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.

Cells

Chapter 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!

Egg cell How did we figure out cells even existed, what they looked like, what they do?...

Bacteria cell Nerve cell

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

launching their app. or by 

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 the cell.

controls 

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 Plants and animal cells.

Animals

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

Phospho lipid??

  

Gylcerol, 2 fatty acid chains, and a phosphate group “ Phospho ”-Hydrophillic (water loving) Polar (heads) “ lipid ”-Hydrophobic (water hating) Non-polar (tails)

Mono layer



Fatty Acids



Cholesterol



How blood can transport Fats in bulk!

Water

Bi layer Water

or other hydro philic substances

Fats ( hydro phobic ) Water

or other hydro philic 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

Carbohydrates



Identify chemical signals

Proteins



Provide channels for transport

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)

(Ions, Sugars, AA’s, nucleotides) T.P

(H 2 O, O 2 , CO 2)

Large and/or Charged-

Transport Protein

Small and/or non polar molecules

Diffusion RULE



Diffusion -

 Movement of molecules concentration to Low random motion from High Concentration by Me

Diffusion RULE



Dynamic Equilibrium -continues movement but no NET overall change

Me

Explain what’s happening…



Perfume-



Food Coloring-

Initial Conditions Low Diffusion High High Low

Diffusion Animations



http://highered.mcgraw hill.com/sites/0072495855/student_view 0/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 Channel Proteins Carrier 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

Chapter 7 Cellular Structure and Function

Transport Proteins Animation



http://www.stolaf.edu/people/giannini/fl ashanimat/transport/channel.swf



http://www.stolaf.edu/people/giannini/fl ashanimat/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/flasha nimat/transport/secondary%20active%20tran sport.swf

Sodium Potassium Pump



http://highered.mcgraw hill.com/sites/0072495855/student_view0/c hapter2/animation__how_the_sodium_pota ssium_pump_works.html



http://www.sinauer.com/cooper/4e/animati ons1302.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 concentration

LOW

water -Remember SALT SUCKS- cell shrinks

22% Salt 5% Salt H 2 O H 2 O

Osmosis- diffusion of water across a membrane

 RULE Water always flows via osmosis from

HIGH

water concentration to

LOW

water concentration -Cell bursts!

22% Salt 45% Salt H 2 O H 2 O

Chapter 7 Cellular Structure and Function

Cellular Structure and Function

Isotonic Solution  Water and dissolved substances diffuse into and out of the cell at the same rate.

Plant Cell Blood Cell

11,397x

Hypotonic Solution  Solute concentration is higher inside the cell.

 Water diffuses into the cell.

Plant Cell Blood Cell

13,000x

Hypertonic Solution  Solute concentration is higher outside the cell.

 Water diffuses out of the cell.

Plant Cell Blood Cell

13,000x

3 Types of Solutions

Cell in ________ Solution Cell in ________ Solution

H 2 O H 2 O H 2 O H 2 O

Cell in ________ Solution

H 2 O H 2 O

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/Os mosis.htm

Osmotic Pressure



Pressure builds up as water moves in and out via Osmosis



In plants called

Turger Pressure  Worksheet

Transport of Large Molecules



Usually Transported by

Vesicles

 Endo cytosis-

Into the cell

Exo cytosis-

Exiting the cell

What kind of molecules do you think are usually found in the Vesicle?