Key Terms
Activation Energy: A threshold that must be crossed to facilitate a chemical reaction.
There are three ways to reach the activation energy: by increasing the
concentration of reactants, by raising
Active sites: Folds and clefts on the surface of an enzyme that enable attachment
to its particular substrate.
Catalysis: A substance that speeds up a chemical
reaction without participating in it. Catalysts, of which enzymes are a good
example, thus are not consumed in the reaction.
Coenzyme: A non protein component sometimes required to allow an enzyme to set
in motion a catalytic reaction.
Enzyme: A protein that acts as a catalyst, a material that speeds up chemical
reactions in the bodies of plants and animals without itself taking part in, or
being consumed by, these reactions.
Fermentation: A process involving enzymes in which a compound rich in energy is
broken down into simpler substances.
Metabolism: The chemical process by which nutrients are broken down and converted
into energy or are used in the construction of new tissue or other material al
in the body.
Molecule: A group of atoms, usual ly but not always representing more than one
element, joined in a structure. Compounds typically are made up of molecules.
Organic: At one time, chemists used the term organic only in reference
to living things. Now the word is applied to compounds containing carbon and
hydrogen.
Proteins: Large molecules built from long chains of 50 or more amino acids.
Proteins serve the functions of promoting normal growth, repairing damaged
tissue, contributing to the body's immune system, and making enzymes.
Reactant: A substance that interacts with another substance in a chemical
reaction, resulting in the formation of a chemical or chemicals known as the
product.
Starches: Complex carbohydrates without taste or odor, which are granular or
powdery in physical form.
Substrate: A reactant that typically is paired with a particular enzyme.
Enzymes often are named after their respective substrates by adding the suffix
ase (e.g., the enzyme lactase is paired with the substrate lactose).
Sugars: One of the three principal types of carbohydrate, along with starches
and cellulose. Sugars can be defined as any of various water-soluble
carbohydrates of varying sweetness. What we think of as "sugar" (i.e., table
sugar) is actually sucrose.
Vitamins: Organic substances that, in extremely small quantities, are essential
to the nutrition of most animals and some plants. In particular, vitamins work
with enzymes in regulating metabolic processes; however, they do not in
themselves provide energy, and thus vitamins alone do not qualify as a form of
nutrition.
There are three ways to reach the activation energy: by increasing the
concentration of reactants, by raising
Active sites: Folds and clefts on the surface of an enzyme that enable attachment
to its particular substrate.
Catalysis: A substance that speeds up a chemical
reaction without participating in it. Catalysts, of which enzymes are a good
example, thus are not consumed in the reaction.
Coenzyme: A non protein component sometimes required to allow an enzyme to set
in motion a catalytic reaction.
Enzyme: A protein that acts as a catalyst, a material that speeds up chemical
reactions in the bodies of plants and animals without itself taking part in, or
being consumed by, these reactions.
Fermentation: A process involving enzymes in which a compound rich in energy is
broken down into simpler substances.
Metabolism: The chemical process by which nutrients are broken down and converted
into energy or are used in the construction of new tissue or other material al
in the body.
Molecule: A group of atoms, usual ly but not always representing more than one
element, joined in a structure. Compounds typically are made up of molecules.
Organic: At one time, chemists used the term organic only in reference
to living things. Now the word is applied to compounds containing carbon and
hydrogen.
Proteins: Large molecules built from long chains of 50 or more amino acids.
Proteins serve the functions of promoting normal growth, repairing damaged
tissue, contributing to the body's immune system, and making enzymes.
Reactant: A substance that interacts with another substance in a chemical
reaction, resulting in the formation of a chemical or chemicals known as the
product.
Starches: Complex carbohydrates without taste or odor, which are granular or
powdery in physical form.
Substrate: A reactant that typically is paired with a particular enzyme.
Enzymes often are named after their respective substrates by adding the suffix
ase (e.g., the enzyme lactase is paired with the substrate lactose).
Sugars: One of the three principal types of carbohydrate, along with starches
and cellulose. Sugars can be defined as any of various water-soluble
carbohydrates of varying sweetness. What we think of as "sugar" (i.e., table
sugar) is actually sucrose.
Vitamins: Organic substances that, in extremely small quantities, are essential
to the nutrition of most animals and some plants. In particular, vitamins work
with enzymes in regulating metabolic processes; however, they do not in
themselves provide energy, and thus vitamins alone do not qualify as a form of
nutrition.