Brainscape's Knowledge GenomeTM

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


See full index

Medical Biochemistry > Heme/Blood > Flashcards

Heme/Blood Flashcards

You may prefer our related Brainscape-certified flashcards:
USMLE® Step 1 flashcards
1
Q

Heme

A

Carries O2, prosthetic group of protoporphyrin IX - tetrapyrrole ring, joined with methene bridges with attached iron

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

Difference between Mb and Hb?

A

Mb - 1 binding site, helps diffuse O2 in the cells, MM and heart, good for diving animals
Hb - 4 binding sites, helps transport O2 from lungs to tissues, RBCs, waste removal, cooperative binding

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

Methemoglobin

A

Fe2+ to Fe3+, removes shield, pocket bind water instead of O2

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

Prox His F8 and dist His F7

A

Prox His F8 - binds heme, is pulled down in T state so O2 cants bind
Dist His F7 - O2

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

HbA

A

major adult Hb, a2b2, acts like two dimers that move relative to eachother, R/T-states

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

P50 values for Mb vs Hb

A

Mb = 1 torr, Hb = 26 torr, Mb has much higher affinity (hyperbolic), Hb (sigmoidal curve with O2 being homotropic allosteric effector)

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

Allosteric Effectors of Hb

A

salt bridges (Cl-) - causes delivery of O2
CO2/H+ - same
BPG - same (when O2 binds BPG is released)

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

Bohr Effect

A

buildup of metabolites in active MM produce low pH and CO2, decreases O2 affinity for Hb, more goes to tissue

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

Rightward shift

A

increased acid, decreased pH, increased CO2, decreases O2 affinity for Hb, more goes to tissue

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

Leftward shift

A

Decreased acid, increased pH, decreased CO2, decrease in temp, increasing O2 affinity for Hb, less goes to tissue

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

CO2 brought to lungs as?

A

Mostly bicarb, little CO2

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

BPG importance

A

important for O2 release in tissue from Hb, if not BPG, then Hb curve looks like Mb (hyperbolic), so it rq for effective deliv. of O2

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

Most important allosteric effectors of Hb

A

BPG and CO2 (both do rightward shifts, better O2 delivery to tissues)

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

Altitude

A

Non-allosteric effectors of Hb, at high alt. induction of BPG, rightward shift

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

Temp

A

Non-allosteric effectors of Hb, at high temp. rightward shift, low temp leftward shift

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

CO

A

binds R state with higher affinity, treated with hyperbaric O2 chambers, force release of Hb

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

NO

A

carried by Hb, hypoxic vasodilation

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

Cadet face right

A

CO2, acid, 2,3DPG (BPG), exercise, high temp, all give shift to the right

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

Gower 1

A

embryonic - zeta2epsilon2

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

Gower 2

A

embryonic - alpha2epsilon2

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

Portland

A

embryonic - zeta2gamma2

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

HbF

A

fetal - 3rd-9th mo, alpha2gamma2, greater affinity for O2 than HbA b/c gamma has lower BPG affinity, leftward shift, increase in thalassemia, in F-cells

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

HbA

A

adult - a2b2, 97% of Hb

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

HbA2

A

adult - a2delta2 - minor Hb 2%

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

development of Hb?

A

5’ to 3’ in gene direction, zeta, epsilon, gamma, alpha, beta/delta

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

HbA1c

A

glycosilated b chain, dependent on blood-glucose [ ], normal <6%, results over 2-3months

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

Heinz bodies

A

precipitates of unstable mutant Hb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Hb Titusville

A

negatively affects O2 binding, binding of subunits, decreases cooperatively and slope

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Hb Helsinki

A

mutation affects BPG binding, leftward shift - erythrocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Hb M

A

mutation leads to production of Methemeoglobin, fatal if homozy., leftward shift, erythrocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What do leftward and rightward shifts produce clinically?

A

L - erythrocytosis

R - anemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

SCA

A

single AA sub causes missense in b chain (made after brith), AR, reduced Hb solubility, worse during O2 deprivation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Sickle cell trait

A

Aa - heterozygous, asymptomatic, protects against malaria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Methemoglobinemia

A

defective NADH methemyoglobin reductase, so cant reduce Fe3+ to Fe2+, brown blood, could be poisoning, treated with methylene blue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Hemoglobin C disease

A

similar to SCA mutation wise, but far less severe, chronic, hemolytic anemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Hemoglobin SC disease

A

double mutation, in HbS B chain, can be fatal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

ALAS 1 v 2

A

1 - non-RBC, hepatic form, somatic, translation dept on low Heme, inducible (P450)
2- RBC form, X-linked, translation dept on high Fe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Series 1 v 3

A

1 - A(M)/P is symmetrical
3 - A(M)/P is not symmetrical around 1 group
Need Uroporphyrinogen III synthase to make series 3 which inverts 1 ring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Is Hb series 1 or 3?

A

3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Acetic acid

A

uro

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Methyl

A

from decarbox A, copro

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Vinyl

A

from decarbox P, heme, only 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

ALA substrates

A

Succinyl CoA and glycine +PLP in MT matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Pyrrole substrates

A

2 ALA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Formation of ALA enzyme

A

ALA synthase, rqs PLP, committed and rate limiting

46
Q

Formation of Porphobilinogen enzyme

A

ALA dehydratase/Porphobilinogen synthase, rqs Zn, inhibited by Pb

47
Q

-Inogen vs -in

A

Inogen - more reduced and colorless

In - oxidized, resonant and photactive

48
Q

Formation of heme enzyme

A

Ferrochelatase (Mt) rqs FAD added Fe to make heme, inhibited by Pb

49
Q

Uro I and copro I -inogen forms are?

A

auto-oxidized, no enzyme to -in forms and then excreted

50
Q

AIP

A

non-RBC, acute, decreased HMB synthase, increased ALAS, buildup of porphobilinogen effects in nervous system, not photoactive, no skin sensitivity

51
Q

PCT

A

non-RBC, chronic, decrease UROD (A to M), increase ALAS, dark urine, skin coloration, can be induced by liver disease

52
Q

Lead poisoning

A

All tissues, decreased ALA dehydratase, ferrochelatase, increased ALA synthase, see nervous system affect and anemia

53
Q

Heme is not reutilized

A

True!

54
Q

Breakdown of Heme

A

Heme broken down into Biliverdin (Green) and Bilirubin (red) are make in macrophages, and then bilirubin travels through blood with albumin and enters liver in unconjugated form where it is converted to bilirubin diglucuronide (addition of UDP-activated sugars - glucuronic acid) and conjugated bilirubin (more sol) leaves liver to become bile

55
Q

how is UCB measured?

A

Indirectly, TB - CB = UCB

56
Q

Gut bacteria (in intestinal tract) do what to bilirubin diglucuronide?

A

remove digluc, to form bilirubin and then convert it to urobilinogen (block hear gives clay colored stools), majority got to large intestines, little reabsorbed by gut, moves to liver/kidney

57
Q

Stercobilin

A

bile pigment that makes stool red-brown

58
Q

Urobilin

A

bile pigment that makes urine yellow

59
Q

Jaundice vs Kernicterus

A

J - deposition of bilirubin in eyes, skin and mucous membranes, yellow apperance
K - deposition of UCB in neurone, resulting in bilirubin encephalopathy - neonates suscep.

60
Q

Excessive production of bilirubin

A

increase UCB in blood, increase CB in bile

61
Q

Decrease/absent conjugation

A

increase UCB in blood, crigler-naijjar syndrome (1 is the worst)

62
Q

Inhibition of excretion of CB

A

increase CB in blood because leaks back since it cant go to bile, mutation in ABC transporter, Dubin-Johnson syndrome, pale stool, dark urine

63
Q

Interference with excretion of biliary network

A

increase CB in blood, pale stool, dark urine

64
Q

Dcytb

A

reduces Fe3+ to 2+ on intestinal lumen side

65
Q

DMT-1

A

transports Fe2+ into enterocyte from intestinal lumen

66
Q

Ferritin

A

storage form of Fe3+

67
Q

Ferroportin

A

transfers Fe2+ (3 to 2 by hephaestin) to basolateral side of enterocyte, IREG, inactivated by hepcidin through internalization and degredation when Iron is high

68
Q

Fe3+ bound in blood to?

A

Transferrin, only about 1/3 saturated, binds TfR1, endocytosed, low pH dissociates Fe from receptor, Tf and TfR1 are both recycled

69
Q

Fe2 vs 3

A

crosses membranes as 2, stored as 3

70
Q

Hereditary hemochromatosis

A

AR, iron overload in liver, heart and other organs, result of lower hepcidin

71
Q

recycled iron meets 90% of daily iron need

A

true!

72
Q

Regulation of Apoferritin

A

binding of IRP at 5’ IRE prevents translation, 3’ IRE promotes translation, b/c lots of IRP means you dont have Fe, so dont want to store it!

73
Q

Regulation of Transferrin receptor

A

binding of IRP at 3’ IRE promotes translation, nothing at 5’ but lack of binding to 3’ end makes mRNA unstable

74
Q

IRP regulated by?

A

FE! when low Fe, IRP can bind IRE, when high Fe, IRP is degraded in proteasome

75
Q

Clotting factors made by?

A

Liver!

76
Q

Activation of clotting factors occurs by?

A

Serine protease cleavage and also conformational change without proteolysis

77
Q

Dicumerol/Warfarin/Coumadin

A

inhibits Vit K needed for clotting to modify Gla

78
Q

Order of Ca, PS, Gla binding

A

PS - Ca - Gla

79
Q

Tissue factor

A

from damaged tissue, not blood, extrinsic pathway, binds to factor 7

80
Q

How does thrombin activate fibrinogen?

A

cleaves (-) tufts off fibrinogen to make fibin that can bind to GP2 and 2a on platelets

81
Q

TFPI

A

shuts down extrinsic ptw quickly

82
Q

Serine proteases

A

2, 7, 9, 10, 11, 12

83
Q

Gla containing proteases

A

2, 7, 9, 10

84
Q

Accessory proteins

A

3, 5, 8

85
Q

GP1b receptor

A

on platelets, binds to vWF

86
Q

Antithrombin III

A

made in liver, inactivates thrombin, affinity for thrombin increases in presence of Heparin

87
Q

Hep vs Warfarin

A

Hep - rapid onset, short 1/2 life, given IV

Warf - delayed onset, long 1/2 live

88
Q

Thrombomodulin

A

converts thrombin to protein of coagulation to protein of anti-coag

89
Q

Protein C

A

activated by thrombomodulin-thrombin complex

90
Q

APC

A

Activated protein C in complex with Protein S (both are gla containing), cleaves 5a and 8a

91
Q

Factor V leiden

A

mutant resistant to APC, causes thrombophilic condition EVERYWHERE IN BODY, causes DVTs and Pes, chest pain, palpitations, shortness of breath

92
Q

What does thrombin activate

A

factors 5, 7, 8, 11, 13, fibrinogen and t-PA secretion

93
Q

7a-TF complex

A

activates 9 in intrinsic ptw

94
Q

12a

A

activates 7 in extrinsic ptw

95
Q

Most common inherited coagulopathy

A

vWF disease, no VWF

96
Q

Deficiency in vWF platelet receptor

A

Bernard-souler syndrome

97
Q

Deficiency in platelet receptor for fibrinogen

A

Glanzmanns

98
Q

Immune thrombocytopenia

A

autoimmune disorder caused by autoAb to fibrinogen platelet receptor

99
Q

Degranulation of platelets releases

A

Delta/dense
1) serotonin: causes vasoconstriction
2) ADP: activates additional platelets;
binds membrane GPCR

Alpha

3) platelet-derived growth factor (PDGF): helps wound healing
4) Va
5) VWF
6) fibrinogen
7) etc.

100
Q

Process of degranulation

A

thrombin binds PARs on platelet surface and endothelial cells, PARs are GPCRs and thrombin is associated with Gq, activation of PLC causes increase DAG, IP3 and Ca, DAG activates PKC leading to degranulation

101
Q

Problem clotting related to TAG synthesis?

A

problem with VLDL secretory ptw, cant get Vit K

102
Q

atherothrombosis

A

Atherothrombosis (formation of intraluminal thrombi) occurs when the fibrous cap
covering a plaque is damaged. Bleeding ensues, platelets adhere and get activated; however, the platelet response frequently goes beyond clotting and wound healing, progressing to intraluminal
thrombus formation, vessel occlusion, and an MI
Treatment with aspirin, an anti-platelet drug that inhibits COX (and therefore TXA2 synthesis in platelets), decreases mortality from an MI.

103
Q

Thrombomodulin

A

glycoprotein expressed on the surface of
undamaged endothelial cells, binds thrombin, decreasing thrombin’s affinity for fibrinogen and increasing its affinity for Protein C.
converts thrombin from a protein of coagulation to a protein of anticoagulation and so limits the extent of clotting

104
Q

tPA vs uPA

A

tPA - endothelial cells is tissue plasminogen activator, secreted in INACTIVE FORM IN RESPONSE TO THROMBIN and becomes activated when binding to fibrin-plasminogen complex, activates to plasmin
uPA - plasminogen activator, isolated from urine, made in kidney

105
Q

Treatment for Therapeutic fibrinolysis

A

treating patients with t-PA or u-PA. t-PA

made by recombinant DNA techniques now is available commercially

106
Q

aPTT

A

intrinsic (AHI) – activated partial thromboplastin time, monitors heparin effect, normally tests for hemo A, B vWF def and lupus, work through common ptw

107
Q

PT

A

extrinsic – prothrombin time (PT) using thromboplastin; expressed as INR (international normalized ratio), monitors warfarin, work through common ptw

108
Q

3 ways to stop clotting

A

1) Antithrombin 3 - inactivates thrombin, factors 9a, 10a, 11a, 12a, and 7a-TF, action increases with hep
2) APC - Protein C and S complex - both gla proteases that degrade factors 5a and 8a
3) TFPI inhibits extrinsic

109
Q

Clot resorption?

A

Plasmin from plasminogen (liver) which binds fibrin/incorporated into forming clot, then activated by t-PA and u-PA

110
Q

How are plasmin and t-PA protected from inhibition?

A

plasmin bound to a2-antiplasmin and t-PA bound to PAI, protected from inhibitors until fibrin clot is dissolved

Medical Biochemistry (5 decks)

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