Midterm 1 study guide

Question 1

What is the difference between subunit polymer and filament of cytoskeletal proteins?

Answer 1

-Subunit is the smallest building block of cytoskeletal filament ( ususlally single protein molecule) that can assemble with other to form a polymer (alpha and betal tublin are dimers
- polymers - protofilaments
-Filament is the final fucntional structure

Question 2

Microtubules are composed of what subunits

Answer 2

alpha and beta dimers

Question 3

Name two functions or roles (of many) of the cytoskeleton

Answer 3

• ( they are used as highways to transport cargo ( kinesin and dynein )
• structural support and shape a maintenance

Question 4

What is a MTOC

Answer 4

The Microtubule-Organizing Center (MTOC) is a cellular structure that nucleates and organizes microtubules. It serves as the main site where microtubules are assembled, anchored, and dynamically regulated.

Question 5

What are the two types of motors used with microtubules? What direction does each motor
move? Can you draw them?

Answer 5

• Kinesin moves towards the ( + ) end of the microtuble.
• Function transports cargo such as vesicles and proteins away from the centrosome
• Dynein moves towards the ( - ) end of the microtuble.
  -Function carries cargo toward the centrosome.

Question 6

Why does the term ‘dynamic instability’ best describe the behavior of microtubules in a cell?

Answer 6

The term “dynamic instability” best describes the behavior of microtubules because it captures their continuous and rapid switching between growth and shrinkage within the cell. This property is essential for cellular processes such as mitosis, intracellular transport, and shape maintenance.

Question 7

If a region of DNA is undergoing transcription, what form must the chromatin be in?

Answer 7

lossley packed not hetrochromatin

Question 8

Humans have diploid cells. What does this mean in terms of chromosome number and
copies?

Answer 8

-Each diploid cell contains 46 chromosomes (organized into 23 pairs).

• Each chromosome pair consists of one chromosome inherited from the mother and one from the father.
  This means humans have two copies of each chromosome, making them homologous pairs (except for sex chromosomes in males, which are XY).