sickle cell disease

Question 1

what is SCD

Answer 1

Sickle Cell Disease is a genetic condition that causes anemia while preventing malaria

Question 2

why has SCD moved to higher altitudes?

Answer 2

As the climate changes, the increase in temperature has allowed mosquitoes to breed at higher altitudes

Question 3

explain how different types of hemoglobin are produced during different life stages?

Answer 3

-hemoglobin has 4 subunits and depending on the life stage, you will get one of those subunits
-initially, the fetal hemoglobin subunits mainly start at alpha and gamma and they have a higher affinity for O2
-but after 6 months, the fetal hemoglobin subunits for alpha and beta

Question 4

what does hydroxyurea do

Answer 4

increase fetal production of hemoglobin

Question 5

what are the functions of blood?

Answer 5

to carry O2 and nutrients around the body

Question 6

What pathologies are associated with mutations in hemoglobin?

Answer 6

mutations in hemoglobin where erythrocytes will sickle

Question 7

what does a lack of a nucleus mean

Answer 7

a short lifespan for erythrocytes

Question 8

erythrocytes lifespan

Answer 8

-erythrocytes are produced in the bone marrow
-at the end of the erythrocyte cycle, the erythrocytes are destroyed by macrophages and their components are recycled

Question 9

what does hypoxia release?

Answer 9

hypoxia releases EPO hormone from the kidney, which produces more erythrocytes

Question 10

what do erythrocytes contain?

Answer 10

large amounts of hemoglobin
which allows them to transport oxygen (and CO2)

Question 11

shape of RBCs

Answer 11

biconcave discs, which allows them to fold up as they move through narrow blood vessels

Question 12

hemoglobin

Answer 12

• a molecule of hemoglobin contains four globin proteins, each of which is bound to one molecule of the iron-containing pigment heme
• A single erythrocyte can contain 300 million hemoglobin molecules, and thus more than 1billion oxygen molecules.

Question 13

plasma

Answer 13

-Proteins: albumin, globulins
-90% water
- Nitrogenous waste
- Electrolytes
- Respiratory gases
- Nutrients

Question 14

Heme Groups

Answer 14

1. Iron is required to build heme groups
2. Folic acid is required for DNA synthesis:
   Thymine
   Deficiency leads to lower RBCs leads to anemia
   * B12 is required for folic acid action (animal sources most efficient)

Question 15

what happens when you substitute valine for glutamine

Answer 15

it changes the properties of the beta subunit of hemoglobin in SCD

Question 16

Hypertonic sodium…

Answer 16

increases sickling, leading to occlusion and adhesion

Question 17

Normal traits

Answer 17

HbA x HbA

Question 18

Sickle Cell Trait

Answer 18

HbA x HbS

Question 19

SCD traits

Answer 19

HbS x HbS

Question 20

Genetic inheritance

Answer 20

relies on the sorting of
chromosomes during meiosis

Question 21

the genetic code

Answer 21

-DNA holds all of the genetic information necessary to build a cell’s proteins
-The nucleotide sequence becomes an amino acid sequence

Question 22

DNA Polymerase

Answer 22

adds new nucleotides to the growing
strand as triphosphates which results in the release of pyrophosphate