bio 205 chapter 6 part 2 lecture

8/14/2019 BIO 205 Chapter 6 Part 2 Lecture

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BIO 205

Chapter 6, Part 2


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Aerobic Respiration

C6H12O6 + 6O2 + 38ADP + 38P 6CO2 + 6H2O +38ATP

Oxidative Phosphorylation

Krebs Cycle

Glycolysis

Three Processes:


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Spitting out carbon dioxide, ATP, NADH, and FADH2

Picking up pyruvate molecules from glycolysis

The Krebs cycle is like a constantly turning wheel:

This releases 2 NADH and 2 CO2

Combine the carbon with coenzyme A (CoA)to form acetyl-CoA

Remove a carbon from each pyruvatemolecule.

Before entering the Krebs cycle, enzymes:

The Krebs cycle is also called the citric acid cycle

The Krebs Cycle Extracts More Energy from Pyruvate.


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2 FADH2

6 NADH

2 ATP

4 CO2

For each two pyruvatemolecules that enterthe cycle, thefollowing moleculesare formed:


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2 FADH2

10 NADH

4 ATP

Totals


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Aerobic Respiration

C6H12O6 + 6O2 + 38ADP + 38P 6CO2 + 6H2O +38ATP


Krebs Cycle

Glycolysis

Three Processes:


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Oxygen accepts the electron pair at the end of the chain, acquires2 protons, and becomes water

NADH and FADH2 provide the source electrons for oxidative

phosphorylation

The electron transport chain is composed of electron carrierscalled cytochromes

The energy released is used to combine phosphate with ADP to

form ATP

Pairs of electrons are passed from one chemical substance toanother (electron transport), releasing energy

Oxidative PhosphorylationIs the Process by Which Most ATPMolecules Form



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ATP synthase harnesses the energy from the flowing protons to phosphorylate ADPinto ATP

A channel opens and the protons flow in through a channel in ATP synthase

The protons outside the membrane build up a concentration gradient

As the electrons move down the chain they use energy, which is harnessed topump protons out of the cell (chemiosmosis)


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Oxidative phosphorylation

The Krebs cycle

Glycolysis

Many mono-, di-, and

polysaccharides can be energysources for prokaryotes

Other Nutrients Represent PotentialEnergy Sources.

Other Aspects of Catabolism

They must all be preparedbefore being processed by:


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Fatty acids are broken down through beta oxidation

Deamination is the replacement of the amino group ina protein with a carbonyl group in protein breakdown

Cells use proteins for energy when fats andcarbohydrates are lacking

Chemical bonds in fats store large amounts of energy,making fats good energy sources


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Anaerobic respiration produces less ATP thanaerobic respiration

In anaerobic respiration, anaerobes use molecules

other than oxygen as the final e- receptor in the ETC

Anaerobic Respiration Produces ATP Using OtherFinal Electron Acceptors


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Pyruvate can be converted to lactic acid to reform NAD+coenzymes so glycolysis can produce ATP from glucose

Fermentation is used when oxygen and other alternativeelectron acceptors are unavailable

Fermentation Produces ATP Using an Organic Final Electron Receptor.


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Eukaryotes also perform fermentation, such as the yeast used in

alcoholic fermentation to create alcoholic beverages


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Patterns of Metabolism

Chemoautotrophs use inorganic compounds as theirenergy source.

Photoautotrophs use light as their energy source.

Autotrophs synthesize their own foods from simplecarbon sources like carbon dioxide.

Autotrophs and Heterotrophs Get Their Energy and

Carbon in Different Ways.


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Chemoheterotrophs use organic compoundsboth for energy and carbon sources.

Photoheterotrophs use light as their energysource and organic compounds as their source ofcarbon.

Heterotrophs gain energy and carbon fromoutside sources.

Parasites feed on living organic matter.

Saprobes feed exclusively on dead organic

matter.


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End of Chapter 6, Part 2

bio 205 chapter 6 part 2 lecture

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