Enzymes Key Word Glossary - Nutrition in Humans

Catalyse A substance that can speed up the rate of a reaction but is not used up or changed itself.

Tissue A group of specialised cells with a similar structure and function

Digestive system Organ system where food is digested and absorbed

Lipases Enzymes that speed up the digestion of lipids into fatty acids and glycerol

Enzyme substrate complex This forms when the enzyme and substrate join.

Active site The region on an enzyme where the substrate bind

Simple sugars Monomers that make up carbohydrates. They contain the elements Carbon, Hydrogen and Oxygen. For example glucose.

Lipids Large organic molecules which include fats and oils. They are made of carbon, hydrogen and oxygen.

Liver This organ produces bile.

Amino acids Monomers made up of carbon, hydrogen, oxygen and nitrogen that are the building blocks of proteins

Organ An aggregation (collection) of different tissues working together to carry out specific functions.

Activation energy This is the energy required to a chemical reaction to occur. Catalysts reduce this and so can speed up the rate of a reaction.

Amylase Enzyme that digests starch to maltose

Organ system A group of organs that work together to carry out specific functions and form organisms.

Metabolism the sum of all the reactions taking place in a cell or the body of an organism.

Denature The breakdown of the molecular structure of an enzyme so that its active site is no longer complimentary to the substrate.

Protease Enzymes that speed up the digestion of proteins into amino acids.

Enzymes Biological catalysts, found in living cells and made from proteins

Proteins Polymers made of long chains of amino acids. They contain the elements Nitrogen, Carbon, Hydrogen and Oxygen. They are used for building the cells and tissues of the body and to form enzymes.

Maltase Enzyme that digests maltose to glucose.

Glycerol One of the components which makes up the structure of a lipid molecule

Gallbladder A small, pear-shaped organ that stores and releases bile to aid in digestion. It is located beneath the liver.

Bile Alkaline substance which neutralises stomach acid and increases the pH to provide optimum conditions for the enzymes produced by the pancreas and small intestine. Also emulsifies lipids.

Hydrochloric acid An acidic substance released by the stomach to lower the pH of the contents within the stomach.

Optimum Describes the conditions which provide the best environment for an enzyme to work in. The enzyme's activity is highest and the rate of the reaction it catalyses is the fastest.

Carbohydrase Enzymes that digest carbohydrates into simple sugars

Fatty acids One of the components that makes up a lipid molecule

Carbohydrates Polymers made from repeating units of simple sugars. They contain the elements carbon, hydrogen and oxygen. Short term source of energy for metabolism

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