Enzyme Inhibition ㅡ Medical Uses of Enzymes

Question 1

An ______________ is a substance that slows or stops the normal catalytic function of an enzyme by binding to it.

Answer 1

enzyme inhibitor

Question 2

A _______ _________ _____ is a molecule that sufficiently resembles an enzyme substrate in shape and
charge distribution that it can compete with the substrate for occupancy of the enzyme’s active site.

Answer 2

competitive enzyme inhibitor

Question 3

A _________ _________ ________ is a molecule that decreases enzyme activity by binding to a site on an enzyme other than the active site.

Answer 3

noncompetitive enzyme inhibitor

Question 4

An ________ _________ __________ is a molecule that inactivates enzymes by forming a strong covalent bond to an amino acid side-chain group at the enzyme’s active site.

Answer 4

irreversible enzyme inhibitor

Question 5

An _______________ is an enzyme with two or more protein chains (quaternary structure) and two kinds of binding sites (substrate and regulator).

Answer 5

allosteric enzyme

Question 6

Substances that bind at regulatory sites of allosteric enzymes are called __________.

Answer 6

regulators

Question 7

______________ is a process in which activation or inhibition of the first reaction in a reaction sequence is controlled by a product of the reaction sequence.

Answer 7

Feedback control

Question 8

A ____________ is an enzyme that catalyzes the breaking of peptide bonds that maintain the primary
structure of a protein.

Answer 8

proteolytic enzyme

Question 9

A _________ is the inactive precursor of a proteolytic enzyme.

Answer 9

zymogen

Question 10

An alternative, but less often used, name for a zymogen is __________.

Answer 10

proenzyme

Question 11

______________ is a process in which enzyme activity is altered by covalently modifying the structure of the enzyme through attachment of a chemical group to or removal of a chemical group from a particular amino acid within the enzyme’s structure.

Answer 11

Covalent modification

Question 12

The process of addition of the phosphate group to the enzyme is called _____________, and the removal of the phosphate group from the enzyme is called ____________.

Answer 12

a. phosphorylation
b. dephosphorylation

Question 13

__________ is an octapeptide hormone involved in blood pressure regulation. It increases blood pressure by narrowing blood vessels.

Answer 13

Angiotensin

Question 14

Structure of Angiotensinogen

Answer 14

Asp-Arg-Val-Tyr-Ile-His-Pro-Phe-His-Leu

Question 15

Representative of ACE inhibitors in use today is the compound _____________, a compound heavily prescribed for treatment of moderately elevated blood pressure conditions.

Answer 15

lisinopril

Question 16

Interestingly, lisinopril, as well as several other ACE inhibitors, was first obtained from snake venom, the
venom of the ________________.

Answer 16

jararaca (a Brazilian pit viper)

Question 17

The 1932 discovery of the antibacterial activity of the compound sulfanilamide by the German bacteriologist _____________ (1895–1964) led to the characterization
of a whole family of sulfanilamide derivatives collectively called sulfa drugs—the first “antibiotics” in the medical field.

Answer 17

Gerhard Domagk

Question 18

An _________ is a substance that kills bacteria or inhibits their growth.

Answer 18

antibiotic

Question 19

Penicillins inhibit ___________, an enzyme that catalyzes the formation of peptide cross links between polysaccharide strands in bacterial cell walls. These
cross links strengthen cell walls

Answer 19

transpeptidase

Question 20

Liver enzymes known as ________________ are involved in the processes by which many prescription medications are metabolized in the body.

Answer 20

cytochrome P450s