Respiration. Respiration Respiration the process by which food molecules are broken down –Food...

RespirationRespiration


• Respiration the process by which food molecules are broken down– Food molecules are 6-carbons sugars – You take in food which is digested and broken

down into 6-carbon sugars– Plants can’t “eat” so they make 6-carbon

sugars with photosynthesis– Mitochondria then transform the “food energy”

into chemical energy


• A 6-carbon sugar contains an enormous amount of energy (for a cell)

• Mitochondria “make change” energetically

• Take the energy in a sugar and convert it into more conveniently-sized packages


C6H12O6 + 6O2 → 6CO2 + 6H2O + energyCarbondioxide

WaterCarbohydrate Oxygen


• Aerobic respiration: processes that require oxygen in order to take place

• Anaerobic respiration: processes that do not require oxygen

Aerobic RespirationAerobic Respiration

• Step 1: Glycolysis

• Step 2: Breakdown of pyruvic acid

• Step 3: Citric acid cycle

• Step 4: Electron transport chain


MATRIX:Breakdown ofpyruvic acid, Citric acid cycle

INNER MEMBRANE:Electron transportchain

Outer membrane

CYTOPLASM:Glycolysis

Step 1: GlycolysisStep 1: Glycolysis

• Occurs in cytoplasm

• Does not require oxygen

• Involves splitting a glucose (6-carbon sugar) into 2 3-carbon molecules: pyruvic acid


• Also produces H+ ions and energizes electrons which are captured by NAD+, forming NADH + H+


Glucose


Glucose

2 ATP 2 ADP


Glucose

2 ATP 2 ADP

P

P

2 PGAL


Glucose

2 ATP 2 ADP

P

P

2 PGAL

4ADP + 4 Pi

2 NAD+ 2NADH + 2H+

4ATP


Glucose

2 ATP 2 ADP

P

P

2 PGAL

4ADP + 4 Pi

2 NAD+ 2NADH + 2H+

4ATP

2 Pyruvicacid


• Net yeild– 2 ATP (uses 2, produces 4)– 2 NADH– 2 pyruvic acid


Step 1: Glycolysis




Step 2: Breakdown of Step 2: Breakdown of Pyruvic AcidPyruvic Acid

• Occurs when pyruvic acid (from glycolysis) enters the mitochondrial matrix

• Requires oxygen– If there is no oxygen present pyruvic acid

enters fermentation


• Involves breaking CO2 off pyruvic acid

• Remaining portion of pyruvic acid combines with coenzyme A to form acetyl-CoA


• Also produces H+ and energizes electrons which are captured by NAD+, to form NADH + H+


To citricacid cycle

Mitochondrialmembrane

“Exhaled”


• Net yeild– 2 NADH– Acetyl-CoA


Step 1: GlycolysisStep 2: Breakdown of pyruvic acid



Step 3: Citric Acid CycleStep 3: Citric Acid Cycle

• Occurs in mitochondrial matrix

• Acetyl-CoA is transformed into citric acid through a series of reactions


• More ATP and CO2 are produced

• More H+ are produced and electrons are energized

• NAD+ and FAD capture them to form NADH + H+ and FADH


CITRICACID

CYCLE

4C

5C

6C – Citric acid


• Net yield– 2 ATP– 6 NADH

– 2 FADH2


Step 1: GlycolysisStep 2: Breakdown of pyruvic acidStep 3: Citric acid cycle


Step 4: Electron Transport ChainStep 4: Electron Transport Chain

• Happens on inner membrane of mitochondria

• Occurs only if oxygen is present– Oxygen is final electron acceptor– If no oxygen is present reaction stops


• Electrons come from NADH and FADH molecules which gathered them during glycolysis and CTA

• Energy from electrons is used to add Pi to ADP, forming ATP

• At the end of the chain, oxygen accepts the electrons and combines with 2 H+ ions to form water


Innermitochondrial

membrane

Outermitochondrial

membrane

Electron transport chain

CytochromesInter-

membranespace

Cytochromes


• Net yeild– 32 ATP


• Step 1: Glycolysis





Glycolysis 2 ATP

Citric acid cycle 2

Electron transport chain **32

ATP

ATP**Makes ATP from electrons carried to it from the first 3 steps


Makes 36 ATP

Anaerobic RespirationAnaerobic Respiration

• Pyruvic acid molecules are still formed through glycolysis

• Broken down differently:– No ATP is produced after glycolysis– NAD+ is regenerated so glycolysis can

continue

Anaerobic RespirationAnaerobic Respiration

• 2 types:– Lactic acid fermentation– Alcoholic fermentation

Lactic Acid FermentationLactic Acid Fermentation

• Lactic acid is end product

• Occurs when muscles require energy at a faster rate than it can be supplied through aerobic respiration

• Causes burning sensation in muscles


GlycolysisGlycolysis


• Net yield– 2 ATP

Alcoholic FermentationAlcoholic Fermentation

• Ethyl alcohol and CO2 are end products

• Occurs in organisms that live in environments lacking oxygen

• Source of bubbles in beer and champagne and causes baking bread to rise


Glycolysis

Glycolysis


Glycolysis

2 Ethanol

2 CO2

Comparison of Aerobic Comparison of Aerobic Respriation and FermentationRespriation and Fermentation

• How many ATP does aerobic respiration produce?

• How many ATP does fermentation produce?

36 ATP 2 ATP

WE’RE DONE!!!!


Glucose

2 ATP 2 ADP

P

P

2 PGAL

4ADP + 4 Pi

2 NAD+ 2 Pyruvicacid


To citricacid cycle

“Exhaled”


CITRICACID

CYCLE

4C

5C

6C – Citric acid

4C


Innermitochondrial

membrane

Outermitochondrial

membrane

Electron transport chain

CytochromesInter-

membranespace

Cytochromes


Glycolysis


Glycolysis

2 Ethanol

2 CO2

Respiration. Respiration Respiration the process by which food molecules are broken down –Food...

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