Cellular Respiration Cellular Respiration

Honors Biology Honors Biology

20122012

Comprehension CheckWhat types of organisms need

energy?What types of organisms can make

their own energy?

Cellular Respiration:Cellular Respiration: DEFINITION: DEFINITION: Complex process in which cells

break down organic compounds to make ATP (ADP + ATP)

We feel hungry because food provides us energy, the biochemical pathway that allows us to get energy from our food is cellular respiration.

Equation for Cellular Respiration:Equation for Cellular Respiration:

FACT:FACT: A working muscle cell converts ADP to A working muscle cell converts ADP to ATP at a rate of 10 million molecules per ATP at a rate of 10 million molecules per second.second.

606022 + C + C66HH12120066 6CO 6CO22 +6H +6H22O +EnergyO +Energy

Main Reactions in Cellular Respiration (depending on presence of O2)

Overview of Glycolysis Overview of Glycolysis Glycolysis: Biochemical pathway which begins Glycolysis: Biochemical pathway which begins bothboth types of types of

cellular respiration. cellular respiration. Occurs in cytosol of cellOccurs in cytosol of cell Breaks down one glucose into two 3-carbon molecules Breaks down one glucose into two 3-carbon molecules

of pyruvic acid (pyruvate)of pyruvic acid (pyruvate)

** Note: 2 ATP’s were used in step 1, but 4 ATP’s were made ** Note: 2 ATP’s were used in step 1, but 4 ATP’s were made in step 4. This is called a in step 4. This is called a NET GAINNET GAIN of 2 ATP of 2 ATP

Glycolysis Animation

ANAEROBIC RESPIRATIONANAEROBIC RESPIRATION1.1. Glycolysis Glycolysis 2.2. Fermentation: absence of oxygen, some Fermentation: absence of oxygen, some

organisms can convert pyruvic acid into another 3-organisms can convert pyruvic acid into another 3-carbon compound, but NO ADDITIONAL ATP ARE carbon compound, but NO ADDITIONAL ATP ARE FORMEDFORMED

Energy released from anaerobic respiration:Energy released from anaerobic respiration: 2 ATP molecules released by glycolysis2 ATP molecules released by glycolysis 0 ATP result because of fermentation 0 ATP result because of fermentation TOTAL ENERGY GAIN = 2 ATPTOTAL ENERGY GAIN = 2 ATP This is only 3.5% of all the energy stored in a single This is only 3.5% of all the energy stored in a single

glucose molecule glucose molecule Much of energy originally contained in glucose is still held Much of energy originally contained in glucose is still held

in the bonds that make up pyruvic acidin the bonds that make up pyruvic acid

Alcoholic Fermentation Alcoholic Fermentation

Process where yeast and bacteria convert Process where yeast and bacteria convert pyruvic acid into ethyl alcohol and COpyruvic acid into ethyl alcohol and CO22

No ATP are gained (regenerates NADNo ATP are gained (regenerates NAD++ for for glycolysis)glycolysis)

Basis of the wine, beer, and baking industriesBasis of the wine, beer, and baking industries

Lactic Acid Fermentation Lactic Acid Fermentation

Enzyme reactions convert pyruvic acid into Enzyme reactions convert pyruvic acid into another 3-carbon compound, lactic acidanother 3-carbon compound, lactic acid– No ATP are gainedNo ATP are gained– LAF occurs in your muscle cells LAF occurs in your muscle cells – Once oxygen is available, the body converts Once oxygen is available, the body converts

lactic acid back to pyruvic acid in our liverlactic acid back to pyruvic acid in our liver

AEROBIC RESPIRATIONAEROBIC RESPIRATIONStage 1: GLYCOLYSISStage 1: GLYCOLYSIS

Stage 2: KREBS CYCLE / CITRIC Stage 2: KREBS CYCLE / CITRIC ACID CYCLEACID CYCLE

Stage 3: Electron Transport Chain Stage 3: Electron Transport Chain

Requires oxygen to be presentRequires oxygen to be present Produces 20 times more ATP than Produces 20 times more ATP than

Glycolysis alone!Glycolysis alone! Prokaryotes can do it, but it occurs Prokaryotes can do it, but it occurs

in the cytosolin the cytosol Eukaryotes have mitochondria Eukaryotes have mitochondria

(matrix and cristae) for this specific (matrix and cristae) for this specific purposepurpose

AEROBIC RESPIRATIONAEROBIC RESPIRATIONKrebs Cycle/Citric Acid CycleKrebs Cycle/Citric Acid Cycle--Pyruvic acid produced by glycolysis enters Pyruvic acid produced by glycolysis enters

mitochondrionmitochondrion--Krebs Cycle occurs in mitochondrial matrix-2 pyruvic acid 2 pyruvic acid 2 acetyl CoA 2 acetyl CoA Citric Acid Citric Acid-The cycle begins and ends with citric acid-The cycle begins and ends with citric acid-Krebs Cycle produces NADH, FADH-Krebs Cycle produces NADH, FADH22, and , and

ATPATPSteps to the Krebs Cycle 1. Acetyl CoA combines with

Oxaloacetic Acid to form 6-carbon Citric Acid

2. Citric Acid releases CO2 and H to form a 5-carbon compound

3. 5-carbon compound releases another CO2 and H to form a 4-carbon compound

4. 4-carbon compound releases H to regenerate oxaloacetic Acid

5. Krebs Cycle runs 2x (1x for each acetyl CoA)

6. There is a net gain of 2 ATPhttp://people.unt.edu/~hds0006/tca/index.htmhttp://people.unt.edu/~hds0006/tca/index.htm

Citric Acid

Oxaloacetic Acid

Electrons pass through molecules in cristae towards a Electrons pass through molecules in cristae towards a lower energy level to final electron acceptor, oxygen lower energy level to final electron acceptor, oxygen

NADH and FADHNADH and FADH22 supply protons (H+) which make ATP supply protons (H+) which make ATP through chemiosmosis through chemiosmosis

In matrix, H+ combines with oxygen to form water In matrix, H+ combines with oxygen to form water and use the extra H+ floating around and use the extra H+ floating around

34 ATP are gained 34 ATP are gained

Electron Transport ChainElectron Transport Chain

Aerobic Respiration Energy Aerobic Respiration Energy YieldYield 38 ATP from a single glucose molecule38 ATP from a single glucose molecule

2 ATP in glycolysis (made 4, but used 2)2 ATP in glycolysis (made 4, but used 2) 2 ATP in Krebs cycle2 ATP in Krebs cycle 34 ATP in ETC 34 ATP in ETC

This total varies from cell to cell, and is usually This total varies from cell to cell, and is usually only 36 ATP per glucose moleculeonly 36 ATP per glucose molecule Plant and animal cells spend 2 ATP in moving Plant and animal cells spend 2 ATP in moving

products though membranes and only net 36 products though membranes and only net 36 ATP per 1 molecule of glucoseATP per 1 molecule of glucose

66% efficient at releasing the energy in the 66% efficient at releasing the energy in the molecule molecule

20X more efficient than anaerobic respiration 20X more efficient than anaerobic respiration

Energy and ExerciseEnergy and Exercise

ATP comes from:ATP comes from:Cellular RespirationCellular Respiration

(long term)(long term)

Lactic Acid FermentationLactic Acid Fermentation(short term)(short term)

Muscle storageMuscle storage(short term)(short term)

Why are you “out of breath” after strenuous exercise?Why are you “out of breath” after strenuous exercise?

Comprehension CheckAnaerobic Respiration

STAGES # of ATP Gained1. ___________ _____2. ___________ _____

TOTAL: _____Aerobic Respiration

STAGES # of ATP Gained1. _____________ _____2. _____________ _____ 3. _____________ _____

TOTAL: _____

SUMMARYAnaerobic Respiration

STAGES # of ATP Gained1. GLYCOLYSIS 22. FERMENTATION 0

TOTAL: 2Aerobic Respiration

STAGES # of ATP Gained1. GLYCOLYSIS 22. KREBS CYCLE 2 3. ELECTRON TRANSPORT CHAIN 34

TOTAL: 38

Review AnimationsReview AnimationsOverall Review: Overall Review: http://www.qcc.cuny.edu/BiologicalSciencehttp://www.qcc.cuny.edu/BiologicalSciences/Faculty/DMeyer/respiration.htmls/Faculty/DMeyer/respiration.htmlGlycolysis:Glycolysis:http://instruct1.cit.cornell.edu/Courses/http://instruct1.cit.cornell.edu/Courses/biomi290/MOVIES/GLYCOLYSIS.HTMLbiomi290/MOVIES/GLYCOLYSIS.HTMLOverview of Photosynthesis and Cellular Overview of Photosynthesis and Cellular RespirationRespirationhttp://highered.mcgraw-hill.com/sites/dl/http://highered.mcgraw-hill.com/sites/dl/free/0078617022/164155/00053412.htmlfree/0078617022/164155/00053412.html