RBC Structure and Function

Question 1

Blood is

Answer 1

Connective Tissue

Derived from mesoderm

Question 2

Function of Circulating Blood

Answer 2

Deliver Oxygen
Control Infection
Requirement for hemostasis

Question 3

Most Sensitive Organs to O2

Answer 3

Brain
Heart
Kidney

Question 4

What is Hematocrit?

Answer 4

the volume percentage of RBC in blood
Males 44%
Females 40%
Infants 50%

Question 5

RBC size and shape

Answer 5

7-8 microns
biconcave disc
stain acidophillic (red)
Anucleated

Question 6

Young Red Blood Cell

Answer 6

Reticulocyte

Question 7

Anisocytosis

Answer 7

Variation in size

Question 8

Poikilocytosis

Answer 8

Variation in shape

Question 9

Chromicity

Answer 9

RBC color

Question 10

Mean Cell Volume

Answer 10

Average volume of RBC

80-100fl

Question 11

Mean cell hemoglobin

Answer 11

Average amount of hemoglobin per RBC

Question 12

Mean Cell hemoglobin concentration

Answer 12

measures amount of hemoglobin in the cell relative to its size
If you just measured hemoglobin one could have very macrocytic RBCs that indicate high hemoglobin
MCHC factors in size of RBC

Question 13

Red Cell distribution width

Answer 13

Make sure cells have tight distribution

i.e. all the cells fall within the same size

Question 14

Hemoglobin

Answer 14

Oxygen and binding delivery
Tetrameric: 4 subunits (globin + heme)
2 alpha -globin
2 beta - globin

Question 15

Hemoglobin vs. Myoglobin

Answer 15

Hemoglobin shows cooperativity and has a sigmoidal curve
Myoglobin, found in muscle, does not show cooperativity and has a hyperbolic curve
NB: myoglobin has a higher binding affinity for O2

Question 16

Right Shift

Answer 16

Decrease affinity for oxygen

Question 17

What causes Right shift?

Answer 17

Increase Temp
Increase CO2
Increase 2,3 DPG
Low pH

Question 18

Left Shift

Answer 18

Increase affinity for oxygen

Question 19

What causes Left Shift?

Answer 19

Decrease Temp
Decrease CO2
Decrease 2,3 DPG
High pH

Question 20

2,3 Diphosphoglycerate

2,3DPG

Answer 20

derived from glycolytic intermediate
regulates the affinity of Hgb for O2
Increase shifts curve to the right
2,3DPG is competitive inhibitor for O2 and makes O2 dissociate more easily

Question 21

R State

Answer 21

Relaxed binds oxygen more easily

Question 22

T state

Answer 22

Tense state binds oxygen less readily

Question 23

What amino acid does heme interact with

Answer 23

Histadine

Question 24

CO poisoning

Answer 24

Binds to heme iron
240 fold higher affinity than O2
Shifts O2 dissociation curve to the LEFT

Question 25

Major and Minor genes for Adult Hemoglobin

Answer 25

Major: alpha 2; beta 2 Minor alpha 2; delta 2

Question 26

Fetal Hemoglobin composition

Answer 26

alpha 2; gamma 2 fetal hemoglobin is resistant to 2,3DPG HbF has higher O2 affinity than adult

Question 27

Sickle Cell Anemia

Answer 27

Glu 6 Val Valine substitution for glutamine Hb becomes insoluble when DEOXYGENATED

Question 28

Methemoglobin

Answer 28

Iron in Hb: Ferrous Fe2+ Oxidative Stress causes transition to Fe3+ Ferric Methemoglobin has Fe3+ Methemoglobin cannot transport O2!!!!

Question 29

Methemoglobin Reaction

Answer 29

Cyt b5ox + NADH --> Cyt b5red + NAD Cyt b5red + Hb-Fe3+ --> Cyt b5ox + Hb-Fe2+ occurs via methmoglobin reductase

Question 30

Superoxide Dismutase

Answer 30

O2 Radical -->H2O2 + H2O

Question 31

Catalase

Answer 31

H2O2 --> H2O + O2 | gets rid of hydrogen peroxide

Question 32

Glutathione

Answer 32

2GSH + H2O2 --> GSSG + 2H2O GSSG + NADPH --> 2GSH + NADP gets rid of hydrogen peroxide

Question 33

Hemoglobin A1C

Answer 33

Glycated Hb Non-enzymatic Proportional to blood glucose levels Integrated measure of glucose control over prolonged period

Question 34

Spectrin

Answer 34

Gives RBC rubber like flexability

Question 35

Ankyrin and Band 4.1

Answer 35

Anchor spectrin to the membrane

Question 36

Band 3

Answer 36

anion exchanger important for moving bicarbonate in and out of cell

Question 37

Cytoskeletal Organization of RBC

Answer 37

Band 3 is found in the membrane Ankyrin binds to band 3 Ankyrin/ Band 3 complex can bind to sepctrin Spectrin forms hexagonal lattice beneath plasma membrane

Question 38

Heriditary Elliptocytosis

Answer 38

Caused by mutation in spectrin