Name: ________________________________
Date: ____________________
Unit 3C Cell Structure and Function
Notes
2 Main Categories of Cells
1. Prokaryotic Cells- DO NOT have “______________________________”
organelles and DO NOT have a ______________________ to hold the DNA
Prok examples: ______________________ (Eubacteria, Archaebacteria)
2. Eukaryotic Cells- contain membrane bound organelles including a nucleus to
hold the DNA
Euk examples: _____________________ (paramecium/ amoeba),
________________ (mushrooms/ yeast), Plants, Animals
Cell Characteristics
Prokaryotic Cell
Eukaryotic Cell
Differences and
Similarities between the
Two Cell Types:
Outer Cell Membrane
Cytoplasm-Cell Fluid
(+ present, - absent)
Ribosome (structures
which form proteins)
Nucleus
Chromosomes
(DNA/RNA)
Membrane Bound
Organelles
Average Size of Cells
Time of Evolution
1-10 μm
2-1000 μm and
larger
3.5 Billion Years
Ago
1.5 Billion Years
Ago
Spherical, rodshaped, spiral
Variety depending
on function
Organisms Exhibiting
this type of Cell
General Shape of the
Cell
1
Personal Notes/Summary:
Eukaryotes
•
Are organisms that have eukaryotic cells (prokaryotes do not)
•
Examples: animals, plants, fungi, protists
•
We will mainly be discussing the parts of eukaryotic cells and comparing prokaryotic and eukaryotic
cells to each other.
Cell Organization
The Nucleus (Euk only)
1. Controls all of the cell’s activities because it…
2. Contains and protects the ______________
3. Surrounded by the nuclear envelope ______________ lipid bilayer with pores that regulates what
enters/exits the nucleus
4. Contains the nucleolus area of the nucleus that makes _______________________
Cytoplasm- the portion of the cell outside of the nucleus
•
Found in both prok and euk
•
Contains an aqueous solution called _____________ containing solutes needed for metabolic reactions
•
Contains the ____________________________ (in euk)
Shade in the region
showing the cytoplasm
Shade in the region
showing the cytosol
Organelles- specialized structures inside the cell (“Little Organs”)
•
Mostly found in the cytoplasm
•
If membrane-bound (surrounded by a membrane)- only found in euk
2
Personal Notes/Summary:
Organelles and Cell Structures
•
The following slides discuss the organelles of a cell, they fall into the following categories:
1. Cellular boundaries
2. Organelles that capture and release energy
3. Organelles that store, clean up, and support
4. Organelles that build proteins
1. Cellular Boundaries
Boundaries keep certain things inside and certain things outside of the cell.
• Cell Walls and Cell Membranes
A. Cell Walls
•
Support, shape, and protect the cell
•
Lie ___________________ the cell membrane
•
Have openings allowing small molecules in and out (semipermeable, not selectively permeable).
•
Found in most prokaryotes, many eukaryotes (protists, fungi, and plant cells), but NOT in animal cells
– Why not?
__________________________________________________________________________________
Cell Wall Composition
– In bacteria- contains various carbohydrates
– In protists- carbs and silica (SiO2)
– In fungi- chitin (a type of carb)
– In Plants- mostly ______________________ (polysaccharide made of glucose monomers)
3
Personal Notes/Summary:
B. Cell (or Plasma) Membranes
•
Found surrounding all cells (prok or euk)
•
Made of a __________________________________
•
Protects and supports the cell
•
Regulates what comes in and out of the cell- selectively permeable
The Fluid Mosaic Model
•
Flexible and contains many transport proteins that help move materials in and out and help cells
communicate.
•
Carbs on the outer surface help with communication and identification of the cell.
2. Organelles that Capture and Release Energy
Are membrane-bound and thus found in eukaryotic cells only
• Chloroplasts- found in plant cells; are the location of ____________________________
• Mitochondria- found in _____________ plant and animal cells; location of energy production (_________)
A. Chloroplasts and Photosynthesis
•
Contain a ________________ colored pigment called chlorophyll which captures ______________
energy to power photosynthesis
•
Have ______________ membranes (inner and outer).
•
Contain a fluid called stroma, stacks called granna of folded structures called thylakoids surrounded by
thylakoid membranes.
•
Photosynthesis: 6CO2 + 6H2O→
C6H12O6 + 6O2
Label the chloroplast to the right:
•
If the pigment chlorophyll causes the
green color in plants, do all plant
parts contain chlorophyll? Support
your answer.
_______________________________
_______________________________
4
Personal Notes/Summary:
•
Some prokaryotic bacteria are photosynthetic. Do they contain chloroplasts?
____________________________________________________________________________________
____________________________________________________________________________________
B. Mitochondria and Cellular Respiration
•
Contain its own unique DNA, proteins, and ribosomes; can self replicate
•
Contains an outer membrane, and a fluid called matrix inside a highly folded inner membrane.
•
This creates folds called cristae for the reactions of
______________________________________________.
•
Cellular Respiration: 6O2 + C6H12O6 → 6CO2 + 6H2O + ATP
Label the Mitochondria to the right:
•
Which do you think would contain more mitochondria, a
heart muscle cell or a skin cell? Why?
________________________________________________________
________________________________________________________
________________________________________________________
3. Organelles that Store, Clean up, and Support
•
Storage: vacuoles (store material) and vesicles (move materials around the cell)
– Vacuoles form by the ________________________ of many vesicles
•
Clean up: lysosomes- contain ______________________ to digest materials
•
Support: the cytoskeleton- meshwork that allows for _______________________ of the cell and
materials throughout the cell
– Contains the centrioles (help the cell divide)
5
Personal Notes/Summary:
A. Vacuoles “Storage”
•
Membrane-bound organelles found in eukaryotic cells
•
In Plant cells- typically have one large central vacuole to store
water, nutrients, wastes, and enzymes.
– Helps maintain turgor pressure- the pressure from
inside the full vacuole that pushes the cell membrane
against the cell wall and helps the plant cell stay
_________________
•
In Animal cells- have varying numbers of small vacuoles that
function to _______________ large molecules like:
– food brought in by a vesicle during endocytosis
– Molecules waiting to be released by exocytosis
•
In Unicellular aquatic organisms- there are specialized vacuoles
called contractile vacuoles which function to _____________
excess water from the cell’s cytoplasm
•
Think back to the unit on cell transport
– Why are contractile vacuoles necessary in unicellular aquatic organisms?
_______________________________________________________________________________________
_______________________________________________________________________________________
B. Lysosomes “Clean up”
•
Found in eukaryotes, though mainly in animal cells (rare in plant cells)
•
Membrane bound sacks that are the site of ___________________
(digestion)
•
Have an ________________ pH and are filled with digestive enzymes
•
Produced by the golgi apparatus
•
Why is it important for the digestive enzymes to be bound by the
lysosome, rather than being in the cytoplasm?
_______________________________________________________________________________________
_______________________________________________________________________________________
6
Personal Notes/Summary:
C. Cytoskeleton “Support”
•
Just like your body depends on your skeleton (bones) to keep your shape, so do cells.
•
Not membrane bound so also in prokaryotes
•
Consist of long networks of _____________________ strands called microfilaments and microtubules.
microfilaments – provide a framework and help move the cell
- made of the protein _______________
Intermediate filaments – help _________________ cells in place using a variety of proteins
microtubules – Act as tracks for organelles to travel on as they move
throughout the cell
- help in cell reproduction and division by forming centrioles (not
found in plant cells)
- made of proteins called ____________________
More on Microtubules
•
May extend outside of the cell
to form cilia
(___________________) or
flagella (long
_______________ hairs)- help
the cell move
Shade
7
Personal Notes/Summary:
4. Organelles that build Proteins
•
•
•
Ribosomes
Rough Endoplasmic Reticulum (ER)
Golgi Apparatus
A. Ribosomes
NOT membrane bound- so also found in prokaryotes
Produced by the ______________________. Which is where? _________________________
There are two types of Ribosomes
Free Ribosomes – move around in the __________________________
ER Ribosomes – are attached to the ________________________________________________
Chloroplasts and mitochondria have their own ribosomes!
(Remember endosymbiosis?)
Ribosome Structure
•
Two parts (subunits)
•
One _____________ subunit and one __________
subunit that fit together
•
Both made of RNA bound with proteins
8
Personal Notes/Summary:
B. Endoplasmic Reticulum (ER)
•
Network of membrane bound ____________ and __________. Constantly forming and breaking down.
There are two types of ER
1. Rough ER- has _______________________ on its surface
-
Proteins are made at the ribosomes and inserted into
the rough ER.
-
The rough ER _________________________ the
proteins; telling the cell where to send them
2. Smooth ER- no ribosomes on its surface
- NOT involved in the synthesis of proteins
- Helps make ___________________
- Site of __________________________ of drugs like alcohol and sedatives
- cells in people who use these drugs from large amounts
of smooth ER.
C. Golgi Apparatus
•
Series of sack-like membranes, drawn like a stack of pita bread
•
Found between the rough ER and cell membrane
•
Modifies, ______________________________________ proteins
coming from the rough ER
•
Sends the finished proteins to their destination by
_________________ which bubble off of the main stacks.
(Proteins may be sent either elsewhere in the cell or to its surface
to leave the cell)
•
Lysosomes are formed from golgi vesicles
– The “________________________” of the cell
9
Personal Notes/Summary:
Differences between Plant and Animal Cells

Plant cells share all the common features of animal
cells, but also contain some additional organelles.


_____________________ to convert sunlight into food
Every plant cell is surrounded by a ________________,
and typically contains large
____________________________.

Plant cells do NOT have _________________________.
Label the cell wall, central vacuole, and chloroplasts on the cell at the right.
Plant Cells
Animal Cells
10
Personal Notes/Summary:
Label the following Eukaryotic Cells
A
AD
B
AE
C_______________________
BC
D
BD
E
BE
AB
CE
AC
Which cell – the one on the right or the left – is the Animal cell?_________ Plant cell?___________
11
Personal Notes/Summary:
Cells can function individually and work together in order for the organism to function as a whole
Homeostasis in Unicellular Organisms
•
Unicellular organism- an organism made of just 1 cell.
– Can perform __________ necessary functions for life
– Must maintain homeostasis
•
By growing, responding to their environment,
transforming energy, and reproducing.
Homeostasis in Multicellular Life
•
Multicellular organisms are made of many cells that _____________________________.
•
Also must maintain homeostasis
– To do this, cells become ___________________ for certain tasks and communicate with each
other.
Cell Specialization
•
Different cells take on different roles
•
The process by which cells specialize is called
______________________________________________.
– Example: human tracheal cells- millions of cilia sweep out debris
that you breathe in. Filled with mitochondria because need
constant supply of ATP to do this day and night!
– What other cells are specialized in the human body?
_________________________________________________________________________________
_________________________________________________________________________________
12
Personal Notes/Summary:
Pick any two cell types from the diagram– compare and contrast their specialized structure, and relate this to
the cells’ function in the body.
__________________________________________________________________________________________
__________________________________________________________________________________________
__________________________________________________________________________________________
__________________________________________________________________________________________
Levels of Organization
•
Cells that work together form ______________________.
•
Tissues that work together form ____________________.
•
Organs that work together form
___________________________________.
•
Organ systems work together to make a fully functioning
______________________________.
Example:
13
Personal Notes/Summary:
Cellular Communication
How do cells interact to form tissues and organs? _________________________________________________
•
•
Cells of the same tissue are connected by an _____________________________________ (ECM) and…
communicate by sending ________________ _________________ to one another.
The ECM is a meshwork of _________________ and _________________________ located between cells that
plays a role in
1) connecting cells into tissues through cell junctions and
2) sending chemical signals between cells using receptor proteins.
1) Cell Junctions
Cell Junctions are connections between
two cells, or between a cell and the ECM
•
•
•
_____________ cells together
Allow signaling molecules to pass
_________________ cells
_________________ the cell to
the ECM
ECM
ECM
2) Receptor Proteins
To respond to a signal, the cell must have a receptor for that signal
•
•
These receptors are proteins and may be in the cell membrane
or in the cytoplasm
When bound by a signaling molecule, the receptor will
_______________ _______________ within the cell
Cell Signaling Is Complex!!
14
Personal Notes/Summary: