Quiz 1 Proteins And Enzymes

Front 1

A giant molecule formed by the joining of smaller molecules, usually by a condensation reaction. Polysaccharides, proteins, and nucleic acids are macromolecules

Back 1

Macromolecule

Front 2

The subunit that serves as the building block of a polymer.

Back 2

Monomer

Front 3

A long molecule consisting of many similar or identical monomers linked together.

Back 3

Polymer

Front 4

A chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule.

Back 4

Dehydration Synthesis

Front 5

A chemical process that lyses, or splits, molecules by the addition of water, functioning in disassembly of polymers to monomers.

Back 5

Hydrolysis

Front 6

A chemical group consisting of a nitrogen atom bonded to two hydrogen atoms; can act as a base in solution, accepting a hydrogen ion and acquiring a charge of 1 + .

Back 6

Amino Group

Front 7

A chemical group present in organic acids and consisting of a single carbon atom double-bonded to an oxygen atom and also bonded to a hydroxyl group.

Back 7

Carboxyl

Front 8

A chemical group consisting of a phosphorus atom bonded to four oxygen atoms; important in energy transfer.

Back 8

Phosphate Group

Front 9

The covalent bond between the carboxyl group on one amino acid and the amino group on the next, formed by a dehydration reaction.

Back 9

Peptide Bond

Front 10

A polymer of many amino aids linked together by peptide bonds.

Back 10

Polypeptide

Front 11

A functional biological molecule consisting of one or more polypeptides folded and coiled into a specific three-dimensional structure.

Back 11

Protein

Front 12

A strong covalent bond formed when the sulfur of one cysteine monomer bonds to the sulfur of one cysteine monomer bonds to the sulfur of another cysteine monomer.

Back 12

Disulfide Bond

Front 13

The level of protein structure referring to the specific sequence of amino acids.

Back 13

Primary Structure

Front 14

the localized, repetitive coiling or folding of the polypeptide backbone of a protein due to hydrogen bond formation between peptide linkages.

Back 14

Secondary Structure

Front 15

One form of the secondary structure of proteins in which the polypeptide chain folds back and forth. Two regions of the chain lie parallel to each other and are held together by hydrogen bonds.

Back 15

Pleated Sheet

Front 16

Irregular contortions of a protein molecule due to interactions of side chains involved in hydrophobic interactions

Back 16

Tertiary Structure

Front 17

The particular shape of a complex, aggregate protein, defined by the characteristic three dimensional arrangement of its constituent subunits, each a polypeptide.

Back 17

Quaternary Structure

Front 18

In proteins, a process in which a protein unravels and loses its native shape, thereby becoming biologically inactive; in DNA, the separation of the two strands of the double helix. Denaturation occurs under extreme (noncellular) conditions of pH, salt concentration, and temperature.

Back 18

Denatured Protein

Front 19

The amount of energy that reactants must absorb before a chemical reaction will start; also called free energy of activation

Back 19

Activation Energy

Front 20

A chemical agent that increases the rate of a reaction without being consumed by the reaction

Back 20

Catalyst

Front 21

A macromolecule serving as a catalyst, A chemical agent that changes the rate of a reaction without being consumed by the reaction.

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Enzyme

Front 22

The reactant on which an enzyme works.

Back 22

Substrate

Front 23

A temporary complex formed when an enzyme binds to its substrate molecules.

Back 23

ES complex

Front 24

The specific portion of an enzyme that binds the substrate by means of multiple weak interactions and that forms the pocket in which catalysis occurs.

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Active Site

Front 25

Induced by entry of the substrate, the change in shape of the active site of an enzyme so that it binds more snugly to the substrate.

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Induced Fit

Front 26

Any nonprotein molecule or ion that is required for the proper functioning of an enzyme. Cofactors can be permanently bound to the active site or may bind loosely with the substrate during catalysis.

Back 26

Cofactor

Front 27

An organic molecule serving as a cofactor. Most vitamins function as coenzymes in metabolic reactions.

Back 27

Coenzyme

Front 28

The place on an enzyme where a molecule that is not a substrate may bind, thus changing the shape of the enzyme and influencing its ability to be active.

Back 28

Allosteric site

Front 29

A method of metabolic control in which the end product of metabolic pathway acts as an inhibitor of an enzyme within that pathway.

Back 29

Feedback inhibition

Front 30

Reversible inhibitors bind to enzymes with non-covalent interactions such as hydrogen bonds, hydrophobic interactions and ionic bonds.

Back 30

Reversible inhibition

Front 31

A substance that reduces the activity of an enzyme by entering the active site in place of the substrate whose structure it mimics.

Back 31

Competitive inhibitor

Front 32

A substance that reduces the activity of an enzyme by binding to a location remote from the active site, changing the enzyme’s shape so that the active site no longer functions effectively.

Back 32

Noncompetitive inhibitor

Front 33

Irreversible inhibitors usually covalently modify an enzyme, and inhibition cannot therefore be reversed.

Back 33

Irreversible inhibition