Structures and their functions Cell Biology Structures and their functions

Cell Theory All life is made of cells Cells are the functional unit of organisms Animal and plant cells are eukaryotic Contain a nucleus (and other organelles)

Plant cells, Animal cells Unique: Cell wall, central vacuole, chloroplasts Unique: centrioles

Cell membrane Outer boundary of all cells Made of a double layer of phospholipid molecules with imbedded proteins Separates cell contents from outer environment Membrane performs important functions for cell

Cell wall Plant cell structure Primary cell wall Secondary cell walls Outside cell membrane Functions: Protection Support Primary cell wall Made of cellulose Secondary cell walls Between primary cell wall & cell membrane Made of lignin (very strong material)

Nucleus Prominent organelle Contains genetic information on chromatin Threadlike strands that condense into chromosomes for cell division Nucleolus is region that produces ribosomal RNA

Nuclear envelope Membrane that separates nucleus from cytoplasm Functions: Maintain nucleus shape Chromatin attachment sites “gatekeeper” of nucleus Only some materials can pass in/out Nuclear pores Allow passage of large molecules Ribosome subunits proteins