Do Now What are cells? Why do we need them? List different types of cells that you know of…
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Transcript of Do Now What are cells? Why do we need them? List different types of cells that you know of…
Do Now What are cells? Why do we need them? List different types of cells that you
know of…
Objectives Describe how cells were discovered
and named. Compare and contrast light
microscopes vs. electron microscopes. Explain what is found in a basic cell.
CellsChapter 7
What are cells? Basic structural and functional unit of
all living organisms! They come in all shapes and sizes Lets take a look…
http://www.cellsalive.com/howbig.htm
Cells!
Bacteria cell
Nerve cell
Egg cell
How did we figure out cells even existed, what they looked like, what they do?...
Robert Hooke 1665- saw dead plant
cells from cork, tree stems, roots and ferns using a light microscope
Called them “cellulae” (small rooms) - reminded him of the cubicles or cells where monks live
Leeuwenhoek First person to observe living cells Made microscope with a magnification
10X that of Hooke’s- “Father of microscopes”
Observed spirogyra and protists
The “Cell Theory”
Scientists expressed 3 main observations about cells: All living organisms are composed of
one or more cells Cells are the basic units of structure
and organization of all living organisms Cells come only from the reproduction
of existing cells
Technology is the key! Cells were discovered using MICROSCOPES! Compound Light Microscopes-
Uses visible light to produce magnified image. Maximum = 1,000x magnification
Electron Microscopes- Specimen must be dead Use magnets and electrons Allows much greater magnification
Ex: Transmission Electron = up to 500,000x
Electron Microscopes
Transmission Electron Microscope- Electrons are sent
through a specimen
Scanning Electron Microscope- Electrons are sent over
the surface of a speciment.
Basic Parts of any Cell DNA/RNA
Needs some type of genetic information!
Plasma membrane Cell’s outer boundary that acts as a barrier
Cytoplasm Region of cell that includes fluid, cytoskeleton and all organelles except the nucleus Cytosol- part of cytoplasm that included molecules and small particles but not
organelles
Control Center Contains a cell’s DNA Nucleus- membrane- bound structure in eukaryotes Nucleoid- region of DNA in prokaryotes
Prokaryotic vs. Eukaryotic
Organisms can be made up of either prokaryotic or eukaryotic cells.
Prokaryotic Cells… Do not have a
distinct nucleus No membrane-
bound organelles Ex: bacteria (many
scientists think that prokaryotes are similar to the first EVER organisms on Earth)
Eukaryotic Cells… Contain a nucleus Contain membrane-bound organelles Makes up most multicellular organisms Ex: US, plants, animals, etc. (also some
unicellular organisms like algae and yeast)
Lets Review! Who discovered cells? Why was Leeuwenhoek so special if
someone had already observed cells before?
What are the different types of microscopes we talked about. Which would be best to look at tiny projections on the surface of a bug?
How are eukaryotes different from prokaryotes?
Do Now Students log in at m.socrative.com or
by launching their app. Do Not register for accounts. Simply enter my unique classroom
number to answer questions 420161 = My Room #
Objectives List the different organelles of a cell. Explain the function of each organelle. Identify each organelle in a diagram of
a cell.
Organelle Jigsaw Activity
Do Now
What are the differences between prokaryotic and eukaryotic cells?
Why do we need so many more organelles than bacteria? Explain.
Objectives To list and explain the different
organelles found in all eukaryotic cells. To compare and contrast animal vs.
plant cells. To understand which information
should be studied for the quiz.
Plasma Membrane
The wall!- protects the internal structures of the cell.
Determines what comes in and out of the cell.
Cytoplasm/Cytoskeleton Cytoplasm- clear
fluid that contains the organelles
Cytoskeleton- Provides the framework for the cell, holds organelles in place.
Nucleus Nucleus- controls
the cell.
Nucleolus- produces ribosomes.
Nuclear Pores- allow things in and out of nucleus.
Ribosomes
Makes polypeptide chains of amino acids, producing Proteins.
Endoplasmic Reticulum Rough- contains
ribosomes and synthesizes proteins.
Smooth- No ribosomes, synthesizes lipids (fats).
Golgi Apparatus
Modifies proteins and fats and gets them ready for export!
Vacuoles Large water
“bubble” in a plant cell.
Maintains the shape of the cell, without it, the plant cell would shrink and the plant would wilt.
Lysosomes Contain enzymes,
break down cellular waste product and debris.
Centrioles
Involved in cell division ( we will talk about this more later when we do mitosis!)
Mitochondria
Convert oxygen into energy (we will talk about this more when we do cellular respiration!)
Cilia and Flagella
Used in cells for movement
Used in stationary cells for moving substances around the outside of the cell.
Chloroplasts
Capture light energy and convert it to chemical energy (sugar).
Cell Wall Rigid structure
Provides strength for the cell.
Works with vacuole to maintain “turgor pressure”
Lets brainstorm…get with a partner!
What are the differences between plants and animals?
http://www.youtube.com/watch?v=-zafJKbMPA8
Compare and contrast plant and animal cells.
PlantsAnimals
Quiz Study Guide Organelles- what each of them do Diagrams- label both plant and animal
cell. Scientists- who were they and what did
they do? Cell Theory- what is it? Prokaryotes vs. Eukaryotes- what’s the
difference?
(the dots)
Start working on your “Journey through a Cell Project”
There is construction paper, colored pencils, and markers here for you to use!
Do Now What is the role of the membrane in the
cell? How do you think it accomplishes this
role? Draw a sketch of what the plasma
membrane looks like.
Objectives Understand the role of the plasma
membrane. Identify the components of the plasma
membrane and their functions. Define diffusion.
What ELSE does the membrane do?
Maintains an internal environment that is different from the external environment.
Regulates what molecules enter and exit the cell.
Made of a phospholipid bilayer
“Fluid Mosaic Model” aka the Plasma Membrane Lipids make it fluid Proteins and other components are
embedded like a mosaic.
http://www.youtube.com/watch?v=Qqsf_UJcfBc
Phospholipid?? Gylcerol, 2 fatty acid chains, and a
phosphate group “Phospho”-Hydrophillic (water
loving) Polar (heads) “lipid”-Hydrophobic (water hating)
Non-polar (tails)
Monolayer Fatty Acids Cholesterol How blood can transport
Fats in bulk!
Water
Bilayer
Fats (hydrophobic)
Water or other hydrophilic substances
Water or other hydrophilic substances
Selective Permeability
controls the movement of substances into and out of the cell
Controls AMOUNT of substances entering and leaving the cell
The bilayer makes up the plasma membrane that surrounds the cell!
Which of the 4 organic molecules do you see in the plasma membrane? –P.C.F.NA.
Cholesterol
Prevents fatty acid tails from sticking together
Identify chemical signals
Carbohydrates
Provide channels for transport
Proteins
Conclusion activity
Do Now- Label the different parts What is the name of the entire
structure?
Objectives Define diffusion. Identify the conditions that effect the
rate of diffusion. Explain facilitated diffusion. Compare and contrast active and
passive transport.
How do things get in and out? Everybody stand up! Gather in a group by the windows,
nobody is allowed behind the lab tables.
Cell Membrane (transport)
(H2O, O2, CO2)
(Ions, Sugars, AA’s, nucleotides)
Large and/or Charged-
Transport Protein
Small and/or non-polar molecules
T.P
Diffusion RULE
Diffusion-
Me
Movement of molecules from High concentration to Low Concentration by random motion
Diffusion RULE
Dynamic Equilibrium-continues movement but no NET overall change
Me
Explain what’s happening… Perfume-
Food Coloring-
Initial Conditions
DiffusionLow High
High Low
Diffusion Animations
http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_diffusion_works.html
Things that Affect the speed of Passive Transport
1. Heat- Hotter the faster 2. Size- The bigger the slower 3. State of Matter
Solid- Slow Liquid – Fast Gas- Fastest
Passive Transport Movement of particles across the cell
membrane without using energy
Diffusion of Water
Diffusion of Water- OSMOSIS
Water can move right through the phospholipids from high to low concentration
Facilitated Diffusion Movement of materials across the
plasma membrane using proteins
Carrier ProteinsChannel Proteins
Transport Proteins`
Channel Proteins- Pores that allow charged ions to pass
through the membrane
Carrier Proteins- Change shape to help molecules pass
through the membrane
Cellular Structure and FunctionChapter 7
Transport Proteins Animation http://www.stolaf.edu/people/giannini/
flashanimat/transport/channel.swf
http://www.stolaf.edu/people/giannini/flashanimat/transport/caryprot.swf
Do Now What does “passive” transport mean? What are the different types of passive
transport? What is the difference between passive
and active transport?
Objectives To explain active transport. To understand what happens during
osmosis. To compare and contrast hypertonic,
hypotonic, and isotonic solutions.
Concept Map of Diffusion
Active Transport
Specific protein can pump molecules across the membrane
Usually in opposite direction of diffusion (Low concentration to high concentration)
Requires ENERGY (ATP)
http://www.stolaf.edu/people/giannini/flashanimat/transport/secondary%20active%20transport.swf
Sodium Potassium Pump
http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_the_sodium_potassium_pump_works.html
http://www.sinauer.com/cooper/4e/animations1302.html
Sodium Potassium Pump
Type of Active Transport Moves three Na+ ions out of the cell
and two K+ ions into the cell
Osmosis RULE
-Water always flows via osmosis from HIGH water concentration to LOW water concentration through a semi permeable membrane.
Osmosis Which container has more water in it?
http://www.stolaf.edu/people/giannini/flashanimat/transport/osmosis.swf
Osmosis- diffusion of water across a membrane RULE
-Water always flows via osmosis from HIGH water concentration to LOW water concentration
-Remember SALT SUCKS- cell shrinks
22% Salt
5% Salt
H2O H2O
22% Salt
45% Salt
Osmosis- diffusion of water across a membraneRULE
-Water always flows via osmosis from HIGH water concentration to LOW water concentration
-Cell bursts!
H2O H2O
Cellular Structure and FunctionChapter 7
Blood CellPlant Cell
Isotonic Solution
Cellular Structure and Function
Water and dissolved substances diffuse into and out of the cell at the same rate.
11,397x
Blood Cell
Hypotonic Solution
Solute concentration is higher inside the cell.
Water diffuses into the cell.
Plant Cell
13,000x
Plant Cell
Hypertonic Solution
Solute concentration is higher outside the cell.
Water diffuses out of the cell.
Blood Cell
13,000x
3 Types of Solutions
Cell in ________ Solution
Cell in ________ Solution
Cell in ________ Solution
H2O H2O H2O H2O H2O H2O
For each solution, determine if the solute concentration of the solution is high, the same, or low as compared the cell.
3 Types of Solutions Plasmolysis: State where plant cells shrink in
hypertonic environment (animal cells= “crenates”)
Turgid: State where plant cells swell in hypotonic solution (animal cells=Lyse)
Flaccid: State where a plant cell is placed in isotonic solution
Cytolysis: State where cells Burst in hypotonic environment
http://www.tvdsb.on.ca/westmin/science/sbi3a1/Cells/Osmosis.htm
Osmotic Pressure Pressure builds up as water moves in
and out via Osmosis In plants called Turger Pressure
Worksheet
Usually Transported by Vesicles
Endocytosis-
Into the cell
Exocytosis-
Exiting the cell
Transport of Large Molecules
What kind of molecules do you think are usually found in the Vesicle?