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Chapter 9 Cellular Respiration: Harvesting Chemical Energy

Chapter 9 Cellular Respiration: Harvesting Chemical Energy

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Chapter 9 Cellular Respiration: Harvesting Chemical Energy. Is this a process of turning food into energy?. Rs - Equation. C 6 H 12 O 6 + 6 O 2 6 CO 2 + 6 H 2 O and energy - PowerPoint PPT Presentation

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Page 1: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Chapter 9 Cellular Respiration: Harvesting Chemical

Energy

Page 2: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Is this a process of turning food into energy?

Page 3: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Rs - Equation

C6H12O6 + 6 O2 6 CO2 + 6 H2O

and energy

The energy is released from the chemical bonds in the complex organic molecules.

Page 4: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Respiration - Preview

The process of releasing Energy from food.

Food - Stored Energy in chemical bonds.

ATP - Useable Energy for cell work.

Page 5: Chapter 9       Cellular Respiration: Harvesting Chemical Energy
Page 6: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Focus of Chapter

1. Purpose - what is the reaction suppose to do?

2. Location - where is it at?3. Requirements - what is

needed to make it run?4. Products - what does it

produce?

Page 7: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Oxidation - definitions

Loss of electrons. Loss of energy. Loss of Hydrogens from

Carbons.

Page 8: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Reduction - definitions

Gain of electrons. Gain of energy. Gain of Hydrogens to

Carbons.Comment - be careful not to

use “reduction” in lay terms.

Page 9: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Redox reactions

Page 10: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Redox reactions

Reactions are usually paired or linked together.

Look for these links as we study Rs.

Many of the reactions will be done by phosphorylation

Page 11: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Phosphorylation

Adding a phosphate group to a molecule.

The phosphate group adds “energy” to the molecule for chemical reactions.

Page 12: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Phosphorylation

Page 13: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Cell Respiration - parts

1. Glycolysis

2. Krebs Cycle

3. Electron Transport Chain

Page 14: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Glycolysis

Glyco- glucose. -lysis: to split Universal step in all Rs types. Likely to earliest type of cell

energy processes.

Page 15: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Glycolysis

Function - To split glucose and produce NADH and ATP.

Location - Cytoplasm.

Page 16: Chapter 9       Cellular Respiration: Harvesting Chemical Energy
Page 17: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Electron Carrier Compounds

Molecules that transport or shuttle electrons within the cell.

Exist it two forms: Oxidized (ox) Reduced (red)

Page 18: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

NAD

Nicotinamide Adenine Dinucleotide

NAD+ + 2 e- NADH

NAD+ = oxidized form

NADH = reduced form

Page 19: Chapter 9       Cellular Respiration: Harvesting Chemical Energy
Page 20: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Glycolysis -Requirements

Glucose 2 ATP 4 ADP 2 NAD+

Page 21: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Glycolysis - Products

2 Pyruvic Acids (a 3C acid) 2 ADP 4 ATP 2 NADH

Page 22: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Net Result

2 ATP per glucose 2 NADH

Page 23: Chapter 9       Cellular Respiration: Harvesting Chemical Energy
Page 24: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Energy Investment Phase

Page 25: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Energy Harvest Phase

Page 26: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Let’s check out the reaction as it happens…

Go to here http://www.science.smith.edu/de

partments/Biology/Bio231/ And click on “Glycolysis”

Page 27: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Krebs Cycle

Also called: Citric Acid Cycle Tricarboxylic Acid Cycle

Page 28: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Krebs Cycle

Function: Oxidize pyruvic acid to CO2

Produce NADH and FADH2

Location: Mitochondria matrix

Page 29: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Formation of Acetyl CoA

Page 30: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Krebs Cycle -Requirements

Pyruvic acid (3C acid) Coenzyme A 4 NAD+

1 ADP 1 FAD Double this list for each

glucose.

Page 31: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Krebs Cycle - Products

3 CO2

Acetyl CoA 4 NADH 1 ATP 1 FADH2

Double this list for each glucose.

Page 32: Chapter 9       Cellular Respiration: Harvesting Chemical Energy
Page 33: Chapter 9       Cellular Respiration: Harvesting Chemical Energy
Page 34: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Krebs Cycle

Produces most of the cell's energy in the form of NADH and FADH2

Does NOT require O2

Page 35: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Comment The ATPs produced directly

in Krebs Cycle and in Glycolysis are by:

Substrate-level phosphorylation

The Pi group is transferred from a substrate to ADP.

Page 36: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Let’s see how the Krebs cycle works…

Go to here http://www.science.smith.edu/departments/Biology/Bio231/

And click on “Citric Acid Cycle” Just another name for the Krebs Cycle!

Page 37: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Electron Transport Chain

ETC or Electron Transport System (ETS).

A collection of proteins that are structurally linked into units.

Page 38: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

ETC

Uses sets of Cytochromes, Fe containing proteins to pass electrons.

The Cytochromes alternate between RED and OX forms and pass electrons down to O2

Page 39: Chapter 9       Cellular Respiration: Harvesting Chemical Energy
Page 40: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

ETC

Function: Convert NADH and FADH2 into ATP.

Location: Mitochondria cristae.

Page 41: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

ETC - Requirements

NADH or FADH2

ADP O2

Page 42: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

ETC - Products

NAD+ and FAD ATP H2O

Page 43: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

ETC - ATP Yields

Each NADH -- 3 ATP Each FADH2 -- 2 ATP

Page 44: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Chemiosmotic Hypothesis

ETC energy is used to move H+ (protons) across the cristae membrane.

ATP is generated as the H+

diffuse back into the matrix.

Page 45: Chapter 9       Cellular Respiration: Harvesting Chemical Energy
Page 46: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

ATP Synthase

Uses the flow of H+ to make ATP.

Works like an ion pump in reverse, or like a waterwheel under the flow of H+ “water”.

Page 47: Chapter 9       Cellular Respiration: Harvesting Chemical Energy
Page 48: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Let’s see how the ETC works!

Go to here http://www.science.smith.edu

/departments/Biology/Bio231/ And click on “ ETC”

Page 49: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Super mega awesome tutorial at this site:

http://student.ccbcmd.edu/biotutorials/cellresp/cellresp_index.html

Let’s go! Here

Page 50: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Catabolism of Proteins and Fats

Can use these as energy sources as well!

Proteins first broken down into AA’s Amino group (containing N) is

removed from each AA by deamination Converts the remaining C chain into a

molecule to be used in the Krebs Cycle or Glycolysis

Page 51: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Cell Resp of Fat Fats are broken down into FA + glycerol

-CH2 links and many H+ in tails provide much energy

FA oxidized in mitochondria where enzymes remove the 2C acetyl groups from whole FA until all is converted – goes to bind w/ coenzyme A = acetyl-CoA

Process is “ oxidation”

Page 52: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Results? Respiration of a 6C FA yields 20% more

ATP than the same glucose Also weighs less than 2/3 as much as

glucose, therefore gram for gram, fat has more kilocalories than glucose

Let’s see that in motion! http://

nutrition.jbpub.com/resources/animations.cfm?id=23&debug=0

Page 53: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Alcoholic Fermentation

Done by yeast, a kind of fungus.

Page 54: Chapter 9       Cellular Respiration: Harvesting Chemical Energy
Page 55: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Alcoholic Fermentation Uses only Glycolysis. An incomplete oxidation -

energy is still left in the products (alcohol).

Does NOT require O2

Produces ATP when O2 is not available.

Page 56: Chapter 9       Cellular Respiration: Harvesting Chemical Energy
Page 57: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Lactic Acid Fermentation

Uses only Glycolysis. An incomplete oxidation -

energy is still left in the products (lactic acid).

Does NOT require O2

Produces ATP when O2 is not available.

Page 58: Chapter 9       Cellular Respiration: Harvesting Chemical Energy
Page 59: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Lactic Acid Fermentation

Done by human muscle cells under oxygen debt.

Lactic Acid is a toxin and causes soreness and stiffness in muscles.

Page 60: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Fermentation - Summary

Way of using up NADH so Glycolysis can still run.

Provides ATP to a cell even when O2 is absent.

Page 61: Chapter 9       Cellular Respiration: Harvesting Chemical Energy
Page 62: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Aerobic vs Anaerobic

Aerobic - Rs with O2

Anaerobic - Rs without O2

Aerobic - All three Rs steps. Anaerobic - Glycolysis only.

Page 63: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Strict vs. Facultative

Strict - can only do Rs this one way.

Facultative - can switch Rs types depending on O2 availability. Ex - yeast

Page 64: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Question

Since yeast can do both aerobic and anaerobic Rs, which is the better process if given a choice?

Check the ATP yields from both processes.

Page 65: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

ATP yields by Rs type

Anaerobic - Glycolysis only Gets 2 ATPs per glucose.

Aerobic - Glycolysis, Krebs, and ETC. Generates many more ATPs per glucose.

Page 66: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Aerobic ATP yield

Glycolysis - 2 ATPS, 2 NADHs Krebs - 2 ATPS, 8 NADHs,

2 FADH2

Each NADH = 3 ATP Each FADH2 = 2 ATP

Page 67: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

ATP Sum

10 NADH x 3 = 30 ATPs 2 FADH2 x 2 = 4 ATPs 2 ATPs (Gly) = 2 ATPs 2 ATPs (Krebs) = 2 ATPs

Max = 38 ATPs per glucose

Page 68: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

However...

Some energy is used in shuttling the NADH from Glycolysis into the mitochondria.

Actual ATP yield ~ 36/glucose

Page 69: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Yeast

Would rather do aerobic Rs; it has 18x more energy per glucose.

But, anaerobic will keep you alive if oxygen is not present.

Page 70: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Importance of Rs

Convert food to ATP. Provides materials for use in

other cellular pathways.

Page 71: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Other Importances of Respiration

Alcohol Industry - almost every society has a fermented beverage.

Baking Industry - many breads use yeast to provide bubbles to raise the dough.

Page 72: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Question

Why is the alcohol content of wine always around 12-14%?

Alcohol is toxic and kills the yeast at high concentrations.

Page 73: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Swiss Cheese

Holes are bubbles of CO2 from fermentation.

Page 74: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Summary

Know the 3 main reactions of Rs and the 4 required items for each.

Appreciate the importances of Rs.

Page 75: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Rs - Equation

C6H12O6 + 6 O2 6 CO2 + 6 H2O

and energy

Which part of the equations represent which of the 3 Rs reactions?

Page 76: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

MatchingSugar Cane Gin

Barley Saki

Grapes Tequila

Juniper Cones Vodka

Agave Leaves Beer

Rice Wine

Potatoes Rum

Page 77: Chapter 9       Cellular Respiration: Harvesting Chemical Energy

Answers!!

Sugar cane Rum Barley Beer Grapes Wine Juniper Gin Agave Tequila Rice Saki Potatoes Vodka Remember…no partaking until

you’re 21!