Chapter 7 ENZYMES: Mechanism Of Action Flashcards

1
Q

The vast majority of enzymes are

A

Proteins

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2
Q

Utilize in the production of cheeses

A

Rennin

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3
Q

Remove lactose from milk for the benefit of lactose-intolerant persona deficient in this hydrolytic enzyme

A

Lactase

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4
Q

True or False

Enzymes can produxe chiral products from nonchiral substrates

A

True

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5
Q

Descriptor for the type of reaction catalyzes

A

Appending the suffix -ase

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6
Q

Enzymes that remove hydrogen atoms are generally referred to as

A

Dehydrogenases

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7
Q

Enzyme that hydrolyze protiens

A

Proteases

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8
Q

Enzyme that catalyze arrangements in configuration

A

Isomerases

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9
Q

What are the 6 classes of Enzymes?

A
  1. Oxidoreductases
  2. Transferases
  3. Hydrolases
  4. Lyases
  5. Isomerases
  6. Ligases
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10
Q

Enzyme that catalyzes oxidations and reductions

A

Oxidoreductases

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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

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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

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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

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14
Q

Enzyme that catalyze geometric or structural changes within a molecule

A

Isomerases

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15
Q

Enzyme that catalyze the joining together (Ligation) of two molecules in reactions coupled to the hydrolysis of ATP

A

Ligases

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16
Q

True or False

Prosthetic groups are not stablh incorporated into a protein’s structure by covalent and noncovaleng forces

A

False

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17
Q

Enzymes that contain tightly bound Fe, Co, Cu, Mg, Mn ans Zn are termed

A

Metalloenzymes

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18
Q

Can associate either directly with the enzyme or in the form of cofactor-substrate complex

A

Cofactors

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19
Q

True or False

Cofactors must be present in the medium surrounding the enzyme for catalysis to occur

A

True

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20
Q

Enzyme require a metal ion cofactor

A

Metal-activated enzymes

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21
Q

Component of redox coenzymes NAD and NADP

A

Nicotinamide

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22
Q

Component of redox coenzymes FMN and FAD

A

Riboflavin

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23
Q

Component of the acyl carrier coenzyme A

A

Pantothenic Acid

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24
Q

Participated in deoxycarboxylation of alpha keto acids

A

Thiamin

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25
Q

Coenzymes function in one-carbon metabolism

A

Folic acid and cobamide

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26
Q

Serve as recyclable shuttles that transport many substrates from one point within cell to another

A

Coenzymes

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27
Q

Functions of Coenzymes

A
  1. Stabilize species that are too reactive

2. Serve as an adaptor or handle that facilitates the recognition and binding of small chemical groups

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28
Q

Cleft or pocket surface of the enzyme

A

Active site

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29
Q

4 mechanisms to achieve dramatic enhancement of the rates of chemical reactions

A
  1. Catalysis by Proximity
  2. Acid-Base Catalysis
  3. Catalysis by Strain
  4. Covalent Catalysis
30
Q

For the molecules to interact, they must come within bond-forming distance of one another

A

Catalysis by Proximity

31
Q

Reactions for which the only participating acid or base are protons or hydroxide ions

A

Specific acid or base catalysis

32
Q

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

A

Acid-Base Catalysis

33
Q

Reactions whose rate are responsive to all the acids or bases present

A

General acid catalysis or general base catalysis

34
Q

Enzymes that typically bind their substrates in a conformation that is somewhat unfaborable for the bond targeted for cleavage

A

Catalysis by Strain

35
Q

Transient species that represents the transition state, or midway point, in rhe transformation of substrates to products

A

Transition state intermediate

36
Q

Formation of covalent bond between the enzyme and one or more substrates

A

Covalent Catalysis

37
Q

Covalent catalysis is particularly common among enzyme that catalyze

A

Group transfer reactions

38
Q

What is “ping-pong” mechanism that covalent catalysis often follows?

A

One in which the first substrate is bound and its product is released prior to binding of the second substrate

39
Q

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)

A

Induced fit model

40
Q

Activated via interaction with histidine 58 and aspartate 102

A

Serine 195

41
Q

A regulatory enzyme of gluconeogenesis, catalyzes the hydrolytic release of the phosphate on carbon 2 of fructose 2,6-bisphosphate

A

Fructose-2,6-biophosphatase

42
Q

Participate in the breakdown of nutrients to supply energy and chemical building blocks

A

Enzymes

43
Q

includes the digestive enzyme pepsin, the lysosomal cathepsins, and the protease produced by the human immunodeficiency virus (HIV), share a common catalytic mechanism

A

Enzymes of the aspartic protease family

44
Q

Proteins that diverged from a common ancestor are said to be ____

A

homologous

45
Q

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 ______

A

conserved residues

46
Q

scientists can now measure the rate of single catalytic events and sometimes the individual steps in catalysis by a process called

A

single-molecule enzymology

47
Q

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

A

high-throughput screening

48
Q

the simultaneous synthesis of large libraries of chemical compounds that contain all possible combinations of a set of chemical precursors

A

combinatorial chemistry

49
Q

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

A

Enzyme-linked immunosorbent assays (ELISAs)

50
Q

molecules whose appearance or levels can assist in the diagnosis and prognosis of diseases and injuries affecting specific tissues

A

Biomarkers

51
Q

Serum Enzyme for Myocardial infarction

A

Aspartate aminotransferase (AST, or SGOT)

52
Q

Serum Enzyme for viral hepatitis

A

Alanine aminotransferase (ALT, or SGPT)

53
Q

Serum Enzyme for Acute pancreatitis

A

Amylase, Lipas

54
Q

Serum Enzyme for Hepatolenticular degeneration (Wilson’s disease)

A

Ceruloplasmin

55
Q

Serum Enzyme for Muscle disorders and myocardial infarction

A

Creatine kinase

56
Q

Serum Enzyme for Various liver diseases

A

Gamma-Glutamyl transferase

57
Q

Serum Enzyme for Liver diseases

A

Lactate dehydrogenase isozyme 5

58
Q

Serum Enzyme for Gaucher Disease

A

Beta Glucoscerebrosidase

59
Q

Serum Enzyme for Various bone disorders, obstructive liver diseases

A

Phosphatase, alkaline (isozymes)

60
Q

The first enzymes used to diagnose MI were

A
aspartate aminotransferase (AST)
alanine aminotransferase (ALT)
lactate dehydrogenase
61
Q

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 )

A

Lactate dehydrogenase (LDH)

62
Q

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.

A

Creatine kinase (CK)

63
Q

is a complex of three proteins involved in muscle contraction in skeletal and cardiac muscle but not in smooth muscle

A

Troponin

64
Q

cleave double-stranded DNA at sites specified by a sequence of four, six, or more base pairs called restriction sites

A

restriction endonucleases

65
Q

occur if a mutation renders a restriction site unrecognizable to its cognate restriction endonuclease or, alternatively, generates a new recognition site

A

restriction fragment length polymorphisms (RFLPs)

66
Q

currently utilized to facilitate prenatal detection of a number of hereditary disorders, including sickle cell trait, beta-thalassemia, infant phenylketonuria, and Huntington’s disease

A

restriction fragment length polymorphisms (RFLPs)

67
Q

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

A

polymerase chain reaction (PCR)

68
Q

The resulting modified protein contains a domain tailored to interact with a specific affinity support.

A

fusion protein

69
Q

the substrate-binding domain of glutathione S-transferase (GST) can serve as a

A

GST tag

70
Q

attach an oligonucleotide that encodes six consecutive histidine residues

A

HIS tag

71
Q

Once the ability to express a protein from its cloned gene has been established, it is possible to employ _____

A

site- directed mutagenesis

72
Q

was the first example of a “molecular machine” to be recognized

A

Ribosome