CELLULAR RESPIRATION

Cellular respiration

It is a fundamental process that occurs in cells to produce energy in the form of ATP (adenosine triphosphate).

Cellular respiration

It involves the breakdown of organic molecules, such as glucose, to release energy that can be utilized by the cell.

Aerobic Respiration

Occurs in the presence of oxygen

Aerobic Respiration

Highly efficient in terms of ATP production

1. Glycolysis

2. Pyruvate Decarboxylation (Transition Reaction)

3. Citric Acid Cycle (Krebs Cycle)

4. Electron Transport Chain (ETC)

5. Chemiosmosis

Stages of Aerobic Respiration

cytoplasm

Glycolysis takes place in the ___

two molecules of pyruvate (3-carbon)

In glycolysis, glucose is broken down into ___

Glycolysis

Generates a small amount of ATP and NADH (reduced form of NAD+)

Glycolysis

Glucose (6-carbon) is broken down into two molecules of pyruvate (3-carbon).

mitochondrial matrix

Pyruvate Decarboxylation (Transition Reaction) takes place in the ____

Acetyl-CoA

in the Pyruvate Decarboxylation, Each pyruvate is converted to

NADH

Pyruvate Decarboxylation Produces ____

mitochondrial matrix

Citric Acid Cycle (Krebs Cycle) Takes place in the ___

Citric Acid Cycle (Krebs Cycle)

Acetyl-CoA enters the cycle and undergoes a series of reactions, producing NADH, FADH2, and ATP.

NADH, FADH2, and ATP

In the Krebs Cycle, Acetyl-CoA enters the cycle and undergoes a series of reactions, producing

Citric Acid Cycle (Krebs Cycle)

Completes the breakdown of glucose.

inner mitochondrial membrane

Electron Transport Chain is located in ____

protein complexes

In the ETC, electrons from NADH and FADH2 are transferred through a series of ___

Electron Transport Chain (ETC)

The energy released is used to pump protons (H+) across the membrane, creating a proton gradient.

ATP

In the ETC, ___ is produced through chemiosmosis as protons flow back into the mitochondrial matrix through ATP synthase

Chemiosmosis

Protons flowing back through ATP synthase drive the synthesis of ATP from ADP and inorganic phosphate.

Anaerobic Respiration

Occurs in the absence of oxygen.

Anaerobic Respiration

Less efficient than aerobic respiration.

1. Lactic Acid Fermentation

2. Alcohol Fermentation

Types of Anaerobic Respiration

Lactic Acid Fermentation

Common in muscles during strenuous exercise.

Pyruvate

In the Lactic Acid Fermentation, ____  is converted into lactic acid.

NAD+

In the Lactic Acid Fermentation, it regenerates ___ for glycolysis to continue

Lactic Acid Fermentation

Regenerates NAD+ for glycolysis to continue

Alcohol Fermentation

Occurs in yeast and some bacteria.

ethanol and carbon dioxide

In the Alcohol Fermentation, Pyruvate is converted into ____

NAD+

Alcohol Fermentation also regenerates _____ for glycolysis

Alcohol Fermentation

it also regenerates NAD+ for glycolysis

Glycolysis:

• 2 ATP (net gain)

Pyruvate Decarboxylation:

• No ATP directly produced

Citric Acid Cycle:

• 2 ATP per glucose

Electron Transport Chain (ETC) and Chemiosmosis:

• About 28-34 ATP per glucose (varies between different sources)

Total ATP Yield (Aerobic Respiration):

• Approximately 32-38 ATP per glucose

Anaerobic Respiration:

• Varies, but much less efficient than aerobic respiration

ATP Yield Summary

Glycolysis:

Pyruvate Decarboxylation:

Citric Acid Cycle:

(ETC) and Chemiosmosis:

Aerobic Respiration:

Anaerobic Respiration:

cellular respiration

it is a complex process involving several stages, with aerobic respiration being more efficient in ATP production compared to anaerobic respiration.

Pyruvate Dehydrogenase Complex

Catalyzes the conversion of pyruvate to Acetyl-CoA.

Pyruvate Dehydrogenase Complex

The complex involves multiple enzymes and coenzymes.

Lactic Acid Fermentation

Catalyzed by lactate dehydrogenase, which converts pyruvate to lactic acid.

lactate dehydrogenase

Lactic Acid Fermentation is catalyzed by ____ which converts pyruvate to lactic acid.

Alcohol Fermentation

Catalyzed by alcohol dehydrogenase and acetaldehyde dehydrogenase, leading to the conversion of pyruvate to ethanol and carbon dioxide.

alcohol dehydrogenase and acetaldehyde dehydrogenase

Alcohol Fermentation is catalyzed by ____, leading to the conversion of pyruvate to ethanol and carbon dioxide.