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Working in groups of two to four and armed with the definitions just provided in lecture, a
textbook, or another reliable source answer the following questions about the cell (Chapter 4). This
assignment is worth 30 points with the possible points for each question in parenthesis.
1. (10) Draw and label a diagram of the arrangement of the molecules found in a plasma
membrane.
2. (10) Label (or draw onto) the cell figure with the following cellular terms
Membrane Bound Organelles: Nucleus, Nuclear Envelope, Nuclear Pore, Nucleolus,
Chromatin, Endoplasmic Reticulum (rough & smooth), Golgi apparatus, Lysosome, Peroxisome,
Mitochondria, Chloroplast, and Vacuoles (those found in either animal or plant cells).
Non-membrane Bound Organelles: Cytoskeletal elements (microfilaments, intermediate
filaments, & microtubules), Centrioles, free ribosome.
Cellular Extensions: Microvilli, Cilia, and Flagella
3. (10) Fill-in the table to show the function(s) of each labeled part and any uniqueness of the
organelles structure.
1. (10) Structure of a plasma membrane (cell membrane or unit membrane)
The four molecules associated with a cell membrane are a backbone (most plentiful) of
phospholipids organized into a bi-layer with the tails (hydrophobic) of the molecule facing each
other and the heads (hydrophilic) facing outward, proteins which can either span the bi-layer
(called integral) or associate with the inside or outside layer of phospholipids (called peripheral),
cholesterol (Sterols in the picture below) embedded into the bi-layer between the phospholipids,
and carbohydrate (called oligosaccharides or glycolipids below) antennae or labels associated with
the inside or the outside or the proteins or the phospholipids (called glycoproteins or glycolipids,
respectfully).
Go to these sites for really cool looking videos of cell membranes.
http://www.youtube.com/watch?v=moPJkCbKjBs, http://www.youtube.com/watch?v=Pfu1DE9PK2w
http://www.ibiblio.org/virtualcell/textbook/chapter3/cmf1.htm
Biology& 100
Mr. Brumbaugh
1
Class Assignment 4
2. (10) Label this cell with the terms from the above list of membrane and non-membrane bound
organelles plus the cellular extensions.
Go to these sites for information of cell structure and function.
http://www.wiley.com/college/boyer/0470003790/animations/cell_structure/cell_structure.htm
http://www.phschool.com/science/biology_place/biocoach/cells/quiz.html
Lysosome
Peroxisome
Cytoskeletal Elements
Mitochondria
Smooth ER
Nuclear Membrane
or Envelope
Golgi apparatus
Nucleolus
Nucleus with
chromatin
Centrioles
Nuclear Pore
Chloroplast with
grana stacks
Rough ER
Cell Membrane
Microvilli
Free Ribosome
Biology& 100
Mr. Brumbaugh
2
Class Assignment 4
3. (10) Fill in this table with the structure names and their functions from the above list of
membrane and non-membrane bound organelles plus the cellular extensions.
Nucleus
Nuclear Envelope
Nuclear Pore
Nucleolus
Chromatin
roughER
smoothER
Golgi Body
Chloroplast
Mitochondria
Lysosome
Peroxisome
Animal Vacuoles
Plant Vacuoles
Cytoskeleton
Centrioles
Free Ribosome
Microvilli
Biology& 100
Mr. Brumbaugh
A double membrane bound container for DNA in eukaryotic cells to protect the chromatin
(DNA or chromosomal material) molecules.
A double phospholipid bi-layer surrounding or limiting the nucleus to protect from unwanted
entry or exit from the nucleus material that could harm or damage the chromatin.
A protein covered (and extending through the width of the pore) port of entry or exit from the
nucleus.
A site where a type of RNA called rRNA (r=ribosomal) is combined with various proteins to
eventually form a ribosome.
This is another name for the Chromosomal material found within the nucleus of eukaryotic
cells. It can be either bound to histone proteins and unavailable for use by the cell (called
heterochromatim which appears as dark stained material in electron microscope images or
euchromatin appears as diffuse material between the heterochromatin), or remains unbound
and accessible by the cell during normal cell function.
A membrane tubular network that has ribosomes attached to the side of the bi-layer facing the
cytoplasm. This is a site of protein building.
A membrane tubular network that doesn’t have ribosomes attached to the side of the bi-layer
facing the cytoplasm. This is a site where lipids can be constructed, ions can be stored, or
toxins can be broken down.
A series of membrane bound sacs which receive protein (or products) filled packets from the
rER and sER, then processes, modifies, and packages the protein (or products) for shipment.
A triple phospholipid bound structure (inner most membrane called the thylakoid membrane)
that functions in most producing organisms to harvest sunlight and fix the energy into glucose
molecules by using CO2 and H2O as building blocks.
A double phospholipid bound structure with the inner membrane thrown into folds called
cristae. It is designed to break down (via the Kreb’s cycle and the Electron Transport Shuttle)
the products of a process called glycolysis and liberate the energy in the form of ATP.
A membrane bound sac that contains enzymes and is used to fuse with other organelles or
vacuoles and the enzymes destroy the material in the other vacuole. (Big Stuff)
A membrane bound sac that contains enzymes and is used to fuse with toxic chemicals and the
enzymes detoxify the chemicals in the vacuole. These are usually smaller than a Lysosome.
(Small Stuff)
Membrane bound sacs used by cells to store items like lipid, glycogen, or other material or
they can be contractile (can change their shape).
Membrane bound sacs used to store starch (amyloplasts), store water (central) (generates
turgid pressure), or store pigments (chromoplasts in flowers chloroplasts in stems and leaves).
Non-membrane bound cytoplasmic proteins used to help move the entire cell
(microfilaments), move the organelles within the cell (microtubules), or make the cell rigid
(intermediate tubules).
Short barrels of microtubules that are used to a build a spindle fiber apparatus that is used to
separate the chromosomal material during the process of nuclear division of cell division.
Grain like structure consisting of rRNA and protein and functions as the site of protein
construction usually to build protein that is to be used inside the cell.
Short membrane extensions designed to increase the overall surface area of the cell. These
are filled with actin microfilaments which will allow the cell to retract or extend the microvilli
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Class Assignment 4
Cilia
Flagella
Biology& 100
Mr. Brumbaugh
to accommodate function and cellular demands.
Extensions of an internal cellular structure called a basal body that extends from the basal
body but remains covered with the cell membrane. They are designed to beat in unison to
move something (like water or mucous) across the cell surface. Most cells (prokaryotic and
eukaryotic), if they have them, will have many of these on their surface.
Long extension of a basal body also covered with a cell membrane and is designed to move the
entire cell. Most eukaryotic cells, if they have these, have only a few, but prokaryotes can
have multiple flagella at one site or at numerous sites along their cell membrane which extend
from a basalk body through their cell walls and capsules.
4
Class Assignment 4