Cell Organelles and their Functions
Chapter 4 Section 2
1. Cell Membrane
Structure Function
• Separates the cell from
• A lipid bilayer its environment
around the cell that • Secretes materials out
contains proteins of the cell
and other markers • A selectively permeable
membrane that
recognizes friendly and
enemy objects and
allows some materials
to enter
2. Mitochondria
Structure
• Large organelles that
contain their own DNA
• Has a double
membrane: a smooth
outer membrane and
very folded inner
membrane (cristae)
2. Mitochondria
Function
• Releases energy in “food” into a form
the cell can use which is called ATP
(cellular respiration)
• Parts of the body that use a lot of
energy will have a lot of mitochondria
(muscle cells)
• Because the mitochondria has its own
DNA, it can reproduce itself.
3. Ribosomes
Structure Function
• Each cell has 1000’s • Protein Synthesis
of ribosomes which
are little spheres
• A ribosome contains
a protein connected
to some RNA.
Ribosomes don’t
have membranes • What is the function of
nucleic acids?
4. Endoplasmic Reticulum ER
Structure
• A membrane system of
folded sacs and tunnels
• When it is covered with lots
of ribosomes= rough ER
• When it lacks ribosomes=
smooth ER
4. Endoplasmic Reticulum ER
Function
• The place where the ribosomes
assembles their proteins
• Intercellular highways (where
materials can move from one
part of the cell to another.
5. Golgi Apparatus
Structure Function
• A system of • Modifies the
flattened sacs & proteins made in the
membranes that ER so they can be
emerge from the ER put into packages
and exported from
the cell
6. Vesicles
Structure
• Little sacs that emerge
from the Golgi
apparatus
Function
• The transport packages
of materials within the
cell
7. Lysosomes
Structure Function
• A sac of very strong • Used to digest food
enzymes in a double molecules and invaders of
membrane the cell
• Common in animal, • Sometime used to “self
fungi and protist destruct” cells suicide sacs
cells, but are rare in
plant cells
8. Nuclear Membrane or
nuclear envelop
Structure Function
• A double membrane • Holds the DNA safe
inside the cell
• Has holes called • Controls what enters
nuclear pores and leaves the
nucleus
9. Nucleolus
Structure Function
• A spherical body in • Makes the ribosomes
the nucleus
10. Chromatin
Structure Function
• A fine strand of DNA • Contains all the
coiled around information for
proteins making proteins
• Is the inherited
information that is
given to the
offspring during
reproduction
11. Chromosomes
Structure Function
• Chromatin that is • Same as chromatid
coiled up tightly except that it is coiled
during cell division up tightly so that it can
be separated cleanly
into the two daughter
cells
12. Microfilaments
Structure Function
• Long threads of • Used when the cell
protein called actin moves and when a
muscle cell contracts
13. Microtubules
Structure Function
• Long, slender tubes • Gives structure to
of protein the cell so it doesn’t
collapse on itself
• During cell division,
microtubules are
used to pull apart
the chromosomes
into the new
daughter cells
14. Cilia
Function
• The cilia beat in unison or
in waves. Cilia are used to
Structure move cells
– e.g. paramecium
• Short, “hair-like”
• Cilia move mucus or fluids
structures that
– e.g. over the cells of human
emerge from the cell trachea and lungs
membrane – Female reproductive system
• A cell may have
1000’s
15. Flagellum
Structure Function
• A long “whip-like” • Whip back and forth
structure that to move a cell
emerges from the through fluid (e.g.
cell membrane sperm or Euglena)
• A cell has only 1-2
flagella
16. Cell Wall
Structure Function
• A rigid covering of: • Gives the cell an
– Cellulose in plants or internal structure so it
peptido-glycan in doesn’t collapse on
bacteria or chitin in itself
fungi
What does an animal cell
have to not collapse?
17. Vacuoles
Structure Function
• An empty sac is • Contains one of
usually large in these materials:
plants • Water, enzymes,
food particles, or
waste
18. Plastids
Structure Function
• Have a double • A chloroplast
membrane and their contains thylakoids
own DNA which absorb solar
• Some plastids have energy. Then
thylakoids which converts it into
contain pigments
chemical energy.
• Thylakoids look like “makes food”
stacks of pancakes
19. Centrioles
Structure Function
• Pair of small • Function in cell
cylindrical bodies division
located near the
nucleus