ATP and Cellular Respiration

ATP and Cellular Respiration• Breakdown of a Glucose Molecule to make ATP so our

cells can perform chemical reactions

THE BASICS OF CELLULAR RESPIRATION• Heterotrophs – organisms that cannot make their

own energy and need to consume other organisms to get energy (consumers)– All animals, fungi, and some bacteria are heterotrophs

Why Make ATP?• Referred to as energy currency of the cell• Provide energy for chemical reactions to take place

in our body (cells)

Mitochondria• Site of cellular respiration (where ATP is made)• Conists of – Outer membrane– Inner membrane– Matrix– Cristae

Cellular Respiration Breakdown• Glycolysis– Located in cytoplasm of

cell• Krebs Cycle – Located in Mitochondrial

Matrix• Electron Transport Chain– Located in mitochondrial

cristae

Glycolysis • Breakdown of a single

Glucose molecule• Reactants – Glucose molecule

• Products – 2 pyruvate molecules– 2 ATP molecules• Energy

– 2 NADH molecules• Electron carriers

Pyruvate• Pyruvate can take 2 paths

from this point:1. Aerobic Respiration (with

oxygen) – Pyruvate moves into

mitochondria and ATP is made via Krebs Cycle and Electron Transport Chain

2. Anaerobic Respiration (without oxygen)– Pyruvate stays in cytoplasm

and is converted into lactic acid -Lactic Acid Fermentation

Aerobic Respiration• Krebs Cycle– Conversion of 2 pyruvate

molecules• Reactants – 2 pyruvate molecules

• Products– 4 CO₂ molecules– 2 ATP molecules

• Energy

– 6 NADH molecules• Electron carriers

– 2 FADH₂• Electron carriers

Aerobic Respiration• Electron Transport Chain– Electrons are transferred to proteins from NADH and FADH₂– Electrons are passed from one protein to the next– Final electron acceptor is Oxygen (O₂)

• Reactants – NADH– FADH₂

• Products – 34 ATP molecules

• Energy

– Water (H₂O)

Anaerobic Respiration• Lactic Acid

Fermentation– Conversion of 2

molecules of pyruvate into lactic acid when oxygen is not present

– Happens during vigorous muscle exercise

– Liver converts lactic acid back into glucose

Anaerobic Respiration • Alcohol Fermentation– Does not occur in

humans– Occurs in yeast when

oxygen is not available• Facultative anaerobes

– Conversion of 2 molecules of pyruvate into ethanol

Photosynthesis and Cellular Respiration