Chapter 3.2

 Remember: These are the bigger and more organized cells that make you what you are.  They are unique because they have a nucleus and organelles.

 The cytoskeleton is a network of proteins that forms long fibers that give structure to the cell.  This is constantly changing in order to help the cell.  3 kinds of fibers make these up:

 Microtubules: ◦ Long hollow tubes that pull apart DNA in division  Intermediate filaments: ◦ Smaller than microtubules and give strength  Microfilaments: ◦ Smallest fibers, allows cells to move and divide.

 The nucleus contains most of the DNA in your cells.  Nucleus serves two roles ◦ DNA has to be protected ◦ DNA must be available for use when needed  Since DNA needs to be accessed, there is a nuclear envelope that allows things to move in.

 Has pores in the envelope that gives access to things (usually proteins)  Nucleolus is the center of the nucleus  This is where ribosomes are assembled.

 An interconnected network of folded membranes.  The more folds it has, the more surface it has.  This allows for the production of many proteins and lipids.

 Some portions of the ER are covered with ribosomes. Some ribosomes float around.  This is where amino acids are linked to make proteins.  ER with these covering it is called the Rough Endoplasmic Reticulum.  Without is called the Smooth Endoplasmic Reticulum.

 This is where proteins go after they are made in the ER.  They are sorted and delivered all around the cell/body from here.  Sometimes proteins are stored here.

 Remember how reactions happen. ◦ We have reactants and products  If reactants mix we start a chemical reaction early, which we don’t want to happen in our cells.  We separate these reactions by using vesicles.  They are membrane bound sacs that are used for transporting materials.

 Supply energy to the cell  Has many folds that allows for a lot of chemical reactions  Have their own DNA and ribosomes

 A fluid-filled sac that usually stores materials that the cell may need later  Animal cells have very small vacuoles  Plant cells have very large vacuoles

 Membrane bound organelles that contain enzymes.  This is used as a recycling system for the cell ◦ Break down old parts ◦ Destroy some viruses and bacteria  Usually “attacks” after a package leaves the Golgi apparatus.

 Rigid layer outside of the cell that gives much of the structure to a cell.  Only found in plant/bacteria/fungi  Not found in animal cells

 Organelles that perform photosynthesis.  This is where solar energy is converted into chemical energy  This also contains chlorophyll – a light absorbing molecule  This is the green part of plants.