Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Lab Diagnosis > Mod 1 Enzymology > Flashcards

Mod 1 Enzymology Flashcards

1
Q

Polypeptide chains that differ in sequence but have similar enzymatic activity

A

Isozymes/ isoenzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Accelerates the rate of chemical reaction

A

Catalyst

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Are protein catalysts utilized by essentially all mammalian cells in specific biochemical reactions

A

Enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Catalysis on an insoluble surface

A

Heterogenous catalysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Defines the capacity of protein catalysts to recognize and bind only one or a few molecules, the substrate excluding all others

A

Binding/ enzyme specificity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

A substrate binding to an active site where it exhibits preformed steric and electronic complementarity to the shape and charge distribution of the substrate. No shape changes necessary for optimal binding

A

Lock and key model

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Model that postulates an initial weak, flexible interaction of the substrate with groups in the enzymes ES binding site. It triggers a conformational rearrangement of the enzymes surface to enhance binding affinity

A

Induced fit model

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Each enzyme has two names:

A

Practical/ trivial (e.g. Trypsin and papain)

Systemic name - unique numeric code designation and the nature of catalytic reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Identify the class described by its type of reaction catalyzed:

Oxidation- reduction reactions

A

Oxidoreductases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Identify the class described by its type of reaction catalyzed:

Transfer of functional groups

A

Transferases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Identify the class described by its type of reaction catalyzed:

Hydrolysis reactions

A

Hydrolases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Identify the class described by its type of reaction catalyzed:

Group elimination to form double bonds

A

Lyases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Identify the class described by its type of reaction catalyzed:

Isomerizations

A

Isomerases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Identify the class described by its type of reaction catalyzed:

Bond formation coupled with ATP hydrolysis

A

Ligases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Identify enzyme:

Catalyze transfer of phosphate group between phosphate and ADP to form creatine+ATP

Cofactor: magnesium

A

Creatine phosphokinase (CPK)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Primary tissue sources of which CK:

Plasma

A

CK-MM with

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Primary tissue sources of which CK:

Brain, smooth muscle, prostate, thyroid, gut and lungs

A

CK-BB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Primary tissue sources of which CK:

Cardiac muscles

A

CK-MB (20-30%), CK-MM (70-80%)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Primary tissue sources of which CK:

Skeletal muscle

A

CK-MB, CK-MM (mostly)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Diagnostic application (CK):

Released during ischemia, injury, inflammation

increased in chronic myopathies, chronic renal failure, acute respiratory exertion

A

CK-MM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Diagnostic application (CK):

Indicated for brain trauma/ surgery, injury to smooth muscles, pts with malignancy: prostate CA, small cell lung CA, intestinal malignancies, transient increase after MI

A

CK-BB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Diagnostic application (CK):

Most commonly requested for detection of acute MI

Following MI: it rises proportional to extent of infarction
Appears in serum within 6 hrs after acute MI
Peak value: 12-24 hrs
Duration: 1.5 - 3 days

A

CK-MB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Normal values of total serum CK:

A

24-170 U/L for women

24-195 U/L for men

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Marked total serum CK (> = 5x normal) can be seen in pts with:

A

Trauma (electrocution, surgery)
Athletic individuals (released during strenuous activities)
Muscular dystrophy
Chronic inflammation of muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Mild/ moderate total serum CK (2 - 4x normal) can be seen in pts with:

A

Hyper or hypothermia
Hypothyroidism
After normal vaginal delivery
Reye’s syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Forms that migrate electrophoretically in positions different from standard ones

A

Atypical isoenzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Catalyze formation of ATP and AMP from ADP

Released from Erythrocyes

A

Adenylate kinase

28
Q

Complex of CK-BB with antibody (IgG)

A

Macro CK Type 1

29
Q

Oligometric variant of CK; mitochondrial

(+) in serum - poor prognostic sign seen in pts with malignancies

A

Macro CK type 2

30
Q

Digestive enzyme that acts extracellularly to cleave starch into smaller groups and to monosaccharides

Major sources: salivary glands, exocrine pancreas

A

Amylase (diastase)

31
Q

It is:
Secreted by pancreozymin
Readily cleared in urine
Enters the duodenum at ampulla of vater via sphincter of oddi
Liw levels found in fallopian tube, adipose tissues, skeletal muscle, small intestine

A

Pancreatic amylase

32
Q

In acute pancreatitis, serum amylase levels rise within ________; remains high for a few days; return to normal in _______ days

A

Rise within 6-24 hours

Returns to normal in 2 -7 days

33
Q

In a normal serum amylase with suspicion of pancreatitis measure:

A

24 hour urine amylase or serum lipase

34
Q

Constrict pancreatic duct sphincter, decrease intestinal excretion and increased absorption in the circulation

A

Morphine administration

35
Q

Optimal pH of 5.0
Common to tissues esp. prostate
Small amounts in rbc, platelet, liver, spleen

A

Acid phosphatase (ACP)

36
Q

Highly specific for prostatic ACP

A

Thymolphthalein monophosphate

37
Q

Is measured typically by its ability to cleave phosphate groups at an acid pH.

Used for diagnosis or monitoring of prostatic adenocarcinoma

A

Total ACP/ acid phosphate

38
Q

Major applications of ACP:

A

Evaluation of prostate CA - not elevated in CA confined within prostate, BPH, prostatitis or ischemia of prostate

Medico Legal evaluation in rape - vagina with little or no ACP, +ACP d/t seminal fluid

39
Q

Widely distributed along the surface membranes of metabolically active cell

Type of hydrolase

Its most abundant isoforms are coded by a single gene on chromosome 1

A

Alkaline phosphatase

40
Q

ALP has very high activity in:

A

Bones, liver, placenta, intestines, kidneys and WBC

41
Q

Has been used to separate at least 6 different isoforms of ALP in healthy individuals

A

HPLC using weak anion exchange columns

42
Q

Easiest and most common method for distinguishing ALP iso enzymes
Heat serum at 53C for 15 minutes then compare with unheated sample

A

Heat fraction

Bone ALP - extremely labile 10-20% retain original activity
Liver and placental ALP - heat stable liver 30 - 50% retained
Placenta will all retained

43
Q

Chemical inhibitors of ALP:
Blocks placental ALP
Blocks liver and bone ALP

A

Urea - placenta

Phenylalanine - liver and bone ALP

44
Q

Small,for the heart
Functions in storage and transfer of oxygen from hemoglobin in the circulation to intracellular respiratory enzymes of contractile cells

A

Myoglobin

45
Q

True or false: myoglobin is one of the first to diffuse out of ischemic muscle cells before CK?

A

True

46
Q

Binds tropomyosin; governs excitation contraction coupling

A

Troponins

47
Q

90% sensitivity for MI 8 hrs after onset of symptoms
95% specificity for MI
36% specificity to unstable angina

A

Troponin I

48
Q

84% sensitivity for MI 8 hrs after onset of symptoms
81% specificity for MI
22% specificity to unstable angina

A

Troponin T

49
Q

Have unique forms expressed in myocardial cells but not in other muscle types -presence in serum highly specific for Myocardial injury

A

Troponin I and troponin T

50
Q

Troponin is released in two phases:

A
  1. Initial damage (acute MI) peaks at 4-8 hours

2. Sustained release from intracellular contractile apparatus - occurs up to days after acute event

51
Q

General advantages of troponin T and I:

A
  1. Released only ff cardiac damage
  2. Present, remain elevated for a long time:

troponin I is detectable up to 5 days
Troponin T 7 to 10 days ff IM

3.very sensitive - measured by immunoassay

52
Q

Catalyze conversion of lactate to pyruvate using NAD as co factor

Present in cytoplasm of cells and all tissues in the body

A

Lactate dehydrogenase

53
Q

Normal pattern of LD:

A

LD2>LD1>LD3>LD4>LD5

54
Q

LD isozymes:

High in the heart, RBC and kidneys

A

LD1 and LD2

55
Q

LD isoenzymes:

High in skeletal muscle and liver

A

LD4 and LD5

56
Q

LD activity can be measured either the:

A

Forward (lactate to pyruvate) or the reverse (pyruvate to lactate)

57
Q

Diagnostic applications of LD:

Markedly increased LD with normal AST, ALT and CK

A

Damage to biochemical dimple cells (RBC, WBC), kidney, lung, tumors

58
Q

Diagnostic applications of LD:

Increased LD and CK; increased AST > ALT

A

Cardiac or skeletal muscle injury

59
Q

Diagnostic applications of LD:

Increased AST snd ALT > LD

A

Transiently in liver disease

60
Q

Used to confirm diagnosis of MI when CK isoenzyme analysis equivocal or after total CL and CK MB release has returned to normal

A

LD

Peak 48-72 hours
Returns to normal after 8 to 10 days

61
Q

Used to estimate tumor mass including metastases

A

Total LD

LD1 or LD2 increase in germ cell tumors ( tumor markers)

62
Q

Flip LD1/LD2 ratio:

A 
Extreme exercise
Acute MI
Hemolytic anemia
Megaloblastic anemia
Renal cortical disease (renal infarct)
63
Q

Isomorphic pattern - Increased total LD, normal isoenzymes with tombstone pattern will lead to:

A

Diffuse tissue damage accompanied by shock and hypoxemia

64
Q

Increased LD 2,3,4

A

Malignancy and tumor burden

65
Q

Increased LD 3,4; decreased LD 1,2:

A

WBC tumors, pulmonary disease

66
Q

Increased LD 4,5

A

Skeletal muscle injury, ischemic toxic hepatic injury

Lab Diagnosis (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions