7-2 Eukaryotic Cell
Structure
Organelles “Little Organs”
Cell Biologists divide eukaryotic cell into 2 parts:
Cytoplasm: portion of
cell outside of nucleus
Nucleus: control
center of the cell
(brain)
Nucleus
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Contains DNA, coded
instructions for making proteins
Nucleus surrounded by nuclear
envelope: nuclear pores that
allow material into and out of
cells
Chromatin: granular material
in nucleus, consists of DNA
bound to protein
During cell division, chromatin
forms chromosomes, contains
genetic info that is passed from
one generation to the next
Nucleolus: small dense region;
assembly of ribosomes begins
Other cell organelles include:
Ribosomes are small RNA particles and
protein that assemble proteins from the coded
instructions that come from the nucleus
The endoplasmic reticulum (ER) acts
like an assembly line, lipid components
of cell membrane assembled here
Rough ER is coated with ribosome
and involved in synthesis of
proteins to be exported
Smooth ER has no ribosomes,
contains enzymes that perform
special tasks (makes lipid
membranes, detoxifies drugs)
Proteins produced in rough
ER move to the golgi next
The golgi apparatus modifies,
sorts, and packages protein/other
materials from the ER for storage
in the cell/secretion out of cell
Proteins have their finishing
touches here then are shipped
to their final destination
throughout the cell or outside
of the cell
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Lysosomes: clean up crew, filled
with enzymes
Digest/breakdown lipids, carbs,
protein to be used by rest of cell
Also breakdown organelles that
have outlived their lives
Eliminate junk so there is no clutter
within the cell
Vacuoles: saclike structures for
storage (water, salt, protein, carb)
Plants able to support
leaves/flowers
Control of water within
Paramecium- homeostasis
Mitochondria convert chemical energy in food into
energy compounds for the cell
Contain their own
DNA
Comes from
the egg, ovum
(from Mom)
Cytoskeletons function as support, aid in
cell division, and carry out cell movement
Microfilaments: made of actin; supports the cell and helps it move
Microtubules: made of tubulins;
maintain cell shape; help in
division by separating
chromosomes; helps build cilia
and flagella that help cells to swim
Centrioles: located near nucleus
to help organize cell division only
in animal cells
Structures found in
plant cells
Central vacuoles for storage (can
also be found in animal cells, but are smaller)
Chloroplast capture suns energy
and converts into chemical energy
for the plant (photosynthesis),
contains chlorophyll and own DNA
Plants have cell walls made of cellulose
Fungi have cell walls made of chitin
Cell walls for support & protection
You will not find cell walls in
animal cells
Cell diagrams
H. ribosomes
I. membrane
J. cell wall
K. nucleus
D. nucleolus
L. membrane
E. nuclear envelope
M. rough ER
A. rough ER
N. chloroplast
G. golgi apparatus
B. centrioles
C. smooth ER
O. vacuole
F. mitochondria