Transcript
Page 1: Cellular Respiration Cellular respiration is the process by which cells make energy. They use glucose and oxygen to produce carbon dioxide, water and ATP

CellularRespiration

Cellular respiration is the process by which cells make energy.

They use glucose and oxygen to produce carbon dioxide, water

and ATP (usable energy)

Page 2: Cellular Respiration Cellular respiration is the process by which cells make energy. They use glucose and oxygen to produce carbon dioxide, water and ATP

A common misconception

Many people think “respiration” refers specifically to “breathing”

Actually respiration refers to the processes of getting energy from food.

All large animals (including humans) need to use oxygen to fully release the energy from food. That’s why the word respiration has also come to refer to breathing.

Page 3: Cellular Respiration Cellular respiration is the process by which cells make energy. They use glucose and oxygen to produce carbon dioxide, water and ATP

The Summary Formula:

C6H12O6 + 6 O2 6 CO2 + 6 H2O + energy Glucose + oxygen carbon dioxide + water Enough energy is released during cellular

respiration to produce up to 38 molecules of ATP

38 ADP + 38 PO4 38 ATP

Energy

Page 4: Cellular Respiration Cellular respiration is the process by which cells make energy. They use glucose and oxygen to produce carbon dioxide, water and ATP

cell

Glucose

Oxygen

Carbon dioxide

Watermitochondrion

Energy

(ATP)

Page 5: Cellular Respiration Cellular respiration is the process by which cells make energy. They use glucose and oxygen to produce carbon dioxide, water and ATP

Where it all happens: Mitochondiron

Glucose

ATP

Oxygen

CO2

Page 6: Cellular Respiration Cellular respiration is the process by which cells make energy. They use glucose and oxygen to produce carbon dioxide, water and ATP

Stages of Respiration:

Stage 1. Glycolysis(The splitting of sugars)

Stage 1. Glycolysis(The splitting of sugars)

Stage 2. Anaerobic(The fermentation of Pyruvic Acid)

Stage 2. Anaerobic(The fermentation of Pyruvic Acid)

Pyruvic Acid(CH3COCOOH)

Pyruvic Acid(CH3COCOOH)

No oxygen available Lots of oxygen available

A little energy (2 ATP / glucose molecule)

A lot of energy (38 ATP / glucose)

Stage 2a. Aerobic(the Krebs Cycle)

Stage 2b. Aerobic(Electron Transport)

Stage 2a. Aerobic(the Krebs Cycle)

Stage 2b. Aerobic(Electron Transport)

Page 7: Cellular Respiration Cellular respiration is the process by which cells make energy. They use glucose and oxygen to produce carbon dioxide, water and ATP

Glycolysis: Splitting the sugar

Glucose is split into two 3-carbon molecules called pyruvic acid

The Steps in Glycolysis are: Phosphate from ATP is joined to glucose, making

a 6-carbon phosphate The 6-C phosphate breaks into 2 PGAL Hydrogen is removed and phosphate added to

make two 3-carbon phosphates The two 3-C phosphates are converted to pyruvic

acid, giving off enough energy for 4 ATP

Page 8: Cellular Respiration Cellular respiration is the process by which cells make energy. They use glucose and oxygen to produce carbon dioxide, water and ATP

Glycolysis Diagram

2 Pyruvic Acid (pyruvate)CH3COCOOH

Glucose C6H12O6 CCCCCC

CCC CCC

6 carbon-phosphate

2 PGAL

3 carbon-phosphate

P-CCCCCC-P

P-CCC P-CCC

P-CCC-P P-CCC-P

2 ATP

2 ADP+P Energy “used”

2 NAD and 2P

2 NADH + H

4 ADP+P

4 ATP Energy “gained”

Page 9: Cellular Respiration Cellular respiration is the process by which cells make energy. They use glucose and oxygen to produce carbon dioxide, water and ATP

Uses of Pyruvic Acid

The Pyruvic acid can be used for one of several different pathways, depending on the organism and the circumstances:1. For alcoholic fermentation (in yeasts)

2. For lactic acid fermentation (in milk bacteria, and emergency systems in animals)

3. For aerobic respiration (the Krebs’ cycle) in most eukaryotes (plants and animals)

In most animals, the pyruvic acid is first changed to Acetyl Co-A before being used in Krebs’ cycle

Page 10: Cellular Respiration Cellular respiration is the process by which cells make energy. They use glucose and oxygen to produce carbon dioxide, water and ATP

Uses of Pyruvic Acid

Pyruvic Acid

Krebs Cycle

Alcoholic Fermentation

Lactic Acid Fermentation

Ethyl Alcohol

Lactic AcidAcetyl Co-A

Co enzyme A

Enzyme Reaction

CO2CO2

NAD

NADH+H

Anaerobic Respiration Aerobic Respiration

2 CO2

Electron Transport

Glycolysis

6 H2O

Page 11: Cellular Respiration Cellular respiration is the process by which cells make energy. They use glucose and oxygen to produce carbon dioxide, water and ATP

Lactic Acid Fermentation in Humans Humans normally undergo aerobic

respiration (we use oxygen) Under extreme exertion (or when

suffocating) we don’t get enough oxygen. Then we use lactic acid fermentation

to produce some energy without oxygen.

Build-up of lactic acid in muscles can cause pain and cramps.

Runners sometimes can’t breath fast enough to supply their bodies with oxygen

Lactic acid build-up causes pain, fatigue, and cramps

Page 12: Cellular Respiration Cellular respiration is the process by which cells make energy. They use glucose and oxygen to produce carbon dioxide, water and ATP

Steps in aerobic respiration1. Pyruvic acid is converted to acetyl Co-A

2. 2 carbons from Acetyl Co-A join onto a 4C compound (oxaloacetic acid) to make citric acid, a 6C compound (citric acid)

3. Citric acid gives off one carbon dioxide to make a 5C compound (α-ketoglutaric acid)

4. This gives off another carbon dioxide to make a 4C compound (succinic acid)

5. The 4C compound rearranged (back into oxaloacetic acid), through two intermediate steps (fumaric acid and malic acid).

6. Captured hydrogen used to make energyKrebs cycle

Page 13: Cellular Respiration Cellular respiration is the process by which cells make energy. They use glucose and oxygen to produce carbon dioxide, water and ATP

The Enzyme Reaction

Pyruvic acid + Co-enzyme A

CO2 + Acetyl Co-A

Acetyl Co-A carries two carbon atoms to the Krebs cycle, before being turned back into co-enzyme A

Page 14: Cellular Respiration Cellular respiration is the process by which cells make energy. They use glucose and oxygen to produce carbon dioxide, water and ATP

Simplified Krebs Cycle Diagram

Citric Acid C6

5-carbon compound C5

(α-ketoglutaric acid)

4 Carbon compound C4

(Succinic acid)

4 Carbon compounds

(fumaric acid & malic acid)

Oxaloacetic Acid C4

Acetyl Co-A

CO2

CO2

NADH+H

NADH+H

FAD

FADH2

NAD

H2OH2O

C2

C4

Page 15: Cellular Respiration Cellular respiration is the process by which cells make energy. They use glucose and oxygen to produce carbon dioxide, water and ATP

Advanced Krebs cycle (Optional Enrichment)

Co2

CO2

Given off

Hydrogen Stored(NADH, FADH2)

Page 16: Cellular Respiration Cellular respiration is the process by which cells make energy. They use glucose and oxygen to produce carbon dioxide, water and ATP

The Electron Transport ChainAKA: cytochrome system

During the reactions of aerobic respiration, lots of Hydrogen has been captured in hydrogen storing compounds, including:

2 NADH from Glycolysis 2 NADH from conversion of Pyruvic Acid 6 NADH from the Krebs cycle 2 FADH2 from the Krebs cycle

Many of the hydrogens have lost electrons Now the energy of those electrons &

hydrogen ions are used to make ATP

Page 17: Cellular Respiration Cellular respiration is the process by which cells make energy. They use glucose and oxygen to produce carbon dioxide, water and ATP

The Electron Transport Chain

Page 18: Cellular Respiration Cellular respiration is the process by which cells make energy. They use glucose and oxygen to produce carbon dioxide, water and ATP

The Electron Transport Chain

Along the inner membrane of the mitochondrion, electrons are passed from molecule to molecule

The energy from these electrons is used to “pump” hydrogen ions (H+) into the space between the membranes

The hydrogen ions diffuse back in, producing ATP by chemiosmosis (similar to photosynthesis)

The hydrogen ions and electrons are combined with oxygen to form water.

Page 19: Cellular Respiration Cellular respiration is the process by which cells make energy. They use glucose and oxygen to produce carbon dioxide, water and ATP

The Electron Transport Chain

The simplified outcome of electron transport: The hydrogen atoms join with oxygen to make

water. Lots of ATP is produced

4 H+ + O2 +4e- H2O + EnergyENERGY

ATP

ADP + P

Page 20: Cellular Respiration Cellular respiration is the process by which cells make energy. They use glucose and oxygen to produce carbon dioxide, water and ATP

Remember, up to 38 ATP molecules can be produced from the complete respiration of a single glucose molecule.

Other organic molecules, such as starches and lipids, can produce even more ATP if they undergo complete respiration.

ATP is the energy exchange medium of the cell. It provides the energy for most cellular activity.

Page 21: Cellular Respiration Cellular respiration is the process by which cells make energy. They use glucose and oxygen to produce carbon dioxide, water and ATP

Cellular Respiration Videos

Cellular Respiration (Overview Lecture)

Sugar Goes to ATP (Hey There Delilah)

Cellular Respiration Song ( I Gotta Feeling)

Cellular Respiration (Californication: too long for class)

Student Made Respiration video (not too bad)

Student-made Respiration song (dreadful and full of

spelling mistakes, but mercifully short)

Page 22: Cellular Respiration Cellular respiration is the process by which cells make energy. They use glucose and oxygen to produce carbon dioxide, water and ATP

Assignments on Respiration.

Read Chapter 7, pp. 127 to 138. Read carefully the chapter summary on page

139. Do exercises on page 140 # 1 to 20 Draw a diagram to represent the Krebs’ cycle


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