Lecture 9

Question 1

Types of enzymes

Answer 1

Hydrolases
Transferases
Oxidoreductases
Lyases
Ligases
Isomerases

Question 2

Hydrolases

Answer 2

catalyze hydrolysis reactions

Question 3

Transferases

Answer 3

move a group, such as an amino group

Question 4

Oxidoreductases

Answer 4

promote oxidation/reduction reactions

Question 5

Lyases

Answer 5

remove a group, but not by hydrolysis

Question 6

Ligases

Answer 6

create new bonds

Question 7

Isomerases

Answer 7

inter-convert isomers

Question 8

Naming substrates

Answer 8

Trivial names formed from the substrate, then the type of reaction, along with the ending: –ase

Question 9

Isoenzymes

Answer 9

Enzymes that have evolved slightly different amino acid sequences
Act on the same substrate, but may be secreted from different types of tissues
function best at different pHs

Question 10

How isoenzymes does Lactose Dehydrogenase (LDH) have?

Answer 10

5 isoforms

Question 11

Apoenzyme

Answer 11

the protein portion of an enzyme
Not functional because it lacks a cofactor

Question 12

Proenzyme

Answer 12

a non-functional form of an enzyme
can be converted into a functional form, often by hydrolysis of a group(s)

Question 13

Cofactor

Answer 13

an inorganic species that is required for the function of an enzyme

Question 14

Coenzyme

Answer 14

an organic cofactor
called a prosthetic group if it is tightly bound
Many coenzymes are vitamins

Question 15

Enzyme units

Answer 15

Enzyme Activity is determined by an assay instead
indicates how much of the enzyme is functioning in the sample
Measured as U or IU of enzyme

Question 16

intracellular enzymes

Answer 16

enzymes detected in serum

Question 17

What does elevated serum enzymes indicate?

Answer 17

trauma
cell death caused by a disease

Question 18

Creatine kinase (CK)

Answer 18

enzyme that phosphorylates creatine into creatine phosphate (CP)

Question 19

What are the isoforms and location for Creatine Kinase?

Answer 19

CK-MM: found in skeletal muscles
CK-MB: found mostly in the heart
CK-BB: found mostly in the brain and smooth muscle

Question 20

Lactate dehydrogenase (LDH)

Answer 20

enzyme that promotes the oxidation of lactate to pyruvate

Question 21

Alkaline phosphatases (ALKP)

Answer 21

Mostly found in bone, kidneys and intestines
Promotes dephosphorylation under alkaline (basic) conditions

Question 22

What essential role does ALKP play in?

Answer 22

bone calcification
Elevated ALKP in several bone diseases and during healing of broken bones

Question 23

Which group is ALKP elevated usually?

Answer 23

Children, growth spurts

Question 24

Acid phosphatases (ACP)

Answer 24

largest amount is in the prostate
Promotes de-phosphorylation under acid conditions

Question 25

When is ACP elevated?

Answer 25

elevated in prostatic carcinoma (malignant cancer)

Question 26

Phosphorylation

Answer 26

addition of a phosphate done by ATP as well as other phosphate sources

Question 27

Dephosphorylation

Answer 27

removal of a phosphate

Question 28

Phosphorylation/Dephosphorylation

Answer 28

Regulates protein function Can activate or inactivate

Question 29

Phosphatases

Answer 29

Enzymes that catalyze phosphorylation/dephosphorylation

Question 30

Phosphorylation/Dephosphorylation reactions are what kind of reaction?

Answer 30

condensation/hydrolysis reactions of esters

Question 31

What enzymes are made in the liver?

Answer 31

Alanine amino transferase (ALT) Aspartate amino transferase (AST) Gamma glutamyl transferase (GGT)

Question 32

Aspartate amino transferase (AST)

Answer 32

catalyzes a reaction between the amino acids aspartate and glutamate important enzyme in amino acid metabolism

Question 33

Alanine amino transferase (ALT)

Answer 33

catalyzes the conversion of alanine, an amino acid found in proteins, into pyruvate important intermediate in cellular energy production

Question 34

Elevation of Liver enzymes indicate what?

Answer 34

○ of hepatitis, cirrhosis, fatty liver disease, alcoholism, etc

Question 35

Pancreatic enzymes

Answer 35

Amylase (AMY) Lipase (LIP)

Question 36

Amylase (AMY)

Answer 36

hydrolyzes polysaccharides to smaller polysaccharides or monosaccharides

Question 37

Lipase (LIP)

Answer 37

hydrolyzes the two end esters of a triglyceride

Question 38

Diagnostic value of enzymes

Answer 38

CK – muscular dystrophy, heart attacks ALT and AST - liver disease/hepatitis GGT – ethanol toxicity to liver ALKP – bone diseases and bone healing ACP – prostate cancer LIP and AMY – pancreatitis

Question 39

Prions

Answer 39

Diseases that are associated with a protein being the infectious agent

Question 40

Immunoassays

Answer 40

Based on the highly specific binding of an antibody to its antigen

Question 41

ELISA

Answer 41

Enzyme Linked ImmunoSorbent Assay

Question 42

Prostate Specific Antigen (PSA) testing

Answer 42

ELISA screening method for prostate cancer