Biology Vocab Unit 8

Activation energy

The amount of energy that reactants must absorb before a chemical reaction will start.

Amino Acid

An organic molecule containing a carboxyl group and an amino group; serves as the monomer of proteins

Catalyst

A substance that speeds up a chemical reaction.

Calvin cycle

The cycle of chemical reactions where the carbon from the carbon cycle is fixed into sugars.

Cellular Respiration

The aerobic harvesting of energy from food molecules; the energy-releasing chemical breakdown of food molecules, such as glucose, and the storage of potential energy in a form that cells can use to perform work; involves glycolysis, pyruvate oxidation and the citric acid cycle, and oxidative phosphorylation. (the electron transport chain and chemiosmosis).

Chemiosmosis

An energy-coupling mechanism that uses the energy of hydrogen ion gradient across membranes to drive cellular work, such as the phosphorylation of ADP; powers most ATP synthesis in cells.

Chlorophyll

A green pigment located within the chloroplasts of plants and algae and in the membranes of certain prokaryotes. Chlorophyll A participates directly in the light reactions, which converts solar energy to chemical energy.

Chloroplast

An organelle found in plants and algae that absorbs sunlight and uses it to drive the synthesis of organic compounds from carbon dioxide and water.

Citric Acid Cycle

The chemical cycle that completes the metabolic breakdown of glucose molecules.

Electron transport chain

A series of electron carrier molecules that shuttle electrons during a series of redox reactions that release energy used to make ATP; located in the inner membrane of mitochondria, the thylakoid membranes of chloroplasts, and the plasma membranes of prokaryotes.

Enzyme

A macromolecule, usually a protein, that serves as a biological catalyst, changing the rate of a chemical reaction without being consumed by the reaction.

Fermentation

A metabolic process where organisms break down organic molecules like sugar (glucose) into simpler compounds, like alcohol or lactic acid, without the presence of oxygen (anaerobically), producing a small amount of energy (ATP) in the process

Glycolysis

A series of reactions that ultimately splits glucose into two molecules of pyruvate; the first stage of cellular respiration in all organisms; occurs in the cytosol.

Light reactions

The first of two stages in photosynthesis; the steps in which solar energy is absorbed and converted to the chemical energy of ATP and NADPH, releasing oxygen in the process.

Mitochondria

An organelle in eukaryotic cells where cellular respiration occurs. Enclosed by two membranes, it is where most of the cell’s ATP is made.

Photosynthesis

The process by which plants, algae, and some protists and prokaryotes convert light energy to chemical energy that is stored in sugars made from carbon dioxide and water.

Substrate

A specific substance (reactant) on which an enzyme acts. Each enzyme recognizes only the specific substrate or substrates of the reaction it catalyzes.

Adenosine Triphosphate (ATP)

High-energy molecule that can be found in all types of cells, including plant cells, muscle cells, nerve cells, and more