Enzymes And Vitamins

Question 1

Are usually proteins that act as a catalyst for biochemical reactions and are not consumed in the reactions.

Answer 1

Enzymes

Question 2

The human body has ______ of enzymes

Answer 2

1000s

Question 3

Enzyme activity is dramatically affected by:

Answer 3

• Alterations in pH
• Temperature
• Other protein denaturants

Question 4

It is a type of enzyme which composed only of protein.

Answer 4

Simple Enzyme

Question 5

It is a type of enzyme which contains a non-protein part in addition to a protein part.

Answer 5

Conjugated Enzyme

Question 6

Are small organic molecules or inorganic ions that are important for the chemically reactive enzymes.

Answer 6

Cofactors

Question 7

A class of enzymes that catalyze an oxidation-reduction reaction.

Answer 7

Oxidoreductase

Question 8

A class of enzymes that catalyze the transfer of a functional group from one molecule to another.

Answer 8

Transferase

Question 9

A class of enzymes that catalyze a hydrolysis reaction. The reaction involves addition of a water molecule to a bond to cause bond breakage.

Answer 9

Hydrolase

Question 10

Subtype of transferases that catalyze the transfer of an amino group to a substrate.

Answer 10

Transaminases

Question 11

Subtype of Transferases that catalyze the transfer of a phosphate group from adenosine triphosphate (ATP) to a substrate.

Answer 11

Kinases

Question 12

A class of enzymes that catalyzes the addition of a group to a double bond or the removal of a group to form a double bond in a manner that does not involve hydrolysis or oxidation.

Answer 12

Lyase

Question 13

Effects the removal of the components of water from a double bond

Answer 13

Dehydratase

Question 14

Effects the addition of the components of water to a double bonds

Answer 14

Hydratase

Question 15

An enzyme that catalyzes the isomerization (rearrangement of atoms) of a substrate in a reaction, converting it into a molecule isomeric with itself.

Answer 15

Isomerase

Question 16

An enzyme that catalyzes the formation of a bond between two molecules involving ATP hydrolysis.

Answer 16

Ligase

Question 17

Relatively small part of an enzyme’s structure that is actually involved in catalysis:

• place where substrate binds to enzymes.
• usually a “crevice like” location in the enzyme.

Answer 17

Enzyme Active Site

Question 18

A model for substrate binding to enzyme in which the enzyme has a predetermined shape for the active site and only substrate of a specific

Answer 18

Lock-and-Key Model

Question 19

A model for substrate binding to enzyme in which substrate contact with enzyme will change the shape of the active site and allows small change in space to accommodate substrate.

Answer 19

Induced Fit Model

Question 20

An enzyme specificity where an enzyme will catalyze a particular reaction for only one substrate – This is most restrictive of all specificities (not common)– E.g., Catalase.

Answer 20

Absolute Specificity

Question 21

An enzyme specificity where an enzyme can distinguish between stereoisomers

– Chirality is inherent in an active site (amino acids are chiral compounds).

– L-Amino-acid oxidase - catalyzes reactions of L-amino acids but not of D-amino acids.

Answer 21

Stereochemical Specificity

Question 22

An enzyme specificity where it involves structurally similar compounds that have the same functional groups.

– E.g., Carboxypeptidase: Cleaves amino acids one at a time from the carboxyl end of the peptide chain.

Answer 22

Group Specificity

Question 23

An enzyme specificity which involves Involves a particular type of bond irrespective of the structural features in the vicinity of the bond– Considered most general of enzyme specificities– E.g., Phosphatases: Hydrolyze phosphate–ester bonds in all types of phosphate esters

Answer 23

Linkage Specificity

Question 24

Higher Temperature - _______ Kinetic Energy

Answer 24

Higher

Question 25

Optimum pH - ________ activity of enzymes

Answer 25

Maximum

Question 26

Increased substrate concentration - _____________ enzyme activity

Answer 26

Increased

Question 27

A microbial enzyme that is active at conditions that would inactivate human enzymes as well as enzymes present in most other organisms.

Answer 27

Extremozyme

Question 28

A substance that slows down or stops the normal catalytic function of an enzyme by binding to it.

Answer 28

Enzyme Inhibitor

Question 29

A type of enzyme inhibitors that compete with the substrate for the same active site. - Will have similar charge & shape

Answer 29

Competitive Inhibitors

Question 30

A type of enzyme inhibitors that does not compete with the substrate for the same active site. - Binds to the enzyme at a location other than active site

Answer 30

Noncompetitive Inhibitors

Question 31

A competitive enzyme inhibitor decreases enzyme activity by binding to the same active site as the substrate. - Binds reversibly to an enzyme active site and the inhibitor remains unchanged (no reaction occurs)

Answer 31

Reversible Competitive Inhibition

Question 32

A noncompetitive enzyme inhibitor decreases enzyme activity by binding to a site on an enzyme other than the active site.

Answer 32

Reversible Noncompetitive Inhibition

Question 33

An irreversible enzyme inhibitor inactivates enzymes by forming a strong covalent bond with the enzyme’s active site.

Answer 33

Irreversible Inhibition

Question 34

An irreversible enzyme inhibitor inactivates enzymes by forming a strong covalent bond with the enzyme’s active site.

Answer 34

Irreversible Inhibition

Question 35

Properties of Allosteric Enzymes - All allosteric enzymes have quaternary structure: – Composed of two or more protein chains - Have at least two of binding sites - Substrate and regulator binding site - Active and regulatory binding sites are distinct from each other: – Located independent of each other – Shapes of the sites (electronic geometry) are different - Binding of molecules at the regulatory site causes changes in the overall three dimensional structure of the enzyme: – Change in three dimensional structure of the enzyme leads to change in enzyme activity – Some regulators increase enzyme activity – activators – Some regulators decrease enzyme activity - inhibitors

Answer 35

TRUE

Question 36

A process in which enzyme activity is altered by covalently modifying the structure of the enzyme.

Answer 36

Covalent Modification

Question 37

Angiotensin II is an octapeptide hormone that increases blood pressure via constriction of blood vessels. _____________ converts Angiotensin I to angiotensin II in the blood. _____________ block ACE reaction and thus reduce blood pressure. – Lisinopril is an example of this.

Answer 37

Ace Inhibitors

Question 38

Derivatives of sulfanilamide ___________ exhibit antibiotic activities Mode of antibiotic activity: - Sulfanilamide is structurally similar to PABA (p-aminobenzoic acid) – Many bacteria need PABA to produce coenzyme, folic acid – Sulfanilamide is a competitive inhibitor of enzymes responsible for converting PABA to folic acid in bacteria

Answer 38

Sulfa Drugs

Question 39

Accidently discovered by Alexander Fleming in 1928 Several naturally occurring penicillins and numerous synthetic derivatives have been produced All have structures containing a four-membered Beta-lactam ring fused with a five-membered thiazolidine ring

Answer 39

Penicillins

Question 40

The antibiotic ciprofloxacin hydrochloride (__________ for short) Considered the best broad-spectrum antibiotics because it is effective against skin and bone infections as well as against infections involving the urinary, gastrointestinal, and respiratory systems.

Answer 40

Cipro

Question 41

Water-soluble vitamins.

Answer 41

B Vitamins

Question 42

Fat-soluble vitamins.

Answer 42

Vitamins A,D,E,K