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Unit Objectives
• Describe a cell. What do cells do? How do they do it?
• Describe how cells differ from one another.
• Name three main structures in a living animal cell, their
locations, and their functions.
• Relate the plasma membrane structure to active and passive
transport mechanisms, then differentiate clearly between the
transport processes relative to energy source, substances
transported, direction, and mechanism. (Or, describe how
things move in and out of cells)
• Review the basic functions of cellular organelles and relate
this to overall cellular function, then describe diseases that
affect organelles and describe how this affects homeostasis.
What are Cells?
For Now…
We will look at these ideas more later. For
now, let’s just say:
Cell: smallest self-contained unit that performs
all of life’s processes
200 different types of cells
A Brief History
The English scientist Robert Hooke first
observed plant cells with a crude
microscope in the late 1600’s. One lazy
Saturday in July he got crazy with the
microscope and started looking at
everything he could, including a cork from
one of the many bottles of wine he had
consumed earlier that morning.
It wasn’t until the late 1830’s that two
German scientists were bold (and sober)
enough to propose that all living things
are composed of matter. The German
pathologist Rudolph Virchow extended
this idea by contending that cells arise
only from other cells. Virchow’s idea was
revolutionary because it openly
challenged the widely accepted theory of
spontaneous generation, which held that
organisms arise from garbage or other
nonliving matter.
Since the late 1800’s, cell research has
been exceptionally fruitful and has
provided us with four concepts
collectively known as the Cell Theory:
Cell
Cell: Smallest unit that can perform all
life’s processes
-Smallest unit of life
-Building blocks of life
Cell Theory
1. All living things are made of one or more
cells
2. Cells are the basic units of structure and
function in organisms
3. All cells arise from existing cells
Why do cells divide?
Surface area/volume relationship
What increases faster? Surface area or volume?
Cells Must Be Small!!!!
• Humans have over http://htwins.net/scale2/?bordercolor=white
100 trillion cells
• Size range from 5
nanometers to 20
nanometers
• All things coming and
going must cross the
cell membrane
• If the cells surface
area to volume ration
is to low things will
take to long to
happen.
Two Types of Cells
Prokaryotes1. Simple Single Cells
2. Earliest Known Cells (3.5
bya)
3. Bacteria Only
4. No nucleus or complex
organelles
5. Have a Cell Wall
Two Types of Cells
Eukaryotes
1. Complex Cells
2. Animals, Plants, Fungi
and Protists have this
type of cell
3. They have a nucleus
and complex
organelles
4. Plants, Fungi and
some Protists have cell
walls Animals do not.
Cytology
is the microscopic study of the
cell and its organelles.
All cells, have at least three main
parts:
1. Plasma membrane
2. Cytoplasm
3. Nucleus
Organelles and Their
Functions
•
•
•
•
•
•
•
-Mitochondria
-Nucleus
-Ribosomes
-Golgi apparatus
-Lysosomes
-Chloroplasts
-Smooth endoplasmic
reticulum
• -Rough endoplasmic
reticulum
• -Styloid process
• -Phagosomes
Nucleus
• “Brain” of the Cell
• Usually the largest of
the organelles
• Holds DNA and
directs the production
of proteins
Ribosome
1. “Protein Factory”
2. Helps create proteins
using mRNA and tRNA
during the process of
protein synthesis
Endoplasmic Reticulum (ER)
1. “Packaging Plant”
2. Takes proteins from the
ribosome and adds things
to them to finish the
protein
Golgi Complex
1. “UPS Store”
2. Takes Proteins from
the ER and packages
them for transport
around and out of the
cell.
Mitochondria
1. “Power House” of the cell
2. Cellular respiration takes
place here
3. Creates ATP
(Adenosine Tri-Phosphate)
from glucose
3. ATP= usable energy for cell
function
Cell Membrane
1. “The Guard”
2. Defines the shape of
the cell.
3. Controls what goes in
and out.
4. Made up of
Phospholipids
Vesicles
1. “Moving Truck”
2. Membrane bound
bubble that helps
move things into,
around, and out of the
cell often created by
the Golgi.
Vacuole
1. “U-Store”
2. Stores water, waste and
nutrients
3. Huge in plants, smaller in
animal cells.
4. Helps give strength to the
cell and stores water for
later use.
5. Plants will wilt when water
is removed from the
Central Vacuole.
Plant cells
Plant cells have all of the same organelles, and
two more only found in plants:
Cell Wall
Chloroplasts
Cell Wall
1. “The 2x4”
2. Found in Plants,
Fungi, Bacteria and
some Protist.
3. NO ANIMALS have
cell walls.
4. Creates strength,
and protection
5. Made of Cellulose in
Plants
Chloroplasts
1. “The Solar Panels”
2. Collects energy from
the sun and turns it
into sugar
(Photosynthesis)
3. Found in
photosynthetic
organisms
4. Uses the Lipid
Chlorophyll (makes
plants green) to do
it’s dirty work.
https://www.youtube.com/watch?v=6y7vBMyQZ3c&feature=fvst
The Nucleus
• The most prominent cellular organelle, the nucleus contains genetic
material: genes, DNA, and Chromosomes.
• Information stored in genes is utilized in everyday cell life and
reproduction.
The Cytoplasm
• Also know as cytosol, its occupies the space between the
nucleus and the plasma membrane. The cytoplasm contains
membrane-bound organelles, ribosomes and a complex
network of complex tubules called the Cyoskeleton.
The cytoplasm is primarily composed of __________.
START
Question: What is the cell membrane
and how do things move across it?
Structure of the Cell Membrane
Passive Vs Active Transport
Simple:
The Cell membrane has two important functions:
1. Controls what goes in and out of cell.
2. Defines the cell shape.
…..HOW???
The Function of the Cell
Membrane
• The flexible plasma membrane defines the
extent of the cell and separates everything
inside the cell from everything outside the
cell. It also separates two of the body’s
major fluid compartments:
1) The intracellular fluid within the cells,
and the
2) extracellular fluid outside of the cells.
The unique structure of the plasma membrane
allows it to play a dynamic role in many
cellular activities.
Cell Transport and the Cell
membrane
Simple:
The Cell membrane has two important functions:
1. Controls what goes in and out of cell.
2. Defines the cell shape.
What is the cell membrane
made of?
•
•
•
•
•
What is the cell membrane made of?
Phosphate+ lipid (fat)
Hydrophobic tail
Hydrophilic head (aligns with water)
Cell Transport
How does the cell membrane maintain
homeostasis?
How do substances get into or out of a
cell?
The Cell Membrane is
semipermeable
Semipermeable/selective permeability: Allows some
things to pass through freely, other substances need help,
and some can’t pass at all.
http://www.youtube.com/watch?v=Pt4Ch-YW-xs
Key Words
• Solution- combination of a solute and a solvent.
• Solute- Substance that is dissolved in a solvent (i.e.
salt, sugar etc)
• Solvent- Substance that other substances are
dissolved into (i.e.- water)
• Concentration Gradient- Difference in solute
concentration from one side of the membrane
compared to the other.
• Equilibrium: state in which the concentration of a
substance is equal throughout a space or across a
membrane.
Different types of
movement
Endocytosis: Taking substances in
Exocytosis: secretion of substances out of a cell
Passive and Active
Transport
Passive transport: substances are able to cross
a membrane without the use of energy
-pass down a concentration gradient
-Move from an area of higher concentration to
an area of lower concentration
-Driven by the energy of the movement of the
molecules (kinetic energy)
Examples: diffusion, facilitated diffusion
Active Transport
Active transport: substances require CELL
energy to pass a membrane
-pass up a concentration gradient
-Move from an area of lower concentration to
an area of higher concentration
-Driven by cellular energy (ATP)
Examples: ion pumps like the sodium potassium
pump
Key Words
• Solution- combination of a solute and a solvent.
• Solute- Substance that is dissolved in a solvent (i.e.
salt, sugar etc)
• Solvent- Substance that other substances are
dissolved into (i.e.- water)
• Concentration Gradient- Difference in solute
concentration from one side of the membrane
compared to the other.
• Equilibrium: state in which the concentration of a
substance is equal throughout a space or across a
membrane.
Diffusion
• Movement of a solute within a solvent from high
concentration to low concentration
• EXAMPLE- Food coloring (Solute) moving from the
high concentration of a drop to the low
concentration of the water (Solvent).
http://highered.mheducation.com/sites/0072495855/student_view0/chapter2/ani
mation__how_diffusion_works.html
Diffusion
Facilitated Diffusion
1. Channel Protein- tunnel in and out. Can be gated to open and
close. Use energy to go against concentration (active transport)
and do not use energy to go with concentration (passive
transport)
2. Receptor Protein- receives chemical signals from the blood and
communicates them to the inside of the cell.
3. Glycoprotein + Carbohydrate- identifies the cell so it will not be
destroyed.
Osmosis
Osmosis: The movement of water across a
selectively permeable membrane until the
relative concentrations of solute to solvent
are equal on both sides
http://highered.mheducation.com/sites/0072495855/student_view0/chapter2/ani
mation__how_osmosis_works.html
Osmosis: the tendency of water to pass through a
semipermeable membrane into a solution where the
solvent concentration is higher, thus equalizing the
concentration of materials on either side of the membrane
Osmosis
• Diffusion of water through a semi-permeable
membrane
• Water is the only substance that can move freely in
an out of cells without using channel proteins.
More Complicated Than That
Why Water Moves
• Hypertonic SolutionThe outside of the cell
has more solute than
inside the cell
• RESULT- Water moves
out and the cell shrinks.
Why Water Moves
• Hypotonic SolutionThe outside of the cell
has less solute than
inside the cell.
• RESULT- Water moves
in and the cell
swells/bursts.
Why Water Moves
• Isotonic SolutionWhen there is an equal
amount of solute inside
and outside the cell
• RESULT- Water moves
both in and out of the
cell at the same rate
and the cell stays the
same
Facilitated Diffusion
1. Channel Protein- tunnel in and out. Can be gated to open and
close. Use energy to go against concentration (active transport)
and do not use energy to go with concentration (passive
transport)
2. Receptor Protein- receives chemical signals from the blood and
communicates them to the inside of the cell.
3. Glycoprotein + Carbohydrate- identifies the cell so it will not be
destroyed.
Active Transport
Active transport: substances require energy to
pass a membrane
-pass up a concentration gradient
-Move from an area of lower concentration to
an area of higher concentration
Examples: ion pumps like the sodium potassium
pump
Sodium-potassium pump
http://highered.mcgrawhill.com/sites/0072495855/student_view0/chapter2/animation__how_the_sodium_potas
sium_pump_works.html
Sodium-potassium pump
http://highered.mcgrawhill.com/sites/0072495855/student_view0/chapter2/animation__how_the_sodium_potas
sium_pump_works.html
Other types of
transport
Co-transport
Counter-transport
Co transport
Counter transport
Animations for sheet
http://www.lonestar.edu/biology1-animations.htm
END
Passive and Active Transport
Passive transport: substances are able to
cross a membrane without the use of energy
-pass down a concentration gradient
The Composite Cell
Although there are many different types of
cells, all cells include three basic
structures:
The Nucleus
The Cytoplasm
The Cell Membrane
Happy Monday.
• Tests/Essays
• Calendar
• Organelle
Functions
• Composite Cells
• Plasma
Membranes
Steps to Protein Synthesis
1. DNA in the Nucleus opens one gene (instructions
for a protein) which is copied by the mRNA.
2. mRNA takes the instructions to the Ribosome
3. The Ribosome creates the protein and sends it to
the Endoplasmic Reticulum (ER).
4. The ER finishes the protein and sends it to the
Golgi Complex to be packaged in Vesicles and
labeled.
5. The Vesicles carry the finished proteins to the Cell
Membrane for removal from the cell to be used
else ware in the body.
Cell Membrane
1. “The Guard”
2. Defines the shape of
the cell.
3. Controls what goes in
and out.
4. Made up of
Phospholipids
The Function of the Cell
Membrane
• The flexible plasma membrane defines the
extent of the cell and separates everything
inside the cell from everything outside the
cell. It also separates two of the body’s
major fluid compartments:
1) The intracellular fluid within the cells,
and the
2) extracellular fluid outside of the cells.
The unique structure of the plasma membrane
allows it to play a dynamic role in many
cellular activities.
The Fluid Mosaic Model
• The fluid mosaic model of membrane structure (Figure
3.2 on page 58) depicts the plasma membrane an
exceedingly thin (7-8 nm) structure composed of a
double layer, or bilayer of lipid molecules with protein
molecules dispersed within it. The proteins floating in
this bilayer form a constantly changing mosaic
pattern, and that’s where the name comes from.
• The lipid bilayer is composed primarily of phospholipids,
with smaller amounts of cholesterol and glycolipids.
• Each of these lollipop-shaped phospholipid molecule
has a polar “head” that is charged and hydrophilic, and
an uncharged, nonpolar “tail” made of two fatty acid
chains that is hydrophobic.
Cell Membrane Functions
Cell Theory
1. All living things are made of one or
more cells
2. All cells arise from other cells
Cells Must Be Small!!!!
• Humans have over http://htwins.net/scale2/?bordercolor=white
100 trillion cells
• Size range from 5
nanometers to 20
nanometers
• All things coming and
going must cross the
cell membrane
• If the cells surface
area to volume ration
is to low things will
take to long to
happen.