Cellular Respiration

chapter 7

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ENERGETICS ch 6&7the Big Picture

A. Autotrophs ex. Plants

make Glucose

from CO2, H2O and Light

in their chloroplasts.

B. Autotrophs & Heterotrophs

make ATP

From C6H12O6 & O2

in their mitochondria.

Q: Animals are heterotrophs… what do they need to live?

A: Food, Oxygen, Water

Q: WHY???

A: To make ATP so their cells can do cellular work.

Ex. powering: active transport, cell division, protein synthesis.

Q: How is food turned to ATP?

A: The biochemical pathway of aerobic respiration OXIDIZES food, removing electrons and H+, which are used to create ATP by chemiosmosis.

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ATP

Chemical work Mechanical work Transport work

PP

P

P

P

P

PADP

Reactants

Product

Molecule formed Protein moved Solute transported

Motorprotein

Membraneprotein Solute

CELLULAR RESPIRATION IS…

The complex biochemical pathway… – Series of linked chemical reactions in which– the product of the first reaction is a reactant in the next

By which cells make ATP by breaking down organic compounds.

1. Carbohydrates (easiest)

2. Proteins

3. Lipids

Enzymes are used at each step in the process…

• What do you remember about enzymes?

ENZYMES• Protein (polypeptide made of amino acids)

catalysts of reactions that aid in all steps of metabolism.

• Shape of “active site” is specific for a certain substrate- so there is a different enzyme used in each rxn.

• Lower the amount of activation energy needed to start a rxn- so they speed up reactions.

• Are reused.• Examples from this unit: Coenzyme A ,

water splitting enzyme, ATP synthase, Rubisco,.

• Enzymes assist in every step of the biochemical pathways of photosynthesis and cellular respiration.

ACTIVATION ENERGY

Amount of energy needed to start a chemical reaction.

HERE’S A REACTION WITH A HELPER… A CATALYST.ENZYMES are biological catalyst.

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SOME RELEASE ENERGYex. cellular respiration

SOME REQUIRE ENERGYex. Photosynthesis.

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

OXIDATION is losing electrons (and protons)

C6H12O6 6 CO2 + 12 H+ + 12 e-

Glucose is oxidized

REDUCTION is gaining electrons (and protons)

6 O2 6 H2O

Oxygen is reduced

The electrons are picked up by “electron carrier molecules” and transported to the Electron Transport Chain of proteins where they do work.

Energy Molecules: ATP & NADH

e- e- H+ATP

NADH

ADP

NAD+

A molecule that gains electrons is REDUCED. A molecule that loses electrons is OXIDIZED.

A molecule that gains a phosphate group is PHOSPHORYLATED.

Energy Molecules

cellular respiration’s breakdown of glucose begins with the biochemical pathway

of GLYCOLYSIS

• means“to cut a sugar”• CREATES:• 2 ATP• 2 NADH• 2 pyruvic acid

• means“to cut a sugar”• CREATES:• 2 ATP• 2 NADH• 2 pyruvic acid

GLYCOLYSIS

TWO PHASES:1. Energy investment

requires 2 ATP2. Energy payoff:

creates 2 NADHcreates 4 ATP

PRODUCTS:1) 2 NADH2) 2 ATP (net gain)3) 2 pyruvic acid

GLYCOLYSIS

TWO PHASES:1. Energy investment

requires 2 ATP2. Energy payoff:

creates 2 NADHcreates 4 ATP

PRODUCTS:1) 2 NADH2) 2 ATP (net gain)3) 2 pyruvic acid

Note: only the carbonSkeleton is shown. There Are oxygens & hydrogensalso

What happens after glycolysis is determined by the presence or

absence of oxygen…

(without oxygen) Anaerobic Respiration

FERMENTATION1. lactic acid

NAD+2. Ethyl alcohol carbon Dioxide NAD+

(with oxygen) Aerobic RespirationOXIDATIVE RESPIRATION1. 6 CO2

2. 8 NADH3. 2 FADH2

4. up to 36 ATP5. 6 H20 molecules

(without oxygen) Anaerobic Respiration

FERMENTATION1. lactic acid

NAD+2. Ethyl alcohol carbon Dioxide NAD+

(with oxygen) Aerobic RespirationOXIDATIVE RESPIRATION1. 6 CO2

2. 8 NADH3. 2 FADH2

4. up to 36 ATP5. 6 H20 molecules

Glycolysis & Fermentation

Q: If fermentation doesn’tproduce any more ATPthen why bother with it???

A: fermentation restoresNADH to NAD+, NAD+ is essential for glycolysis.

If oxygen is present… reactions occur in the MITOCHONDRIA

1. Oxidation of Pyruvate2. Reduction of NAD+ & FAD3. Electron Transport Chain4. Proton Pumping5. Concentration Gradient6. Chemiosmosis 7. ATP synthesis

1. Oxidation of Pyruvate2. Reduction of NAD+ & FAD3. Electron Transport Chain4. Proton Pumping5. Concentration Gradient6. Chemiosmosis 7. ATP synthesis

Pyruvic acid conversion to Acetate & The Krebs Cycle

• pyruvic acid diffuses into the matrix & is oxidized

• NAD+ is reduced NADH.• A molecule of CO2 is given off • The remaining 2 carbon fragment

(acetate)joins with co-enzyme A

1. Acetyl-CoA enters the Krebs cycle and joins with a 4 carbon compound (OAA)

2. 2 more CO2 are released and the energy is transferred into: 3 NADH, 1FADH2, 1ATP

3. OAA is regenerated4. Process repeats

Pyruvic acid conversion to Acetate & The Krebs Cycle

• pyruvic acid diffuses into the matrix & is oxidized

• NAD+ is reduced NADH.• A molecule of CO2 is given off • The remaining 2 carbon fragment

(acetate)joins with co-enzyme A

1. Acetyl-CoA enters the Krebs cycle and joins with a 4 carbon compound (OAA)

2. 2 more CO2 are released and the energy is transferred into: 3 NADH, 1FADH2, 1ATP

3. OAA is regenerated4. Process repeats

Electron Transport Chain• NADH and FADH2 supply

electrons to the ETC.• Series of proteins that electrons

travel through. • Oxygen is the final electron

acceptor at the end of the ETC- water is formed.

• Some energy is used to pump H+ into the Inter Membrane Space.

• CHEMIOSMOSIS • Kinetic Energy of H+ diffusing

through ATP synthase channels is used to produce 34 ATP.

• (2 + 2 + 34 = 38)

Electron Transport Chain

• NADH and FADH2 supply electrons to the ETC.

• Series of proteins that electrons travel through.

• Oxygen is the final electron acceptor at the end of the ETC- water is formed.

• Some energy is used to pump H+ into the Inter Membrane Space.

• CHEMIOSMOSIS • Kinetic Energy of H+ diffusing

through ATP synthase channels is used to produce 34 ATP.

• (2 + 2 + 34 = 38)

VOCAB SCRAMBLE

ATP NADH FADH2 NADPHATP synthase ADP PSII PS1Water oxygen pigments chloroplastMitochondria Coenzyme A CO2 Calvin CycleKrebs Cycle chemiosmosis RUBP PGALGlycolysis ETC Rubisco

protonpumpPhotons NAD+ FAD NADP+Chlorophyll A Chlorophyll B carotenoids PGA

Make a VENN DIAGRAM showing these words’associationPHOTOSYNTHESIS BOTH RESPIRATION

VOCAB SCRAMBLEPHOTOSYNTHESIS BOTH RESPIRATION• used WATER formed• formed OXYGEN Used• formed GLUCOSE used• Rubisco ENZYME Co-A• chloroplast ORGANELLE mitochondrionPigments:Chlorophyll A&B, Carotenoids glycolysis• Photons-Photosystems 1 &2• Endergonic RXN Exergonic• NADP+/NADPH electron carriers NAD+/NADHFAD/FADH2

• Calvin CYCLE Krebs• RuBP OAA• ATP/ADP ATP synthase• ETC/proton pump/chemiosmosis•