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Flashcards in Hemoglobin Deck (48)
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1
Q

The Hill Equation

A

Ys = (P02)nH / { (P50)nH + (P02)nH }

2
Q

Sickle Cell Disease is significant only in ___________state

A

homozygous

3
Q

Where does heme synthesis occur?

A

Bone marrow

4
Q

Haldane Effect

CO2_______ affinity of Hb for oxygen

CO2 stabilizes ___________ by reacting with terminal amino groups to form _______; these induce T-state

CO2 also stabilizes deoxy-Hb by causing a_______

A

Lowers

deoxyhemoglobin; carbomates

pH drop

5
Q

2,3-BPG binding lowers O2 affinity by_________T-state

A

Stablizing

6
Q

Major hemoglobins in adults

A

Alpha, beta, delta, and gamma

7
Q

Sickle cell disease is caused by mutation in gene for_________ subunit of adult hemoglobin (Hb)

A

B

8
Q

Myoglobin Hemoglobin

O2 ______ protein O2_________ protein

Location? Location?

of Hemes? # of Hemes?

of Globin Chains? # of Globin Chains

Allosteric effectors? Allosteric effectors? ________ Curve _________ Curve

A

Storage; carrier

Muscle; erythrocyte

1; 4

1; 4

None; H+,CO2 2,3-BPG, Cl-

Hyperbolic; sigmodial

9
Q

Major hemoglobins in embryonic state

A

Zeta, alpha, gamma, and epsilon

10
Q

Symptoms of Sickle cell disease

A

anemia

swelling of extremities

higher risk of stroke and infection

11
Q

CO Inhalation leads to nonfunctional ___________ and _________hypoxia, pO2 may be normal but ______is high.

A

Hb; tissue; lactic acid

12
Q

When are symptoms of Sickle Cell Disease seen?

A

Symptoms not seen until 6 months after birth

13
Q

BPG-induced shifts O2 dissociation curve to the ________

A

Right

14
Q

Does adult hemoglobin or fetal hemoglobin have a higher O2 affinity?

A

Fetal hemoglobin

15
Q

In blood, ___________is a major target for CO poisoning

A

Hemoglobin

16
Q
  • Interactions with _________must be broken for T-to-R transition to occur
  • When 2,3-BPG is present, more __________ sites must be occupied to induce transition

Gamma subunit of HbF lacks _______; affinity with 2,3-BPG less, and O2 moves from _________ Hb to _________.

A

2,3- BPG

O2

His-143; maternal; HbF

17
Q

_________ = Globin alone.

__________= Heme + the globin chain.

A

Apoprotein

Holoprotein

18
Q

Abnormal Oxidation of Heme Iron Pathway

A

(Fe+3) —> HEMICHROMES —> HEINZ BODIES

—-> RBC LYSIS——> Reticulocytes ↑, Bilrubin↑ (Jaundice), Hematocrit ↓

19
Q
  • Heme composed of __________ IX ring and _______ion
  • Fe++ ion coordinated by 4_________atoms of ring, a proximal ______ residue and an ________molecule (in oxy-hemoglobin); 6th position empty in _________.
  • ________ histidine H-bonds to the bound O2
A

Protoporphyrin; Fe2+

Nitrogen; histidine; O2; deoxyHb

Distal

20
Q

Normal Adult Hemoglobin

  • Each subunit adopts ________ fold; has no______; has ______ heme prosthetic group buried in crevice within subunit.
  • The only charged residues in interior are histidine ______and ________, which bind_________or ________.
  • __________ contacts between unlike subunits (ab) strongest: dimer of dimers
  • Two a and two b subunits; a and b similar but not ______
  • ________protein; inhibited by ___, _____, ______, ______, which lower __________affinity
A

Globin; B-sheets; one

E-7; F8; O2; Fe2+

Dimeric

Identical

Allosteric; H+; CO2; 2,3 BPG; Cl-; oxygen

21
Q

Causes of Hypoxia: ________

A

Pre pulmonary (bronchitis)

22
Q

Which is more strongly inhibited by 2,3BPG, adult or fetal hemoglobin?

A

Adult

23
Q

Which version of iron is nonfunctional in hemoglobin?

A

Fe3+

24
Q

The flow of oxygen

A

O2 —> Bronchi —> Lungs —> Hemoglobin —> (Myoglobin) —-> Mitochondria —> H2O

25
Q

What problems can the sickle shape of cells cause?

A

The inability of RBC to fit through small capillaries

26
Q

Aged RBC are taken up by _______ in the _______ and excreted in _______, during the process ______ are also released.

A

Phagocytes; spleen; bile; amino acids

27
Q

Effect of CO

Binds to some ______ sites. Remaining “open” sites are shifted toward _______affinity

A

O2; higher

28
Q

___________result from diminished production of a or b chains. Leads to unstable forms of ______ that are not fully functional and have low __________

A

Thalasssemias; Hb; solubility

29
Q

Increase in hemocrit process

A

Renal pO2 decreases, which causes and increases in the Hypoxia inducible factor (HIF-1). Erythropoietin increases and then hemocrit increases.

30
Q

Heme and Hemoglobin synthesis

A

Glcyine +Succinyl Co A—> 4 Pyrroles—-> Porphyrins + Fe2+—-> Heme + Globin Chains (alpha or beta)—-> Hemoglobin

31
Q

Adult Blood: 96.8 % __________

  1. 7 % __________
  2. 47 % ___________

Fetal Blood: 90 % ___________

A

HbA1 (a 2b 2)

HbA2 (a 2d 2)

HbF (a 2g 2)

HbF

32
Q

In “pure Hb,” _____-state highly unstable; ______-state favored

A

T; R

33
Q

In beta hemoglobin types, the first amino acid is ______ and the last amino acid is _______

A

Valine; histidine

34
Q

____________________________________________________________________

FORM OXID. 5TH COORD. 6TH COORD.

STATE

___________________________________________________________

DeoxyHb ___ His-F8 _______

OxyHb ___ His-F8 ________

Carbo-

monoxy Hb1 ___ His-F8 _______

Met Hb1 ____ His-F8 _______

Cyano Met

Hb 1 * _____ His-F8 ________

A

2+; Empty

2+; O2

2+; CO

3+; CN-, H2O, Cl-

3+; CN-

35
Q

Aged red blood cells are taken up by the _________

A

Spleen

36
Q

The _________ is the measure of degree of cooperative interaction between oxygen binding sites.

A

Hill coeffecient (nH)

37
Q

A capillary is ________micrometers, but the RBC is _________ micrometers. The normal lifetime of a RBC

is ___________ days.

A

2-3; 8; 120

38
Q

In alpha hemoglobin tyoes, the first amino acid is ______ and the last amino acid is _______

A

Valine; arginine

39
Q

____ binding changes position of _____ Ion, which causes a global _________ change.

A

O2; Fe2+

40
Q

Major hemoglobins in fetal stage

A

Alpha and gamma

41
Q

Aged red blood cells are excreted in ___________

A

Bile

42
Q

Total oxygen content

A

O2 on Hb (SaO2) + dissolved O2 (PO2 )

43
Q

Hemoglobin hues:

________ - Healthy and robust

________ - Anemic

_______ - Hypoxemia - Cyanosis

_________ - Jaundiced (Bilirubin↑)

_________ - CO poisoning

_________ - Methemoglobinemia (Chocolate cyanosis)

A

Red

Pale

Blue

Yellow

Cherry Red

Brown Blue

44
Q

What is hemocrit?

A

the ratio of the volume of red blood cells to the total volume of blood.

45
Q

2,3-BPG is an __________ inhibitor

A

Allosteric

46
Q

Bohr Effect

______ acidity gives more oxygen delivery

3 amino acid residues form 2________ bridges that stabilize the_______structure of deoxy-Hb

Addition of a proton to _________ is required

Protonation also occurs on ________ of a chains and ________ of a chains

A

Higher

Salt; T

His B 146

Amino-termini; His- 122

47
Q

Anion transporter involved in O2-binding to hemoglobin. Symyporter or antiporter?

A

HCO3– Cl- antiporter

48
Q

Chloride Effect

Cl- likewise promotes formation of _______

Cl- interacts with________ side chains of deoxy Hb and stabilizes ______ interactions

A

T-state

Positive; Ionic