Proteins + Enzymes

Question 1

Activation energy

Answer 1

The required energy to enable a reaction to occur.

Question 2

Active site

Answer 2

Area on an enzyme molecule to which substrate binds to.

Question 3

Alpha helix

Answer 3

Protein secondary structure- coiling of polypeptide chain to form right-handed spiral held in place by Hydrogen bonds between C=O and NH groups.

Question 4

Amino acids

Answer 4

Monomer of polypeptide, contains amine group (-NH2) and a carboxyl group (-COOH).

Question 5

Amphotenic

Answer 5

Molecule which can act as acid and base.

Question 6

Beta pleated sheet

Answer 6

Folded protein secondary structure held by H-bonds.

Question 7

Biuret test

Answer 7

Biochemical test for presence of proteins.

Question 8

Buffer

Answer 8

Substance which resists a change in pH when acid/ alkali is added.

Question 9

Catalyst

Answer 9

Substance that increases rate of reaction but doesn’t take part in reaction, so is reusable.

Question 10

Coenzyme

Answer 10

Organic non-protein molecules which bind temporarily with the substrate to an enzyme active site, essential for enzyme activity.

Question 11

Cofactor

Answer 11

Molecule or ion helping enzyme work.

Question 12

Competitive Inhibitor

Answer 12

Substance which reduces rate of enzyme-controlled reaction by binding to enzyme active site.

Question 13

Condensation

Answer 13

Type of chemical reaction in which 2 molecules are joined together by covalent bonds forming larger molecules and releases water.

Question 14

Denaturation

Answer 14

Irreversable change to tertiary structre of protein molecule, leads to loss of function in most proteins.

Question 15

Disulphide bridge

Answer 15

Covalent bond formed between sulphur atoms in 2 cytosine and amino acid residues.

Question 16

End product inhibition

Answer 16

Regulation of metabolic pathways where last product in sequence of enzyme-controlled reaction becomes the inhibitor of 1 enzyme earlier in sequence.

Question 17

Enzyme

Answer 17

Biological catalyst speeds up metabolic reactions inside cells.

Question 18

Enzyme substrate complex

Answer 18

Intermediate structure formed when substrate molecule binds to enzyme active site.

Question 19

Fibrous protein

Answer 19

Protein with relatively long, thin structure, which is insoluble in water and metabolically inactive. Often has structural role within organism.

Question 20

Globular protein

Answer 20

Proteins with relatively spherical molecules, soluble in water, often have metabolic role in organisms.

Question 21

Hydrogen bonds

Answer 21

Weak electrostatic attraction between partially positively and negatively charged toms in polar molecules.

Question 22

Hydrolysis

Answer 22

Reaction where large molecules are broken into 2 smaller ones by addition of water and breaking of covalent bond.

Question 23

Induced-fit hypothesis

Answer 23

Theory of enzyme action where enzyme molecule changes shape to fit substrate molecule more closely as it binds to it.

Question 24

Inhibition

Answer 24

Slowing of enzyme-controlled reaction using substrate which slows/prevents formation of enzyme-substrate complex.

Question 25

Ionic bond

Answer 25

Electrostatic attraction between oppositely charged ions.

Question 26

Lock + key hypothesis

Answer 26

Theory of enzyme action where enzyme active site is complementary to substrate molecule.

Question 27

Metabolism

Answer 27

Chemical reactions which occur inside cells of organisms.

Question 28

Non-competitive inhibitors

Answer 28

Inhibitor of enzyme controlled reaction which binds to enzyme at site, a region away from active site.

Question 29

Peptide bond

Answer 29

Covalent bond formed when amino acids are joined in condensation reactions.

Question 30

Polypeptide

Answer 30

Polymer consisting of many amino acid monomers covalently bonded by peptide bonds.

Question 31

Primary structure

Answer 31

Sequence of amino acids found in polypeptide (peptide bonded)