Brainscape's Knowledge GenomeTM

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


See full index

clinical biochem year 2 > lecture 5 - enzymes as biomarkers > Flashcards

lecture 5 - enzymes as biomarkers Flashcards

1
Q

what are enzymes

A

protein catalysts

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

what are the definitions of enzymes

A

type of protein that accelerates the speed of chemical reaction

by binding to a substrate to form a complex

lowers activation energy in the reaction without being consumed, or changing equilibrium of reaction

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

why do we use enzymes as markers

A

amplification of signal over time

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

what are the two ways you can measure enzyme activity

A

stop the reaction and measure product formed (kinetic fixed time)

repeatedly measure product formation(kinetic continuous time)

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

what does ELIZA stand for

A

Enzyme-linked immunosorbent assay

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

what are isoenzymes

A

enzymes that differ in amino acid sequence yet catalyse the same reaction

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

what are biomarkers

A

biological molecules who’s concentration changes in response to a specific disease or intervention

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

what do biomarker lead to when in disease state

A

moderate or extensive tissue damage

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

what happens to the cardiac myocyte after SOME tissue damage

A

membrane ruptures

this damage can be repaired

enzyme levels are only elevated while damage persists

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

what happens to the cardiac myocyte after MORE tissue damage

A

cell dies

cellular necrosis

cell contents released

test blood for specific enzymes

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

what is the aetiology for cardiac disease

A

blockage of blood vessels supplying to the heart

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

what does the blockage of blood vessels lead to

A

deficiency of oxygen (ischemia)

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

what is non reversible damage that leads to cell death called

A

infarction

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

what is acute myocardial infarction

A

a heart attack

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

what does angina cause

A

heart pain

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

what is the aetiology of angina

A

reduced blood flow to the heart

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

what is the development of heart disease

A
  1. plaques form on the artery wall
  2. macrophages accumulate in the endothelial lining
  3. narrowing of the artery
  4. 70% reduced blood flow -> ischemia
18
Q

what are the stages leading to myocardial infarction

A
  1. Tear or erosion of the plaques
  2. Cause an intraplaque thrombus
  3. Platelets accumulate to repair the damage
  4. Aggregated platelets break off and are swept downstream
  5. Aggregated platelets block downstream vessels
19
Q

what is the treatment for platelet aggregation

A

antiplatelet

antithrombotic

20
Q

what is the treatment for after clot formation

A

thrombolytic drugs

catheterisation and angioplasty

21
Q

what are the cardiac biomarkers

A

aspartate amino transferase - elevated 12 hours

lactate dehydrogenase - elevated 36 hours

creatine kinase - elevated 4-6 hrs

22
Q

what is the product of creatine + atp?

A

creatine phosphate + ADP

23
Q

what are the sources of creatine kinase

A

skeletal muscle

brain

cardiac muscle

24
Q

what can mask myocardial infarction

A

more skeletal muscle than cardia muscle

25
Q

what is the specimen for CK anaylsis

A

non - hemolyzed serum

storage in refrigerator or freezer

26
Q

what are the sources of error in CK analysis

A

sample not fresh or exposed to heat

anticoagulants such as citrate or fluoride

27
Q

what is lactate dehydrogenase inhibited by

A

mercuric ions

28
Q

what are sources of lactate dehydrogenase

A

heart

liver

kidney

skeletal muscle

29
Q

what is the clinical significance of Lactate dehydrogenase

A

myocardial infarction

hemolytic conditions

malignancies

renal disease

30
Q
A
31
Q

what does troponin T do

A

binds to myosin

32
Q

what does troponin I do

A

inhibit actin-myosin binding

33
Q

what does troponin C have

A

Binding sites for ca2+

34
Q

what happens in the absence of calcium

A

troponin prevents myosin from interaction with actin

prevents contraction

35
Q

what are the advantages of troponin-tropomyosin

A

sensitive - able to detect cardiac troponin T and troponin I in more than 50% of individuals

better detection than CKMB/total CK

36
Q

what tests are required to detect AMI

A

electrocardiogram

detection of enzymes released into the blood

37
Q

what is rhabdomyolysis

A

rapid breakdown of damaged muscle tissue

38
Q

what are the biomarkers for skeletal muscle

A

Rhabdomyolysis

Spills over into the urine

myoglobin

39
Q

what are natriuretic peptides

A

small circular peptides (cardiac hormones) that PROMOTE loss of sodium from the kidneys

40
Q

what are the key aims of future biomarkers

A

predicting the rupture of placques

detecting ischemia prior to cell death (necrosis)

clinical biochem year 2 (9 decks)

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