Lesson #7

Question 1

Proteins of microtubules:

Answer 1

Tubulin.

Question 2

Proteins of microfilaments:

Answer 2

Actin + myosin.

Question 3

Proteins of intermediate filaments, and their tissue type:

Answer 3

1. Epithelial tissue - keratin protein.
2. Messenchymal tissue - Vimentin protein.
3. Muscle tissue - Desmin protein.
4. Glial tissue - glia fibrillary acidic proteins.
5. Nerve tissue - Neurofilaments.

Question 4

Function of microfilaments (actin and myosin) cannot function without their two actin-binding proteins, what are the two types:

Answer 4

1. Anchoring.
2. Cross-linking.

Question 5

Ankyrin, spectrin, and dystrophin are all __________ ___________.

Answer 5

Anchoring proteins.

Question 6

Actinin and filamin are both _______-________ _________.

Answer 6

Cross-linking proteins.

Question 7

Name the autosomal dominant disorder that causes deformation of RBC’s, leading to them being phagocytosed by macrophages.

Answer 7

Spherocytosis.

Question 8

Why do spherocytes have an increased permeability to sodium?

Answer 8

Because the membrane is damaged and the Na+/K+ ATPase pump is dysfunctional.

Question 9

Spherocytosis, a RBC condition, is caused by a mutation in -

a. Actinin and filaminin.
b. Ankyrin and spectrin.
c. Actinin and ankyrin.
d. Filamen and spectrin.

Answer 9

B - Ankyrin and spectrin.

Question 10

What disease is caused by mutations in keratins 5 & 14 - Manifesting as blisters that develop soon after birth?

Answer 10

Epidermolysis bullosa simplex (EBS)

Question 11

What disease is caused by mutations in keratins 1 & 10 - and cause excessive keratinization leading to break down of the skin?

Answer 11

Epidermoyltic hyperkeratosis. (EH)

Question 12

What disease is caused by mutations in keratin 9, and manifests as skin issues in the palms and soles?

Answer 12

Epidermoyltic plantopalmer keratoderma. (EPK)

Question 13

Abnormal keratin genes will generally do what to the cell?

Answer 13

Weaken mechanical strength of cells.

Question 14

Where are the microtubules found?

Answer 14

Mircrotubules are found in the cytoplasm of the cell, radiating out from the centrosome.

Question 15

Microtubule specialized structures found in ALL cells:

Answer 15

Mitotic spindle and centrioles.

Question 16

Microtubule specialized structures found in specific cells:

Answer 16

Cillia, flagella, and basal bodies.

Question 17

Assembly MAPs:

Answer 17

Promote polymerization of microtubules, and inhibit depolymerization of microtubules.

Question 18

Motor MAPs:

Answer 18

Walk along microtubles like a track.

Dynein and kinesin.

Question 19

Axonemal dynein:

Answer 19

Moves 1 microtubule across the surface of another neighboring microtubule.

Question 20

________ _____ are found in most cells, cannot move but are involved in signalling pathways, and function as mechanoreceptors to Ca++ flow.

Answer 20

Primary cilia.

Question 21

_________ _______ disease is autosomal dominant. Has abnormal primary cilia function. And allows for renal epithelial tissues to have high rates of proliferation and apoptosis.

Answer 21

Polycystic kidney disease.

Question 22

In polycystic kidney disease - The polycystin-2 protein, does what?

Answer 22

It will be a dysfunctional Calcium channel when diseased.

Question 23

In polycystic kidney disease - The polycystin 1 protein (PC1), does what?

Answer 23

Is a large dysfunctional transmembrane protein, that functions as a sensor. Dysfunctional when diseased.

Question 24

What genes encode for PC1 and PC2?

Answer 24

PKD1 and PKD2 (PKD = polycystic kidney disease)

Question 25

True or false: Autosomal recessive polycystic kidney disease is the most common genetic disorder of the kidneys?

Answer 25

False - Autosomal DOMINANT polycystic kidney disease is the most prevalent genetic disease of the kidneys.

Question 26

True or false: Polycystic kidney disease is the cause of 20% of end-stage renal disease.

Answer 26

FALSE - Polycystic kidney disease is only responsible for 10% of end-stage renal disease.

Question 27

Immotile cilia syndrome is also know as:

Answer 27

Kartagener’s syndrome.

Question 28

___________ __________ is an autosomal recessive condition that results from an abnormal axoneme due to defective of absent dynein.

Answer 28

Kartagener’s syndrome.

Question 29

Kartagener’s syndrome manifestations -

Answer 29

1. Prevents mucociliary clearance, causing frequent lung infections.
2. it reduces sperm motility and egg transport - causing infertility.
3. Causes situs inversus in 50% of patients - when the organs are on the wrong sides.

Question 30

How do anti-mitotic drugs (taxol) work as an anti-tumor therapy?

Answer 30

The mitotic spindle is made up of microtubules, that polymerize and depolymerize to manipulate the movements of mitosis. The drug Taxol, prevents polymerization/depolymerization of the microtubules, which in turn stops mitosis from occurring, and prevents cell replication. This is vital to slow the spread of cancerous tumor cells.