UNIT 1 - CHAPTER 3: CELLS
3.1
CELLS ARE THE BASIC UNITS OF THE BODY
The ____________ is the basic unit of structure and function in living things
3.2.
A COMPOSITE CELL
A.
Introduction: A composite cell or typical animal cell contains three major
cell parts including the __________________________, which is the outer
boundary of the cell, the ________________________, which holds the cellular
organelles which perform specific functions of the cell, and the
________________, or control center of the cell. See Fig 3.3, page 87.
B.
Cell Membrane
1.
Membrane Structure = Fluid Mosaic Model
See Fig 3.5, page 89 and Fig 3.6, page 90.
The
cell
membrane
is
composed
of
a
__________________________________ with many protein molecules
dispersed within it.
a.
The surfaces of the membrane are ________________ due to the
polar phosphate heads;
b.
The internal portion of the membrane is _________________ due
to the non-polar fatty acid tails;
c.
The _________________________ also have both hydrophilic and
hydrophobic properties.
C.
_______________________ = the jelly-like fluid (52-70% water) that holds the
cytoplasmic organelles and occupies the space between the nucleus and cell
membrane. It contains abundant protein rods and tubules that form a supportive
framework (i.e. cytoskeleton, see below).
D.
Ribosomes:
1.
2.
3.
E.
small granules dispersed throughout the cytoplasm and on the membranes
of some ____________________________ See Fig 3.8 a and b, page 92.
composed of _________ and ________________
Function = _______________________________
Endoplasmic Reticulum (ER):
1.
See Fig 3.8, page 92.
A network of interconnected parallel membranes (maze), that is
continuous with the nuclear membrane.
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UNIT 1 - CHAPTER 3: CELLS
2.
Two types:
a.
Rough Endoplasmic Reticulum (RER): Fig 3.8a & b, page 92.
o
ER studded with __________________
o
Function = _______________________
b.
Smooth Endoplasmic Reticulum (SER): Fig 3.8c, page 92.
o
lacks ribosomes
o
Function = ____________________________________
F.
_____________________
1.
membrane transport sacs
2.
made by ER and Golgi (see G. below).
G.
Golgi Apparatus (Complex):
1.
2.
3.
See Fig 3.9, page 93.
Description: _________________________________________________
Function = __________________________________________________
Vesicles pinch off as "secretory vesicles", which are transported out of the
cell. See Fig 3.9b, page 93 and Fig 3.10, page 94.
H.
Mitochondria: See Fig 3.11, page 95.
1.
kidney-shaped organelle whose inner membrane is folded into shelf-like
partitions called __________________.
2.
Function = __________________________________________________
I.
Lysosomes: See Fig 3.12, page 95.
1.
spherical membranous sacs containing ___________________________
2. Function = _____________________________________________________
J.
Peroxisomes:
1.
membranous sacs containing ___________________________
2.
Function = __________________________________________________
K.
Other Cellular Structures:
1.
Microfilaments, Microtubules, and Intermediate Filaments
(Cytoskeleton Components): See Fig 3.13 and Fig 3.14, page 97.
a.
Microfilaments
o
tiny rods composed of the protein ___________________
o
form meshworks and bundles
o
compose myofibrils allowing muscle cells to move/contract
b.
Microtubules
o
long, slender rods composed of the globular protein
____________
o
2-3x diameter of microfilaments
o
are rigid and maintain shape of the of the cell (i.e. form
3-2
UNIT 1 - CHAPTER 3: CELLS
o
allow for ______________________
c.
L.
M.
____________________________
o
are composed of several different proteins
o
form dimers entwined into nested, coiled rods
o
Example is keratin proteins in skin which form a strong
inner scaffolding that help cells attach and provide barrier.
Cytoskeleton Components
1.
________________________:
See Fig 3.15, page 98.
a.
pair of microtubules located near the nucleus
b.
aid in movement of chromosomes during mitosis.
2.
Cilia and Flagella
a.
________________________ See Fig 3.16, page 98.
o
short, hair-like cellular extensions (eyelashes)
o
help move substances through passageways
o
located in lining of trachea and fallopian tube
b.
________________________ See Fig 3.17, page 99.
o
tail-like projection
o
only one flagellum per cell in humans
o
aid(s) in cell locomotion
o
Example is sperm cell.
Cell Nucleus = the central core, control center or "brain" of the cell. See Fig 3.18,
page 99.
1.
Largest organelle of the cell (which is filled with nucleoplasm).
3.
Contains three distinct regions:
a.
_________________________ is a double membrane that
separates the contents of the nucleus from the cytoplasm.
o
At various points, these two membranes fuse =
_______________________
o
The nuclear membrane is "selectively permeable"; pores
serve as sites where ______________ can pass out of the
nucleus during protein synthesis, and how ribosomes exit
the nucleus.
b.
Nucleolus = dense spherical body within the nucleus; A cell may
have more than one; pl = nucleoli.
o
composed of _________ and ____________;
o
Function = ____________________
c.
______________________ = loosely coiled fibers of DNA and
histone proteins present in the nucleus.
3-3
UNIT 1 - CHAPTER 3: CELLS
3.2
A COMPOSITE CELL: SUMMARY TABLE OF CELL PARTS
See Table 3.2, page 100 in text and key at the end of the outline.
CELL COMPONENT
DESCRIPTION/
STRUCTURE
FUNCTION(S)
CELL MEMBRANE
CYTOPLASM
RIBOSOMES
ROUGH ENDOPLASMIC
RETICULUM (ER)
SMOOTH ER
GOLGI APPARATUS
VESICLES
MITOCHONDRIA
LYSOSOMES
PEROXISOMES
CENTROSOMES
CILIA
FLAGELLA
MICROVILLI
CYTOSKELETON
OTHER STRUCTURES
NUCLEUS
NUCLEOLUS
CHROMATIN
3-4
UNIT 1 - CHAPTER 3: CELLS
3.3
MOVEMENTS INTO AND OUT OF THE CELL (Membrane Transport)
A.
Introduction: The passage of a substance through the cell membrane may be
physical (passive, requires no energy expenditure) or physiologic (active process,
requires energy expenditure).
1.
2.
B.
In _________________________________, substances move from where
they are in high concentration to where they are in low concentration.
Passive transport processes include diffusion, facilitated diffusion,
osmosis, and filtration.
In _________________________________, substances move from where
they are in low concentration to where they are in high concentration at the
expense of cellular energy (ATP). Active processes include active
transport, endocytosis, exocytosis and transcytosis.
Physical (Passive) Transport Processes (require no energy expenditure):
1.
Diffusion:
a.
Molecules or ions spread spontaneously (up / down) (circle one) a
concentration gradient.
b.
Molecules/Ions will continue to spread until a state of
______________ is reached.
c.
Give an example:
o
______________________________________________
2.
Facilitated Diffusion:
a.
b.
c.
3.
a special case of diffusion.
Molecules or ions spread spontaneously (up / down) (circle one) a
concentration gradient.
How is facilitated diffusion different from regular diffusion?
_____________________________________________________
Osmosis:
a.
b.
c.
See Fig 3.22, page 102.
See Fig 3.23, page 103.
Diffusion of _______________ molecules through a
____________________________________ (i.e. cell membrane),
in an attempt to dilute a particular solute.
Remember that water can pass through the membrane, but the
solute cannot!!!
Osmosis is demonstrated nicely with red blood cells (rbc's) being
placed in solutions of varying tonicity. See Fig 3.24, page 104.
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UNIT 1 - CHAPTER 3: CELLS
o
4.
C.
Three (3) conditions may exist:
1.
Isotonic
a.
Water moves (into / out of / no net
movement) (circle one) the cell
b.
Resulting in: _________________________
2.
Hypertonic
a.
Water moves (into / out of / no net
movement) (circle one) the cell
b.
Resulting in: _________________________
3.
Hypotonic
a.
Water moves (into / out of / no net
movement) (circle one) the cell
b.
Resulting in: _________________________
Filtration:
See Fig 3.25 and Fig 3.26, page 104.
a.
Water and solutes are forced through a body membrane by the
__________________________ of blood (i.e. blood pressure).
b.
Concentration gradient is _________________ to _____________.
Physiologic (Active) Transport Processes (require energy expenditure)
1.
Active Transport: See Fig 3.27, page 105.
a.
Molecules or ions move from an area where they are in
_____________ concentration toward an area where they are in
_____________ concentration at the expense of cellular energy
(i.e. ATP).
2.
Endocytosis
a.
Molecules or particles that are too large to enter the cell by passive
transport or active transport (above) are brought into the cell within
a ______________ formed from a section of the cell membrane.
b.
Examples:
o
_________________ = cell drinking; the cell brings in
liquid droplets which may contain dissolved substances.
See Fig 3.28, page 106.
o
_________________ = cell eating; the cell engulfs and
brings in a solid particle. See Fig 3.29 and Fig 3.30, page
106.
o
Receptor-Mediated Endocytosis =
________________________________________________
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UNIT 1 - CHAPTER 3: CELLS
See Fig 3.31, page 107.
3.
Exocytosis: See Fig 3.32, page 107.
a.
Definition = ___________________________________________
Also see Fig 3.10, page 94.
4.
Transcytosis: See Fig 3.33, page 108.
a.
combines __________________________ with ______________.
b.
Particles travel (through / around) (circle one) the cell from
apical to basal surfaces.
3-7
UNIT 1 - CHAPTER 3: CELLS
MOVEMENTS INTO & OUT OF THE CELL SUMMARY TABLE (Keyed at the end of the
outline)
TRANSPORT
PROCESS
IS ENERGY
REQUIRED?
[ ]
Gradient
GENERAL
DESCRIPTION
EXAMPLE
IN
HUMANS
SIGNIFICANCE
DIFFUSION
FACILITATED
DIFFUSION
OSMOSIS
FILTRATION
ACTIVE
TRANSPORT
ENDOCYTOSIS
EXOCYTOSIS
TRANSCYTOSIS
3-8
UNIT 1 - CHAPTER 3: CELLS
3.4
THE CELL CYCLE
The life cycle of a cell is divided into two major portions that include ________________
and _____________________. Remember that the process of cell division is continuous.
It is only divided into stages for convenience and to help you learn.
See Fig 3.34, page 110, which illustrates the cell cycle as a continuum.
A.
______________________ = cell growth and DNA replication. See Fig 3.35a,
page 111.
1.
Interphase is divided into 3 parts:
a.
_________ = rapid growth and replication of centrioles.
b.
_________ = growth and DNA replication.
c.
_________ = growth and final preparations for cell division.
B.
MITOTIC PHASE (M):
1.
The mitotic phase (M) is divided into 2 parts that include
_______________ and __________________.
a.
Mitosis = division of nuclear parts includes four parts:
o
___________________:
1.
2.
3.
See Fig 3.35b, page 111.
Distinct pairs of ________________ become
apparent.
a.
Chromosomes pairs are composed of
identical ___________________________
held together by centromeres.
_____________________ pairs migrate to opposite
ends of cell, and spindle fibers form between them.
Nuclear
envelope
and
nucleolus
____________________________
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UNIT 1 - CHAPTER 3: CELLS
2.
________________________:
See Fig 3.35c, page 111.
o
Chromosomes line up in an orderly fashion midway
between the centrioles (i.e. along equatorial plate).
o
Centromere holding chromosome together attaches to
spindle fiber between centrioles.
3.
______________________:
See Fig 3.35d, page 111.
o
Centromere holding chromosome pair together splits/
separates.
o
Individual chromosomes migrate in opposite directions on
spindle fibers toward polar centrioles.
o
cytokinesis begins.
4.
_______________________:
o
o
o
o
o
b.
See Fig 3.35e, page 111.
Chromosomes complete migration toward centrioles.
Nuclear envelope develops around each set
chromosomes.
Nucleoli develop and reappear.
Spindle fibers disintegrate.
Cleavage furrow is nearly complete.
of
Cytoplasmic Division (Cytokinesis; forming of 2 daughter cells)
1.
begins during ____________________, when the cell membrane
begins to constrict (pinch) around daughter cells.
2.
is completed at the end of ___________________ when nuclei and
cytoplasm of two newly formed daughter cells (in interphase) are
completely separated by cleavage furrow.
3.
See Fig 3.36c, page 112.
* See Table 3.4, page 110, Major Events in Mitosis.
* See Figure 3.36, page 112, to observe scanning electron micrographs of cell division.
3-10
UNIT 1 - CHAPTER 3: CELLS
3.4
THE CELL CYCLE: See Table 3.4, page 110 and key at end of this outline.
NAME OF PHASE
DESCRIPTION OF
EVENTS
TYPICAL SKETCH
INTERPHASE
PROPHASE
METAPHASE
ANAPHASE
TELOPHASE
3-11
UNIT 1 - CHAPTER 3: CELLS
3.5
CONTROL OF CELL DIVISION
A.
Significance of cell division: _________________________________________
B.
Length of the Cell Cycle
1.
2.
3.
C.
3.6
3.7
varies with cell type, location, and temperature
Average times are 19-26 hrs.
______________, __________________, and ___________________ do
not reproduce.
Abnormal Cell Division (CANCER) See Table 3.5 page 113.
1.
When cell division occurs with no control (goes awry), a ____________
results.
2.
A ___________________ tumor is a cancerous growth; a non-cancerous
tumor is a _________________ tumor;
a.
Malignant tumors may spread by metastasis to other tissues by
direct invasion, or through the bloodstream or lymphatic system.
STEM AND PROGENITOR CELLS: See Fig 3.39, page 115.
Allow for continued growth and renewal of cells
A.
______________ cell
1.
divides by mitosis to yield another stem cell and
2.
a partially differentiated progenitor cell.
B.
_________________ cell
1.
committed to a specific cell line
C.
D.
E.
____________________ cells – can become any cell type.
____________________ cells – can become many cell types, but not all.
_____________________ is the process of specializing cell types. It
occurs due to gene activation.
CELL DEATH
A.
___________________ = programmed cell death; a fast, orderly contained
destruction that packages cellular remnants into membrane-enclosed pieces that
are then removed.
B.
___________________ = disordered form of cell death associated with
inflammation and injury.
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UNIT 1 - CHAPTER 3: CELLS
3-13