 go?

Electron Transport Chain (ETC)

Summary Chart StepInputOutputATP GlycolysisGlucose 2 pyruvic acids 2 ATP Pyruvic acid conversion 2 Pyruvic acids 2 CO 2 2 Acetyl CoA 0 ATP Kreb Cycle2 Acetyl CoA (1 per cycle) 4 CO 2 2 ATP (1 made per cycle) ETCO 2 FADH2 NADH H2OH2O34 ATP

WHAT HAPPENS IF NO OXYGEN IS PRESENT?? Can’t do Electron Transport Chain so… no use doing Kreb cycle. Why not? -NADH and FADH 2 have nowhere to go if ETC not running.

ANAEROBIC PATHWAYS Alcohol Fermentation – organism produce alcohol from pyruvic acid ex. Yeast cells Lactic Acid Fermentation – muscle cells not receiving enough oxygen so they produce lactic acid from pyruvic acid

Alcohol Fermentation How many ATP? 2

Lactic Acid Fermentation How many ATP? 2

Pros and Cons of Lactic Acid Fermentation Pros – your muscle will keep working even without sufficient oxygen

Cons – you feel it, lactic acid causes sore muscles and cramping Your body will get rid of lactic acid – it diffuses into blood and goes to liver where it is converted back to pyruvic acid – ready for O 2 LIVER

RECAP C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + energy (ATP) GLUCOSE becomes… CO 2 Oxygen is needed… to accept the electrons at the end of ETC CO 2 goes… into blood, lungs, exhaled Water is produced when… O 2 collects enough e- and H+ to become water ATP is produced… in glycolysis, Kreb Cycle and mainly in ETC due to chemiosmosis

Pyruvic acid is made … at the end of glycolysis (3C) NADH and FADH 2 carry … Electrons and H+ to the ETC Protons (H+) build up in the …due to… Intermembrane space, ETC pushing them out ATP synthase allows H+ to … and … Back into the matrix, produces ATPs If no oxygen, yeast produce… ethanol If no oxygen, muscle cells produce… Lactic acid

The ETC produces ATPs In aerobic respiration, Pyruvic acid is converted to… Acetyl CoA The molecule that must be recycled in the Kreb cycle is… Oxaloacetic acid The break down of one glucose gives… 38 total ATP

Autotrophs… Make their own food/chemical energy Heterotrophs… Must eat other things to obtain chemical energy Aerobic respiration requires… Oxygen

EAT AND BREATHE: IT’ GOOD FOR YOU!

The other half of the story=PHOTOSYNTHESIS