Cell Analogy: A easy way to remember cell organelles and their
jobs…
Cells are very similar to car factories.
Cells produce proteins while factories
produce cars. To stay alive and function
properly, cells have smaller parts in
them called organelles which perform all
the different jobs that are also found in
factories. Here, we will examine cells as
protein-producing factories.
Copyright 1996 Shawn Glynn
Some important structures inside the
cell are the cell membrane, the cell
wall, and the cytoplasm. The CELL
MEMBRANE (also known as the plasma membrane) regulates what enters or leaves
the cell. It acts like the gate of the factory that allows some materials in and keeps
others out. It also functions as the communications department because it is where
the cell makes contacts with what is outside of the cell (the external environment).
The Cell wall provides structure for the cell. This is like the brick wall that surrounds
the factory, providing structure and regulation. Finally, the CYTOPLASM is the fluid
that surrounds everything between the cell membrane and the nucleus. It contains
various kinds of cell structures and is the site of most cell activity. The cytoplasm is
similar to the factory floor where most of the products are assembled, finished, and
shipped
Organelles are “little organs” that perform all the jobs in the cell. The following
organelles all complete important functions that allow the cell to survive and build
proteins.
The NUCLEUS contains DNA which holds all the instructions for how the cell can
produce proteins. It determines what proteins are to be made and stores all the plans
for any proteins that the cell currently makes or has made in the past. The nucleus is
like the boss at a car factory because it controls the activities in the factory just like
the nucleus controls the activities of the cell.
RIBOSOMES are the workers that build proteins. Think of them as the factory
workers that build the cars. Without them, no cars would be built! Similarly, with no
ribosomes, the cell can’t produce protein!
Most factories have power plants in which generators burn fuel to produce energy.
Building proteins is the main function of cells, but this takes energy! A cell must have
an energy source in a form it can use. The MITOCHONDRION (aka mitochondria) and
A cell can be thought of as a "factory," with different
departments each performing specialized tasks.
the CHLOROPLAST are the two organelles responsible for making food and energy.
The chloroplast makes carbohydrates (food) from sunlight through a process called
photosynthesis. The mitochondria release energy called ATP that the cell can use to
fuel the protein builders (ribosome). Think of the chloroplast as the coal, which is
type of fossil fuel. Think of the mitochondria as the furnace, burning the coal to make
energy the cell can use. After proteins are made, they can go on to do different
things. They can stay in the cell or even leave the cell and move to other cells.
Sometimes excess water, enzymes and other proteins might be stored in VACUOLES
and wait to be used by the cell for various functions. This is like a warehouse in a
factory.
Questions about the Cell Factory:
1. Summarize the analogy below:
Cell membrane = gate
Cell wall =
Nucleus =
Ribosomes =
Cytoplasm =
Mitochondria =
Chloroplast =
Vacuole =
2. What does the cell produce?
3. What two structures provide energy for the factory? Explain their relationship
below.
4. Where are the instructions for making proteins found?
5. Who makes the proteins?
6. What organelle protects the cell?
7. What organelle determines what can go in and out of the cell?
8. What is the job of a vacuole?
9. If the factory workers went on strike, no cars would be made at the factory. What
would happen in the ribosomes in the cell were destroyed by a deadly disease?
What would happen to the cell if the Nucleus was destroyed (think about the factory
analogy…)?