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2015 Cell Unit Notes
Microscopes
One of the major developments in the field of biology was the invention of the
_____________________. This device provides an ___________ image of a small
object, an object otherwise too small to be seen with an unaided eye. One of the first
microscopes was made by _________________________________. This microscope
only had one lens mounted to a metal support and is known as____________________
microscope. Its total magnification was about 300X.
A short time later, scientists began using the ______________________ microscope,
which is composed of ________ lenses. The strongest of the compound microscopes
is about ___________________ times. The limitation of the compound microscope is
its _____________________ power. The resolving power is the ability of an instrument
to separate and distinguish two objects. Example: Look at the two lines on the side of
your notes. When you are close to them, you can easily tell that they are separate.
When you are far from them, they appear to be one line. At this point, your eye can no
longer resolve the two lines.
The problem of the resolving power of the compound microscope was solved in the
1940’s when the _____________________ microscope was invented. This method
uses a beam of electrons rather than light. The limitation of microscope is that it cannot
be used to study living specimens. The organisms must be sliced very thinly and fixed
with toxic chemicals.
The most recently developed microscope is the __________________
________________ microscope. Specimens do not have to be sliced thin for viewing
so living organisms may be observed. In the images below, the first is a virus viewed
with an electron microscope.The second is a tick’s mouth parts taken with a scanning
electron microscope.
The diagram above illustrates the capabilities and limitations of these microscopes.
Below is a diagram of a compound microscope similar to those that we will be using in
class.
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Modern Cell Theory
All living things are made up of _____________.
Organisms containing only one cell are called __________, while
organisms that are made up of many cells are called
_________________. You are _______________ because you
are made up of _____________ of cells.
Cells were first examined by __________________ in 1665 when he observed cork
under a microscope.
Understanding of the cell increased with the discoveries of the following scientists:
_______________________:discovered the nucleus (1831).
______________________:stated that the cell is the unit of structure in plants (1838).
________________________:cell is the unit of structure in animals (1839).
________________________:all cells come from preexisting cells (1859).
The Modern Cell Theory: *know this*
1.
2.
3.
Cell Structures and Functions Notes
Cells differ in
1. _____________________________________
2. _____________________________________
3. _____________________________________
Internal Organization
_______________: contains _______ which directs the activity of the cell
________________: a cell component that performs specific functions in the cell
_________________: cells that contain a nucleus and membrane-bound organelles
_________________: cells that lack nuclei and membrane-bound organelles
Eukaryotes (______________, _____________, ___________, ____________) and
prokaryotes (______________) differ greatly in structure.
Prokaryotes
Eukaryotes
1 - 10 μm
10 - 50 μm
billion years ago
billion years ago
nucleus?
membrane-bound
organelles?
size
when evolved?
cytoplasm?
cell membrane?
cell wall?
Some Do
ribosomes?
DNA?
examples
Circular
Free Floating
Cells can differ greatly from one another in size and shape. In multicellular organisms, there is
tremendous diversity among cells because they are specialized to perform certain functions.
There is a strong correlation between shape and function. Cells are built a certain way in order
to perform their particular function more efficiently. The organelles inside a cell dictate what the
job of the cell will be.
Each living cell carries out the tasks of __________________, transforming food into
____________, getting rid of _____________, and ____________________.
Cell Structure or Organelle
Description and functions
the outermost living ___________ of animal cells.
______________ the exchange of substances
between the __________ and its environment.
a ______________, non-.living, rigid structure that is
produced by some cells; found outside of the cell
membrane; ________________ and
___________________ the cell; not present in
____________________.
thick __________ filling cell’s interior; location of most
metabolic activity; contains the
____________________
a network of __________ constructed of microtubules
and microfilaments; __________ cell and maintains
_______________.
membrane-bound; controls _______ activities such as
_____________.
outer boundary of _______________; consists of
double membrane containing ___________.
the ___________ material of the cell; in non-dividing
cells they appear as thin, threadlike strands called
_______________________.
spherical structure involved in the synthesis and
assembly of _______________; one or more may
appear in nucleus
Cell Structure or Organelle
Description and functions
the fluid-filled interior of the _______
in which the other parts are suspended
a system of membranous tubules that penetrates
through out the cytoplasm & is continuous with the
nuclear envelope. Intercellular highway (a path along
which molecules move from one part of the cell to
another)
has ___________ attached to it; helps to store and
transport _______
lacks _______________; functions in metabolic
processes including synthesis, storage, and transport
of ______ and carbohydrates w/in cell.
tiny particles floating freely in cytoplasm or attached to
ER; NOT
membrane-bound; aggregates of protein and RNA
molecules; location of
___________________synthesis;
bacteria cell
_________________
human liver cell _______________
stacks of flattened membranous sacs surrounded by
transport vesicles; receives proteins from the rER and
distributes them to other organelles or out of the cell
(receiving, processing, packaging, and shipping)
large oval organelles; double membrane; inner
membrane is _______________ which is folded to
provide increased surface area; involved in production
of ________ as cell ______________ occurs here.
membrane-bound vesicles; formed by pinching off
Golgi apparatus;
contain _______________ enzymes;
digests _______ molecules, invading objects, or worn
out cell ________
________________ cells only
Cell Structure or Part
Description of Functions
use ___________ to break down fats (these molecules
then go to the mitochondria as fuel for respiration);
when in the liver, they detoxify alcohol and other
harmful cmpds; Degrade hydrogen peroxide, a toxic
compound that can be produced during metabolism,
into __________.
large membrane sacs used as _____________
chambers within the cytoplasm;
contain ________ molecules the cell has engulfed or
stored molecules such as lipids, pigments, or wastes;
Animal cells: they are ___________ and small
Plant cells: ________________: one single large
vacuole taking up to _____% available space; contains
mostly ________ & provides internal support
paired cylinders of microtubules @ ____________
angles;
usually near the ______________;
involved in cell division in ___________________ cells
found in _______; contain pigments
colorless plastid; store __________
contain ________________ pigments that give
_____________, flowers, and autumn leaves their hues
green organelles found in plants & other photosynthetic
organisms;
double membrane; interior contains ______________
membranes where the pigment ____________ is
found;
chlorophyll is essential for photosynthesis
Cell Structure or Part
Description of Functions
hair-like organelles that extend from the surface of
cells
–When they are present in large numbers on a cell
they are called _________ ex:
___________________
–When they are less numerous and longer they
are called ___________ex. __________ & algae
for cell motility & to move ____________over
surface
Animal cells are very similar to plant cells except for the following major differences:


Animal cells do not contain _____________________
Animal cells are not surrounded by _______________________
 The vacuoles in ____________ are much larger than those of _____________
Animal cell
Plant Cell
Photosynthesis and Cellular Respiration:
Photosynthesis ___________________TRAPS _________________ AND CHANGES IT INTO
____________________ (sugar); Energy can convert from one form to another.
 Process completed by __________________ (producers that make their own
food) only. Examples- plants, some algae, & some bacteria
 Photosynthesis occurs in the _______________ of the cell in the leaves of the
plant
Photosynthesis Equation-
Light energy + CO2 + H2O
carbon
dioxide
→
C6H12O6 + O2 + H2O
water
glucose
sugar
Reactants
oxygen water
Products
Cellular Respiration

USE CELLULAR RESPIRATION AS A TOOL TO ________________________
(GLUCOSE) INTO _________________ (ATP) THE BODY CAN USE
Cellular respiration occurs in the ____________________ of the cell
Cellular Respiration Equation-
C6H12O6 + O2 + H2O
Glucose
sugar
oxygen
→
water
Reactants
energy + CO2 +
ATP
carbon
dioxide
H2O
water
Products
How are these two processes linked?


Cellular respiration and photosynthesis are linked b/c they’re opposites
The products of photosynthesis are the reactants of cellular respiration
 Remember plants (autotrophs) can do both photosynthesis & cellular respiration
b/c they have chloroplasts and mitochondria while animals (heterotrophs) can
only do cellular respiration because they only have mitochondria and no
chloroplasts
Molecule movement and Cells
_______________________:
All organisms encounter great fluctuations in their environments (change in
______________, ______________, ________________, etc) that cause them to
struggle continuously to maintain a steady state. The process of maintaining a relatively
constant internal environment despite changing external conditions is called
__________________________.
If a cell is to maintain its identity and remain alive, it must maintain an internal
environment that is __________________ from its surroundings. The __________
__________________ separates the chemicals in the cell from those in its environment.
The plasma membrane can be described according to its
________________________________:
1. __________________________: the membrane is impermeable when a
substance cannot pass through.
2. __________________________: the membrane is permeable when a
substance can pass through.
3. __________________________ (semi-permeable): the membrane allows
some substances through while others cannot.
Moving Materials Into and Out of Cells:
Particles move into or out of a cell by passing through the cell’s _________
_________________. _______________ transport is the movement of a substance
through a cell’s membrane ______________ the cell using any ______________.
There are several different types of passive transport:
1. ______________________: A net movement of particles from an area of
_____________ concentration to an area of _______________ concentration. In the
example below, a drop of ink diffuses until it fills the volume uniformly. At this point the
system can be described as being in ______________________. Equilibrium means
that the _______________ of a substance is the same throughout a __________.
Equilibrium
Key terms:
a) ___________: a substance that _______________ in another. Examples:
sugars, amino acids, and ions are solutes in cells.
b) _____________: the more plentiful substance that dissolves the solute; in cells,
the solvent is ________________.
c) ______________: the mixture of solutes and solvent.
d) ______________________________: the difference in concentration of a
substance across a space.
2. The second type of passive transport is __________. Osmosis is simply the
diffusion of water molecules through a ___________ from an area of __________
concentration to an area of ________ concentration.
We are comparing the concentrations of two solutions. ___________ is how the
concentrations of solutes in two solutions compare; determines movement of water into
or out of cells. The comparisons fall into one of three categories:
A. _______________ solution = solute concentration inside and outside cells is
_________. There is ___ net movement of water into or out of cell.
___% water in cell : ___% water out of cell
B. ______________ (low) solution = low in solutes (high in water molecules).
Therefore water moves _______ cell.
______% water in cell (______): _______% water outside cell (________)
C. ________________ (high) solution = high in solutes (low in water molecules).
Therefore water moves ________ cell.
_______% water in cell (_______): ____% water outside cell (________)
In the example below, side B has a higher concentration of water molecules to side A
(side B is hypotonic, side A is hypertonic). Water will move from side B to side A.
Before
After
Above is an example of a human blood cell in the 3 types of solution. Note the cell is
maintaining homeostasis in the isotonic solution. The cell gains water in the
_____________ solution until it has __________ or ruptured. The cell __________ in
the ____________ solution because it loses water.
This second example demonstrates the effect of osmosis on plant cells. In the first
picture, plant cells have been placed in a ___________ solution so that water has
entered the cells. The _____________ keep the cells from rupturing. The pressure
within the cell (_________ _________) is great and the cell is said to be ___________.
The second picture illustrates a plant cell in _____________ solution. _____________
has occurred and the plant is ___________ (low _______________ pressure).
3. The third type of passive transport is ______________ diffusion. In this type of
transport, some molecules such as _____________ is transported across the
membrane from _________ conc. to __________ conc. by a _________________.
The protein is specific in the molecule it can carry.
__________________: ________________ is required to move a material across the
cell membrane ________________ a concentration difference (low to high
concentration).
These are the types of active transport:
1) _______________ pumps: cause the production of ____________ molecules
(the form of energy used by a cell); these pumps transport protons through the internal
plasma membranes of the mitochondria and chloroplasts.
2) ____________________ Pumps and couple channels: Uses the energy of
___________ to power the active transport of sodium (Na+) ions out through a cell’s
membrane and potassium (K) in. This is the most important energy-using process in
your body!!!!! More than 1/3 of all the energy used by a human cell (that is not dividing)
is used to transport sodium ions.
Why? 1) This is how nerve cells send impulses (more later)... and....
2) They help to transport _________ particles and a variety of other particles
into your cells by two different kinds of channels. One is the sodium-potassium pump.
The other channels are coupled channels.
How?
1. Active transport of Na+ out of the cell increases the Na+ concentration
outside the cell (as many as 300 per sec). This increase leads to step 2.
2. Na+ move back into the cell by the coupled channels that also carry
sugar molecules. The coupled channel contains two passageways through the
membrane. The force of the Na+ is so great that it pulls sugar molecules into the cell
too.
How Molecules Cross the Membrane
Active/passive Molecules
that move
Diffusion
direction
Energy
needed
Protein
needed
Osmosis
Facilitated
diffusion
Active
transport
Sometimes food particles are too large to enter through protein channels. In this case,
the cell engulfs the particle by means of ______________. If the material is liquid and
contains dissolved molecules, the endocytosis is called _______________. Human egg
cells receive nourishment via __________________. If the material brought into the
cell is another cell or other fragment of organic matter, the process is called
________________________. Ex: white blood cells, Amoebas.
phagocytosis
pinocytosis
Phagocytosis &
the Amoeba
_________________ is the opposite of endocytosis. This is when the cell
___________________________ waste materials out of the cell.
The Cell Membrane Notes
Cell Membrane Structure
The _________________________________________________ of the cell membrane
shows that it is composed of proteins that are similar to shifting tiles. The spaces
between the tiles are filled with fluid-like ________________________________.
Phospholipids consist of ___________________________ (water-loving) heads, which
point towards the outside environment and the cytoplasm. The
_____________________________________________ repel the water and point in.
Extracellular fluid (watery environment)
Phospholipid
Hydrophobic tails
Memorize cell
membrane
components!
bilayer
Hydrophilic heads
cytoplasm (watery environment)
This causes the phospholipids to form a double layer (bilayer) that acts like a barrier
between the cell and the environment. The ___________________________________
also contains _____________________________, which makes it stronger, more
flexible and more permeable.
The purpose of the membrane is to control what goes in and out of the cell!