Photosynthesis, Cellular Respiration, and Metabolic Processes Flashcards

Vocabulary flashcards covering key concepts of photosynthesis, cellular respiration, anaerobic fermentation, and chemosynthesis.

Metabolism

The total sum of chemical processes that occur in living organisms to maintain life.

Autotroph

An organism that can create its own chemical energy (food) using sunlight or chemical compounds, such as plants, algae, and chemo-autotrophic microbes.

Heterotroph

An organism that obtains chemical energy by consuming other living or recently killed organisms.

Photosynthesis

The process by which green plants, algae, and some protists convert light energy, carbon dioxide ($\text{CO}_2$), and water ($\text{H}_2\text{O}$) into chemical energy in the form of glucose ($\text{C}_6\text{H}_{12}\text{O}_6$) and oxygen ($\text{O}_2$).

Light-Dependent Reactions

The first step of photosynthesis that requires light and water ($\text{H}_2\text{O}$) to produce oxygen ($\text{O}_2$), $\text{ATP}$, and $\text{NADPH}$ inside the thylakoids.

Light-Independent Reactions

The second step of photosynthesis (Calvin Cycle) that takes place in the stroma, using carbon dioxide ($\text{CO}_2$), $\text{ATP}$, and $\text{NADPH}$ to produce glucose ($\text{C}_6\text{H}_{12}\text{O}_6$).

Thylakoid

Flattened sacs inside chloroplasts arranged in stacks called grana where light-dependent reactions take place.

Stroma

The fluid surrounding the thylakoids inside a chloroplast where the light-independent reactions (Calvin Cycle) occur.

Bromothymol Blue (BTB)

A chemical indicator used to test carbon dioxide ($\text{CO}_2$) levels in a solution, turning blue in low $\text{CO}_2$, green in medium $\text{CO}_2$, and yellow in high $\text{CO}_2$ concentration.

Light Saturation Point

The threshold of light intensity where all photosynthetic pigments are being fully utilized, causing the rate of photosynthesis to level off.

Cellular Respiration

A set of metabolic reactions that converts food energy from glucose ($\text{C}_6\text{H}_{12}\text{O}_6$) and oxygen ($\text{O}_2$) into usable $\text{ATP}$ energy, releasing carbon dioxide ($\text{CO}_2$) and water ($\text{H}_2\text{O}$) as waste.

Glycolysis

An anaerobic process occurring in the cytoplasm where a 6-carbon molecule of glucose is split into two 3-carbon pyruvate molecules, generating a net total of $2\,\text{ATP}$ (producing $4\,\text{ATP}$ but using $2\,\text{ATP}$ to start).

Pyruvate

A 3-carbon organic molecule produced by the breakdown of glucose during glycolysis, serving as the ion form of pyruvic acid.

Ion

A molecule or atom that has lost or gained one or more electrons.

Krebs Cycle

An aerobic stage of cellular respiration that takes place in the mitochondrial matrix, consuming pyruvate to produce carbon dioxide ($\text{CO}_2$) as a waste product and $2\,\text{ATP}$.

Electron Transport Chain

An aerobic stage of cellular respiration occurring in the inner mitochondrial membrane that uses oxygen ($\text{O}_2$) to produce water ($\text{H}_2\text{O}$) and approximately $34\,\text{ATP}$.

ATP (Adenosine Triphosphate)

A cellular energy molecule consisting of adenosine bonded to three phosphate groups; breaking its phosphate bonds releases energy for cell work.

Mitochondria

The eukaryotic organelle responsible for carrying out cellular respiration to convert food energy into $\text{ATP}$.

Anaerobic Respiration

The metabolic process of synthesizing small amounts of $\text{ATP}$ without oxygen.

Aerobic Respiration

The efficient metabolic process requiring oxygen that completely breaks down glucose to produce an average yield of $38\,\text{ATP}$.

Fermentation

An anaerobic pathway that allows glycolysis to continuously make $\text{ATP}$ when oxygen is absent by recycling $\text{NADH}$ back to $\text{NAD}^+$.

Lactic Acid Fermentation

An anaerobic process occurring in muscle cells, other vertebrates, and microorganisms where pyruvate is converted to two lactic acid molecules ($\text{C}_3\text{H}_6\text{O}_3$), causing muscle soreness.

Alcoholic Fermentation

An anaerobic process occurring in yeasts and some plants where pyruvate is converted into ethyl alcohol and carbon dioxide ($\text{CO}_2$).

Chemosynthesis

The process by which chemo-autotrophic organisms convert chemical energy (such as hydrogen sulfide, $\text{H}_2\text{S}$) into carbohydrates in environments without sunlight.

Hydrothermal Vents

Deep seafloor structures near volcanic activity where water heated up to $400\,^\text{o}\text{C}$ ($752\,^\text{o}\text{F}$) releases chemical fluids that sustain chemo-autotrophic communities.