Cellular Respiration Overview and Stages

Cellular respiration is the process where living organisms convert food energy (glucose) into chemical energy in the form of ATP. This energy is used to power various cellular processes.

Both plants and animals use the same cellular respiration process to break down glucose and release energy.

Aerobic respiration occurs in the presence of oxygen and involves the Krebs Cycle and Electron Transport Chain, taking place within the mitochondria of the cell.

Anaerobic respiration happens without oxygen. It involves fermentation, which occurs in the cytoplasm and produces either ethanol and CO2 (like in yeast) or lactic acid (during muscle exertion).

Oxidation is a chemical reaction where a molecule combines with oxygen (O2). In cellular respiration, glucose is oxidized, releasing energy in the form of ATP.

Glycolysis is the first step in both aerobic and anaerobic respiration. It occurs in the cytoplasm and breaks down glucose into pyruvate, releasing a small amount of ATP.

Aerobic respiration requires oxygen to function properly. In contrast, anaerobic respiration can proceed without oxygen.

The fermentation process is characteristic of anaerobic respiration. It occurs when oxygen is not available and results in the production of either ethanol and CO2 or lactic acid.

Alcoholic fermentation is a type of anaerobic respiration used by organisms like yeast to produce energy in the absence of oxygen. It results in the formation of ethanol and carbon dioxide as byproducts.

Lactic acid fermentation is a type of anaerobic respiration that occurs in muscle cells during intense physical activity. It produces lactic acid as a byproduct.

The process of cellular respiration is more efficient (produces more ATP) when oxygen is available. This is called aerobic respiration.

Anaerobic respiration occurs when oxygen is not available. It is less efficient than aerobic respiration, meaning it produces less ATP from the same amount of glucose.

Anaerobic respiration produces less energy (ATP) than aerobic respiration because glucose is not fully broken down.

The first step in both aerobic and anaerobic respiration, breaking down glucose into pyruvate.

The Krebs cycle and electron transport chain are only involved in aerobic respiration, where oxygen is present.

Acetyl-CoA is produced during the prep stage of aerobic respiration by converting pyruvate.

Aerobic respiration requires oxygen and produces significantly more ATP than fermentation. Fermentation occurs without oxygen and produces less ATP.

Alcoholic fermentation, carried out by yeast and some bacteria, produces ethanol and CO2. Lactic acid fermentation, carried out by muscles and some bacteria, produces lactic acid.

Both types of fermentation begin with glycolysis, but pyruvate does not go through the Krebs cycle or electron transport chain.

Fermentation produces only 2 ATP molecules during glycolysis because the glucose molecule is not fully broken down.

Adenosine triphosphate, a molecule that serves as the primary energy source within cells. The breakdown of ATP releases energy that is used to power cellular processes.

Adenosine diphosphate, a lower energy form of ATP created by removing one phosphate group. ADP is formed when ATP releases its energy.

The process of breaking down glucose to produce pyruvate, generating a small amount of ATP and NADH. This occurs in the cytoplasm of the cell.

The Krebs cycle, a series of reactions that occur in the mitochondria, oxidizing pyruvate and yielding ATP, NADH, and FADH2. It requires oxygen and is part of aerobic respiration.

The electron transport chain (ETC) is the final stage of aerobic respiration, where electrons are passed down a chain of molecules in the mitochondrial membrane, generating the greatest amount of ATP.

Nicotinamide adenine dinucleotide (NAD+), a coenzyme that acts as an electron carrier in cellular respiration. NADH is the reduced form with added electrons.

A molecule similar to NADH, carrying electrons to the ETC. It also plays a role in cellular respiration.

A process that occurs in the absence of oxygen, converting pyruvate into lactate or ethanol, yielding a small amount of ATP. This is an alternative way to generate energy when oxygen is limited.