RCB BIOLOGY TEST STUDY GUIDE

Metabolism

All the chemical reactions that occur within a living organism to sustain life.

Adenosine triphosphate (ATP)

The primary usable energy carrier of the cell, storing energy within high-energy phosphate bonds.

Mechanism of energy release from ATP

The removal of the terminal phosphate group from ATP, breaking a high-energy bond and forming ADP.

Chloroplast

The plant cell organelle in which photosynthesis takes place.

Chlorophyll

The primary pigment in chloroplasts that absorbs red and blue light to harness energy while reflecting green light.

Chemical equation for photosynthesis

$$6CO_2 + 6H_2O + \text{light energy} \rightarrow C_6H_{12}O_6 + 6O_2$$

Light reactions of photosynthesis

The initial stage of photosynthesis that requires sunlight and water to produce ATP, NADPH, and oxygen ($O_2$).

Calvin cycle (light-independent reactions)

The second stage of photosynthesis that utilizes $CO_2$, ATP, and NADPH to synthesize glucose.

Cellular respiration

The biochemical pathway that breaks down glucose in cells to release energy and produce ATP.

Chemical equation for cellular respiration

$$C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{ATP}$$

Glycolysis

The first step of cellular respiration that takes place in the cytoplasm, breaking down glucose to yield a net of $2$ ATP.

Krebs cycle

The aerobic stage occurring in the mitochondria that continues breaking down glucose derivatives and releases carbon dioxide ($CO_2$).

Electron transport chain (ETC)

The mitochondrial inner membrane pathway that uses high-energy electrons from NADH and $FADH_2$ to produce most of the ATP and water.

Aerobic vs. Anaerobic respiration

Aerobic respiration requires oxygen and produces a net of $36\text{--}38$ ATP, whereas anaerobic respiration occurs without oxygen and yields only a net of $2$ ATP.

Fermentation

An anaerobic cellular process that regenerates $NAD^+$ to allow glycolysis to continue producing ATP in the absence of oxygen.

Lactic acid fermentation

An anaerobic process occurring in animal muscle cells during strenuous activity and in bacteria used to produce yogurt and cheese.

Alcohol fermentation

An anaerobic pathway occurring in yeast cells that breaks down sugars into ethanol and $CO_2$, commonly used in baking and brewing.

Independent variable

The single factor or condition deliberately manipulated or changed by the scientist in an experiment.

Dependent variable

The factor that is measured or observed to evaluate the effect of the independent variable.

Controlled variables (constants)

All conditions and parameters kept strictly identical across experimental and control groups.

Hypothesis

A testable and falsifiable scientific statement predicting the effect of an independent variable on a dependent variable.