Download Cell Membrane

Cells- The smallest units of Life
Breast Cancer Cell
Cell- basic units of structure and function in living things
History
1600’s
Anon Van Leeuwenhoek- Dutch Biologist- built first simple
microscope
-discovered: bacteria, protists, sperm cells, blood cells to
name a few
Robert Hooke- English Scientist, first to study cells (cork)
1800’s
Robert Brown- Scottish, discovered the nucleus
CELL THEORY- Based on historical
data
1. All living things are
composed of cells
2. Cells are the basic
structure and function of
living things
3. Cells come from other cells
Types of cells:
Prokaryote- smaller, simplifier cells that do not
contain a nucleus.
Eukaryotic Organisms have 3
basic structures in common
1. Nucleus 2. Cell Membrane 3. Cytoplasm
Prokaryote vs. Eukaryote
Nucleus- information center and directs all activities in the cell
• where DNA is found
• How do Prokaryotes and Eukaryotes differ in terms of
the nucleus?
• Nuclear Envelope- surround the nucleus
• Nuclear Pores- holes in envelope, allows for movement
• Nucleolus- ribosome’s are made here
• Chromosomes (Chromatin)- long strands of DNA that
contain genetic info for reproduction
Cell Membrane- surrounds the cell and regulates
what enters and exits the cell
• adds support and some limited protection
• made of phospholipids, Cholesterol- helps
maintain structure, Proteins and
Carbohydrates
• Phospholipids have a charge of 0 and are polar one end +
• create a lipid-bi-layer
• heads face out, tails in
Cytoplasm- jelly-like fluid that the organelles are found in
Cytoskeleton- structural element that makes up the cytoplasm
• made of 2 main parts
• Microtubules- hollow tubes of protein
• Organelles can move around the inside of the cell on
these
• Form centrioles (small set of microtubules) in animal
cells
• Help move chromosomes around during cell division
• In some single celled animals they form cilia and
flagella
• Microfilaments- smaller than microtubules
• Helps with support and organelle movement
1 Mitochondria- where cellular respiration takes
place
• found in both plant and animal cells
• powerhouse of the cell
• Where ATP is produced
from glucose.
2 Ribosomes- where proteins are assembled
• made of RNA and proteins in the
nucleolus
• smallest of the organelles
• can be attached or free
• translate mRNA into polypeptide chains
• made of 2 subunits
• both plant and animals
contain ribosomes
3 Endoplasmic Reticulum
Smooth- synthesize lipids, detoxify drugs(liver), stores Ca,
stores enzymes, and transports
Rough- has ribosomes attached to it, modifies proteins from
protein synthesis
4 Golgi Appratus- flattened stack of membranes that modifies,
collects, packages and distributes molecules
• makes lysosomes
• last stop for a molecule before it leaves the cell
• both plant and animals have these
Can you tell the difference
between ER and Golgi?
5 Lysosomes-suicide sacs, destroy foreign material and recycle
cell parts
• found in animals and plants
• Tay Sachs Disease- no lysosomes, can’t metabolize fats,
builds up in brain (100% fatal)
http://highered.mcgraw-hill.com/olc/dl/120067/bio01.swf
Animation
6 Chloroplast- site where photosynthesis takes
place
• found in plants, some protists and some bacteria
7 Cell Wall
• protects and supports most cells
• only found in plants
• very porous
• made of polysaccharide – cellulose
• has pectin- sticky (polysaccharide), helps hold cells together
breaks down to a monosaccharide as fruit over-ripens
• wood bearing plants have lignin- makes cellulose rigid
8 Vacuoles- storage sites for water, salts, proteins, and
carbohydrates
• found in animals and plants but are different sizes
9 Plastids- organelles of storage
• Chloroplasts- stores chlorophyll
• Chromoplasts- store pigments other than
chlorophyll
• Leukoplast(Amyloplast)- storage of
starches
Starch grains in a
potato tuber
1. Come up with your analogy
2. Cut out paper in the shape of your analogy
3. Draw a plant or animal cell
Cell Movements
• cells are surrounded by liquid which makes
movement of molecules easier
Plasma (Cell) Membrane Types (depends on what
is trying to get
1Permeable
through
2Semi/Selectively Permeable
3 Impermeable
Passive Transport- movement of molecules
without the use of energy
1 Diffusion- movement
of molecules from areas
of high concentration to
areas of low concentration
until equilibrium is reached
2 Osmosis- movement of water from areas of
high concentrations to low concentrations
through a semi-permeable membrane until
equilibrium is reached.
• both work on concentration gradients
• phospholipid membrane is permeable to
water
• Penicillin- disrupts bacterial cell membrane
structure and kills by osmotic pressure
3 Facilitated Diffusion- molecules are moved
across a membrane by a carrier protein, from
high concentration to low concentration
• must have a concentration gradient
• example: moving glucose into red blood
cells
Hydrostatic Pressure- known as osmotic pressure, is the
pressure of water placed on walls and membranes
How do Single Celled Organisms compensate for
osmotic pressure
1. minimize contact with fresh water
2. have a cell wall (plants/bacteria) to resist expansion
(balloons)
3. have a contractile vacuole- type of active transport
which moves water out
Active Transport- processes that require energy and
generally move materials against a concentration
gradient
1 Molecular Pumps- use energy to pull molecules
across a membrane
Ex: Contractile Vacuole
Ex: Sodium Potassium
2 Endocytosis- bringing large materials into the cell by
folding the cell membrane
A Pinocytosis- taking in large amounts of liquid
B Phagocytosis- taking in large amounts of
solids
3 Exocytosis- removing large amounts of material from
the cell
Cell Specialization
• all cells have a specialized
function within an organism
Specialized CellsPancreas- contain large amounts
of organelles involved with protein
synthesis (ER, RIbosomes, Golgi)
make enzymes that go
to your stomach for digestion
Lungs- lined with cells that have
cilia- hair-like projection that helps
clean the air
• also can secrete mucus which
can be coughed up
Red Blood Cells- specialized for
oxygen transport
White Blood Cells- fight against
disease (lysosmes)
Levels of Organization in Multicellular
organisms
• Cells
• Tissues
• Organs
• Organ System
• Organism
Tissues- cells are organized into tissues and they
perform a particular function
4 tissue types
1 Muscle- contains muscle & nerve cells
2 Epithelial- linings for body cavities, ducts,
tubes- single layer (skin)
3 Nerve- many different types of nerve cells
(brain, spinal cord)
4 Connective Tissue- bone, blood,
cartilage, tendons, ligaments
Organs- groups of tissue working together to
perform a special function
• each muscle is an organ
• muscle- contains muscle, nerve and
connective tissue
• all needed to make the muscle function
properly
Organ Systems- groups of organs working together to
perform specialized functions
• 10 organ systems in the human body
• can you name them?
Division of labor- everything has a job, they all work
together for proper functioning, if something isn’t doing its
job the structure won’t work as a whole.
Improper functioning
Organism- Made up of organ systems
Chromosome Structure
Chromatids- identical forms
across from each other
Centromere- central structure that
joins the chromatids
Growth Factor and the Cell Cycle
• most cells don’t divide unless they are signaled to do so
Cell-Cycle Control System- set of proteins in the cell that both trigger and
coordinate major events in the cell cycle
• the control system sends signals at 2 critical points
• G1 checkpoint- enter the S phase
• M checkpoint - enter the M phase
• Nerve and Muscle cells are permanently stopped at the G1 checkpoint (no
growth factor)
Cell Cycle includes the following: Interphase, G1, S, G2, Mitosis
G2- growth needed for cell division
Gap 1
cell growth and
development
Interphase- includes G1, G2, and S phases
S- DNA synthesis (replication)
The Cell Cycle- follows the life of the cell
• includes: cell growth, preparation for division,
cytokinesis
• all cells move through it at different rates
• one turn covers birth to division/death
• CANCER- uncontrolled cell growth
Cell Cycle Animation
http://www.cancerquest.org/index.cfm?page=58
Mitosis- cellular division (nuclear)
Cytokinesis- splitting of cell into 2 daughter
cells
Phases of Mitosis
Prophase- longest phase
• cells spend 50 to 60% of time here
• chromosomes start to appear
• centrioles separate and move to opposite
sides of the nucleus
• spindle fiber forms
• chromosomes attach to the spindle
• nucleolus disappears and nucleus breaks
apart
Prophase Animation
http://www.phschool.com/science/biology_place/biocoach/mitosisisg/prophase.html
Plant Prophase
Animal Prophase
Metaphase
• shortest phase
• chromosomes line up on
the equator
• centromeres attach to the
spindles
Metaphase Animation
http://www.phschool.com/science/biology_place/biocoach/mitosisisg/meta.html
Anaphase
• centromeres split
• sister chromatids split and move
towards the poles
• cytokinesis starts here- in late
anaphase (the cell starts to split)
Anaphase Animation
http://www.phschool.com/science/biology_place/biocoach/mitosisisg/anaphase.html
Telophase
• final phase
• chromosomes began to uncoil
• nucleus begins to reform around chromatin
• spindle breaks up
• nucleolus becomes visible in both cells
• cytokinesis continues, plants do not go through
cytokinesis they form a CELL PLATE
• mitosis is complete, cytokinesis is not
Telophase animation
http://www.phschool.com/science/biology_place/biocoach/mitosisisg/telo.html
Mitosis Summary
http://www.sumanasinc.com/webcontent/animations/content/mitosis.html
Interactive
http://www.cellsalive.com/mitosis.htm