Dissecting the cell

 Cells must control the materials that enter and leave.  The PM is the boundary between the cell and it’s environment.

 Homeostasis is the process of maintaining the cell’s environment.  Selective permeability is the process where a cell allows some molecules into the cell and not others.

 PM is made of a phospholipid bilayer  Two phospholipid layers  Hydrophilic – “likes” water  Hydrophobic – “afraid” of water

 Thick jelly-like substance that fills the cell  Allows material to be moved around the cell.

The Nucleus

 The nucleus contains the genetic material for the cell  Chromosomes  Nuclear Envelope  Double membrane  Nuclear pores

 Chromosomes are made of DNA.  DNA is the genetic material that holds all the information in the organism.  Located inside the nucleus

 Organelle Summary Sheet  Flashcards

Other organelles

 Ribosomes control protein synthesis  Made by the nucleolus  Found floating freely in the cytoplasm or on the rough endoplasmic reticulum

 Site of chemical reactions in the cells  Rough ER  Covered in ribosomes  Smooth ER  No ribosomes

 Sorts and packages products of the ER  Sends packaged proteins to various locations around the cell  Uses vesicles as packaging

 Vacuoles are used in temporary storage of materials  Plant cells have one large vacuole while animal cells have many smaller vacuoles  Lysosomes contain digestive enzymes that break apart cellular waste for re-use

Mitochondria

 Energy powerhouses for the cell  Found in plant and animal cells  Double membrane  Increased surface area for reactions

 Interior network of support in cells  Criss-crossed web of small “support beams”  Microtubules  Microfilaments

 Organelle Summary Sheet  Flashcards