Chapter 4Cellular Respiration

GCAMr. Cobb

Cellular respirationFood (glucose) into ATP

Not “breathing”

It can be either aerobic or anaerobic

Aerobic – require oxygen

Anaerobic – does not require oxygen

3 Stages of 3 Stages of Aerobic Cellular RespirationAerobic Cellular Respiration

Glycolysis

Preparation Step &

Citric Acid Cycle (Kreb’s Cycle)

Electron Transport

Glycolysis1st step in aerobic or anaerobic

Location: cytoplasm of cell

Glucose 2 Pyruvic Acid molecules

This process does not require Oxygen.

Total energy made is 4 ATP, but 2 is needed to start the rxn. 2 ATP is extra.

What is made? 2 NADPH, 2 ATP, 2 Pyruvic Acids

Glycolysis

glucose pyruvate

Glycolysis

Glucose Pyruvic acid

Pyruvic Acid

AerobicO2 required

Release H2O and CO2 and energy

Remember that cellular respiration is the opposite of photosynthesis.

C6H1206 + 6 O2 6 CO2 + 6 H2O + ATP

Aerobic RespirationGlycolysis is 1st step and in both aerobic or

anaerobic respiration

2 Steps in Aerobic Respiration:

2. Citric Acid Cycle or Krebs Cycle

3. Hydrogen and Electron Transport System

Cellular Respiration Flowchart (aerobic)

Glucose(C6H1206)

+Oxygen

(02)

Glycolysis KrebsCycle

ElectronTransport

Chain

Carbon Dioxide

(CO2)+

Water(H2O)

+ATP

Citric Acid Cycle (Krebs)2 Pyruvic acids from glycolysis diffuses into the

mitochondria.

Pyruvic acid is turned into acetyl CoA and CO2 is released.

One glucose molecule makes the cycle turn twice

Chemical rxns in Mitochondria

Products: 6 NADH, 2 FADH2, 2 ATP and 4 CO2

Krebs cyclepyruvate acetyl CoA & CO2

Citric Acid Production

 The Krebs Cycle

Section 9-2

Mitochondrion

H+ and e- transport molecules:

1) NADH

2) FADH2

Electron Transport NADH and FADH2 from Krebs Cycle are pumped

by electron energy across the inner membrane (cristae) and creates a concentration difference.

The H ions come back across through the ATP synthase and create ATP.

Oxygen (from what we breathe in) comes in and binds to the H ions to make water.

Electron Transport32 ATP

Water is made from the Hydrogen and Oxygen.

Electron TransportElectron Transport

Mitochondria * two membranes

- outer - inner (folded)

Animationhttp://www.science.smith.edu/departments/

Biology/Bio231/krebs.html

ELECTRON TRANSPORT

CHAIN

matrix

HH++

HH++

HH++

HH++

HH++

HH++

MitochondriaMitochondria

HH++

HH++

NADH

HH++

FADH2

e-

HH++

HH++ e-

HH++

Electrons

* passed across inner membrane

* their energy gradually decreases

* energy used to transport HH++

into the intermembrane space.

OxygenOxygen * the final electron acceptor * joins with HH++ to produce HH22O.O.

If there is no oxygen,the electron chain stops

because there is no way to release electrons . .

electrons

matrix

HH++

HH++

HH++

HH++

HH++

HH++

MitochondriaMitochondria

HH++

HH++

NADH

HH++

FADH2

e-

HH++

HH++ e-

HH++

What happens when there is no oxygen

to accept the electrons?

* glycolysis done

* then fermentation in cytoplasm

2 kinds

1)lactic acid

2)ethanol

26

Products of Fermentation

fermentation

0 ATP

Just takes e-& H+ off NADH

so glycolysis can continue

Alcoholic FermentationAlcoholic Fermentation

After glucose broken down to pyruvate,

then pyruvate broken down

to CO2 and ETHANOL.

Alcoholic FermentationAlcoholic Fermentation

by bacteria & yeast

used to make bread, alcohol,

Lactic Acid fermentation

By human muscle cells& bacteria

Used to make cheese, yogurt, sour kraut

If you work anaerobically,

fermentation occurs in your muscles

lactic acid builds up

results in results in muscle sorenessmuscle soreness