Cellular Respiration

Cellular Respiration

Glycolysis

How much energy is in food?

• 1 gram of glucose = 3811 calories– calorie – amount of energy needed to raise

the temp of water by 1°C

• Calorie with a capital “C” = a kilocalorie– Calories are how foods are labeled– 1 kilocalorie = 1000 calories

Glycolysis

• The gradual release of energy from glucose molecules within the cell

• There are two paths after glycolysis:– With O2 = Cellular Respiration

– Without O2 = Fermentation

Glycolysis Video

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Section 9-1 Glycolysis

One moleucle of glucose is broken into 2 molecules of pyruvic acid (a 3-carbon sugar)

Glycolysis: ATP Production

• To make energy you need to invest a little 1st to break the glucose apart– 2 ATP put in

• How many ATP are gained from glycolysis?– 2 ATP (4 total, but 2 cancel out with the initial investment)

Glycolysis: NADH Production

• 4 high energy electrons are removed from glucose

• They are added to the electron carrier NAD+

– This produces 2 NADH

Advantages of Glycolysis

• Happens very quickly– Even though energy output is small, it

happens so often that it produces large amounts of energy

• Does not require oxygen– Can happen anytime

Disadvantage of Glycolysis

• Happens to fast sometimes– When it produces to much ATP all of the cell’s

avalible NAD+ is used up– Without NAD+ glycolysis can not continue


• Process that releases energy by breaking down glucose and other food molecules in the presences of oxygen

• 6 O2 + C6H12O6 → 6 CO2 + 6 H2O + Energy

GlucoseGlycolysis

Cytoplasm

Pyruvic acid

Electrons carried in NADH

Krebs Cycle

Electrons carried in

NADH and FADH2 Electron

Transport Chain

Mitochondrion


Mitochondrion

Section 9-1

Homework

• Pg 225 Section Assessment– #1, 2, 4, & 5


The Krebs Cycle &

Electron Transport Chain

Review

• Glycolysis happens with or without O2

– Goes to Cellular respiration with O2

• aerobic

– Goes to Fermentation without O2

• anerobic

GlucoseGlycolysis

Cytoplasm

Pyruvic acid


Krebs Cycle



Transport Chain

Mitochondrion


Mitochondrion

Section 9-1

Krebs Cycle

• Pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions.

Krebs Cycle

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Krebs Cycle


• Uses high energy electrons from the Krebs Cycle & Glycolysis to convert ADP to ATP


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The Electron Transport Chain

Section 9-2

Glucose(C6H1206)

+Oxygen

(02)

GlycolysisKrebsCycle

ElectronTransport

Chain

Carbon Dioxide

(CO2)+

Water(H2O)


Classwork/Homework

• Explain the entire cellular respiration process. – Use words and/or pictures.


Fermentation

Review

• Everything starts with Glycolysis– With oxygen – goes to Cellular Respiration– Without oxygen – goes to Fermentation

GlucoseGlycolysis

Cytoplasm

Pyruvic acid


Krebs Cycle



Transport Chain

Mitochondrion


Mitochondrion

Section 9-1

Fermentation

• Glycolysis + new process = Fermentation

• Fermentation releases energy from food molecules by producing ATP in the absences of oxygen

• During fermentation, cells convert NADH to NAD+ by passing high-energy electrons back to pyruvic acid.

Two Types of Fermentation

• Alcoholic – Pyruvic acid + NADH → alcohol + CO2 + NAD+

– Done by yeast and other microorganisms

• Lactic Acid– Pyruvic acid + NADH → lactic acid + NAD+

– Done in humans and other animals

Lactic Acid Fermentation

Energy & Exercise

• How does your body obtain energy for quick exercise?

• How does your body obtain energy for long exercise?

• Why do runners breathe heavily after a race?

• Why do your muscle hurt after exercise?

Classwork/Homework

• Pg 237– # 1-10 – just the letter of the answer– #12-13 & 15-19 – complete sentences


Cellular Respiration vs. Photosynthesis

Documents

Cellular Respiration