Normal RBCs

Question 1

What component of RBC carries O2

Answer 1

Hb

Question 2

RBC do/not have a nucleus

Answer 2

do not

Question 3

RBCs do/not have mitochondria

Answer 3

do not

Question 4

What does a high SA:V ratio allow for in the RBC

Answer 4

gas exchange

Question 5

What is a consequence of RBC being packed with Hb

Answer 5

creates a high oncotic pressure - cell wants to swell

O2 rich environment - risk of oxidation and damage

Question 6

consequence of no mitochondria in RBC

Answer 6

energy production limited to glycolysis

- low energy yield

Question 7

what is special about the RBC membrane

Answer 7

it is complex

contains proteins which make it flexible

Question 8

How is water kept out of RBCs

Answer 8

via Na/K ATPase

this requires energy

Question 9

Describe the structure of Hb

Answer 9

tetrameric globular protein
2 alpha and 2 beta chains - globin
haem = Fe2+ and porphyrin ring

Question 10

O2 can bind to Fe3+, true or false

Answer 10

FALSE

O2 can only bind to Fe2+

Question 11

What are the chemical symbols for ferrous and ferric

Answer 11

ferrous = Fe2+
ferric = Fe3+

Question 12

what is the function of Hb

Answer 12

carry oxygen to tissues
acts as a buffer for H+
involved in CO2 transport

Question 13

which hormone regulates RBC production and from where is it secreted

Answer 13

erythropoeitin

kidneys

Question 14

where and what happens in RBC destruction

Answer 14

occurs in spleen
macrophages take up aged cells
raw materials are recycled

Question 15

what is the pathway in the breakdown of haem

Answer 15

haem 
biliverdin 
unconjugated bilirubin 
conjugated bilirubin 
urobilinogen - urine
stercobilinogen - stool

Question 16

what can the presence of free radicals cause

Answer 16

oxidation of Fe2+ to Fe3+ meaning it cant carry O2

causes damage to proteins

Question 17

what is the Embden-Meyerhof pathway also known as

Answer 17

Glycolysis

ATP production in the absence of O2

Question 18

what is the overall net gain in glycolysis

Answer 18

2 ATP + NADH

Question 19

what molecule is used to prevent oxidation of Fe2+ to Fe3+

Answer 19

NADH (proton donor)

Question 20

What are reactive oxygen species

give examples

Answer 20

free radicals containing unpaired electrons - damaging

superoxide and hydrogen peroxide (H2O2)

Question 21

which enzyme converts superoxide into H2O2

Answer 21

superoxide dismutase

Question 22

what does catalase do

Answer 22

convert H2O2 into H20

Question 23

what is the function of Glutathione (GSH)

Answer 23

protects us from H2O2by binding with it to form H20 and an oxidised side product GSSG

Question 24

How does GSSG become GSH again

Answer 24

via NADPH

Question 25

How is NADPH generated

Answer 25

via hexose monophosphate shunt

Question 26

which enzyme is the rate limiting enzyme in the hexose monophosphate shunt

Answer 26

G6PD

Question 27

How is CO2 transported to the lungs

Answer 27

10% dissolved in solution 30% bound to Hb 60% as bicarbonate

Question 28

Cl- entry into RBC causes it to swell/shrink

Answer 28

swell

Question 29

Cl- exit from RBC causes it to swell/shrink

Answer 29

shrink

Question 30

what is partial pressure of a gas

Answer 30

pressure that a gas (in a mixture of gases) would exert if it were alone

Question 31

how many O2 molecules bind to Fe2+ in haem

Answer 31

1

Question 32

how many O2 molecules bind in 1 RBC

Answer 32

4

Question 33

at the lungs, pO2 is high/low

Answer 33

high | Hb needs to bind easily

Question 34

at the tissues, pO2 is high/low

Answer 34

low | Hb needs to release O2

Question 35

What pattern is shown when O2 binds to haem

Answer 35

allosteric effect

Question 36

what is cooperative binding

Answer 36

binding of 1 O2 molecule makes it easier to bind the next etc...

Question 37

For the same pO2, you will saturate more HbF than HbA, true or false

Answer 37

true

Question 38

what is the shape of the curve in HbA binding

Answer 38

sigmoid curve

Question 39

in which pathway is 2,3 BPG generated

Answer 39

Rapapoport-Lubering Shunt

Question 40

what activates the Rapapoport-Lubering Shunt

Answer 40

chronic hypoxia and anaemia | increase 2,3 BPG levels

Question 41

``` high levels of: H+ 2,3BPG temperature causes a shift to the left/right? ```

Answer 41

right

Question 42

``` low levels of: H+ 2,3BPG temperature causes a shift to the left/right? ```

Answer 42

left

Question 43

more oxygen is delivered to tissues in times of stress for example

Answer 43

anaemia, metabolic acidosis, increased CO2 concentration