SBI4U1: Anaerobic Pathways and Fermentation

Comprehensive vocabulary flashcards covering anaerobic cellular respiration, lactic acid fermentation, alcohol fermentation, practical applications, and laboratory design concepts.

Anaerobic Cellular Respiration

A respiratory pathway occurring in some prokaryotes without mitochondria that utilizes specialized membranes and an inorganic compound other than oxygen (such as $\text{SO}_4^{2-}$, $\text{NO}_3^-$, or $\text{Fe}^{3+}$) as the final electron acceptor.

Fermentation

An anaerobic pathway utilized by eukaryotes and some bacteria following glycolysis to oxidize $\text{NADH}$ back into $\text{NAD}^+$, allowing glycolysis to continue generating ATP in the absence of oxygen.

Glycolysis Anaerobic Yield

An initial metabolic process that operates anaerobically to yield a net output of $2\,\text{ATP}$ and $2\,\text{NADH}$ per molecule of glucose.

Lactic Acid Fermentation

An anaerobic pathway found in certain bacteria and eukaryotic cells (such as human muscle cells) in which pyruvate is reduced by $\text{NADH}$ to produce lactate and regenerate $\text{NAD}^+$.

Lactic Acid Fermentation Equation

$$2\,\text{pyruvate} + 2\,\text{NADH} \rightarrow 2\,\text{lactate} + 2\,\text{NAD}^+$$

Reversal of Lactate Reaction

The reaction that takes place when oxygen is restored to cells, wherein lactate is oxidized by $\text{NAD}^+$ to regenerate pyruvate and $\text{NADH}$ for pyruvate oxidation.

Post-Workout Muscle Soreness

A physiological burning sensation after intense exertion that is primarily caused by micro-tears in muscle fibers rather than accumulated lactic acid.

Lactic Acid Clearance

The filtration of temporary lactic acid from the blood by the liver and kidneys, where it is converted back into glucose.

Otto Meyerhof

The scientist awarded the 1922 Nobel Prize in Physiology or Medicine who studied electrical stimulation of frog legs in airtight jars and linked the appearance of lactic acid to muscle fatigue.

Alcohol Fermentation

An anaerobic pathway occurring in yeasts and some bacteria where pyruvate is decarboxylated to acetaldehyde and then reduced by $\text{NADH}$ into ethanol and $\text{NAD}^+$.

Acetaldehyde

The two-carbon intermediate produced when pyruvate releases $\text{CO}_2$ during alcohol fermentation, which subsequently acts as an electron acceptor from $\text{NADH}$.

Alcohol Fermentation Equation

$$2\,\text{pyruvate} + 2\,\text{NADH} \rightarrow 2\,\text{ethanol} + 2\,\text{CO}_2 + 2\,\text{NAD}^+$$

Bread Rising Mechanism

The expansion of dough caused by the release and trapping of $\text{CO}_2$ gas produced by yeast during alcohol fermentation.

Nuruk

A fermentation starter made by inoculating rice with molds, which is subsequently fermented by yeasts to produce chongju (rice wine).

Lactic Acid Fermentation Foods

Fermented food products produced using lactic acid bacteria, including yogurt, kefir, kimchi, and pickles.

Industrial Fermentation Products

Non-culinary applications of fermentation that yield pharmaceuticals (such as insulin and penicillin), beauty products, biofuels (ethanol), and meat or plastic alternatives (such as tempeh and PLA).

Yeast Fermentation Rate Variables

The potential independent variables that can be manipulated in an experimental investigation of yeast fermentation rate: pH, sucrose concentration, temperature, or yeast concentration.