Transcript Agenda 8/2/05 1. Plasma Membrane – Notes 2. Work on Cell

The Cell Membrane
A. Phospholipid
1. They have a polar head that is hydrophilic (water-loving).
2. They are made of nonpolar tails that are hydrophobic
(water-fearing).
B. Phospholipid Bilayer
1. The plasma membrane is made of 2 layers
of phospholipids with polar heads pointing
out and nonpolar tails pointing in.
What the phospholipid bilayer
look like?
C. 3 Proteins in the Membrane
1. Transport protein: act like doors or
channels that allow molecules to pass
through the membrane. (Cell phone)
2. Receptor proteins: transfer information to
the inside of the cell. (Texting)
3. Recognition proteins or glyco-proteins.
These are name tags. (caller ID)
Movement Through the
Cell Membrane
D. Selectively Permeable Membrane
Only certain molecules are
allowed to pass freely.
So how do materials move in and out of a
cell?
1.
Passive transport – NO energy
A. Simple Diffusion (Osmosis)
B. Carrier-facilitated Diffusion
2. Active transport – needs energy
Diffusion of Kool Aide in water
A. Simple Diffusion
•
No energy is needed.
Molecules move from an area of high concentration
(where there are many molecules) to an area of low
concentration (where there are less molecules).
•
Molecules spread out evenly and reach an equilibrium.
B. Osmosis
1. Osmosis is the Diffusion of WATER.
Water molecules move from an area of high
concentration (where there are many water) to an area
of low concentration (where there are less water).
2. NO energy needed!
1. Water moves by diffusion.
2. Membrane is selectively permeable.
Dictionary says:
“Facilitate: to make easier; to
help something happen”
So who facilitates in the cell
membrane?
C. Facilitated Diffusion
•
The TRANSPORT PROTEINS move molecules, they are
facilitators or helpers.
•
No energy needed because molecules are moving from
a higher concentration (lots of molecules) to a lower
concentration (few molecules).
Active Transport
•
Transport Proteins move or pump molecules by
using energy.
 Why is energy needed?
• Molecules move from a low concentration (few) to a
higher concentration (many).
What do you
know?
Use your notes to help!!
Name differences between
simple diffusion & facilitated diffusion.
What is the
smallest living
thing?
Power Point #2
The
Cell
Name a structure
found in eukaryotes
but not in
prokaryotes.
Nucleus,
Organelles
Bacteria is what type
of cell?
Prokaryotic Cell
Are prokaryotes
simple cells or
complex cells?
Simple Cells
Are prokaryotes
unicellular or
multicellular?
Unicellular
Are plants and animal
cells eukaryotic cells
or prokaryotic cells?
Eukaryotic Cells
Are eukaryotic cells
simple cells or
complex cells?
Complex Cells
Are eukaryotic cells
unicellular or
multicellular?
They can be both
unicellular or
multicellular
Is a virus living or
nonliving?
Nonliving
What is the function
of the cell
membrane?
Acts as a boundary
between the cell and
its environment.
Controls what enters
and leaves the cell
What is the
cytoplasm?
A jelly-like substance
in the cell that holds
the organelles in
place
What is the function
of the lysosomes?
To break down worn
out organelles and
debris
What is the function
of the nucleus?
It contains the DNA.
Control center for the
cell
What is the function
of the smooth ER?
To synthesize lipids
Which organelle
packages proteins
into vesicles?
The Golgi Complex
Which type of cell
transport (active or
passive) requires no
energy?
Passive Transport
How do cells move
material from an area
of high concentration
to an area of lower
concentration?
Active Transport
Which part of the
phospholipid is water
loving?
The polar head is
hydrophilic
What is the function
of the receptor
protein?
Transfers information
to the inside of the
cell
What is a recognition
Protein?
These are the name
tags
What are the Transfer
Proteins?
Doors or channels
that allow molecules
to pass through the
membrane
Energy is stored in fats
or proteins. Which
organelle produces
ATP from these energy
sources?
Mitochondria