Diffusion Diffusion:

• The net movement of particles from an area of higher concentration to an area of lower concentration. Due to random movement

The Rate of Diffusion is affected by 3 different factors:

1. Temperature

2. Concentration

3. Pressure

Osmosis Is the diffusion of

water through a semipermeable membrane

• Movement of water is from an area of low concentration (of solute) to and area of high concentration (of solute)

Hypertonic, Hypotonic, Isotonic

Hypertonic:• A solution with a high concentration of solute

Hypotonic:A solution with a low concentration of solutes

IsotonicA solution that has the same or equal strengths of

solutes in a solution

The Cell Watch Intro Video

• Answer the following questions What is a prokaryote? Where did modern plant/animal cells come from? What is a eukaryote?

http://www.dnatube.com/video/2318/Cell-Biology

The Cell

The Cell

The Discovery

The Cell Theory 1. All organisms are composed of one

or more cells.

2. The cell is the basic unit structure and organization of all organisms.

3. All cells come from preexisting cells.

The CellTHERE ARE 2 TYPES OF CELLS…

Prokaryotes Eukaryotes

http://videos.howstuffworks.com/hsw/23414-cell-cell-characteristics-video.htm

Prokaryotic Cells Cells that DO NOT contain membrane

bound organelles (no nucleus)

Most bacteria and unicellular organisms

Eukaryotic Cells Cells containing membrane bound

organelles

Most of multicellular life fits into this category.• However some unicellular life as well

Amoebas, algae, etc

The Plasma Membrane The flexible boundary between the

cell and its environment

• Responsible for letting things in and out of the cell and maintaining homeostasis in the cell.

The Plasma Membrane

The Plasma Membrane Has Selective Permeability-

• The means it allows some molecules to pass through while others or kept out

Transport Proteins: specialized proteins that move molecules into and out of the cell

The Plasma Membrane The plasma membrane is composed

primarily of a phospholipid bilayer

• Phospholipids have a polar head (hydrophilic) and a nonpolar (hydrophobic) tail.

• Why?

The Plasma Membrane The Fluid Mosaic Model

The Cell Wall The cell wall: is a rigid structure that

is located outside of the plasma membrane that provides additional support and protection.

Found in Plant cells not Animal cells• Also in some bacteria, fungi and protists.

Cell Wall

Organelles Are specialized subunits within a cell

that have specific functions• Mini Organs is another way to think about it.

Remember Organelles are only in Eukaryotes

Membrane bound

Organelles Nucleus

Considered the “CONTROL CENTER” of the cell.

Site where DNA (genetic information) is stored as Chromatin

Organelles Nucleolus

• non-membrane bound structure composed of proteins and nucleic acids found within the nucleus

Ribosomes are made here

Ribosomes Ribosomes

• Sites of Protein Synthesis

• Not bound, can freely move to different partsof the cell.

Found in both eukaryoticand prokaryotic cells

Cytoplasm Cytoplasm

• The clear gelatinous fluid inside a cell

• Contains nutrients that allow for cell to grow and develop

Organelles Endoplasmic Reticulum (rough)

• Site of cellular chemical reactions Help finish protein synthesis

• Highly folded Allows for lots of work in a little space

E.R. (smooth)• Involved in lipid production and storage of lipids

Organelles Golgi Apparatus (complex):

• Protein Post Office of a cell

• Packages proteins into vesicles to be sent to appropriate destinations in the cell

Organelles Vacuole

• Membrane-bound compartments used for storage of materials

Lysosome• The garbage disposal of a cell• Uses digestive enzymes to get rid of

viruses, bacteria, and old parts of the cell.

Organelles Mitochondria

• The power plants of cells

• Transform energy for cell use in the form of ATP.

Chloroplast Capture energy from sunlight

and convert it into chemical energy (ATP) in a process called photosynthesis

Primarily in Plants

Has green chlorophyll (a pigment that captures sunlight)

Cytoskeleton Is the network of protein filaments

that help a cell maintain its shape

• Can also aid in cell movement

• Microtubules, microfilaments and centrioles are part of the cytoskeleton