MODULE
Lesson 6: The cytoskeleton and cell motility
Learning Outcomes:
At the end of this module, students are expected to:
Describe the structure of the cytoskeleton
Identify the major functions of the cytoskeleton
Appreciate the role of cytoskeleton in our body
Time Frame: 3 hrs. / Week 6
Introduction:
Welcome Students for our lesson today. It’s all about the Cytoskeleton and Cell
motility.
Activity:
Write your answer on a separate clean sheet of paper.
• Do all cells have cytoskeleton?
Do humans have cytoskeleton?
Analysis:
Write your answer on a separate clean sheet of paper.
• What happens when the cytoskeleton malfunctions?
Abstraction:
Cytoskeleton
Major function of the cytoskeleton
Microtubules
The microtubule network is recognized for its role in regulating cell growth
and movement as well as key signaling events, which modulate
fundamental cellular processes.
Microfilaments
Microfilaments assist with cell movement and are made of a protein called
actin. Actin works with another protein called myosin to produce muscle
movements, cell division, and cytoplasmic streaming. Microfilaments keep
organelles in place within the cell.
Intermediate filaments
Intermediate filaments provide structural support, regulate key signaling
pathways, and facilitate the movement of proteins to specific domains of
polarized cells, such as Sertoli cells.
Cell Motility
Cellular motility is the spontaneous movement of a cell from one location
to another by consumption of energy. The term encompasses several types
of motion, including swimming, crawling, gliding and swarming.
Movement is guided by the cell's cytoskeleton and can involve specialized
organelles like cilia and flagella. Cells can know where and how to move based
on genetics.
MOTOR PROTEINS?
Motor proteins are the driving force behind muscle contraction and are
responsible for the active transport of most proteins and vesicles in the
cytoplasm. They are a class of molecular motors that are able to move along the
surface of a suitable substrate, powered by the hydrolysis of ATP.
Two major classes of major proteins
Application:
Answer the ff. questions. Write the correct letter.
1. A genetic defect involving the tubulin molecules will affect which of the following
processes?
a. Mitosis
b. None of these will be affected
c. Both of these will be affected
d. Axonal transport in neurons
2. Which of the following cytoskeleton components is comprised of G-actin subunits
organized polymers?
a. Septins
b. Microfilaments
c. Microtubules
d. Intermediate filaments
3. Which cell organelle can be described as a big tail projecting from the cell like a
motor?
a. Flagellum
b. Cytoskeleton
c. Centriole
d. Mitochondrion
4. Microtubules are present in which of the following structures?
I. Cilia
II. Flagella
III. Microvilli
a. I and III
b. II only
c. I and II
d. I,II and III
5. In which of the following is the cytoskeleton involved?
I. Contractile ring formed during cytokinesis
II. Anchoring the extracellular matrix
III. Post- translational modification of proteins
IV. Post- transcriptional modification of mRNA
a. I and II
b. I,II and III
c. II and IV
d. I only
Essay: 10 points
1. How does cytoskeleton help in motility?
