Transcript Resource

Chapter 8
Cellular Transport
and the
Cell Cycle
Section 8.1
Section 8.2
Section 8.3
Cellular Transport
Section 8.1
Movements across the plasma
membrane can be divided into
two groups!
• Passive Transport
• Active Transport
Passive
- always high to
low conc.
- does not require
energy
Active
- always low to
high conc.
- NEEDS energy
1. Diffusion (simple) 1. Endocytosis
2. Osmosis
2. Exocytosis
3. Facilitated diffusion
• Diffusion- movement of particles
from an area of higher
concentration (more particles) to an
area of lower concentration (less
particles) until an equal
concentration is met
1. Simple Diffusion
• Diffusion of particles by using
channel proteins
• Does not require energy
• Movement of small molecules like
CO2 and O2
Visit www.unitedstreaming.com and
search for the video titled Cells the
Building Blocks of Life and view the
segment called Cell Membrane:
Diffusion
2. Facilitated diffusion – passive
transport of material across the
plasma membrane with the aid of
transport proteins
• Diffusion with the help of
carrier proteins
• Movement of large molecules
like glucose
3. Osmosis – diffusion of water
across a selective permeable
membrane
What’s going to happen in this picture?
(Blue in water and Green in salt)
http://www.biologycorner.com/resources/osmosis.jpg
Water is always trying to reach an
equal concentration between a cell
and its environment
http://www.biologycorner.com/resources/osmosis.jpg
•Osmosis – diffusion of water across a selective permeable membrane
http://www.biologycorner.com/resources/osmosis.jpg
One factor that controls osmosis
is a concentration gradient.
• Concentration Gradient – an
unequal distribution of
particles
• The greater the concentration
gradient, the more likely
osmosis will occur
Three types of solutions:
1. Isotonic solution – the concentration
of dissolved particles in the
solution is the same as the
number of dissolved particles in the
cell
-“ Iso” – means same, like an
isosceles triangle (two sides are
the same length)
2. Hypotonic solution – the
concentration of dissolved
particles in the solution is
less than the number of
dissolved particles in the cell
- “hypo” means low, as in
hypoglycemia (low blood
sugar)
3. Hypertonic solution – the
concentration of dissolved
particles in the solution is
more than the number of
dissolved particles in the cell
- “hyper” means high, as in
hyperactive (over excited)
What’s important about osmosis?
How does it affect our cells?
• Our cells holds 0.9% salt, NO MORE NO
LESS
• Any solution that is = 0.9% is an isotonic
solution to our cells
• Any solution that is > 0.9% is a
hypertonic solution to our cells
• Any solution that is < 0.9% is a hypotonic
solution to our cells
A simple rule to remember is:
SALT SUCKS
• Salt is a solute, when it is
concentrated inside or outside the
cell, it will draw the water in its
direction. This is also why you get
thirsty after eating something
salty.
www.esu7.org/~lweb/Lakeview/science/sea.htm
Passive
- always high to
low conc.
- does not require
energy
Active
- always low to
high conc.
- NEEDS energy
- NOT diffusion
1. Endocytosis
1. Diffusion (simple)
2. Exocytosis
2. Osmosis
Visit www.unitedstreaming.com
3. Facilitated diffusion and search for the video titled
Cells the Building Blocks of Life
and view the segment called Cell
Membrane: Active Transport
1. Endocytosis – process by
which a cell surrounds (with
vacuole) and takes in large
molecules or groups of molecules
• ENDO – means “in” to the cell
2. Exocytosis – process in which
a cell expulses or secretes
materials from cell
• Exo – means “exit” or excrete
• Used when cells need to expel
wastes
• Used when cell need to secrete
hormones
http://www.biologie.uni-hamburg.de/b-online/library/biology107/bi107vc/fa99/terry/images/ExocyAnA.gif
Cell Growth and Reproduction
Section 8.2
The Cell Cycle
- sequence of growth (interphase)
and division (mitosis) of one cell
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/cellcycle.gif
MITOSIS
The process in which cells divide
and create two daughter cells with
the same genetic material as the
parent cell
Phases of Mitosis:
1.
2.
3.
4.
Prophase
Metaphase
Anaphase
Telophase
1. PROPHASE


http://www.fatherryan.org/academic/schmidtl/BioIchapt%208%20notes_files/image004.jpg
Longest phase
Sister chromatids
appear and are
held together by a
centromere
• Centrioles –
located outside
the nucleus
www.google.com/images
• Spindle
fibers form
•Nucleus
starts to
disappear
www.google.com/images
www.google.com/images


www.google.com/images
Shortest phase
Chromosomes
attach to
spindle fibers
by their
centromere and
line up in the
middle

www.google.com/images
Sister
chromatids
are pulled
apart
www.google.com/images
•Spindle begins
to break down
• New nuclei
begin to form
www.google.com/images
CYTOKINESIS


End of telophase
The division of
cytoplasm to form
two new cells
www.google.com/images
Or
Tissues

http://washington.uwc.edu/about/faculty/schaefer_w/TISSUES/fibrous_connective_tissue_tendon.jpg
Group of
cells that
begin to work
together
ORGAN

Group of
tissues
designed to
perform a
specific
function
http://www.yankeetown.org/plangley/7.html
ORGAN SYSTEMS

http://www.tqnyc.org/NYC063547/urinarysystem.html
Group of organs
that work
together
Control of the Cell Cycle
Section 8.3
I. Normal Control of the Cell Cycle
A. Enzymes Control the Cell Cycle
1. Necessary to begin and drive the cell
cycle, and control the cycle through it’s
phases
2. Uncontrolled dividing comes from failure
in the production enzymes
3. Cancer – one result of uncontrolled cell
division
Enzymes are directed by genes
located on the chromosomes
5. Gene – segment of DNA that
controls the production of a
protein
6. Several enzymes trigger DNA
replication
4.
II. Cancer:
A Mistake in the Cell Cycle
Damaged genes are prompt
into action
 Tumors – mass of cancer cells
 Metastasis – cancer cells can
be seen in the circulatory
system (spreads the cancer)

Tumors can benign or malignant.
Metastasis = Malignant
http://blog.wired.com/photos/uncategorized/2007/05/22/metastasis.jpg
Cancer
 2nd
Leading
cause of
death in
U.S.A.
 Most
prevalent –
lung, colon,
breast and
prostate
http://mbbnet.umn.edu/icons/cancercell.jpeg
A. Causes of Cancer
1.
2.
3.
Genetic
Environmental – cigarette
smoke, air and water pollution,
UV radiation
Viral infections that damage
genes
B. Cancer Prevention
1.
a)
b)
c)
d)
e)
Healthy Lifestyle
Low fat diets
High fiber diets (fruits,
vegetables, and grain products)
Vitamins and Minerals
(carontenoids, Vit A, C and E)
Daily exercise
Not using Tobacco Products