Thermodynamics and Cellular Respiration Overview

First Law of Thermodynamics

Energy cannot be created or destroyed, only transformed.

Second Law of Thermodynamics

Systems trend towards disorder, increasing entropy.

Cellular Respiration Example (1st Law)

Glucose breakdown transforms potential energy into kinetic energy.

Cellular Respiration Example (2nd Law)

Less than 36 ATP produced due to proton leakage.

ATP Structure

Composed of adenine, ribose, and three phosphate groups.

ATP Energy Source

Energy released when phosphate bonds are broken.

Coupled Reactions

Reactions that occur together, exchanging energy or electrons.

Reduction-Oxidation Reactions

Involve electron exchange; reduction gains electrons, oxidation loses.

Endergonic Reactions

Absorb energy; powered by energy released from exergonic reactions.

Exergonic Reactions

Release energy; coupled with endergonic reactions for efficiency.

Electron Carriers

NADH and FADH2 transport electrons during cellular respiration.

Glycolysis Location

Occurs in the cytosol of the cell.

Pyruvate Oxidation Location

Takes place in the mitochondrial matrix.

Krebs Cycle Location

Occurs in the mitochondrial matrix.

ETC Location

Takes place in the inner mitochondrial membrane.

Glycolysis Steps

Investment, conversion, and payoff phases produce ATP and NADH.

Pyruvate Oxidation Steps

Oxidizes pyruvate, removes CO2, forms Acetyl-CoA.

Krebs Cycle Steps

Produces NADH, FADH2, GTP, and releases CO2.

Oxidative Phosphorylation Steps

Electrons create a proton gradient to produce ATP.

Substrate-Level Phosphorylation

Direct ATP production via enzyme-catalyzed reactions.

Oxidative Phosphorylation

ATP production using energy from electron carriers.

Fermentation Purpose

Regenerates electron carriers when oxygen is absent.

Lactic Acid Fermentation

Occurs in muscle cells, converts pyruvate to lactate.

Ethanol Fermentation

Occurs in yeast, converts pyruvate to ethanol and CO2.

Aerobic Respiration Equation

Glucose + oxygen → carbon dioxide + water + energy.

Energy Loss in Respiration

Energy lost as heat, during transport, and proton leakage.

ATP Production in Oxidative Phosphorylation

Proton gradient drives ATP synthase to produce ATP.

Aerobic vs Anaerobic Respiration

Aerobic produces 30-32 ATP; anaerobic produces 2 ATP.

Oxygen's Role in Respiration

Lack of oxygen halts electron transport chain and ATP production.