Cytoplasm and its Organelles
Organelles Cytoplasm
*Membrane
enclosed structures in
the cytoplasm that
serve specific
functions and gives
cell a division of labor.

Protoplasmic material
between plasma
membrane and nucleus.
Contains thickened gellike fluid called cytosol
which contains water,
proteins, and small
amounts of fats,
carbohydrates and
electrolytes.
5 Major Organelles Found in Cytoplasm
1. Mitochondria
2. Endoplasmic reticulum
3. Golgi apparatus
4. Lysosomes
5. Peroxisomes
1. Mitochondria
“Energy
powerhouse”
 Spherical or
sausage shape
 2 layers of
lipid bilayer
membrane. Only
organelle to have
double bilayer
*Inner layer is folded
into cristae to increase
surface area so that
metabolic enzymes
can occur along their
surface, outer layer is
selectively permeable
*Can self duplicate
during times of highenergy need.
Mitochondria
 Break down process is
called cellular respiration
which produces ATP, has
enzyme which breaks
down nutrient molecules.
 In addition to enzymes, it
has a concentration of
DNA to help synthesize
protein.
 Found a lot in muscle cells
(muscle cells need high
energy)
2. Endoplasmic Reticulum
ranching and rejoining
hollow tubes.
 Serves as transportation
network for newly
synthesized molecules.
 Contains 2 types: rough and
smooth.
*rough is abundant in WBC.
It contains ribosomes and
works in protein synthesis
*smooth is abundant in liver
cells. It does not have
ribosomes and it is used in
lipid synthesis.
3. Golgi Apparatus
Found near nucleus
Composed of flattened
disc shape sacks called
cisternae.
 As molecules are ready to
be secreted, a portion of
the golgi apparatus
pinches off to form a
secretory vesicle. This
then fuses with plasma
membrane to release
packaged material to
outside.
4. Lysosomes
Spherical structures.
Recycles other
organelles.
as hydrolytic
enzyme.
Since these can
destroy the cell itself,
they are called “self
destructive bags” or
“suicide packets”.
Releases enzymes by
exocytosis to break
down material outside
the cell.
*An impairment of the
lysosomes is called
Tay-Sachs disease.
Lysosomes
5. Peroxisomes
Spherical
 Detoxify
various
molecules like
fatty acids.
Cytoskeleton
ot an organelle.
Does not have
selectively permeable
membrane.
 Made of 2 types of
proteins which give
structural framework
of cell.
1. Microtubules
*long hollow tubes
*maintain shape of cell
2. Microfilaments
*thin and thread-like and
arranged in bundles
*provide cellular
movement
*called myofilaments in
muscles.
Questions 74-104
?
Nucleus: “Kernel”




Control center of cell
Largest thing in cell
Primary function is
protein synthesis
Contains DNA and
RNA
Spherical
Located near center
A. Nuclear Membrane
Surrounds nucleus
Selectively permeable
Double lipid bilayer
*Contains pores which
allows movement of
molecules produced
during protein synthesis
to pass between
nucleoplasm and
cytoplasm
B. Nucleoplasm
Gel-like sap in
nuclear
membrane.
 Contains nucleoli
(site of ribosome
synthesis) and
chromatin.
C. Nucleolus
Site of RNA
synthesis
Small and spherical
Prominent during
interphase but not
during cell division
 Composed of
protein and RNA
D. Chromatin
In interphase, it appears
as tiny granules.
During cell division, it
starts to organize into
chromosomes which are
composed of a single
DNA molecule. Genes are
segments of DNA
molecules.
 DNA and its genes
control the regulation of
protein synthesis.
Questions 105-130
Wkst on the anatomy of the cell.
Followed by quiz on organelles and
nucleus.