Chapter 7 ENZYMES: Mechanism Of Action Flashcards
(72 cards)
1
Q
The vast majority of enzymes are
A
Proteins
2
Q
Utilize in the production of cheeses
A
Rennin
3
Q
Remove lactose from milk for the benefit of lactose-intolerant persona deficient in this hydrolytic enzyme
A
Lactase
4
Q
True or False
Enzymes can produxe chiral products from nonchiral substrates
A
True
5
Q
Descriptor for the type of reaction catalyzes
A
Appending the suffix -ase
6
Q
Enzymes that remove hydrogen atoms are generally referred to as
A
Dehydrogenases
7
Q
Enzyme that hydrolyze protiens
A
Proteases
8
Q
Enzyme that catalyze arrangements in configuration
A
Isomerases
9
Q
What are the 6 classes of Enzymes?
A
- Oxidoreductases
- Transferases
- Hydrolases
- Lyases
- Isomerases
- Ligases
10
Q
Enzyme that catalyzes oxidations and reductions
A
Oxidoreductases
11
Q
- Enzymes that catalyze transfer of moieties such as glycosyl, methyl, or phosphoryl groups
- moving functional group from one molecule to another
A
Transferases
12
Q
- Enzymes that catalyze hydrolytic cleavage of C-C, C-O, C-N, and ofher covalent bonds
- needs water to break bond
A
Hydrolases
13
Q
- Enzymes that catalyze cleavage of C-C, C-O, C-N and other covalent bonds by atom elimination, generating double bonds
- splitting of chemical into smaller parts without using water (catabolic) via elimination
A
Lyases
14
Q
Enzyme that catalyze geometric or structural changes within a molecule
A
Isomerases
15
Q
Enzyme that catalyze the joining together (Ligation) of two molecules in reactions coupled to the hydrolysis of ATP
A
Ligases
16
Q
True or False
Prosthetic groups are not stablh incorporated into a protein’s structure by covalent and noncovaleng forces
A
False
17
Q
Enzymes that contain tightly bound Fe, Co, Cu, Mg, Mn ans Zn are termed
A
Metalloenzymes
18
Q
Can associate either directly with the enzyme or in the form of cofactor-substrate complex
A
Cofactors
19
Q
True or False
Cofactors must be present in the medium surrounding the enzyme for catalysis to occur
A
True
20
Q
Enzyme require a metal ion cofactor
A
Metal-activated enzymes
21
Q
Component of redox coenzymes NAD and NADP
A
Nicotinamide
22
Q
Component of redox coenzymes FMN and FAD
A
Riboflavin
23
Q
Component of the acyl carrier coenzyme A
A
Pantothenic Acid
24
Q
Participated in deoxycarboxylation of alpha keto acids
A
Thiamin
25
Coenzymes function in one-carbon metabolism
Folic acid and cobamide
26
Serve as recyclable shuttles that transport many substrates from one point within cell to another
Coenzymes
27
Functions of Coenzymes
1. Stabilize species that are too reactive
| 2. Serve as an adaptor or handle that facilitates the recognition and binding of small chemical groups
28
Cleft or pocket surface of the enzyme
Active site
29
4 mechanisms to achieve dramatic enhancement of the rates of chemical reactions
1. Catalysis by Proximity
2. Acid-Base Catalysis
3. Catalysis by Strain
4. Covalent Catalysis
30
For the molecules to interact, they must come within bond-forming distance of one another
Catalysis by Proximity
31
Reactions for which the only participating acid or base are protons or hydroxide ions
Specific acid or base catalysis
32
The rate of reaction is sensitive to changes in concentration of protons or hydroxide ions, but is independent of concentratins of other acids or bases in the solutin or at the active site
Acid-Base Catalysis
33
Reactions whose rate are responsive to all the acids or bases present
General acid catalysis or general base catalysis
34
Enzymes that typically bind their substrates in a conformation that is somewhat unfaborable for the bond targeted for cleavage
Catalysis by Strain
35
Transient species that represents the transition state, or midway point, in rhe transformation of substrates to products
Transition state intermediate
36
Formation of covalent bond between the enzyme and one or more substrates
Covalent Catalysis
37
Covalent catalysis is particularly common among enzyme that catalyze
Group transfer reactions
38
What is "ping-pong" mechanism that covalent catalysis often follows?
One in which the first substrate is bound and its product is released prior to binding of the second substrate
39
States that when substrates approach and bind to an enzyme they induce a conformational change that is analogous to placing a hand (substrate) into a glove (enzyme)
Induced fit model
40
Activated via interaction with histidine 58 and aspartate 102
Serine 195
41
A regulatory enzyme of gluconeogenesis, catalyzes the hydrolytic release of the phosphate on carbon 2 of fructose 2,6-bisphosphate
Fructose-2,6-biophosphatase
42
Participate in the breakdown of nutrients to supply energy and chemical building blocks
Enzymes
43
includes the digestive enzyme pepsin, the lysosomal cathepsins, and the protease produced by the human immunodeficiency virus (HIV), share a common catalytic mechanism
Enzymes of the aspartic protease family
44
Proteins that diverged from a common ancestor are said to be ____
homologous
45
The common ancestry of enzymes can be inferred from the presence of specific amino acids in the same position in each family member. These residues are said to be ______
conserved residues
46
scientists can now measure the rate of single catalytic events and sometimes the individual steps in catalysis by a process called
single-molecule enzymology
47
he discovery of new drugs is greatly facilitated when a large number of potential pharmacophores can be assayed in a rapid, automated fashion—a process referred to as
high-throughput screening
48
the simultaneous synthesis of large libraries of chemical compounds that contain all possible combinations of a set of chemical precursors
combinatorial chemistry
49
use antibodies covalently linked to a "reporter enzyme" such as alkaline phosphatase or horseradish peroxidase whose products are readily detected, generally by the absorbance of light or by fluorescence
Enzyme-linked immunosorbent assays (ELISAs)
50
molecules whose appearance or levels can assist in the diagnosis and prognosis of diseases and injuries affecting specific tissues
Biomarkers
51
Serum Enzyme for Myocardial infarction
Aspartate aminotransferase (AST, or SGOT)
52
Serum Enzyme for viral hepatitis
Alanine aminotransferase (ALT, or SGPT)
53
Serum Enzyme for Acute pancreatitis
Amylase, Lipas
54
Serum Enzyme for Hepatolenticular degeneration (Wilson's disease)
Ceruloplasmin
55
Serum Enzyme for Muscle disorders and myocardial infarction
Creatine kinase
56
Serum Enzyme for Various liver diseases
Gamma-Glutamyl transferase
57
Serum Enzyme for Liver diseases
Lactate dehydrogenase isozyme 5
58
Serum Enzyme for Gaucher Disease
Beta Glucoscerebrosidase
59
Serum Enzyme for Various bone disorders, obstructive liver diseases
Phosphatase, alkaline (isozymes)
60
The first enzymes used to diagnose MI were
```
aspartate aminotransferase (AST)
alanine aminotransferase (ALT)
lactate dehydrogenase
```
61
is a tetrameric enzyme consisting of two monomer types: H (for heart) and M (for muscle) that combine to yield five LDH isozymes: HHHH (I1 ), HHHM (I2 ), HHMM (I3 ), HMMM (I4 ), and MMMM (I5 )
Lactate dehydrogenase (LDH)
62
has three isozymes: CK-MM (skeletal muscle), CK-BB (brain), and CK-MB (heart and skeletal muscle). CK-MB has a useful diagnostic window. It appears within 4–6 h of an MI, peaks at 24 h, and returns to baseline by 48–72 h. As for LDH, individual CK isozymes are separable by electrophoresis, thus facilitating detection.
Creatine kinase (CK)
63
is a complex of three proteins involved in muscle contraction in skeletal and cardiac muscle but not in smooth muscle
Troponin
64
cleave double-stranded DNA at sites specified by a sequence of four, six, or more base pairs called restriction sites
restriction endonucleases
65
occur if a mutation renders a restriction site unrecognizable to its cognate restriction endonuclease or, alternatively, generates a new recognition site
restriction fragment length polymorphisms (RFLPs)
66
currently utilized to facilitate prenatal detection of a number of hereditary disorders, including sickle cell trait, beta-thalassemia, infant phenylketonuria, and Huntington's disease
restriction fragment length polymorphisms (RFLPs)
67
employs a thermostable DNA polymerase and appropriate oligonucleotide primers to produce thousands of copies of a defined segment of DNA from a minute quantity of starting material
polymerase chain reaction (PCR)
68
The resulting modified protein contains a domain tailored to interact with a specific affinity support.
fusion protein
69
the substrate-binding domain of glutathione S-transferase (GST) can serve as a
GST tag
70
attach an oligonucleotide that encodes six consecutive histidine residues
HIS tag
71
Once the ability to express a protein from its cloned gene has been established, it is possible to employ _____
site- directed mutagenesis
72
was the first example of a "molecular machine" to be recognized
Ribosome
