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Cellular RespirationCampbell Chapter 9

Slide shows modified from: Glenbrook High School AP site

http://gbs.glenbrook.k12.il.us/Academics/gbssci/bio/apbio/Index/index.htm

& Dr. Chuck Downing http://gohs.tvusd.k12.ca.us/TeacherWebs/Science/CDowning/default.aspx

http://www.clickatutor.com/mitochondria.jpg

___________ use energy from sunlight or chemicals to make their own food

AUTOTROPHShttp://www.inclusive.co.uk/downloads/images/pics2/tree.gif

In the last chapter green plantsused ________________trap energy from __________ and make ______________

sunlightfood (glucose)

PHOTOSYNTHESIS

http://206.173.89.42/REALTYWITHALOHA_COM/piphoto/funny%20sun%20with%20sunglasses.gif

We get our energy from the __________ plants made during _______________ when we eat plants or eat animals that ate the plants.

GLUCOSE

In this chapter we will learn how ______________

get their energy by consuming other

organisms.

 Image from: http://ag.ansc.purdue.edu/sheep/ansc442/Semprojs/2003/spiderlamb/eatsheep.gif

HETEROTROPHS

http://www.cibike.org/Eating.htm

PHOTOSYNTHESIS

In this chapter, we will learn how this glucose is ____________ by organisms and the _______ is stored as _______

What kind of organisms do this?

energybroken down

ATP

Animals(Including humans)

ALL LIVING THINGS NEED ENERGY!All organisms burn glucose for fuel

fungi bacteria

plants

PHOTOSYNTHESIS

___________ + _________ + ___________ →_______________ + __________6 CO2 6 H2O C6H12O6 6O2

_____________ + _________ →________ + __________ + __________

______________________________________________________________

CELLULAR RESPIRATIONC6H12O6 6O2

6 CO2 6 H2O

The two equations are exact opposites!

OXIDATION REDUCTIONIs Loss of electrons Is Gain of

electronsRemove H Add HReleases energy Stores energyExergonic Endergonic

REMEMBER: OIL RIG

Loss of hydrogen atoms

Gain of hydrogen atoms

Energy

OXIDATION

REDUCTION

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CELLULAR RESPIRATION happens __________ in ________________.

If all the energy was released in one step… most would be lost as ____________________!

http://plato.acadiau.ca/COURSES/comm/g5/Fire_Animation.gif

slowly many steps

light and heat

See why cells use cellular respiration

• Prevents energy release in 1 explosive step• Allows energy to be released slowly in steps

and captured as ATP

• Electron route: food → NADH → ETC → oxygen

ELECTRON TRANSPORT CHAIN

MITOCHONDRIA = cell power plantSurrounded by ___________ membrane

Outer membrane & Inner membrane (called

_______________ )

Space between inner membrane & outer membrane

= ____________________

Space inside cristae folds

= _________________

INTERMEMBRANE SPACE

DOUBLE

MATRIX

CRISTAE

FAD → FADH2

NAD+ → NADH

HIGH ENERGY ELECTRON CARRIERS

See glycolysis movie

The first step in cellular respiration = _______________

• happens in the ________________ outside the mitochondria• occurs _________________________

GLYCOLYSIS

CYTOPLASM

with or without oxygen

• Details of glycolysis

Steps – A fuelmolecule is energized,using ATP.

1 3

1

GlucosePREPARATORY

PHASE(energy investment)Step

2

3

4

Glucose-6-phosphate

Fructose-6-phosphate

Glyceraldehyde-3-phosphate (G3P)

Step A six-carbonintermediate splits into two three-carbon intermediates.

4

Step A redoxreaction generatesNADH.

55 ENERGY PAYOFF

PHASE1,3-Diphosphoglyceric acid(2 molecules)

6

Steps – ATPand pyruvic acidare produced.

6 9 3-Phosphoglyceric acid(2 molecules)7

2-Phosphoglyceric acid(2 molecules)8

2-Phosphoenolpyruvate(2 molecules)

9

(2 moleculesper glucose molecule)

Pyruvic acid

Fructose-1,6-diphosphate

Glycolysis (GLYKOS = ________ LYSIS= ___________ )

Requires ____________to get it started.

Split apartsweet

ENERGY

MITOCHONDRION

= using energy from breaking a chemical bond to add a P directly from a phosphorylated molecule to ADP without a proton gradient

SUBSTRATE LEVEL PHOSPHORYLATION

PYRUVIC ACID MOVES TO NEXT STEP

IF THERE IS NO OXYGEN (______________)

IF THERE IS OXYGEN (_____________)

= ANAEROBIC

= AEROBIC

Cellular respiration

•Glycolysis: cytosol; glucose → pyruvate

•Kreb’s Cycle: •mitochondrial matrix;

•pyruvate → CO2

•NADH made

Electron Transport Chain: cristae; NADH & FADH2 donate electrons → oxygen

Pyruvate is transported into mitochondrion and Acetyl CoA produced

For each pyruvate converted into acetyl CoA 1 molecule of CO2 is released;NAD+ ---> NADH;Coenzyme A (from B vitamin)

Krebs Cycle Animation-

Kreb’s Cycle =Citric Acid Cycle

OAA CITRIC ACID

Krebs Cycle Animation

Kreb’s Cycle• Oxaloacetate (OAA) combines with 2

C’s from Acetyl CoA to make Citric acid

• CoA recycles• 2 C atoms from pyruvate → exit as CO2

For each pyruvate that enters:2 CO2 released 3 NAD+ reduced to 3 NADH; 1 FAD+ reduced to 1 FADH2 (riboflavin, B vitamin); 1 ATP molecule

Electron transport chain

More on Making ATP

• 3 places in the chain make ATP

NADH

FADH2

• Electrons from NADH start “higher” in the waterfall, so they generate more ATP than FADH2 electrons, which start “lower” in the waterfall and miss one ATP-generating step.

Electron transport chain• ETC includes

Cytochromes Ubiquinone (Q)

• NADH & FADH2 pass electrons pass down ETC

• Energy from moving electrons concentrates H+ ions in __________________

• ________________: harnesses the flow of H+ back into the matrix make ATP (oxidative phosphorylation)

• ________ is final electron acceptor → ________

intermembrane space

ATP synthase

Oxygen H2O

Cellular Respiration Grand Total• Glycolysis: →2 ATP

(substrate-level phosphorylation)

• Kreb’s Cycle:→ 2 ATP (substrate-level phosphorylation)

• Electron transport & oxidative phosphorylation: 2 NADH (glycolysis) → 6ATP 2 NADH (acetyl CoA) →6ATP 6 NADH (Kreb’s) → 18 ATP 2 FADH2 (Kreb’s) → 4 ATP

38 TOTAL ATP from 1 molecule of glucose (-2 ATP to transport 2 pyruvate into mitochondria)

NET of 36 ATP

WHAT IF THERE IS NO OXYGEN?

IF THERE IS NO OXYGEN (______________)

IF THERE IS OXYGEN (_____________)

= ANAEROBIC

= AEROBIC

Related metabolic processes

Fermentation:• alcohol~

pyruvate →ethanol • lactic acid~

pyruvate → lactate

_______ +_____ →__________ + ______ + _____

ALCOHOLIC FERMENTATION

PYRUVIC ACID

ALCOHOL

• Happens when yeast makes bread dough rise• CO2 bubbles make air spaces in bread• Alcohol evaporates during cooking

CO2 NAD+

http://www.deliciousdelicious.com/archives/herb%20bread%201.jpg

_______ +_____ →__________ + ______ + _____

ALCOHOLIC FERMENTATION

PYRUVIC ACID

ALCOHOL

Used to makealcoholic beverages

CO2 NAD+

http://www.firstpath.com/images/alcohol.jpg

_______ +_____ →______________ + ________

LACTIC ACID FERMENTATION

PYRUVIC ACID

LACTIC ACID

Happens in muscles during exercise when body can’t get oxygen to tissues fast enough.

Lactic acid builds up in muscles causing soreness

NAD+

http://www.miranda.com/library.en/Images/Pictures/girls-runners.jpg

_______ +_____ →______________ + ________

LACTIC ACID FERMENTATION

PYRUVIC ACID

LACTIC ACID

Happens when bacteria are used to make foods and beverages like yogurt, cheese,buttermilk, sauerkraut, kimchi

NAD+

http://chronicle.augusta.com/images/headlines/032200/DANNON_YOGURT.jpghttp://www.reillydairy.com/natural_cheese.html

WITHOUT OXYGEN, PYRUVIC ACID ___________ and all the _______ carriers get full.

Eventually glycolysis will

WHY DO FERMENTATION?WHY NOT JUST KEEP MAKING ATP USING GLYCOLYSIS?

builds up

NAD+

NAD+

_______ +_____ →__________ + ______ + _____

FERMENTATION HAPPENS so cells can ____________________ needed to keep glycolysis going

PYRUVIC ACID

ALCOHOL

→

CO2 NAD+

REGENERATE the NAD+

LACTIC ACID NAD+

→

You get the NAD+ carriers back

______

__________________________= organisms that can make ATP using

either fermentation or cellular respiration

Ex: yeast and many bacteria

With oxygen pyruvate → Krebs cycle

Without oxygen → fermentation

FACULTATIVE ANAEROBES

Organisms can use a variety of molecules for fuel

__________________=breakdown of fatty acids into 2 carbon fragments that enter Krebs cycle as acetyl CoA

1 g of fat → twice as muchATP as 1 g of carbohydrate

Beta oxidation=

Evolutionary Significance• Most widespread metabolic pathway… suggests ancient

prokaryotes probably used glycolysis to make ATP before oxygen was present

• Earliest fossil bacteria present 3.5 billion years ago but large amounts of oxygen not present until 2.7 billion years ago

• Glycolysis happens in cytoplasm without membrane bound organelles suggests it was found in early prokaryotic cellssince eukaryotes appeared 1 billion years after prokaryotes (Endosymbiotic theory)

VOCAB OVERLOAD ?

CHEMIOSMOSIS

http://student.ccbcmd.edu/~gkaiser/biotutorials/energy/atpsynthase_il.html

= Generation of ATP from a proton gradient. It occurs in all living things

Chloroplasts do it to make ATP in light reactions

Mitochondria do itto make ATP following ETC

Prokaryotes creategradient across cellmembrane to make ATPto pump nutrients & waste and move flagella

PHOTOPHOSPHORYLATION= Using hydrogen gradient generated by

thylakoid membrane during the light reactions of photosynthesis to make ATP

CHLOROPLAST

MITOCHONDRION

= using proton gradient created by electron transport chain in cristae membrane to make ATP

OXIDATIVE PHOSPHORYLATION

MITOCHONDRION

= using energy from breaking a chemical bond to add a P directly from a phosphorylated molecule to ADP without a proton gradient

SUBSTRATE LEVEL PHOSPHORYLATION