Cellular Respiration Chapter 9

Ms. McCaughan La Serna High School 2007-2008

Energy Review

Energy Storing Molecules

ATP, NADPH (NAD+), FADH (FAD+), FADH2

ATP supplies most of the energy that drives metabolism in living things ATP releases energy when converted into ADP

Cellular Respiration OverviewChapter 9-1

Living things get most of the energy they need from glucose.

Autrotrophs make glucose using photosynthesis Heterotrophs get glucose from food they eat The process that releases energy by breaking down glucose and other food molecules in the presence of oxygen.

Cellular Respiration

Cellular Respiration Overview

Cellular Respiration Overall Equation 6O2 + C6H12O6 6CO2 + 6H2O + Energy Three Stages1. 2. 3.

Glycolysis Kreb’s Cycle Electron Transport Chain

The Main form of Energy produced = ATP

Figure 9–2

Cellular Respiration: An OverviewMitochondrion Electrons carried in NADH Pyruvic acid Electrons carried in NADH and FADH2

GlucoseGlycolysis

Krebs Cycle

Electron Transport Chain

Mitochondrion Cytoplasm

Glycolysis

Glyco = Glucose lysis = Breakdown Occurs in the cytoplasm of the cell Molecules of GLUCOSE are broken down into 2 molecules of Pyruvic Acid. Cell must use (invest) 2 ATP Produces Energy Carrier Molecules

4 ATP 2 NADH

Glycolysis

Pyruvate = Pyruvic Acid

Glycolysis

Glucose Pyruvic AcidTo the Electron Transport Chain

Pyruvic Acid

The “Mighty” Mitochondria

The mitochondria is the organelle where the final stages of cellular respiration occurs.

Kreb’s Cycle Electron Transport Chain

Cells that use a lot of energy have high numbers of mitochondria.

Example: Muscle cells in the heart!!

Kreb’s CycleChapter 9-2

Aerobic Process = Only if oxygen is present!! Occurs in the MATRIX of the mitochondria Pyruvic Acid from Glycolysis enters to form 1 ATP 3 NADH 1 FADH2 CO2 (which is released when we exhale!!) AKA….Citric Acid Cycle

Kreb’s Cycle

Electron Transport ChainChapter 9-2

Energy carrier molecules produced during Glycolysis and the Kreb’s Cycle enter the ETC

NADH FADH2

Occurs in the folds of the Inner Membrane of the Mitochondria (Cristae) The electrons are passed down a chain of proteins until they reach the final electron acceptor…..oxygen!

So this step is aerobic (requires oxygen)

The ETC produces 32 ATP and H2O

Electron Transport Chain

The chain then repeats in the same way with FADH2

Section 9-2

Cellular Respiration FlowchartCarbon Dioxide (CO2) + Water (H2O)

Glucose (C6H1206) + Oxygen (02)

Glycolysis

Krebs Cycle

Electron Transport Chain

What happens if NO OXYGEN is available??The Kreb’s Cycle and Electron Transport Chain can’t function!! These are anaerobic conditions!!

FermentationChapter 9-1

The cell can use Fermentation instead!! Occurs in the Cytoplasm Just like

glycolysis!! Fermentation A series of reactions that convert NADH (from glycolysis) back into NAD allowing glycolysis to keep producing a small amount of ATP