 Smallest unit of life, Discovered by Robert Hooke 1695  Cell Theory:  1. All living things have cells  2. Cells are the basic unit of life and function  3. Cells only come from preexisting cells

 Variety of sizes and shapes  Nerve cells shaped like fingers  Most cells are round in shape  Some cells change shape ◦ White blood cells  The shape of a cell depends on the cell membrane and it’s function

 Cells are microscopic for the most part  Some can be as large as 6ft in giant algae  The cell size is limited by the ______________ of the cell membrane  A cell can only grow so large then it will burst

 : structures in a cell that perform a specific function  : these are cells with membrane-bound organelles and a nucleus  : these are cells that do not have membrane-bound organelles or a nucleus

 It is : only certain things may pass through  Forms a : 2 layers of lipids like a sandwich  1. Maintains the shape of the cell and 2.protects it  Fats and proteins are embedded in the phosholipid bilayer

 : have two ends on them that keep water and nutrients inside  Form a bond that is difficult to break  These lipids are vital to the cell’s survival  Acts like a floating layer, constantly changing shape

 Do 3 things:  1. Hold the membrane together  2. Allow for channels to be made in the membrane  3. Act as receptors for hormones and other compounds

 Model of the cell membrane that shows it’s “dynamic ability”, how it is more like a liquid than a solid  The patterns of lipids and proteins are always changing

 Powerhouse of the cell  Transfers energy from ATP to make the cell function  Has it’s own DNA,most important organelle to the cell  Muscle cells will have more mitochondria than other cells

 Most numerous organelle in a cell  Found in both prokaryotes and eukaryotes  They are not covered in a membrane  They synthesize, or create, proteins  Smallest of the organelles  Vital to cell function and reproduction  Found floating in the cytoplasm and on the rough ER ◦ Proteins made on free-floating ribosomes are used within the cell; proteins made on rough ER are usually shipped to the cell membrane or out of the cell

 Known as the ER, System of tubes and channels  “highway” inside of the cell  2 types rough and smooth  Rough ER has ribosomes along the outside of it  Smooth ER lacks ribosomes and is found in liver cells  The amount of ER in a cell will fluctuate depending on how active a cell is in the body

 Makes proteins that are shipped to the cell membrane or out of the cell completely; the proteins made here are sent to the Golgi apparatus for packaging and export

 System of membranes within the cell used to package and ship proteins  “UPS” of the cell  Modifies or changes proteins before they leave the cell  Allows cells to take proteins and ship them to other cells to be used  Often located next to the ER

 Small spheres containing enzymes used for digestion  Also eat up harmful bacteria and cells  Not found in plant cells, only animal cells  In humans, these organelles aid in development by destroying certain fetal tissues

 Houses the DNA in the cell  Largest organelle in the cell  Controls all of the functions of the cell  Must divide when cells reproduce  Has it’s own membrane around it  Controls growth, metabolism and genetics of a cell  Nucleolus: small part inside nucleus that makes ribosomes

 Found in plant cells  Less flexible than cell membrane  Gives plant cells the ability to stand up and grow into trees, flowers etc.  Cell wall is thicker than cell membrane

 : Contain digestive enzymes in plants.  Some plants will store toxins in the vacuoles that are poisonous, like poison ivy  : contain chlorophyll so that plants can make food from sunlight  Chlorophyll is usually a shade of green

 Long protein strands found in the cell  Provide support for the cell  Help to maintain the shape of a cell  Help in the movement of chromosomes when the cell divides  Vital to the survival of the cell, if these proteins die the cell will loose it’s shape and die as well

 Assist in movement of the cell  : Hair-like extensions on the outside of the cell membrane  : whip-like tail on the cell membrane of cells  Sperm cells use flagella to swim towards the egg cell  Cilia are found in lung cells to sweep out debris

 Similar cells that are grouped together form.  4 main types of tissues: muscle, nervous, connective and epithelial.  Organs are a bunch of tissues that work together to perform a function. Example: the heart  Many organs working together are an : digestive system uses the stomach, intestines, kidneys etc.  Organelles Cells Tissues Organs  Organ systems Organism