Download Cell membrane

Get out your vocab assessment!
*Grab the Notes Sheet from side table!
BrainWork #12
What do you know about cells?
*sorry I do not have all of your
tests graded yet, I am waiting on
some people to take them!
Number 1-10 in your notes. For each
statement hypothesize if it is True or
False. Do not re-write the statements.
CHAPTER 6:
CELL STRUCTURE & FUNCTION
SOME RANDOM CELL FACTS
The average human being is composed of around 100
Trillion individual cells!!!
 It would take as many as 50 cells to cover the area of a
dot on the letter “i”

WOW!!!
I.Cell Theory
A. 1665- Robert Hooke- used microscope to see cork
cells- named them “cells”
*Hooke named them this because he believed they
looked like the little rooms monks lived in at
monasteries which were called cells.
B. 1673 Anton van Leeuwenhoek- Used a handmade
microscope to observe pond scum & discovered
single-celled organisms
•He called them “animalcules”
•He was the first to make a simple light microscope.
Microscopes
2 main types of microscope:
1. Electron microscopes:
a. forms an image of a specimen using
a beam of electrons rather than light
b. Specimen placed in a vacuum so no
living samples are used
2. Light microscopesa. uses two lenses
b. light from the base shines up through the
specimen
c. Ocular lens is 10x, objective lens is either 10x,
or 40x
Ex: What is the magnification of an object which
uses the 40x objective lens?
Ocular 10x * Objective 40x= 400x
Development of Cell Theory
D. 1838- Matthias Schleiden (German Botanist)
-Concluded that all plant parts are made of cells
E. 1839- Theodor Schwann (German physiologist)
-Stated that all animal tissues are composed of
cells.
F. 1858- Rudolf Virchow (German physician)
-Concluded that cells must arise from pre-existing
cells.
3 Parts of the cell theory:
A. All living things are composed of cells
B. Cells are the basic units of structure
and function
C. New cells are produced from existing
cells
Cell Theory Song!
http://www.youtube.com/watch?v=KuJqqiATlqw
HOW HAS THE CELL THEORY BEEN
USED?
 The
basic discovered truths about cells, listed in
the Cell Theory, are the basis for things such as:
 Disease/Health/Medical Research and
Cures(AIDS, Cancer, Vaccines, Cloning, Stem
Cell Research, etc.)
Due: Reading Questions…Get out and put
on YOUR desk!
BrainWork #13
Without looking in your notes…
What are the 3 parts to the cell theory??
Objective for today:
Compare and Contrast
Prokaryotic cells to Eukaryotic cells
WHAT ARE THE DIFFERENCES?
Eukaryotic Cell
Cells are divided into two categories:
1. Prokaryotes
a. much smaller and simpler, no organelles
b. no membrane bound nuclei
c. contain cell membrane, DNA, cytoplasm
ex: bacteria
2. Eukaryotes- more complex!
a. contain many organelles, larger, true nucleus
1.) organelle- specialized structure
that has a specific function (in cell)
b. All plants, animals, and fungi are eukaryotes
*all our cells are
Eukaryotic!
Lets go back and check your
guesses!
9/19 Due: Nothing
BRAINWORK #14?
Compare and Contrast a
Prokaryotic cell to a Eukaryotic cell
Objective of the Day:
Osmosis and Diffusion
1. LABEL EACH SIDE OF THE VENN DIAGRAM
A
B
- Small
- Large & Complex
& simple
- No nucleus
- Cell membrane
- Contain Nucleus
- Contain DNA
- Membrane-bound
organelles
- No organelles
- Cytoplasm
- Bacteria
- Make up plants,
animals, fungi,
and protists
2. What type of cell is
this?
3. Name one reason
you know it is this
type of cell
4. This cell has whiplike flagellum, what
do you think those
might be used for?
5. Do you think it
would be more
likely to assume
this is a bacteria or
plant cell? Why?
Cell membrane
6. What type of cell is this?
(prokaryotic/eukaryotic?)
7.Name one thing about this cell that helped
you know it was that type of cell:
8. Do you think this is more likely a plant cell
or an e-coli cell?
Cell Structures
A. Cell membrane –thin, flexible barrier around cell
B. Cytoplasm- jelly-like material in-between the cell
membrane and nuclear membrane
( all organelles reside in the cytoplasm)
C. Cytoskeleton- protein filaments that help to maintain
cell shape-flexible framework
1.) Microtubules (bigger)- hollow tubes, shape cell and
help organelles move *used to make cilia and flagella
2.) Microfilaments (smaller)- very narrow-help shape
and move the cell *making of and breaking down of
microfilaments causes the cytoplasm to change shape,
moving organisms like amoebas
Cell membrane
A. Cell membrane- controls what enters and leaves
the cell
1. Lipid bilayer- double layer of phospholipids
a. phosphate head and two fatty acid tails
B. Proteins go through the bilayer working as
channels and pumps
C. Movement of molecules
1. Concentration- the mass of a solute in a given volume of
solution
ex: 12 grams of sugar in 3 liters of water
(4 grams/Liter)
2. Diffusion- Molecules move from high to low concentration
as they try to reach equilibrium
b. Diffusion uses no energy from the cell
D. Osmosis- no energy used
1. Diffusion of water through a selectively permeable
barrier (like a cell membrane)
A. Selectively permeable –not all things go
through
2. Water moves in direction of where there are more
solutes
Ex:
3. Isotonic solution- cell and solution both have the
same conc. of water and solutes
Ex: blood cells in plasma
4. Hypertonic solution- Solution surrounding the cell
has more solutes than the cell
a. Water moves out of the cell-cell shrivels
5. Hypotonic solution- cell has more solutes than the
solution around it
a. Water moves into the cell
-cell could burst
-plant cell wall prevents that
Blood cell/ body cells in animals not usually surrounded by
pure water!
 Assignment:

6.3 Vocabulary Terms
Assess yourself on if you know the
terms or not.
Read Section 6.3 to fill out the sheet
Define each term OR give an
example from the text!


EGGS
E. Facilitated Diffusion
1. Carrier protein- used in facilitated diffusion-transport
protein that carries something across the cell membrane
Which direction are the molecules moving?
Do you think this will require energy?
F. Active Transport- movement of a substance from an area of
low conc. to an area of high conc.
(the opposite of the normal way)
1. Energy is used in the form of ATP
2.Membrane pumps- proteins move substances from an
area of low to high conc.
ex: Sodium-Potassium pump
Don’t require
energy
G. Vesicles can be used to transfer items across the cell
membrane
1. Endocytosis- move substance inside cell
2. Exocytosis- moving a substance
out of the cell
a.) fuse with membrane, releasing
contents
ex: proteins leave the cell in this way
D. Nucleus- controls cell and contains DNA
1. nucleolus- starts assembly of ribosomes
2. nuclear envelope- surrounds nucleus, lots of pores for
items to move in and out
H
E
F
D
G
C
J
B
A
III. MAKING OF A PROTEIN
A.
Nucleolus makes ribosomes which then leave the
nucleus and attach to E.R.
2. Ribosome- place of protein production (may be
free or attached)
B. Endoplasmic Reticulum- parts of cell membrane are
made and proteins are modified
1. Rough E.R.- covered in ribosomes
a. Proteins are made on the ribosomes (on the
ER) and travel directly into the e.r.
C. Golgi Apparatus- package and sort proteins
1. Proteins go from the R.E.R. to the G.A. and are then
sent to their final destination
D. Vesicles- small sac that transports items around the
cell
E. Lysosomes- small sacs filled with enzymes which
breakdown food particles or old organelles
F. Centrioles are organelles found only in animal cells
that help with cell division.
G. Mitochondria- “powerhouse” of the cell
1. Converts food molecules to energy (glucose to ATP)
IV. Plant cell organelles
A. Vacuoles- saclike structures that hold water, a full vacuole
allows for plant cells to stay rigid
B. Chloroplasts- capture sunlight and make energy
(photosynthesis)
C. Cell Wall- provide support and structure for the cell
DIFFUSION QUESTIONS:
1. If I placed a piece of celery into a solution with a very high
concentration of salt, what would happen?
2. What would happen to the molecules in this cell when place in
pure water?
3. Which has a higher concentration of sugar, soda or milk?
4. Why aren’t the lipid tails of the phospholipids facing the
outside of the cell?
5. Draw a picture of a section of the cell membrane
PICTURE QUIZ!!
What type of solution was this cell placed in?
Original cell:
Cell in solution:
a.
b.
What is this structure? (the whole thing)
.
IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII
C. What type of
solution is this?
d. The water moving towards where
there are more solutes is called what?
e. Where is there a higher concentration of sugar molecules?
Inside or outside the cell?
sugar molecule
f. Based on your answer for e, which direction will sugar be
moving (into or out of the cell)?
g. Which type of molecule movement requires energy from the
cell:
a. Osmosis
B. diffusion
C. protein channels
D. Protein pumps
1. Are bacteria prokaryotic or eukaryotic?
2. What is the difference?
3. This picture shows substances entering the cell, what is the
process called?
4. List 2 ways diffusion and active transport are different.
5. Proteins can work as channels or membrane ____________.
6. The cell membrane is made of a ___________________ bilayer.
7. List the three organelles specific to plant cells
8. Who coined the name “cells” after looking at a piece of cork
cell?
9. Coiled up (condensed) DNA is called what? (*we have 46 of
these)
10. What organelle is responsible for making proteins?
11. Where are proteins packaged and sorted?
F
H
E
D
G
C
B
A
EXAMPLE OF SCIENCE PARAGRAPH
The outside of an animal cell is covered in a cell
membrane,which allows substances to pass in and out. Inside
of the cell from the cell membrane to the nuclear envelope is
cytoplasm. Cytoplasm contains enzymes because it is the
location where many chemical reactions take place. The
nuclear envelope serves as the outer boundary of the nucleus
and has many pores that allow materials inside and out. Inside
the nucleus is the nucleolus which makes ribosomes. These
ribosomes leave the nucleus through the pores in the nuclear
envelope.
Test Warm up:
1.) A group of tissues working together becomes a
what? (think of the levels)
2.) Trace the path of a protein!
3.) What items are found inside
the nucleus?
4.) What types of solute
movement require energy?
5.) Describe a cell wall
Describe a cell membrane
6.) If I put a piece of potato in pure water. What
would happen to the size of the potato? What about
a red blood cell?