Physiology - Haemoglobin and Haemoglobin genes

Question 1

What is adult Haemoglobin made up of ?

a. 2 alpha chains + 2 beta chains
b. 2 alpha chains and 2 gamma chains
c. 2 alpha chains and 2 beta chains 6 glu->val

Answer 1

a.2 alpha chains + 2 beta chains

Question 2

what dictates the shape and properties of a protein?

a. polypeptide bonds
c. hydrogen bonds
d. amino acids
e. carboxyl groups

Answer 2

d.amino groups

Question 3

proteins fold into conformations of?

a. lowest energy
b. highest energy
c. lowest bonds
d. highest bonds

Answer 3

a.lowest energy

Question 4

what is the role of proteins known as molecular chaperones?

a. form polypeptide bonds
b. increase efficiency of folding
c. strength and support

Answer 4

b. increase efficiency of folding

Question 5

the linear sequence of amino acids refers to what level of protein structure?

a. primary
b. secondary
c. tertiary
d. quaternary

Answer 5

a.primary

Question 6

the folding and stabilisation of the primary structure into regular elements eg a helix and b pleated sheet by H bonds and others
refers to what level of protein structure?

a. primary
b. secondary
c. tertiary
d. quaternary

Answer 6

b.secondary

Question 7

the folding and stabilisation of secondary structure into a 3d shape refers to what level of protein structure?

a. primary
b. secondary
c. tertiary
d. quaternary

Answer 7

c.tertiary

Question 8

intergration of distinct polypeptide chains into oligomeric complexes refers to what level of protein structure ?

a. primary
b. secondary
c. tertiary
d. quaternary

Answer 8

d.quaternary

Question 9

polar side chains form which element of the compact protein conformation?

a. hydrophobic core region
b. hydrophillic outside of the molecule

Answer 9

b.hydrophillic outside of the molecule

Question 10

which directions to genes run?

a. 5’ to 3’
b. 3’ to 5’

Answer 10

a.5’ to 3’

Question 11

how do genes run within a protein?

a.5’ to 3’
b.3’ to 5’
c. N terminus to C terminus
d,C terminus to N terminus

Answer 11

c. N terminus to C terminus

Question 12

what best describes an alpha helix ?

a. left handed corkscrew
b. right handed corkscrew
c. stretched out structure

Answer 12

b. right handed corkscrew

Question 13

where do the hydrogen bonds run in an alpha helix?

a. between peptide bonds
b. between C-O and NH groups

Answer 13

a. between peptide bonds

Question 14

Where do H bonds run in a beta pleated sheet?

a. between peptide bonds
b. between C-O and NH groups

Answer 14

b. between CO and NH groups

Question 15

what does the proline side chain do to the alpha helix to stabilise it ?

a. make it too flexible
b. make it too rigid

Answer 15

b. make it too rigid

Question 16

what does the glycine side chain do to the alpha helix to stabilise it ?

a. make it too flexible
b. make it too rigid

Answer 16

a,make it too flexible

Question 17

what effect do oxidants have on the disulphide bonds in a proteins tertiary structure?

a. changes their angle
b. changes their properties
c. breaks them
d. forms them

Answer 17

d.forms them

Question 18

what effect do reductants have on the disulphide bonds in a proteins tertiary structure?

a. changes their angle
b. changes their properties
c. breaks them
d. forms them

Answer 18

c.breaks them

Question 19

what are the distinct regions pf a protein known as?

a. bonds
b. sections
c. domains

Answer 19

c.domains

Question 20

what are gene families?

a. similar genes evolved from an evolutionary precursor often regulated in a coordinated manner and arranged in clusters on a chromosome
a. multiple copies of the same gene evolved from an evolutionary precursor often regulated in a coordinated manner and arranged in clusters on a chromosome

Answer 20

a.similar genes evolved from an evolutionary precursor often regulated in a coordinated manner and arranged in clusters on a chromosome

Question 21

What is fetal Haemoglobin made up of ?

a. 2 alpha chains + 2 beta chains
b. 2 alpha chains and 2 gamma chains
c. 2 alpha chains and 2 beta chains 6 glu->val

Answer 21

b.2 alpha chains and 2 gamma chains

Question 22

What is sickle cell Haemoglobin made up of ?

a. 2 alpha chains + 2 beta chains
b. 2 alpha chains and 2 gamma chains
c. 2 alpha chains and 2 beta chains 6 glu->val

Answer 22

c. 2 alpha chains and 2 beta chains 6 glu->val

Question 23

the affinity of fetal Hb for O2 is ….. than the affinity of maternal Hb for O2?

a. lower
b. greater
c. the same

Answer 23

b.greater

Question 24

in sickle cell anaemia what causes the haemoglobinopathy?

a. mutations in Hb genes leading to altered amino acids, so altered properties of the Hb protein chains
b. defective regulation of Hb gene expression , altered ratios of the Hb chains, altered properties of the complex

Answer 24

a.mutations in Hb genes leading to altered amino acids, so altered properties of the Hb protein chains

Question 25

in thalassaemias what causes the haemoglobinopathy? a. mutations in Hb genes leading to altered amino acids, so altered properties of the Hb protein chains b. defective regulation of Hb gene expression , altered ratios of the Hb chains, altered properties of the complex

Answer 25

b.defective regulation of Hb gene expression , altered ratios of the Hb chains, altered properties of the complex

Question 26

what is the phenotype of people hetrozygous for the sickle cell gene mutation? a. sickle cell disease b. normal red blood cells

Answer 26

b. normal red blood cells

Question 27

in sickle cell anaemia which chain of the haemoglobin molecule has a point mutation? a. beta b. alpha

Answer 27

a. beta

Question 28

what is the effect of the point mutation occuring in the B chain of haemoglobin in sickle cell anaemia? a. Val -> Glu b. Val -> Gly c. Glu-> Val d. Gly-> Val

Answer 28

c. Glu-> Val

Question 29

what is the effect of glu being switched for val ? a. an acidic non polar residue becomes hydrophobic b. an acidic polar residue becomes hydrophobic c. an alkanline polar residue becomes hydrophillic d. an alkaline polar residue becomes hydrophobic

Answer 29

b.an acidic polar residue becomes hydrophobic

Question 30

what is the effect of an acidic polar residue in the Hb B protein chain becoming hydrophobic? a. 6 th amino acid switched from Glu -> val b. small sticky patches form on the surface of the B chains that cause them to polymerise and form fibres c. b.small sticky patches form on the surface of the B chains that cause them to break down

Answer 30

b.small sticky patches form on the surface of the B chains that cause them to polymerise and form fibres

Question 31

At which amino acid does the point mutation occur in the B chain that causes sickle cell anaemia? a.6th b5th c.4th d.3rd

Answer 31

a.6th

Question 32

What causes the sickle shape of RBC in sickle cell anaemia? a. fibres of polymerised B cells being broken down b. fibres of polymerised B cells breaking off to form platelets c. HbS fibres distorting the shape of the RBC

Answer 32

c.HbS fibres distorting the shape of the RBC

Question 33

How do sickle cells lead to anaemia?

Answer 33

cells more rigid so block capillaries and have a shorter life span

Question 34

Hb SS represents which state? a. adult Haemoglobin b. adult homozygous for sickle cell c. adult hetrozygous for sickle cell

Answer 34

b. adult homozygous for sickle cell

Question 35

Hb AS represents which state? a. adult Haemoglobin b. adult homozygous for sickle cell c. adult hetrozygous for sickle cell

Answer 35

c.adult hetrozygous for sickle cell

Question 36

At what age does sickle cell disease manifest? a. 2 years b. 3 months c. 12 months d. 6 months

Answer 36

d. 6 months | as the normal HbF decreases to adult levels

Question 37

what happens to sickle cells in low O2 environments? a. cells die b. altered affinity for one another and form filaments c. b.small sticky patches form on the surface of the B chains that cause them to break down

Answer 37

b. altered affinity for one another and form filaments

Question 38

where are sickle shaped red cells destroyed? a. kidney b. liver c. spleen

Answer 38

c.spleen

Question 39

patient with spenomegaly (enlarged spleen) tests show patient is anaemic. what is the most likley diagnosis? a. sickle cell anaemia b. iron deficiency anaemia c. thalassaemia

Answer 39

a.sickle cell anaemia

Question 40

Which of these is not an effect of a patient with sickle cell being in a low O2 environment? a. vessels clocked causing blockage and poor tissue viability b. splenomegaly c. bone marrow goes into overdrive to make enough RBC (hyperplasia) d. sickle cells decrease further in size and deformed shape

Answer 40

d. sickle cells decrease further in size and deformed shape