Key Words - Biological Molecules Flashcards
Activation energy
Energy required to bring about a reaction.
Active site
A group of amino acids that makes up the region of an enzyme into which the substrate fits to catalyse a reaction.
Alpha Glucose
An isomer of glucose that can bond together to form starch or glycogen.
Amine group
The -NH2 group of an amino acid
Amino Acid
A monomer which makes up proteins. Has a central carbon atom which is bonded to: a carboxylic acid group, an amino group and a R group.
Amino acid
A monomer which makes up proteins. Has a central carbon atom which is bonded to a: carboxylic acid group, an amino group, a hydrogen atom and a R group.
Benedict’s reagent
Blue solution, which is used to test for reducing or non reducing sugars.
Beta Glucose
An isomer of glucose that can bond together to form cellulose.
Biuret test
A simple biochemical reaction to detect the presence of protein, if the Biuret’s Solution turns purple bum protein is present.
Carboxyl group
The -COOH group of an amino acid.
Cellulose
A polysaccharide made up of beta-glucose found in plant cells. (beta 1,4-glycosidic bonds).
Competitive inhibitor
A form of inhibitor which binds to the active site of the enzyme preventing the binding of substrate.
Complimentary
Describes the relationship between the active site of an enzyme and the substrate molecule - the way in which the fit together.
Condensation Reaction
Chemical process in which two molecules combine to form a more complex one with the elimination of a simple substance, usually water. Many biological polymers (e.g polysaccharides, polypeptides) are formed by condensation.
Covalent Bond
Type of chemical bond in which two atoms share a pair of electrons.
Disaccharide
Made up of two sugar units that are formed by a condensation reaction. Monosaccharides are joined by a glycosidic bond.
Disulphide bridge
Bond formed between sulphur atoms in R groups of amino acids.
Emulsion test
Test for lipids. Mix your sample with ethanol and then add water. If a white cloudy emulsion forms, then a lipid is present.
Enzyme
A protein that acts as a catalyst and so lowers the activation energy needed for a reaction.
Enzyme-substrate (ES) complex
The intermediate formed when a substrate molecule interacts with the active site if an enzyme.
Glucose
C6H12O6 - a single sugar which is used in respiration.
Glycerol
A molecule which combines with three fatty acids to form triglycerides. It is a carbon chain with 3 hydroxyl groups.
Glycogen
A highly branched polysaccharide made up of alpha glucose found in animal cells (alpha-1,4 and alpha-1,6 glycosidic bond).
Glycosidic bond
Bond between sugar molecules in disaccharides and polysaccharides.
Hexose sugar
A sugar made up of 6 carbons.
Hydrogen bond
Chemical bond formed between the positive charge on a hydrogen atom and the negative charge on another atom of an adjacent molecule. Often between a negative oxygen and positive hydrogen atoms.
Hydrolysis
The breaking down of large molecules into smaller ones by the addition of water molecules.
Hydrophilic
Section of a molecule which is attracted to water.
Hydrophobic
Section of a molecule which is repulsed by water.
Induced fit model
A mechanism of interaction between an enzyme and a substrate. As the substrate fits into the active site the active site of the enzyme changes shape to allow an enzyme-substrate complex to be formed.
Inhibitor
A substance which reduces the activity of an enzyme.
Ionic bond
A bond between the positive ion which has lost an electron(s) and a negative ion which has gained an electron(s).
Isomer
Two or more compounds with the same formula but a different arrangement of atoms in the molecule and therefore different properties.
Kinetic energy
The energy of motion, observable as the movement of an object, particle or set of particles.
Lipid
A class of organic compounds that are fatty acids in their deriatives and are insoluble in water but soluble in organic solvents. They include triglycerides, phospholipids, waxes and steroids.
Lock and key model
An analogy for how enzymes work - only the correctly sized key fits into the keyhole (active site) of the lock (enzymes).
Metabolism
All of the chemical processes that take place in living organisms.
Mono-unsaturated fatty acid
Fatty acid which possesses a carbon chain with a single double bond between carbon atoms.
Monomer
One of many small molecules that combine together to form a polymer.
Monosaccharide
A single sugar e.g. glucose. The monomers of long chain carbohydrate polymers.