Brainscape's Knowledge GenomeTM

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


See full index

M2M Unit II > Hemoglobinopathies > Flashcards

Hemoglobinopathies Flashcards

1
Q

defective globin switching

A

persistence of fetal hemoglobin

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

microcytosis

A

small cells

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

hydrops fetalis

A

fetal death due to complete lack of alpha hemoglobin genes

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

What is the embryonic hemoglobin?

A

HbG

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

The tense hemoglobin state is the ______ state, while the relaxed state is _______ and planar.

A

deoxygenated; oxygen-bound

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

Where are most structural hemoglobin variants found?

A

in the Beta-globin chain

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

hemoglobin H disease

A

severe anemia because only 1/4 alpha globin gene is functional

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

What is non-covalently linked in between the globins?

A

iron and a heme group

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

How many genetic variants of hemoglobin are known?

A

600

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

What is the fetal hemoglobin?

A

HbF (alpha 2 gamma 2)

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

How do you test for sickle cell?

A

1) DNA sequencing with PCR or electrophoresis 2) southern blot

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

Thalassemia minor

A

mild phenotype; doesn’t req transfusions

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

In beta-thalassemia, defects are seen _____.

A

postnatally only

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

How are hemoglobin C and hemoglobin S different?

A

Same codon, different mutations, different phenotypes

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

HbKemsey has _____ O2 binding while hemoglobin Kansas has ______ O2 binding.

A

too tight; too weak

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

Which form of hemoglobin is the best oxygen carrier?

A

alpha-beta

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

Where is hemoglobin synthesized?

A

in the bone marrow

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

How many copies of the beta globin gene are there?

A

1

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

What is the major adult hemoglobin?

A

HbA

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

In HbKempsey, the O2 binding affinity is _____, so _____ O2 is delivered to the tissues, and to compensate, red blood cells are ________. This condition is called _______.

A

higher; less; overproduced; polycythemia

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

The 5’-3’ ____ order of genes within each cluster coincides with the _____ order of their expression during development.

A

spatial; temporal

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

structural variants/qualitative hemoglobinopathies

A

mutations that alter the globin’s properties without affecting its synthesis

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

Phenotypically, having 2 out of the 4 alpha globin genes results in _____.

A

mild anemia

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

How many oxygens does each globin bind?

A

one each; 4 per molecule

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

hypochromia

A

pale blood cells

20
Q

What is hereditary persistence of fetal hemoglobin?

A

benign conditions that impair the perinatal switch from gamma to beta globin synthesis (high GbF in adults)

21
Q

Beta-thalassemia is most often caused by _______.

A

point mutations in the beta-globin gene

22
Q

Alpha-thalassemia is a ______ of alpha-globin and an excess of _____.

A

low or no amount; beta and gamma

23
Q

thalassemia major

A

beta-zero; no beta proteins being produced

24
Q

How many identical copies of the alpha globin gene are there on each chromosome?

A

2

25
Q

What does the alpha cluster encode?

A

zeta- alpha2- alpha1

26
Q

Where is embryonic hemoglobin made?

A

in the yolk sac

27
Q

What do structural variants of hemoglobin do?

A

alter O2 binding

29
Q

What does the beta cluster encode?

A

epsilon- gamma G-gamma A- delta- beta

31
Q

Why is delta hemoglobin transcribed less?

A

it has a weaker promoter

32
Q

thalassemias

A

low to no synthesis of one globin chain

33
Q

What is globin switching?

A

transitioning between hemoglobins as development progresses

34
Q

What kind of globin is expressed in fetal development?

A

gamma

36
Q

What are the 3 genetic disorders of hemoglobin?

A

1) structural variants 2) thalassemias 3) defective globin switching

37
Q

What is a pseudogene?

A

a gene that doesn’t make a protein

39
Q

Why does globin switching occur?

A

HbF in fetal blood is better suited to bind O2 at the placenta than HbA (lower pO2), which binds O2 better in the lung (higher pO2)

40
Q

hemolysis

A

destruction of blood cells

41
Q

Where is fetal hemoglobin made?

A

in the liver

42
Q

Why is beta globin often affected by mutations?

A

there are only 2 copies of it, not 4 like alpha

43
Q

Complex beta-thalassemia is caused by ____.

A

large deletions

44
Q

In sickle cell anemia, a glutamate at position 6 is changed to ______, which changes the position that Mst II cleaves at, making a ______ protein than the wildtype.

A

valine; larger

45
Q

What is the minor form of adult hemoglobin?

A

HbA2 (alpha 2 delta 2)

46
Q

What is the solubility of hemoglobin S?

A

normal when oxygen is bound, but only 20% of normal when unbound

47
Q

What happens when the LCR is knocked out of the beta cluster?

A

beta thalassemias result and alpha-globin chains precipitate

48
Q

Alpha-thalassemia is occasionally caused by _______.

A

deletions in the LCR or the beta-gene cluster

49
Q

In HbKansas, the O2 binding affinity is _____, so _____ O2 is delivered to the tissues, and ______ occurs.

A

decreased; less; cyanosis

50
Q

Alpha-thalassemia is caused by _______.

A

a deletion of the alpha-globin gene(s)

52
Q

Where is the alpha globin gene cluster located?

A

chromosome 16

54
Q

Which is the first globin expressed?

A

epsilon

55
Q

What does LCR stand for?

A

locus control region

56
Q

Beta-thalassemia is a ______ of beta-globin and an excess of ________.

A

low or no amount; alpha-globin

57
Q

Hemoglobin is a tetramer of 2 _____ polypeptides and 2 _____ polypeptides.

A

alpha; beta

58
Q

What is the LCR of hemoglobin?

A

the promoter region about 20kb away from the first hemoglobin gene that regulates sequential transcription of all the genes

59
Q

In alpha-thalassemia, defects are seen _____.

A

fetally and postnatally

60
Q

Where is the beta globin gene cluster located?

A

chromosome 11

M2M Unit II (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions