2: Normal red cells

Question 1

What organelles do RBCs lack?

Answer 1

Nucleus

Mitochondria

Question 2

RBCs are flexible, so their ___ ___ must be flexible as well.

Answer 2

cell membrane

to prevent bursting

Question 3

Which transporter keeps water out of RBCs?

Answer 3

Sodium potassium pump

Na+ OUT and water follows Na+

Question 4

What do red blood cells require to keep water out of their cytoplasm?

Answer 4

Specialised cell membrane

ATP (to power sodium-potassium pump)

Question 5

Why must RBCs be broken down?

Answer 5

Lack a nucleus, so therefore lack ability to self-repair

i.e they get less efficient over time - “sell by date”

Question 6

Where does RBC breakdown occur?

Answer 6

Spleen

Question 7

What is Hb broken down into?

Answer 7

Amino acids

Iron

Bilirubin

Question 8

Which hormone controls red blood cell production?

Answer 8

Erythropoeitin

Question 9

Which organ releases erythropoietin?

In response to what?

Answer 9

Kidney

Hypoxia

Question 10

What is the action of erythropoietin?

Answer 10

Stimulates RBC production by bone marrow

Question 11

Which molecule acts as a reducing agent for Fe2+ i.e prevents the oxidation of haemoglobin?

Why is this important?

Answer 11

NADH

If Fe2+ is oxidised to Fe3+ it can’t carry oxygen

Question 12

What important protein do red blood cells contain?

Answer 12

Haemoglobin

Question 13

What are the components of adult haemoglobin?

Answer 13

2 alpha subunits

2 beta subunits

One Fe2+ bound to each, meaning each protein can pick up 4 oxygens

Question 14

To which iron ion can an oxygen molecule bind in haemoglobin?

Answer 14

Fe2+ only

Question 15

What is the function of haemoglobin?

Answer 15

Oxygen delivery to tissues

Question 16

By which process do red blood cells produce ATP?

Answer 16

Glycolysis

remember that they have no mitochondria

Question 17

Which reactive oxygen species can cause damage to DNA and proteins?

Answer 17

Superoxide

Hydrogen peroxide

Question 18

Which molecule removes reactive oxygen species from red blood cells by converting them to water?

Answer 18

Glutathione

Question 19

Which enzyme is the rate limiter in glutathione’s removal of reactive oxygen species?

Answer 19

Glucose-6-phosphate dehydrogenase

Question 20

Most ___ is transported to the lungs by haemoglobin.

Answer 20

CO2

Question 21

In what form do RBCs carry CO2 to the lungs?

Answer 21

Bicarbonate

Question 22

When combined with water, CO2 is converted to carbonic acid and subsequently H+ and HCO3- (bicarbonate).

What happens to each of these?

Answer 22

H+ buffered by Hb-

CO2 carried to the lungs in the RBC

Question 23

What factors shift the oxygen dissociation curve to the RIGHT i.e increase oxygen delivery to tissues?

Answer 23

CADET face RIGHT

Increased carbon dioxide conc.

Acid (so decreased pH)

Increased 2,3-DPG conc.

Exercise

Increased temperature

Question 24

Foetal haemoglobin has a (greater / smaller) affinity for oxygen than adult haemoglobin at equal oxygen pressures.

Answer 24

greater

Question 25

What is the structural difference between adult and foetal Hb?

Answer 25

Adult Hb - 2 alpha, 2 beta subunits

Foetal Hb - 2 alpha, 2 gamma subunits