Chapter 9: Cellular RespirationChapter 9: Cellular Respiration

Cellular Respiration

Cellular RespirationCellular RespirationLiving cells require

Organisms use as their main energy

source

Cellular respiration is the process of

Energy is released in the process of respiration when the cells of plants and animals

RespirationRespiration The breakdown of organic

molecules is Aerobic respiration

consumes

Anaerobic respiration is similar to aerobic respiration but

Fermentation is a

The breakdown of organic molecules is

Aerobic respiration consumes

Anaerobic respiration is similar to aerobic respiration but

Fermentation is a

Cellular RespirationCellular Respiration

Cellular respiration includes both but is

often used to refer to Although carbohydrates, fats, and

proteins are all consumed as fuel, it is helpful to trace cellular respiration with the :

Cellular respiration includes both but is

often used to refer to Although carbohydrates, fats, and

proteins are all consumed as fuel, it is helpful to trace cellular respiration with the :

Redox ReactionsRedox Reactions The during chemical reactions This released energy is used to Chemical reactions that transfer electrons

between reactants are called

In oxidation, a substance , or is

In reduction, a substance , or is

In cellular respiration, the

The during chemical reactions This released energy is used to Chemical reactions that transfer electrons

between reactants are called

In oxidation, a substance , or is

In reduction, a substance , or is

In cellular respiration, the

NAD+NAD+ In cellular respiration, glucose

and other organic molecules are broken down in a series of steps

• As an electron acceptor, NAD+ functions as an

• Each NADH (the reduced form of NAD+)

• NADH passes the electrons to the

In cellular respiration, glucose and other organic molecules are broken down in a series of steps

• As an electron acceptor, NAD+ functions as an

• Each NADH (the reduced form of NAD+)

• NADH passes the electrons to the

Electron Transport ChainElectron Transport Chain Unlike an uncontrolled

reaction, the electron transport chain passes electrons in a series of steps instead of one explosive reaction• O2 pulls electrons

• The energy yielded is

Unlike an uncontrolled reaction, the electron transport chain passes electrons in a series of steps instead of one explosive reaction• O2 pulls electrons

• The energy yielded is

Stages of Cellular Respiration

Stages of Cellular Respiration

1) Glycolysis - Anaerobic

2) Citric Acid Cycle - Aerobic

3) Oxidative phosphorylation - Aerobic

1) Glycolysis - Anaerobic

2) Citric Acid Cycle - Aerobic

3) Oxidative phosphorylation - Aerobic

MitochondriaMitochondria

1) Glycolysis•

2) Citric Acid Cycle•

3) Oxidative Phosphorylation (ETC)•

1) Glycolysis•

2) Citric Acid Cycle•

3) Oxidative Phosphorylation (ETC)•

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Step 1: GlycolysisStep 1: Glycolysis

“Splitting of sugar” Breaks down glucose

(C6H12O6) into

Occurs in the NAD picks up H+ and

electrons to form NADH2

“Splitting of sugar” Breaks down glucose

(C6H12O6) into

Occurs in the NAD picks up H+ and

electrons to form NADH2

Glycolysis SummaryGlycolysis Summary

Reactants

Reactants

Products

• **

Products

• **

Location:

Simple Summary

Summary total

Bridge ReactionBridge Reaction In the presence of O2, Before the citric acid cycle can begin, In the mitochondria matrix…

1) Pyruvic Acid loses a C to form

2) The lost carbon

3)Acetic acid binds with

In the presence of O2, Before the citric acid cycle can begin, In the mitochondria matrix…

1) Pyruvic Acid loses a C to form

2) The lost carbon

3)Acetic acid binds with

Step 2: The Kreb’s Cycle(Citric Acid Cycle)

Step 2: The Kreb’s Cycle(Citric Acid Cycle)

Takes place within the

There are , each catalyzed by a specific enzyme

The acetyl group of acetyl CoA joins the cycle by combining with oxaloacetate

The next seven steps

Takes place within the

There are , each catalyzed by a specific enzyme

The acetyl group of acetyl CoA joins the cycle by combining with oxaloacetate

The next seven steps

Step 2: The Kreb’s Cycle(Citric Acid Cycle)

Step 2: The Kreb’s Cycle(Citric Acid Cycle)

2 molecules of CO2 are NAD+ and FAD (flavin adenine dinucleotide -

another ion carrier)

The NADH and FADH2 produced by the cycle relay electrons extracted from food

The cycle generates

Recall that two molecules of pyruvate are formed during glycolysis resulting in

2 molecules of CO2 are NAD+ and FAD (flavin adenine dinucleotide -

another ion carrier)

The NADH and FADH2 produced by the cycle relay electrons extracted from food

The cycle generates

Recall that two molecules of pyruvate are formed during glycolysis resulting in

Kreb’s Cycle SummaryKreb’s Cycle Summary

Reactants

Reactants

Products

Products

Location:

Kreb’s Summary

Kreb's Summary 2

Step 3: Electron Transport Chain (ETC)

Step 3: Electron Transport Chain (ETC)

•

Takes place in the A series of molecules that

excited electrons pass along,

Most of the chain’s components are , which exist in

•

Takes place in the A series of molecules that

excited electrons pass along,

Most of the chain’s components are , which exist in

Step 3: Electron Transport Chain (ETC)

Step 3: Electron Transport Chain (ETC)

Following glycolysis and the citric acid cycle, NADH and FADH2 account for most of the energy extracted from food

These two electron carriers donate electrons to the electron transport chain, which powers ATP synthesis via

The carriers alternate as they accept and donate electrons

Electrons They are finally passed to O2

,forming

Following glycolysis and the citric acid cycle, NADH and FADH2 account for most of the energy extracted from food

These two electron carriers donate electrons to the electron transport chain, which powers ATP synthesis via

The carriers alternate as they accept and donate electrons

Electrons They are finally passed to O2

,forming

NADH and FADH2NADH and FADH2

Dump the electrons and protons they’ve gathered throughout glycolysis and the citric acid cycle

Again, • O2 + 2e- + 2H+ H2O

Electrons are passed through a number of proteins

The chain’s function is to break the large free-energy drop from food to O2 into smaller steps that release energy in manageable amounts

Dump the electrons and protons they’ve gathered throughout glycolysis and the citric acid cycle

Again, • O2 + 2e- + 2H+ H2O

Electrons are passed through a number of proteins

The chain’s function is to break the large free-energy drop from food to O2 into smaller steps that release energy in manageable amounts

ChemiosmosisChemiosmosis Electron transfer in the ETC causes

proteins to H+ then moves back across the

membrane, passing through channels in

ATP synthase uses the exergonic flow of H+ to drive

This is an example of chemiosmosis,

Electron transfer in the ETC causes proteins to

H+ then moves back across the membrane, passing through channels in

ATP synthase uses the exergonic flow of H+ to drive

This is an example of chemiosmosis,

ETC Summary

ETCETC

ETC SummaryETC Summary

Reactants

Reactants

Product • •

Product • •

Location:

Simpler ETC Summary

Best ETC Summary

Whole Respiration Process

Whole Respiration Process

Song I Found...

Total EnergyTotal Energy

Total ATP from 1 molecule of glucose in   Stage ATP + 4 TotalGlycolysis (b/c 2 are used in the first step) CA Cycle ETC

_________________ TOTAL  During cellular respiration, most energy flows in this sequence: Glucose -> NADH -> electron transport chain -> proton-motive force -> ATP

FermentationFermentation

Most cellular respiration requires Glycolysis can produce ATP

, glycolysis couples with to

produce ATP Fermentation uses instead of an electron

transport chain to generate ATP 2 Types:• •

Most cellular respiration requires Glycolysis can produce ATP

, glycolysis couples with to

produce ATP Fermentation uses instead of an electron

transport chain to generate ATP 2 Types:• •

Lactic Acid FermentationLactic Acid Fermentation In lactic acid fermentation,

Lactic acid fermentation by some fungi and bacteria is used

Human muscle cells use lactic acid fermentation

In lactic acid fermentation,

Lactic acid fermentation by some fungi and bacteria is used

Human muscle cells use lactic acid fermentation

Lactic Acid FermentationLactic Acid Fermentation Example: Burning feeling in

muscles during a workout

• From oxygen debt

•

• Lactate

Example: Burning feeling in muscles during a workout

• From oxygen debt

•

• Lactate

Alcohol FermentationAlcohol Fermentation In alcohol fermentation,

pyruvate is • Bacteria and fungi (yeast)

Alcohol fermentation by yeast is used in

In alcohol fermentation, pyruvate is • Bacteria and fungi (yeast)

Alcohol fermentation by yeast is used in

FermentationFermentation Obligate anaerobes carry out

fermentation or anaerobic respiration and

Yeast and many bacteria are facultative anaerobes, meaning that

Obligate anaerobes carry out fermentation or anaerobic respiration and

Yeast and many bacteria are facultative anaerobes, meaning that

Review

Role of MacromoleculesRole of Macromolecules Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration Glycolysis accepts a wide range of • Amino groups can feed

Fats are digested to • Fatty acids are broken down by beta oxidation and yield

An oxidized gram of produces more than twice as much ATP as an oxidized gram of

Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration Glycolysis accepts a wide range of • Amino groups can feed

Fats are digested to • Fatty acids are broken down by beta oxidation and yield

An oxidized gram of produces more than twice as much ATP as an oxidized gram of

Regulation of Cell Respiration

Regulation of Cell Respiration

is the most common mechanism for control• If ATP concentration begins to , respiration

• When there is of ATP, respiration Control of catabolism is based mainly on

is the most common mechanism for control• If ATP concentration begins to , respiration

• When there is of ATP, respiration Control of catabolism is based mainly on

Review QuestionsReview Questions1. Define cellular respiration and state its importance as a life process.2. Differentiate between aerobic respiration, anaerobic respiration, and

fermentation.3. State and explain the chemical equation for cellular respiration.4. Define oxidation and reduction and explain the idea of redox reactions.5. Explain the use of NAD+ as a coenzyme.6. Explain the electron transport chain (ETC).7. Name the 3 major stages of cell respiration, along with their locations.8. Explain glycolysis, stating the reactants, products, and major activities.9. Explain the bridge reaction, stating the reactants, products, and major

activities.10. Explain the Kreb’s cycle, stating the reactants, products, and major

activities.11. Explain glycolysis, stating the reactants, products, and major activities.12. Explain the ETC, stating the reactants, products, and major activities.13. Explain the role of oxygen in the ETC.14. Define chemiosmosis and explain its role in cellular respiration.15. Differentiate between lactic acid fermentation and alcohol

fermentation.16. Differentiate between oblicate anaerobes and facultative anaerobes.17. Explain the role of macromolecules in cellular respiration.18. Explain how cell respiration is regulated.