BIOL 1000 Exercise 9: Cellular Respiration Vocabulary

Vocabulary flashcards reviewing core concepts, key chemical pathways, equations, substrate efficiencies, titration mechanics, and milk quality dye reduction assays from BIOL 1000 Exercise 9.

Aerobic Respiration

A catabolic process requiring oxygen that completely oxidizes glucose to $\text{CO}_2$ and$\text{H}_2\text{O}$, producing $\sim 30\text{--}32\text{ ATP}$ per glucose.

Anaerobic Fermentation

A catabolic process occurring that does not need oxygen and partially oxidizes glucose, generating only $2\text{ ATP}$ net via glycolysis.

Alcoholic Fermentation

The anaerobic conversion of pyruvate into ethanol and carbon dioxide gas ($\text{CO}_2$), carried out by yeast.

Lactic Acid Fermentation

The anaerobic conversion of pyruvate into lactate/lactic acid, carried out by animal muscle cells and bacteria.

Cellular Respiration Reaction

The balanced chemical reaction $\text{C}_6\text{H}_{12}\text{O}_6+6\,\text{O}_2\longrightarrow6\,\text{CO}_2+6\,\text{H}_2\text{O}+\text{ ATP}$ .

Alcoholic Fermentation Reaction

The chemical reaction $\text{C}_6\text{H}_{12}\text{O}_6 \longrightarrow 2\,\text{C}_2\text{H}_5\text{OH} + 2\,\text{CO}_2\uparrow + 2\text{ ATP}$ carried out by yeast.

Lactic Acid Fermentation Reaction

The chemical reaction $\text{C}_6\text{H}_{12}\text{O}_6 \longrightarrow 2\,\text{C}_3\text{H}_6\text{O}_3\text{ (Lactic Acid)} + 2\text{ ATP}$ carried out by muscle cells and bacteria.

Carbon Dioxide

Gas produced during yeast/alcohol fermentation

Carbohydrates used during yeast fermentation

Glucose (monosaccharide), sucrose (disaccharide), and starch (polysaccharide); water serves as a non-fermentable negative control establishing a baseline.

Glucose (in Yeast Fermentation)

A monosaccharide substrate that acts as a direct fuel for glycolysis without requiring a cleavage step, resulting in the fastest/highest fermentation rate.

Sucrose (in Yeast Fermentation)

A disaccharide substrate composed of glucose and fructose that is enzymatically cleaved quickly, resulting in a rapid/moderate fermentation rate.

Starch (in Yeast Fermentation)

A complex polysaccharide substrate that requires extracellular amylase to hydrolyze, resulting in a very slow/minimal fermentation rate.

Titration

A technique used to see how much acid or base there is in a solution

Carbonic Acid Formation Reaction

The equilibrium reaction $\text{CO}_2 + \text{H}_2\text{O} \rightleftharpoons \text{H}_2\text{CO}_3$ where dissolved carbon dioxide forms carbonic acid.

Carbonic Acid Neutralization Reaction

The neutralization reaction $\text{H}_2\text{CO}_3 + 2\,\text{NaOH} \longrightarrow \text{Na}_2\text{CO}_3 + 2\,\text{H}_2\text{O}$ occurring during titration.

Carbonic Acid Respiration

Carbon dioxide emitted during respiration dissolves in water to form weak carbonic acid (H2 CO3) lowering solution pH. Titrating this acid with a base quantifies the amount of CO2 generated.

Phenolphthalein

A $\text{pH}$ indicator that turns pink in basic conditions ($\text{pH} > 8.2$); the number of drops of $\text{NaOH}$ required to reach a faint pink color directly correlates with $\text{CO}_2$ content.

Sodium hydroxide

The basic titrant that neutralizes carbonic acid

Dye Reduction Test for Milk Quality

The bacteria in milk consume oxygen and reduce indicator dyes (such as Resazurin or Methylene Blue) via electron transport chain activity, where color change time measures bacterial load.

Fresh Milk Assay Results

Milk characterized by low/minimal bacterial population, blue/purple resazurin dye color, and slow/no decolorization ($> 6\text{ hours}$).

Raw / Slightly Aged Milk Assay Results

Milk characterized by a moderate bacterial population, pink resazurin dye color, and intermediate decolorization time ($2\text{--}6\text{ hours}$).

Spoiled / Unpasteurized Milk Assay Results

Milk characterized by a high/dense bacterial population, white/colorless resazurin dye state, and rapid decolorization ($< 2\text{ hours}$).

Product of Lactic Acid Fermentation

Lactic Acid

Yeast

Responsible for carrying out anaerobic alcoholic fermentation.

Bacteria

Responsible for carrying out anaerobic lactic acid fermentation.

PH of different solutions

Dip a strip of pH paper into the solution and compare the resulting color change against a standard color chart to determine the relative acidity or basicity.

Funciton of Resazurin

It was the final electron acceptor and was reduced

Other Organism that produces lactic acid

Humans

PH change of the milk

The production of lacic acid from the bacteria

Starch and Lactose

Not good sources of nutrition for yeast because their enzymes broke the sugar

Glucose and Sucrose

Good sources of nutrition because they had the most bubbles or CO2 produced