Video Transcript
Some structures found within the
cell are provided: (I) microtubules, (II) chromatin, (III) microfilaments, (IV)
lysosomes, (V) intermediate filaments. Which of these structures make up
the cytoskeleton?
First, let’s remember what the
cytoskeleton is. The cytoskeleton is a network of
protein filaments within the cell that positions the organelles, provides structural
support, and allows some cells to move. The term “cyto-” means cell, so the
cytoskeleton literally translates to the cell’s skeleton.
Our question presents us with
several different structures contained in eukaryotic cells. Let’s discuss these structures.
The first structure mentioned is
the microtubules. You might recall that microtubules
are made up of a protein called tubulin and that microtubules are responsible to
provide structure and shape and have an important function in cell division in
eukaryotic cells. They are a component of the
cytoskeleton. So the first structure should be
included in our answer.
The second structure, chromatin,
refers to the condensed structure of DNA which is part of a chromosome. This does not have any implication
to the cytoskeleton of the cell, so it can be ignored.
The third structure,
microfilaments, are composed of actin monomers. And they are the smallest
structural components in a cell. Microfilaments especially function
to keep organelles in their place. And they are considered a main
component of the cytoskeleton. Therefore, our answer should
include microfilaments.
Lysosomes, the fourth structure
mentioned, are organelles whose function is mainly to break down excess or damaged
proteins in the cell. This is not a component of the
cytoskeleton, so the fourth structure should be ignored.
Finally, the fifth structure
mentioned, intermediate filaments, are those that are middle in size to microtubules
and microfilaments. Intermediate filaments provide the
majority of mechanical support to the plasma membrane, though they do not affect the
movement of the cell. They are considered part of the
cytoskeleton. So this answer should be included
as well.
Now that we have discussed all of
the structures that are mentioned in our question stem, we can choose the correct
answer. Because structures (I), (III), and
(V) are involved with the cytoskeleton, the correct answer to our question is (I),
(III), and (V).
The structures from this list that
are part of the cytoskeleton are (I), (III), and (V).
