RespirationReleases energy from glucose ATP

Respiration

Glucose + oxygen carbon dioxide + water + ATP

C6H12O6 + 6O2 + 38 ADP + 38 Pi 6 CO2 + 6 H2O + 36 ATP

http://videos.howstuffworks.com/hsw/12580-the-science-of-life-cellular-respiration-video.htm (introduction, 1.5min)

• Rod shaped

• Double membrane

• Inner membrane folded extensively into cristae to increase surface area for reactions

ATP (Adenosine Tri-Phosphate)

Adenosine Diphosphate phosphate

ADP + Pi + energy ATP

High energy phosphate bonds

Universal energy carrier

Quick easy source of energy (compared to glucose)

PiAdenosine Pi Pi

PiPiAdenosine

Pi

Energy from Glucose

Energy for Life

Respiration – 3 phases

1. Glycolysis (cytoplasm) Glucose 2 pyruvate

2. Krebs Cycle (matrix) Pyruvate CO2 & H

3. Electron transfer chain (mitochondrial membrane). Electrons are passed along a series of carriers. Oxygen is the final acceptor of H+ and e- to make water.

cytoplasm matrix membranes

GLUCOSE

PYRUVATE

2ATP

GLYCOLYSIS

2ATP 34ATP

OXIDATIVE PHOSPHORYLATION

CO2

NADH2

NAD FAD

NADH2 FADH2

KREB’S CYCLE

NAD

O2

H2O

ELECTRON TRANSPORT

CHAIN

Glycolysis

• Glucose too large to diffuse into mitochondria

• Glucose (6C) 2 pyruvate (3C)

• NAD NADH + H+

• 2 ATP

• Does not require oxygen

Cytoplasm Membrane Mitochondrion

Glucose (6C)

Alcohol & CO2

Lactic acid

yeas

t fe

rmen

tatio

n lactic

fermentation

Pyruvate (3C)

low oxygennormal

2 ATP

4 ADP

4 ATP

CO2 + H2O

36 ADP

36 ATP

GLYCOLYSIS

Kreb’s (citric acid) Cycle

• Pyruvate acetyl coA in mitochondria

• acetyl-coA 2 CO2 (waste) + coA (recycled) + H2

– NAD + H2 NADH2

– FAD + H2 FADH2

Krebs Cycle

Pyruvate

Acetyl coA

CO2

(waste)

coA

NAD & FADA co-enzyme carrier molecule

NADH2

FADH2

Electron Transfer Chain

• NADH2 + FADH2

NAD + FAD + H+ + high energy electrons

• e- transferred along a series of electron carriers, cytochromes, in the cristae. Energy from the electrons is used to produce ATP at each move.

• Oxygen is the final hydrogen acceptor water

NADH+

H+

e-

e-

e-

e- e-

e- e-

e-

O

ATP

ATP

ATP

ATP

NADH2

e-

e-

H2H2O

34 ATP

This cannot occur without oxygen!!!!!

Rate of respiration1. ↑Temperature ↑reaction rate (up to an optimum temp.)

(↑ energy of enzymes and substrate ↑collisions).

2. ↑ Body’s energy demands ↑ rate of respiration (Eg running muscle cells need more energy)

3. Poisons. Eg Cyanide prevents O2 combining with hydrogen ( ↓ respiration).

Where would you expect to find the most mitochondria?

eg Muscle and liver cells

Active cells with high energy needs

MENU

Key Words

Exercises

Quick Quiz

MCQ

Videos

Key words• respiration• mitochondria• cristae• surface area• matrix• ATP• glycolysis• Kreb’s cycle• citric acid cycle• electron transport chain• glucose• pyruvate• electron carrier• final acceptor

• acetyl coA• NADH2

• FADH2

• oxidative phosphorylation• lactic fermentation• yeast fermentation• anaerobic

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QUICK QUIZ1. Cellular respiration takes place in the ____

2. Glucose is broken down into ____ during ____

3. ____ is small enough to enter the mitochondrion

4. ____ in the matrix catalyse the reactions of the ____ cycle

5. The inner mitochondrial membrane is folded to increase ____

6. NAD and FAD carry ____ to the electron transport chain

7. ____ is the universal energy carrier

8. Most ATP is produced in the ____ stage

9. ____ respiration yields 34-38 ATP

10. ____ respiration occurs in the absence of sufficient oxygen

11. Yeast undergoes ____ under anaerobic conditions

12. Animals produce ____ under anaerobic conditions

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Answers

QUICK QUIZ1. Cellular respiration takes place in the mitochondria

2. Glucose is broken down into pyruvate during glycolysis

3. pyruvate is small enough to enter the mitochondrion

4. enzymes in the matrix catalyse the reactions of the Krebs cycle

5. The inner mitochondrial membrane is folded to increase surface area

6. NAD and FAD carry electrons to the electron transport chain

7. ATP is the universal energy carrier

8. Most ATP is produced in the electron transport chain stage

9. aerobic respiration yields 34-38 ATP

10. anaerobic respiration occurs in the absence of sufficient oxygen

11. Yeast undergoes fermentation under anaerobic conditions

12. Animals produce lactic acid under anaerobic conditions

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Exercise

• Workbook pp 67-72, all questions• Pathfinder p45 q5

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READING• Pathfinder p43• Excellence in Biology 126-130

VideosBack to menu

These videos contain more detail than you need, but the basics are very good!

• http://www.5min.com/Video/Glycolysis-and-the-Krebs-Cycle-150946257 (summary, Wolfe, 8 min)

• http://www.5min.com/Video/Oxidative-Phosphorylation-150626566 (ATP, 10min)

• http://www.articlesbase.com/videos/5min/150626157 (Glycolysis, 14min)

proteins lipidspolysaccharides

amino acids monosaccharides fatty acids + glycerol

pyruvate

acetyl coA

NADH2 + FADH2

wastes - CO2 + H2O

Krebs

Location Needs Makes ATP yield

Glycolysis

Krebs cycle

Electron transfer

chain

Location Needs Makes ATP yield

Glycolysis cytoplasm Glucose Pyruvic acid & hydrogen

2

Krebs cycle

matrix Pyruvate(or acetyl

coA)

Cyclic but releases ATP & hydrogen

(CO2 as waste)

2

Electron transfer

chain

cristae Hydrogen and oxygen

ATP & water 32-4