Cellular Respiration

Key Vocabulary

Aerobic

Relating to processes that require oxygen to produce energy in cells, typically through the breakdown of glucose.

Acetyl CoA

A central metabolite in cellular respiration, Acetyl CoA is produced from pyruvate and enters the citric acid cycle to generate ATP and other energy carriers.

anaerobic

glycolysis

link reaction

The link reaction, also known as the pyruvate decarboxylation, is the process that converts pyruvate into Acetyl CoA, producing carbon dioxide and NADH in the process.

mitochondria

Organelles in eukaryotic cells that are the sites of aerobic respiration and energy production through ATP synthesis.

cytoplasm

The gel-like substance within the cell membrane where glycolysis occurs, containing organelles and various molecules.

Krebs Cycle

A series of enzymatic reactions that occur in the mitochondria, where Acetyl CoA is oxidized to produce ATP, NADH, and FADH2, along with releasing carbon dioxide.

ATP

Adenosine triphosphate, the primary energy carrier in cells, generated during cellular respiration processes such as glycolysis and the Krebs Cycle.

NADH

A reduced form of nicotinamide adenine dinucleotide, NADH serves as an electron carrier that transports electrons to the electron transport chain during cellular respiration, contributing to ATP production.

FADH2

A reduced form of flavin adenine dinucleotide, FADH2 acts as an electron carrier in cellular respiration, delivering electrons to the electron transport chain, thus aiding in ATP synthesis.

cellular respiration equation

The overall chemical reaction of cellular respiration that converts glucose and oxygen into carbon dioxide, water, and ATP. It can be summarized as: C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP.

glucose

A simple sugar that is an essential energy source for living organisms. In cellular respiration, glucose undergoes glycolysis and is broken down to produce ATP.

pyruvate

The end product of glycolysis, pyruvate is a three-carbon molecule that can be converted into acetyl-CoA for entry into the citric acid cycle or used in fermentation under anaerobic conditions.

electron transport

chain: A series of protein complexes and other molecules that transfer electrons from NADH and FADH2 to oxygen, resulting in the production of ATP through oxidative phosphorylation.

electrons

Negatively charged subatomic particles that are involved in the transfer of energy during cellular respiration, playing a crucial role in the electron transport chain.

oxygen

A vital molecule for aerobic respiration, oxygen serves as the final electron acceptor in the electron transport chain, allowing for the production of ATP and water.

water

A compound formed when oxygen reacts with hydrogen during cellular respiration, serving as a byproduct of the electron transport chain.

carbon dioxide

A waste product of cellular respiration, carbon dioxide is produced during the Krebs cycle and is expelled from the body during exhalation.

inner membrane of mitochondria

The site of the electron transport chain and ATP synthesis in mitochondria, the inner membrane is highly folded into structures called cristae to increase surface area for cellular respiration.

fermentation of yeast

A metabolic process that converts sugar to acids, gases, or alcohol in the absence of oxygen. Yeast fermentation produces ethanol and carbon dioxide, commonly used in brewing and baking.

fermentation in animal cells

A process that converts glucose to lactic acid when oxygen is scarce, often occurring in muscle cells during intense exercise. This allows for ATP production without oxygen, but results in lactic acid buildup.

lactic acid

produced during anaerobic respiration in animal cells, lactic acid fermentation occurs when glucose is converted into energy without oxygen, resulting in lactic acid accumulation in muscles.