Cellular Respiration and Fermentation

The mitochondrial matrix is the fluid-filled space within the inner membrane of the mitochondria. It contains enzymes, ribosomes, and DNA, which are essential for cellular respiration.

The inner membrane of the mitochondria is the selectively permeable membrane that encloses the mitochondrial matrix. It plays a crucial role in the electron transport chain and ATP production.

The cristae are folds in the inner membrane of the mitochondria that increase the surface area for ATP production. They are essential for efficient energy generation.

Aerobic cellular respiration is a process that uses oxygen to break down glucose and produce ATP. It involves glycolysis, the Krebs cycle, and the electron transport chain.

Anaerobic cellular respiration is a process that produces ATP without using oxygen. It involves glycolysis and an electron transport chain that uses a final electron acceptor other than oxygen.

Fermentation is a metabolic process that produces ATP through the breakdown of glucose without oxygen. It typically occurs in the absence of oxygen and generates lactic acid or ethanol as a byproduct.

Aerobic cellular respiration occurs in organisms that live in oxygen-rich environments, while anaerobic cellular respiration occurs in organisms that live in oxygen-poor environments.

Fermentation is an anaerobic process that occurs in organisms that lack the necessary enzymes for aerobic respiration. It generates ATP through the breakdown of glucose without using oxygen and typically produces byproducts like lactic acid or ethanol.

Aerobic cellular respiration is a series of reactions that take place in the mitochondria of plant and animal cells, using oxygen to break down glucose and extract energy. It involves oxidation and reduction reactions to generate NADH and FADH2, which carry electrons to the electron transport system.

During glycolysis, glucose is broken down into pyruvate in the cytoplasm, producing a small amount of ATP and NADH. The process involves 10 enzymatic steps, each catalyzed by a specific enzyme.

Pyruvate, produced in glycolysis, is transported into the mitochondria and converted into acetyl-CoA, which is then used in the Krebs cycle. This step also generates NADH and carbon dioxide.

The Krebs cycle, also known as the citric acid cycle, occurs in the mitochondrial matrix. It uses acetyl-CoA to generate ATP, NADH, FADH2, and carbon dioxide through a series of enzymatic steps. It's a cyclic process, meaning the starting molecule is regenerated after each turn.

The electron transport system (ETS) is located in the inner mitochondrial membrane. NADH and FADH2 deliver electrons to the ETS, which are then shuttled through a series of protein complexes. This process drives proton pumping across the membrane, creating a proton gradient.

The proton gradient generated by the ETS is a form of potential energy. This energy is used by ATP synthase, an enzyme embedded in the inner mitochondrial membrane, to synthesize ATP from ADP and inorganic phosphate.

Fermentation is an anaerobic process that occurs in the cytoplasm of cells. It is less efficient than aerobic respiration because it doesn't use oxygen and generates fewer ATP molecules.

Lactate fermentation occurs in the cytoplasm of animal cells due to oxygen debt. Pyruvate is converted into lactate, regenerating NAD+ needed for glycolysis.

Ethanol fermentation occurs in the cytoplasm of yeast. Pyruvate is converted into ethanol and carbon dioxide, generating NAD+ to sustain glycolysis.

Fermentation is less efficient than aerobic respiration because it produces fewer ATP molecules per glucose molecule. It relies on glycolysis and doesn't use the electron transport system.