Red Blood Cells

Question 1

What is significant about red blood cells not having a nucleus?

Answer 1

They cannot replicate or repair damage therefore they have a limited lifespan

Question 2

Why do RBCs need to go through the process of glycolyisis?

Answer 2

They do not have any mitochondria

Glycolysis is the only way they can produce ATP

Question 3

What is significant about the biconcave shape of a RBC

Answer 3

Has a high surface are : volume ration

Extremely flexible

Question 4

What shape is haemoglobin?

Answer 4

Tetrameric globular protein

Question 5

What is the normal globulin structure in a Hb molecule?

Answer 5

2 alpha chains and 2 beta chains

Question 6

What type of haemoglobin molecule has 2 alpha and 2 gamma chains?

Answer 6

Foetal Hb

Question 7

What is metHb?

Answer 7

When the haem group is Fe3+ and not Fe2+

It cannot carry ocygen

Question 8

How does metHb occur?

Answer 8

The iron becomes oxidised through free radicals

Question 9

What are the 3 main functions of haemoglobin?

Answer 9

Deliver O2 to tissues
Act as an H+ buffer
CO2 transport

Question 10

Where does RBC destruction normally occur?

Answer 10

The spleen

Question 11

What happens to globulin cells when Hb isbroken down?

Answer 11

They become recycled as amino acids

Question 12

What are the breakdown products of haem?

Answer 12

Bilirubin and iron

Question 13

What happens to bilirubin when Hb is first broken down?

Answer 13

Taken to the liver and conjugated

Question 14

How is bilirubin excreted?

Answer 14

In bile

Colours the faeces and urine

Question 15

What role do macrophages play in the destruction of RBCs

Answer 15

They take aged RBCs out of the circulation

Question 16

What hormone secreted by the kidneys is responsible for the production of RBCs?

Answer 16

Erythropoietin

Question 17

What triggers the release of erythropoietin?

Answer 17

Hypoxia

Question 18

Where are RBCs produced?

Answer 18

The bone marrow

Question 19

What molecule prevents the oxidation of Fe2+ to Fe3+ ?

Answer 19

NADH

In the glycolysis pathway

Question 20

What removes hydrogen peroxide by converting it to H2O?

Answer 20

Glutathione

Question 21

What is the rate limiting enzyme in the process of Glutathione reacting with H2O2

Answer 21

Glucose-6-phosphate dehydrogenase

Question 22

What is significant about the gene that codes for Glucose-6-phosphate dehydrogenase?

Answer 22

Its X linked

Meaning any kind of deletion or mutation can cause significant problems, especially in men

Question 23

What generates NADPH

Answer 23

Hexose Monophosphate Shunt

Question 24

How muh CO2 is removed through dissolving in solution>

Answer 24

10%

Question 25

How much CO2 is removed as bicarbonate?

Answer 25

60%

Question 26

What does CO2 bound with Hb make? And how much CO2 is removed this way?

Answer 26

Carbamino-Hb 30%

Question 27

What is significant about the saturation of foetal Hb?

Answer 27

It saturates more at the same level of pO2 than adult Hb does

Question 28

What is the molecule responsible for regulating O2 release from haemoglobin?

Answer 28

2,3-bisphosphoglycerate | 2,3-BPG

Question 29

What pathway is 2,3-BPG produced in?

Answer 29

The Rapoport-Lubering Shunt

Question 30

What direction does 2,3-BPG shift the curve?

Answer 30

Right | Increases release of O2 to tissues

Question 31

What cells in the kidneys detect hypoxia and where are they located?

Answer 31

Cortical Interstitial fibroblasts | Near peritubular capillaries and proximal convoluted tube

Question 32

Other than erythropoietin, what else is required to make red blood cells?

Answer 32

B12 | Folate

Question 33

What is the definition of haemopoiesis?

Answer 33

Production of blood cells

Question 34

How many RBCs are produced per minute?

Answer 34

100million roughly

Question 35

What type of stem cell do erythrocytes (RBCs) come from?

Answer 35

Myeloid Stem Cells

Question 36

At what point is the nucleus of an erythrocyte lost?

Answer 36

When the reticulocyte is formed

Question 37

List the stages of erythropoiesis from pronormoblast --> RBC

Answer 37

``` Pronormoblast Basophillic / early normoblast Polychromatophilic normoblast Orthochromatic normoblast Reticulocyte Erythrocyte ```

Question 38

Where is a common site for bone marrow aspiration and biopsy?

Answer 38

Posterior iliac crests

Question 39

In an adult, where does haemopoiesis occur

Answer 39

Bone marrow of vertebrae, pelvis, sternum and proximal ends of the femur and humerous. Small contribution from ribs, scapulae and skull

Question 40

What is the name of the transcription factor which enhances cells to increase their expression of erythropoietin gene?

Answer 40

Hypoxia-Inducible Factor | HIF-1

Question 41

How is iron transported in the blood?

Answer 41

As transferrin

Question 42

How is iron stored?

Answer 42

As ferritin | usually in the liver