Download Cellular Organelles

Cells
Chapter 5
Cell Theory

1. All organisms are made up of
one or more cells and the products
of those cells:




May be single cell
May be many celled
2. All cells carry on life activities
3. New cells arise only from other
living cells by the process of cell
division
Attributes of Cells
A. Plasma or Cell membrane
B. DNA
C. Cytoplasm
D. Obtain energy and nutrients
from their environment
Plasma or Cell Membrane




Thin, flexible barrier around the cell,
selectively permeable
Controls movement in & out of cells
Lipid bilayer (double layer)
Contains many proteins that cut
through the membrane & proteins that
lay on its surface
Cytoplasm



Jelly-like substance
fills inside of cells
Holds the
organelles
Location for
chemical reactions
Cell types
Prokaryotic—very small,
no nucleus, scattered
DNA, ribosomes
Eukaryotic—larger,
nucleus with
chromosomes/DNA,
membranous organelles
Prokaryotic Cells




Have no membrane-bound
organelles
Include true bacteria
On earth 3.8 million years
Found nearly everywhere


Spores of bacteria in each
breath; intestines
Naturally in soil, air, hot
springs
nucleoid (DNA)
ribosomes
food granule
prokaryotic
flagellum
plasma membrane
cytoplasm
cell wall
Eukaryotic Cells



Nucleus
Have specialized membrane bound
structures called organelles
Various types & forms found in:


Plants, animals, fungi, protists
Multicellular organisms have specialized
cells
nuclear pore
chromatin (DNA)
nucleus
nucleolus
nuclear envelope
flagellum
rough endoplasmic
reticulum
cytoplasm
plasma
membrane
ribosome
lysosome
microtubules
smooth endoplasmic
reticulum
Golgi
Bodies
free ribosome
vesicle
mitochondrion
vesicle
microtubules
(part of cytoskeleton)
mitochondrion
chloroplast
Golgi Bodies
central vacuole
smooth endoplasmic
reticulum
vesicle
cell wall
rough endoplasmic
reticulum
Cell
membrane
nucleolus
nucleus nuclear pore
chromatin
nuclear envelope
ribosomes
free ribosome
Eukaryotic cell structure

Nucleus is “control center” of the cell



1. Membrane bound (nuclear envelope
with nuclear pores)
2. Contains Chromosomes which are
composed of DNA and proteins
3. Contains nucleolus- produces
ribosomes
nuclear
envelope
nucleolus
nuclear
pores
Chromatin/
Chromosomes
nucleus
nuclear
pores
chromatin
chromosome
Eukaryotic cell structure
Organelles
1.
2.
3.
Endoplasmic reticulum consists of folded
membranes attached to the nucleus
Rough ER is covered with ribosomes
E.R. are involved in transport of
materials throughout cell
rough endoplasmic reticulum
ribosomes
0.5 micrometers
smooth endoplasmic reticulum
0.5 micrometers
vesicles
Eukaryotic Cell Structure
Organelles (cont.)
1. Ribosomes assemble amino acid into
2.
polypeptide chains i.e. protein synthesis
Can be found attached to the E.R. or
floating freely in the cytoplasm
ribosomes
rough endoplasmic reticulum
0.5 micrometers
Eukaryotic Cell Structure

Organelles (cont.)
1.
2.
Golgi Bodies are membranous sacs
associated with ER
Process, package, sort, in vesicles,
substances synthesized by the cell
for transport (secretion) out of the
cell
vesicles
from ER
vesicles
leaving
Golgi
Bodies
Golgi
Bodies
Eukaryotic cell structure
Organelles (cont.)
1.
2.
3.
Lysosomes (suicide sac) are Golgi-derived
vesicles containing digestive enzymes
Enzymes may be secreted or may be used
in a food vacuole to digest food in the cell
Breaks down old warn-out organelles
(autophagy)
Eukaryotic Cells: Organelles
Energy sources for cell activities
Mitochondria are the sites for cellular
Respiration.
• Provide/releases energy that powers
cellular activities
• Have their own DNA and ribosomes;
self-replicate
5 micrometers
Eukaryotic Cells: Organelles
Chloroplasts—site of photosynthesis

Green—contain chlorophyll pigment

Have their own DNA and ribosomes;
self-replicate

Up to 100 per cell
Cell Wall (Plant cells )


Made of cellulose
Tough, flexible but sometimes fairly
rigid layer (chain link fence)
Cytoskeleton


Network of fibers that organizes
structures and activities within cells
Consists of:
Microtubules
Microfilaments (Actin filaments)
Intermediate filaments
Microtubules




Help maintain
cellular shape
Cell movement
Chromosome
movement during
cell division
Organelle
movement
Microfilaments (Actin filaments)





Help maintain cell
shape
Involved with
changes in cell
shape
Muscle contraction
Cytoplasmic
streaming
Division in animal
cells (cleavage
furrow)
Intermediate filaments


Help maintain cell
shape
Anchor nucleus
Plant & Animal Cells

Similarities

Both constructed from eukaryotic cells

Both contain similar organelles

Both surrounded by cell membrane
Plant & Animal Cells

Differences


Plants have
 Cell wall – provides strength & rigidity
 Have chloroplasts, photosynthetic
Animals have
 Lysosomes more common than plants
 Centrioles, important in cell division
 Less strength and rigid shape
Brief Look at Viruses



Infectious particle (genes packaged
within a protein coat)
Not considered to be living (cannot
reproduce or carry out metabolism
outside of host cell)
Cause serious diseases in most
organisms
Integrating Cell Structures




In order to understand how
structures relate, you must
understand that all of the processes
performed are CHEMICAL in nature.
Chemical Rxns
Chemical reactions are controlled by
ENZYMES
Each different chemical reaction is
stimulated by a specific enzyme
Integrating Cells cont.


Enzymes are proteins
Some proteins are structural-some
are enzymes
Integrating cont.





Interaction of nucleusribosome
Nucleus is the control
center of the cell-You
already know this much
Now, what does it
control?
It controls the chemical
reactions that occur in
the cell
This is done by
controlling what
enzymes are made at
what time