- NOTE:This lesson is inteded to be taught over a 3-5
day period. Student questions and explanations, especially in a beginner
class will make it impossible to teach about more than 2-3 organelles per
- Math Background
Necessary for Teachers:
- The teacher
must have an in-depth knowledge of how cells function and interact.
In particular the teacher should have great understanding of the major
organelles in the cell.
should have taken Molecular Cell Biology or some equivalent class before
teaching this class.
should have already received instruction on the cell membrane before
giving this lesson series.
- To examine
the structure and function of the major organelles in animal cells.
it is so hard for students to conceptualize what a living cell looks
like for the first time, it is best to start off using a enlarged
the students the various organelles in the model and go over general
cell structure, remembering to include the cytoplasm.
by placing a picture of a mitochondria on the projector and point
out the basic gross anatomical features.
the basic function, introducing the terms cellular respiration,
oxidative phosphorylation, and substrate phosphorylation. We
will use these terms in the next lesson, Cellular Respiration.
on to the endoplasmic reticulum (ER). Begin with an explanation
and diagram of the Rough ER, explaining why it is termed rough (ribosomes)
and what the function of the RER is versus the Smooth ER.
electron microscope pictures of the two types of ER side by side
and ask the students to identify which is which and have them go
over the different characteristics. This acts as reinforcement of
what you have just said, and guages their understanding of the concept.
will easily transfer into the unit the ribosome. Simply explain
that the ribosome creates proteins. Explain that free ribosomes
exist in the cytoplasm as well. Make sure not to go into the translational
process, as this will only confuse the students and sidetrack
here, move on to the golgi apparatus, placing a diagram on the projector.
The golgi apparatus is involved in transport and packaging of proteins
for excretion outside of the cell. It has 3 faces: Cis, Medial,
cis face receives proteins for secretion from the RER and sometimes
modifies these proteins by adding carbohydrates to the of the protein,
forming a glycoprotein, which as earlier discussed is inserted into
the cell membrane.
proteins move from the cis to the medial to the trans face, where
they bud off forming vessicles, which move to the cell membrane
to either be secreted outside the cell as hormones, or into the
membrane as stated above.
addition, other vessicles are encoded to go to the lysosome. Explain
the function of the lysosome:
lysosomes exist in a cell. The lysosome is a membrane bound organelle,
which digests proteins, and other molecules so that their raw materials
(i.e. amino acids) can be used by the cell, or because there is
a plethora of that protein in the cell.
have digestive enzymes, and a low, acidic pH.
lysosome is an important part of apoptosis (programmed cell death).
When signaled, lysosomes will burst, and "eat through"
the cell, killing it.
is a normal event. Millions of cells undergo apoptosis a day in
a single human.
final major animal organelle to discuss is the nucleus. The nucleus
is the center of the cell and is a quite complicated structure.
primary function of the nucleus is to contain the DNA of an animal,
preventing the DNA from moving to the cytoplasm, where it will be
destroyed and lost.
nucleus is a specialized membrane that contains nuclear pores
so that RNA can move into the cell to encode proteins and so
DNA and RNA building blocks can move into the nucleus.
to the nucleus is RER, which help in transport and protein creation.
unit, combined with the lesson on the chloroplast contain enough
material for an exam.
the material is so dense, it is also suggested that homework questions
be given that cause the students to integrate the given information:
Starting from the nucleus, explain how an RNA that encodes a
protein destined for secretion is secreted.
form of question will cause the students to think instead of regurgitate