Cellular Respiration in Anaerobic Conditions

Flashcards covering key vocabulary related to cellular respiration, focusing on anaerobic conditions, yeast fermentation, respiratory pathways, and energy production.

Saccharomyces cerevisiae

A species of yeast (Domain: Eukaryota; Kingdom: Fungi) commonly used in baking and alcohol production, capable of anaerobic respiration.

Anaerobe

An organism, such as S. cerevisiae in the absence of oxygen, that can produce energy in anaerobic conditions.

Ethanol

An alcohol produced as a byproduct of anaerobic respiration (fermentation) by some microorganisms like S. cerevisiae.

CO2

Carbon Dioxide, a gas produced as a byproduct of S. cerevisiae's anaerobic respiration.

Simple Fermentation Chambers

Experimental setups, typically plastic pipettes, containing 'yeast broth' to observe and measure anaerobic respiration.

Yeast Broth

The liquid in a fermentation chamber that contains water, carbohydrates, and respiring S. cerevisiae.

Meniscus Displacement

The downward movement of the yeast broth meniscus in a fermentation chamber, which is proportional to the volume of CO2 produced and used to estimate respiration rate.

Glycolysis

The multistep breakdown of glucose to pyruvate, which is the initial stage of respiration and common to both aerobic and anaerobic organisms.

Pyruvate

A compound produced from glucose during glycolysis, which can then be reduced via fermentation in anaerobic conditions or converted to CO2 and water in aerobic conditions.

Fermentation

A process occurring in oxygen-poor environments where anaerobes reduce pyruvate to either CO2 plus ethanol (some microorganisms) or lactic acid (other microorganisms and animal muscles).

Lactic Acid

A compound produced as a byproduct of fermentation in oxygen-deprived muscles of animals.

Aerobic Respiration

The process where pyruvate is converted to CO2 and water via the citric acid cycle in the presence of oxygen, resulting in a significantly higher ATP yield.

Citric Acid Cycle (Krebs cycle)

A metabolic pathway that converts pyruvate to CO2 and water when oxygen is present, contributing to aerobic respiration.

NAD+ (Nicotinamide adenine dinucleotide)

A carrier molecule that accepts electrons during aerobic respiration and donates them to the electron transport chain.

Electron Transport Chain

A series of molecules that receive electrons from carrier molecules like NAD+ during aerobic respiration to produce ATP.

ATP (Adenosine triphosphate)

The primary energy currency of the cell, with aerobic respiration producing approximately 18 times more molecules than glycolysis alone.

Anaerobic Conditions

Environments characterized by the absence or scarcity of oxygen, under which certain organisms like S. cerevisiae perform anaerobic respiration.