Download Ch.4 Cell Notes - Milan Area Schools

Cell Organelles and Features
What do all of
the parts do in
a cell?
Plasma (Cell) Membrane
●
●
This surrounds the cell & controls what
moves in and out of the cell like a
gatekeeper
Made of two layers of phospholipids (aka
phospholipid bilayer)
Phospholipid bilayer
has polar heads that
one layer
point out & nonpolar
of lipids
tails that point in Figure 4.3
one layer
of lipids
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Membrane Proteins
Recognition
protein
Receptor
protein
extracellular
environment
lipid bilayer
cytoplasm
Membrane
proteins
act
as
channels
to
move
Protein pump
Protein channel
Protein pump
across bilayer
across bilayer
substances
that can't diffuse
though the
Figure 4.4
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membrane to enter into the cell
Functions of Nucleus
●
●
Keeps the DNA molecules of eukaryotic
cells separated from the organelles in
the cytoplasm
Makes it easier to organize DNA and to
copy it before parent cells divide into
daughter cells
Components of Nucleus
nuclear envelope
nucleoplasm
nucleolus
chromatin
Nuclear Envelope
●
Two outer membranes (lipid bilayers)
●
Innermost surface has DNA attachment sites
●
Allows RNA to move in and out of the nucleus
through nuclear pores
Nuclear pore
bilayer facing cytoplasm
Nuclear envelope
bilayer facing
nucleoplasm
Figure 4.12b
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Mitochondria
●
ATP-producing powerhouses (power
plant of the cell)
●
Membranes form two distinct
compartments
●
ATP-making machinery embedded in
inner mitochondrial membrane
Mitochondrial Origins
●
Mitochondria resemble bacteria
–
Divide on their own
May have evolved from ancient bacteria
that were engulfed but not digested
–
●
Have own DNA, ribosomes
Endoplasmic Reticulum
●
Aka “ER” - acts like a highway in the cell moving
molecules from 1 part to another
●
Extends throughout cytoplasm
●
Two regions
- rough (w/ ribosomes) – manufactures proteins
- smooth (w/o ribosomes) – manufactures lipids
Golgi Body
●
●
●
●
Puts finishing touches on proteins and
lipids that arrive from ER
Packages finished material for shipment to
final destinations
(shipping department of the cell)
Material arrives and leaves in vesicles
budding
vesicle