Download Honors Biology Name Cells Notes, continued… PROKARYOTIC

Honors Biology
Name
Cells Notes, continued…
PROKARYOTIC AND EUKARYOTIC CELLS
Cells either be divided into one of two major categories. Cells can be
A.___________________________________
includes: ___________________
or
B._____________________________________
includes: 1. _______________________
2. ______________________
3. ______________________
4. ______________________
Structural Differences
Prokaryotic
Eukaryotic
1.______________________________________
1._____________________________________
2.______________________________________
2._____________________________________
3.______________________________________
3._____________________________________
4.______________________________________
4._____________________________________
Structural Similarities
1.___________________________________________________________________________________
2.___________________________________________________________________________________
3.___________________________________________________________________________________
4.___________________________________________________________________________________
5.___________________________________________________________________________________
6.___________________________________________________________________________________
Look at the illustrations of these two different types of cells and notice the differences and similarities.
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EUKARYOTIC CELL STRUCTURE
Plasma Membrane (cell membrane)
1. Function
1. ______________________________________________________________________________
2. ___________________________________________________________________________________________
_________________________________________________________________
Other functions of the cell membrane will be discussed under structure.
2. Structure.
1. ______________________________________________________________________________
______________________________________________________________________________
2. ___________________________________________________________________________________________
_________________________________________________________________
The proteins in the membrane can have various functions. Some of these are:
a. ___________________________________________________________________________________________
___________________________________________________________________________________________
____________________________________________________
b. ______________________________________________________________________________
c. ______________________________________________________________________________
Three important factors that determine where molecules will pass across the membrane, either into or out of the cell, are
polarity, charge and size. Decide where the following five substances will pass, and why.
Where it passes through
Polar
Nonpolar
Charged
Bilayer
Protein Pore
Water
Fatty acids
Glucose
Amino Acids
Ions
Steroids
Note: Most molecules other than lipids will need to move through protein channels in order to pass across the membrane.
NOTE: Even though water can pass across the bilayer because it is a very small molecule, most water passes through
channels called aquaporins.
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NOTE: There are other cell membranes in addition to the plasma membrane. These membranes surround or are a part of
many cell organelles. The structure of these membranes is similar to that of the plasma membrane. All of these membranes
are semipermeable, but the specific function will change from organelle to organelle. The reason the function changes is
because the types and amounts of proteins and phospholipids within the membrane will vary.
NOTE: Since prokaryotic cells do not have any intracellular membranes, they must use their plasma membrane for any
chemical reactions that require a membrane surface. An example would be the chemical reactions of cell respiration that
occur on the mitochondrial cristae membrane of eukaryotes must occur on the plasma membrane of some prokaryotes
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Cell Communication
Messenger molecules like hormones can be secreted from 1 cell into
the body and travel to other cell via the blood stream. Messenger
molecules allow cells to communicate with each other. In this
diagram the hormone is “telling” cell 2 to produce a new protein
Cells communicate with each other by way of hormones or other messenger
molecules binding to receptors of other cells
Steps of cellular communication
1. Hormone binds to receptor (on
cell 2) and the receptor changes
shape (shown as 1).
2. Receptor with new shape can
now bind to another protein (2) it
couldn’t bind to before.
3. The #2 protein then changes
shape and can bind to #3 protein
that it couldn’t bind before.
4. This domino effect continues
until a transcription factor (TF)
changes shape and can bind to the
promoter of a specific gene.
5. The gene is then transcribed by
RNA polymerase and translation
will produce the new protein.
The new protein can then change
the function of cell 2 in some way
(Ex: enzyme) or it can be secreted
from cell 2 and carry a message to
another cell. (Ex: pancreas cell
produces and secretes insulin)
Note: This is just one example of how transcription factors get activated so
they can turn on genes. Sometimes the signal or message does not have to
come from outside the cell, it can come from inside the cell.
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Cell Wall
A. Structure and Function
1. _______________________________________________
2. _______________________________________________
Organisms that contain cell walls:
__________________________________________________________________________________________________
________________________________________________________________________
Cytoplasm
A. Structure
1. _______________________________________________________________________________
______________________________________________________________________________________________
____________________________________________________________________
B. Function
1. _______________________________________________________________________________
2. _______________________________________________________________________________
_________________________________________________________________________________
Microfilaments and Microtubules (microtubules make up centrioles, flagella, cilia, spindle fibers … Cytoskeleton
contain both microfilaments and microtubules )
Microfilaments:
1. _______________________________________________________________________________
2. _______________________________________________________________________________
Microtubules:
1. ___________________________________________________________________________________________
_________________________________________________________________
2. ______________________________________________________________________________
Many cell structures are made from microfilaments and microtubules. One of them is the cytoskeleton that we will
examine now. The other structures we will look at later in the unit.
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Cytoskeleton
A. Structure
1. _______________________________________________________________________________
_________________________________________________________________________________
2.________________________________________________________________________________
_________________________________________________________________________________
B. Function
1. _______________________________________________________________________________
2. _______________________________________________________________________________
_________________________________________________________________________________
Nucleus
A. Structure
1. _______________________________________________________________________________
_________________________________________________________________________________
2.________________________________________________________________________________
3. _______________________________________________________________________________
4. nucleolus: ______________________________________________________________________
______________________________________________________________________________________________
______________________________________________________________________________________________
_______________________________________________________
B. Function
1. _______________________________________________________________________________
_________________________________________________________________________________
2. _______________________________________________________________________________
_________________________________________________________________________________
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Endoplasmic Reticulum (ER)
A. Structure
1. _______________________________________________________________________________
_________________________________________________________________________________
2. _______________________________________________________________________________
B. General Functions
1. _______________________________________________________________________________
2. _______________________________________________________________________________
_________________________________________________________________________________
3.________________________________________________________________________________
Specific Functions of the RER and SER
RER 1.___________________________________________________________________________
2.___________________________________________________________________________
SER 1.___________________________________________________________________________
2.___________________________________________________________________________
Vesicle
A. Structure
1. _______________________________________________________________________________
_________________________________________________________________________________
B. Function
1. _______________________________________________________________________________
Ribosomes
A. Structure
1. _______________________________________________________________________________
_________________________________________________________________________________
2. _______________________________________________________________________________
B. Function
1. _______________________________________________________________________________
Ribosomes can be found either:
a. _____________________________________ b. ________________________________________
Some proteins need to be translated on free ribosomes, and some need to be translated on bound ribosomes. The
differences will be discussed later.
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Ribosome Production
In order to produce a ribosome you need to produce rRNA and ribosomal proteins.






Ribosome Production diagram
True or False? “You need a ribosome to make a ribosome”. Explain your answer.
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Golgi Apparatus (Golgi Bodies)
A. Structure
1. _______________________________________________________________________________
_________________________________________________________________________________
B. Function
1. _______________________________________________________________________________
_________________________________________________________________________________
2. _______________________________________________________________________________
_________________________________________________________________________________
a. _______________________________________________________________________________
b. _______________________________________________________________________________
c. _______________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
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Lysosomes
A. Structure
1. _______________________________________________________________________________
______________________________________________________________________________________________
____________________________________________________________________
Enzymes in the lysosome require an acidic pH (~5) for optimal activity. The membrane of the lysosome helps to
provide a separate, optimal environment for the enzymes and protects the contents of the cytoplasm from the
enzymes’ action.
B. Function
1. _______________________________________________________________________________
______________________________________________________________________________________________
____________________________________________________________________
2. _______________________________________________________________________________
_________________________________________________________________________________
3. _______________________________________________________________________________
_________________________________________________________________________________
Cells that contain lysosomes
a. ____________________________________________________________________________
b. ____________________________________________________________________________
Tay-Sachs Disease
___________________________________________________________________________________________
_________________________________________________________________
______________________________________________________________________________
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Proteins produced at the free floating ribosomes and those produced at the ribosomes on the RER have different
functions. The following diagram shows how the various organelles of the cell function together to produce proteins that
need to be secreted out of the cell (secretory proteins). It will include coding of, production, refinement, packaging, and
transport of a secretory protein.
Note: Notice the relationship among the different membranes within the cell. Although each membrane has a unique
arrangement of lipids and proteins to suit its function, these membranes are related through direct physical contact, or
through the transfer of membrane-bound vesicles. The latter occurs by the pinching off (budding) of a section of
membrane (vesicle), and its later fusing with the membrane of another organelle, or the plasma membrane. Membrane
structures can fuse with each other because they are made of similar material.
ENDOMEMBRANE SYSTEM OF A EUKARYOTIC CELL
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Differences between the production of a secretory protein, lysosomal enzymes, and membrane proteins such as
receptors or channels on the plasma membrane or on organelle membranes
Proteins produced at ribosomes on the rough ER and Golgi
Secretory, lysosomal enzymes, and membrane proteins are produced by the following steps because they are
usually used in cells other than those in which they are produced.
• Translated on the ribosomes, modified on the rough ER and Golgi
• Secretory proteins (messenger molecules, antibodies)
• Lysosomal enzymes
• Membrane proteins (channel proteins, enzymes, receptors)
Proteins produced at free floating ribosomes
The proteins produced at free floating ribosomes are modified in the cytoplasm and are primarily used right in
the cell in which they are produced.
• Translated on free floating ribosomes, modified by enzymes in the cytosol
• RNA polymerase, DNA polymerase
• Transcription factors
• Proteins in microtubules and microfilaments
Steps in the Production, Modification, Transport, and Sorting of a Secretory Protein
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
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11.
12.
These are the 3 possible products of the EMS (Endomembrane system) of the cell:
1. Secretory Protein ___________________________________________________________________
_____________________________________________________________________________________
2. Lysosomal Enzyme __________________________________________________________________
_____________________________________________________________________________________
3. Membrane-bound Enzyme ___________________________________________________________
_____________________________________________________________________________________
Notice that all of these proteins are produced on ribosomes that are attached to the ER. This is because they need to be
inside a vesicle, or part of a vesicle membrane at some point in their production. Proteins that are produced on free
ribosomes are usually proteins that are needed within the cytoplasm of the cell. Examples of these types of proteins would
be: cytoplasmic enzymes, and proteins making up microtubules and microfilaments, nuclear enzymes, ribosomal proteins.
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Mitochondria
A. Structure
1. _______________________________________________________________________________
2.________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
3.________________________________________________________________________________
B. Function
1. _______________________________________________________________________________
_________________________________________________________________________________
2. _______________________________________________________________________________
_________________________________________________________________________________
Because of their function, mitochondria are often referred to as the “power houses” of the cell. Most eukaryotic
cells contain mitochondria, but they are especially abundant in animal muscle and liver cells.
Remember that plant cells also contain mitochondria, in addition to chloroplasts. These two organelles have
totally different functions. Many students confuse this issue and think that only animal cells contain mitochondria,
while plant cells contain only chloroplasts.
Chloroplasts
A. Structure
1. _______________________________________________________________________________
2.________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
3. ______________________________________________________________________________
4. ______________________________________________________________________________
B. Function
1. _______________________________________________________________________________
_________________________________________________________________________________
2._____________________________________________________________________________________________
Refer to page 334 in your textbook OR the four-slide PPT
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The Endosymbiosis Hypothesis
The Endosymbiosis Hypothesis helps to explain how eukaryotic organisms with many organelles may have evolved from
less complex prokaryotes. Specifically, it helps to explain how mitochondria and chloroplasts may have evolved. It is
believed that these structures were once free-living prokaryotes that were engulfed by other prokaryotes, and eventually
became unable to live independently. They entered a symbiotic relationship with the organism that engulfed them.
Mitochondria were probably aerobic prokaryotes that later became organelles that were responsible for aerobic respiration
within a larger organism, while chloroplasts were probably photosynthetic prokaryotes that later became organelles
responsible for photosynthesis.
Theory -
Evidence for the Endosymbiosis Hypothesis
Mitochondria and chloroplasts:
__________________________________________________________________________________________________
__________________________________________________________________________________________________
__________________________________________________________________________________________________
__________________________________________________________________________________________________
_________________________________
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A plastid is a type of organelle bound by a double-membrane that is found in plant cells. A chloroplast is one type of
plastid, but there are several others.
Plastids other than chloroplasts:
1. Leucoplast _________________________________________________________________________
2. Chromoplast _______________________________________________________________________
________________________________________________________________________
Vacuoles
A. Structure
1. _______________________________________________________________________________
B. Function
1. _______________________________________________________________________________
Vacuoles can be found in many different organisms, where they have varied functions.
a. Central vacuole in plants ______________________________________________________
______________________________________________________________________________
b. food vacuole in protists ________________________________________________________
______________________________________________________________________________
c. contractile vacuole in protists __________________________________________________
______________________________________________________________________________
Paramecium: are fresh-water
protists. The concentration of
water in their environment is VERY
HIGH. As such, it tends to move
into the body of the paramecium,
where the concentration of water
is LOWER. This is natural diffusion
of water from [high]  [low]
Cilia and Flagella
A. Structure
1. _______________________________________________________________________________
_________________________________________________________________________________
B. Function
1. _______________________________________________________________________________
_________________________________________________________________________________
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Differences between cilia and flagella:
Cilia
_________________________________________
_________________________________________
Cilia are found:
1.________________________________________
__________________________________________
__________________________________________
__________________________________________
2. ________________________________________
__________________________________________
__________________________________________
Flagella
_________________________________________
_________________________________________
Flagella are found:
1. _______________________________________
2. _______________________________________
Note that centrioles are only found in
Centrioles
animal cells.
A. Structure
1. _______________________________________________________________________________
_________________________________________________________________________________
B. Function
1. _______________________________________________________________________________
_________________________________________________________________________________
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COMPARISON OF CELLULAR STRUCTURES
STRUCTURE
Prokaryotes
Protists
Fungi
Plants
Animals
Cell Wall
Cell Membrane
Cytoplasm
Vacuoles
Chloroplasts
Centrioles
Nuclear
Membrane
Nucleolus
Chromosomes
Ribosomes
Mitochondria
ER
Golgi Apparatus
Lysosomes
Microtubules
Cytoskeleton
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How Cells Are Studied
1. Microscopes
A. Compound Light Microscope ___________________________________________
_______________________________________________________________________
Light microscopes use light and class lenses to magnify the image. Although they are very important
tools that are necessary to study cellular structure, they can only magnify the image clearly up to about
2000X. If you want to study cell structure in more detail you must use an electron microscope. This type
of microscope uses electrons instead of light and magnetic lenses instead of glass and can therefore
increase the magnification and clarity of the image.
B. Transmission Electron Microscope _______________________________________
________________________________________________________________________
C. Scanning Electron Microscope __________________________________________
________________________________________________________________________
Micrograph _____________________________________________________________
Microscopes are used to study the stricter of cells, but if you want to learn about the function of the
various cell organelles you have to study their biochemistry and metabolism. In order to do this you
must first isolate the organelles from each other in a process known as cell fractionation
2. Cell Fractionation
1. ______________________________________________________________________
________________________________________________________________________
2. ______________________________________________________________________
________________________________________________________________________
3. ______________________________________________________________________
________________________________________________________________________
Cell Fractionation Animation http://www.sumanasinc.com/webcontent/animations/content/cellfractionation.html
Virtual Microscopy http://micro.magnet.fsu.edu/primer/virtual/virtual.html
University of Delaware Virtual Microscope https://www.udel.edu/biology/ketcham/microscope/
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