Download Cell Structures and Functions, Microscopy, and - Parkway C-2

Biology Test #3 Notes: Cell Structures, Functions, and Membrane Transport
I. Cell Theory (data gathered over a 200 year period by several scientists)

All living things are made up of at least one cell.

The cell is the basic/smallest unit of structure and function in living things (the bricks of buildings).

_____________________________________________________________________________

In 1665, Robert Hooke was the 1st to see and name the cell from cork found in plants using a ______________.

In 1676 Anton Von Leeuwenhoek was the 1 st to view a _______________ _____________.

Robert Brown in 1831 was the 1st to see and name the _______________ of a cell.
Why did it take more than 160 years for Brown to view the nucleus after Leeuwenhoek’s discovery?
II. Types of Cells
A) Prokaryote - Cells lacking membranes around organelles (no nucleus).
Kingdoms: _________________ , ___________________ (Monera)
B) Eukaryote – Cells having membranes around their organelles (with nucleus).
Kingdoms: ________________, ________________, ________________, __________________
II. Cell Shape & Function, Size Limitations, and Cell Types
A. Cell Shape
 The cell is the smallest living portion of any organism, unicellular
(one-celled) or multicellular (many-celled). In a multicelled organism,
like a human, there can be over 200 different types of cells, trillions in all.
3 characteristics determine a cell’s function:
a)
b)
c)
 In multi-celled organisms, individual cells may specialize. Specialized
cells perform a limited amount of jobs.
Advantage of Cell Specialization – Increased ____________________
(_____________________________________________________).
Disadvantage of Cell Specialization – Increased __________________
(_____________________________________________________).
B. Cell Size Limitations:
 If a cell gets too large, the distance between the nucleus (containing DNA which controls protein synthesis) and
other organelles becomes too great for effective control and communication.
 As a cell grows, its surface area (cell membrane) grows at a slower rate than its volume (organelles, cytoplasm, &
nucleus).
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For simplicity, in this surface area:volume ratio example, let’s assume that a particular cell type is cube-shaped. If
this cube-shaped cell has 1cm sides, its surface area (# of sides [length x width]) = 6, and its volume (L x W x H) = 1.
The SA/V ratio is 6/1 = 6. Complete the data table below and compare the surface area to volume ratio of cells of
varying size. Use a calculator to give a decimal answer. An example of a round cell is just below the data table you
are completing.
Side Size (cm)
1
Surface Area (cm2)
Volume (cm3)
Surface/Volume Ratio
2
4
Why is surface area so important?
III. Parts of a Cell and Their Generalized Functions (3 general areas – cell membrane, cytoplasm w/organelles,
and the nucleus)
1. Cell Membrane – A bilipid structure that is the outermost portion of the cell
Functions include:
(a) A boundary between the cell’s contents and the
environment which regulates what enters and exits
the cell.
Hydrophilic
Head
Hydrophobic
Tail
(b) Communicates with other cells within an organism
or unicellular organisms.
(c) _________________________________________.
(d) It serves as an attachment site for some organelles and near-by cells
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2. Cytoplasm and it’s Organelles- Cytoplasm may also be called the Intra-Cellular Fluid/ICF or Cytosol.
a) Cytoplasm is a viscous fluid made up of water, minerals, organic molecules, and organelles. It is located
between the cell membrane and the nuclear membrane.
b) Organelles, or “little organs”, perform specific functions for the cell (division of labor).
_________________________________________________________________________________________________
1) Ribosome
Site of _______________ _______________ where amino
acids are assembled into proteins using directions from DNA.
_______________________________________________________________________________________________
2) Endoplasmic Reticulum
______________________________________
______________________________________.
 Rough ER
Holds ribosomes (which build proteins) on its outer
membranes. Ex: rER sends enzymes to Golgi to
produce lysosomes for the cell.
 Smooth ER
Makes new membranes for both the cell and its
organelles using lipids, carbohydrates, and proteins.
SER also detoxifies drugs & poisons.
_______________________________________________________________________________________________
3) Golgi Body/Apparatus
Builds carbohydrates from monosaccharides and
packages molecules such as proteins by ________
_____________________________________.
The molecules built by the Golgi are then sent
elsewhere in the cell or out of the cell. When
digestive enzymes (sent from the rER) are packed
in membrane bound vesicles, they become
lysosomes.
_______________________________________________________________________________________________
4) Mitochondria
Site of ________________ ________________
Oxygen is used to break down sugar to release
energy for the cell to use to build proteins in the
ribosome, make membranes in the ER, and
transport molecules in and out of the cell.
Mitochondria have their own ______________.
_______________________________________________________________________________________________
5) Lysosome
Holds digestive enzymes that break down old cell
parts, nutrients, and foreign substances (toxins,
bacteria, viruses, etc.). Found in animal cells but
not plant cells.
_______________________________________________________________________________________________
6) Cytoskeleton
An arrangement of structural proteins giving the
cell shape and support. The cytoskeleton is made
of many proteins. You will only be responsible for
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microfilaments and microtubules.
______________________________________
______________________________________
_______________________________________________________________________________________________
7) Centrioles
Organize spindle fibers during cell division so that
all cell parts get divided equally into two new cells.
______________________________________
They are found in the cytoplasm of most
eukaryotic cell, but are not found in plant cells.
_______________________________________________________________________________________________
8) Cilia
______, ___________ microtubules on outside of
cell membranes that function in the movement of
some single-celled organisms or the movement
of substances near a cell.
9) Flagella
Large, usually _________ microtubule for the cell
membrane that functions move a cell (sperm tail).
______________________________________________________________________________________________
10) Cell Wall
A tough, supportive and protective covering of
plant cells (made of cellulose), fungal cells (made
of chitin), most bacteria, and some protists. The
cell wall is located outside the cell membrane
and allows most molecules to pass.
Not found in animal cells.
_______________________________________________________________________________________________
11) Vacuole
Large storage sacs (proteins, lipids, carbohydrates,
water, colored pigments, and waste). Vacuoles aid
structural support to cells by providing turgor
pressure (water pushing on the cell membrane,
helps maintain cell shape in plant cells).
Found in plant cells but not animal cells.
_______________________________________________________________________________________________
12) Plastids – Storage sac’s holding macromolecules & pigments. Pigments allow photosynthesizers to absorb
light energy .
 Chloroplasts – Green pigmented plastid (filled w/chlorophyl)
that absorbs light. Have their own DNA.
Photosynthesis occurs here when the green
pigment chlorophyll that absorbs light allowing it
to make glucose (photosynthesis). Chloroplasts
have their own DNA.
Found in plant cells, many bacterial cells, many
protist cells, but not in animal or fungal cells.
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
Chromoplasts – Yellow, orange, and red plastids that absorbs light.

Leucoplasts – Nonpigmented plastids that store starch (carbohydrate), proteins, and lipids.
3. Nucleus – Contains genetic information in the form of DNA that codes for biological functions.

Surrounded by the ______________________________ which envelops nucleoplasm that protects DNA.

DNA makes __________. RNA then travels to the cytoplasm to make ___________________. Proteins determine an
organism’s traits.

Contains the ____________________ which makes ribosomes.

Ribosomes (made up mostly of RNA) then travel to the
cytoplasm where most will attach themselves to
_______________ ER.

Only found in Eukaryotic cells, not prokaryotic cells.
Describe the process that occurs as proteins are made and shipped out of the cell, as shown below: ________
_______________________________________________________________________________________
_______________________________________________________________________________________
Cell Structure/Organelle
Found in Prokaryotic Cells?
(Bacteria)
Nucleus
No
Nucleolus
Yes
Ribosomes
Yes
Smooth Endoplasmic Reticulum
No
Rough Endoplasmic Reticulum
No
Golgi Apparatus
No
Mitochondrion
No
Lysosome
No
Cytoskeleton
No
Centrioles
No
Found in Plant Cells?
(Eukaryotic cells)
Found in Animal Cells?
(Eukaryotic cells)
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Cell Wall
Yes
Cell Membrane
Yes
Vacuole
No
Chloroplast
No
IV. Membrane Transport (Active and Passive)
Q: How do cells get important nutrients needed for life such as amino acids to build proteins, nucleotides to
build DNA & RNA, sugars and fats for energy, vitamins, and minerals?

Plants acquire _________________________________________________________________________

Animals acquire _______________________________________________________________________
Once inside the organism, how do these nutrients get inside individual cells?
Just like unicellular organisms (bacteria, yeast, amoeba, etc.) nutrients and gasses must pass through each cell’s
membrane for it to survive. Let’s look at humans for example.

We ingest/eat some food, digest it (break down big food molecules into small molecules or monomers) using
teeth, saliva, stomach, enzymes, etc. until it gets to the intestines.

Once the broken molecules (water, nucleotides, amino acids, monosaccharides, fatty acids, etc.) reach the
intestines, these small molecules will then travel through the walls of the intestine and into our bloodstream.

After the small molecules have been absorbed into our bloodstream, they will be delivered to every living cell in
our bodies through blood vessels called _________________ carrying blood away from the heart,
______________ carry blood toward the heart and ___________________ which are only one cell layer thick
and connect the arteries & veins.

Once the blood (carrying water & nutrients) has entered the very thin (1 cell layer thick) capillaries, the digested
molecules will travel through the capillary membrane into the area around cells. Water and nutrients that leave
the capillaries and move into the area surrounding the cells becomes part of the ECF or ExtraCellular Fluid.

If a cell needs water, glucose, calcium, etc. to carry out its life activities (making proteins, photosynthesis, etc.)
it can get them from the ECF just outside the cell’s membrane.
ECF
ICF
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Sequence of Digestive System (once food has been chewed and moistened with saliva in the mouth)
______________
_____________
stomach
_____________
blood
_________
(throat)
ICF (cells)
Homeostasis – Homeostasis is an organism’s way of maintaining normal function.
Examples include: ______________________________________________________________
- Because cells are the basic unit of structure and function, if they die, the tissues they comprise may
die. If tissues die, organs may fail. If organs fail, the organism can die.
Maintaining the cells internal environment (the fluid that surround cells – ECF/Extra Cellular Fluid)
so the cell has all the raw materials needed to live and function properly is vital to the organism’s
survival.
- Homeostasis must be maintained even under times of stress.
-
Stress includes: ________________, malnutrition, physical exertion, pathogen ____________
(bacteria, viruses, etc.), and temperature ____________________.
-
The ________________of molecules (hormones to be transported to other cells, excess water,
and waste products) from the ICF/IntraCellular Fluid (or Cytoplasm) to the ECF (outside the
cell) is as essential to maintaining homeostasis as the entrance into the cell of molecules
that provide the raw materials and energy needed for biochemical processes.
-
The cell’s membrane structure allows it to be semi- or selectively _____________________,
allowing some, but not all molecules through.
Permeability fluctuates according to the ever changing needs of the cell. For example, if the cell
needs more glucose (sugar), the cell membrane will be more permeable to sugar, allowing more
sugar to enter the cell.
Six things influence the rate of diffusion:
Concentration gradient
Size of molecule involved
Distance the molecule has to travel
Temperature
Solubility of the molecule
Surface area of the membrane over which the molecule can work
1. Passive Transport – The movement of molecules (H20 or solutes) across a cell’s membrane (in or out) from an
area of high concentration to an area of low concentration (also referred to as along the
concentration gradient without the use of _________ to achieve equilibrium. Equilibrium
is an equal concentration of a particular molecule ECF and ICF.
a) Simple Diffusion –is when a small, non-polar molecule passes through a
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lipid bilayer from an area of ______ concentration
to an area of _______ concentration.
In simple diffusion, a hydrophobic molecule (such as CO2, O2 & ethanol)
can move into the hydrophobic region of the membrane without getting rejected.
The cell’s membrane acts as a _______________________
or boundary between areas of differing concentrations.
b) Facilitated Diffusion– The movement of molecules that move through specific channels/holes via proteins
embedded in the cell membrane. ________ _________ (like glucose) or __________
____ (like Na+ or Cl-) require a protein to enter the cell.
Molecules may enter or exit, but only traveling down a gradient, or area of high to low
concentrations. As with simple diffusion, facilitated diffusion occurs with no energy
being used.
c) Osmosis – The movement of ___________ molecules across a cell’s membrane from an area of higher to lower
concentration w/o the use of energy.
As the amount of water increases in the ICF/cytoplasm, so does the pressure is exerts on the
cell membrane. The force of water on the cell
membrane is termed ________________
(or osmotic) pressure.
When turgor pressure is too low the cell wilts \
(plasmolysis) and when turgor pressure is too high
the cell bursts (cytolysis).
Type of Transport
Diffusion
Osmosis
Facilitated Diffusion
Active Transport
Materials Moved
(ex: water & minerals)
Direction of movement (example,
High conc. to Low conc.)
Energy Requirements
Q: What determines whether or not a molecule will cross a membrane?
_____________________________________
___________________________________
_____________________________________
___________________________________
* Terminology associated with the movement of molecules across a cell’s membrane *
Hypertonic– The area (ICF or ECF) that possesses a higher concentration of a solute and a lower concentration of
water.
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Hypotonic – The area (ICF or ECF) that possesses a lower concentration of a solute and higher concentration of
water.
Isotonic– A condition in which the ICF and the ECF are in equilibrium, or an equal molecule concentration.
_________tonic
_________tonic
ECF =
42% solute
ECF = 42% solute
_________tonic
ECF =
42% solute
ECF = 42% solute
ECF = 42% solute
Indicate, using red arrows, the direction solute molecules are moving (diffusion) in each of the cells above.
Indicate, using blue arrows, the direction water molecules are moving (osmosis) in each of the cells above
2. Active Transport – The movement of molecules from an
area of lower concentration to an area
of higher concentration. To move
molecules against the concentration
gradient, cellular energy is needed (ATP).
a) Endocytosis – The movement of substances into a cell by
being surrounded/engulfed by the cell’s
membrane.
 Phagocytosis – Endocytosis of a large molecule
or small unicellular organism.
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 Pinocytosis – Endocytosis of large quantities
of fluids or dissolved substances.
b) Exocytosis – Movement of large molecules or quantities
of fluids/dissolved substances out of the cell.
Biology Test #3 Format: Cell Structures & Functions, and Cell Membrane Transport
I. Multiple Choice







What are the points of the cell theory? (p. 1)
Characteristics that determine the function(s) of a cell (1)
Distinguish between prokaryotic and eukaryotic cells (1)
What are the functions of the cell membrane? (2)
What are the characteristics of the cell membrane (structure, macromolecules)? (2)
Describe the pathway that proteins take, from being made to their exit out of the cell? (5)
What is the main function of the organelles (p. 2-5)
Transport (Types, concentration gradient – Notes pages (7-9)
o
What is the pathway that nutrients follow to get from your food to your cells? (6)
o
Distinguish between three types of passive transport (similarities & differences)? (6)
o
What direction do molecules move without requiring energy? (7)
o
When is ATP/energy required for movement of molecules? (8)
o
What is the result when a cell is placed in a hypotonic environment? Hypertonic? Isotonic? (8)
o
Exocytosis v. Endocytosis (9)
Constructed Response: Complete with the best possible answer

Discuss in sentence format, a positive and negative aspect of “Cell Specialization”.

Be able to discuss which organelles are found exclusively in plant cells and which can be found in both plant and animal cells.

Draw and label a segment of a cell/plasma membrane that contains the following:
protein channel
hydrophobic tail
hydrophilic head
ECF
ICF

Discuss, in sentence format, the process that occurs as proteins are made and shipped out of the cell.

Do all cells have the same number of individual organelles? Explain.

Describe what is occurring during an experiment regarding diffusion or osmosis.

What organelle produces glucose?
What organelle converts glucose into a different form of energy?

Create a graph of the % change in mass per gram of grapes and using the following information. Analyze data from the graph
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