2Prokaryote bacteria cells Eukaryote animal cells Types of cells- no organelles- organellesEukaryote animal cellsEukaryote plant cells
3Why organelles? mitochondria chloroplast Golgi ER Specialized structuresspecialized functionscilia or flagella for locomotionContainerspartition cell into compartmentscreate different local environmentsseparate pH, or concentration of materialsdistinct & incompatible functionslysosome & its digestive enzymesMembranes as sites for chemical reactionsunique combinations of lipids & proteinsembedded enzymes & reaction centerschloroplasts & mitochondriachloroplastGolgiWhy organelles?There are several reasons why cells evolved organelles. First, organelles can perform specialized functions. Second, membrane bound organelles can act as containers, separating parts of the cell from other parts of the cell. Third, the membranes of organelles can act as sites for chemical reactions.Organelles as specialized structuresAn example of the first type of organelle is cilia, these short filaments act as "paddles" to help some cells move.Organelles as ContainersNothing ever invented by man is as complex as a living cell. At any one time hundreds of incompatible chemical reactions may be occurring in a cell. If the cell contained a uniform mixture of all the chemicals it would not be able to survive. Organelles surrounded by membranes act as individual compartments for these chemical reactions. An example of the second type of organelle is the lysosome. This structure contains digestive enzymes, these enzymes if allowed to float free in the cell would kill it.Organelle membranes as sites for chemical reactionsAn example of the third type of organelle is the chloroplast. The molecules that conduct the light reactions of photosynthesis are found embedded in the membranes of the chloroplast.ER
4Cells gotta work to live! What jobs do cells have to do?make proteinsproteins control every cell functionmake energyfor daily lifefor growthmake more cellsgrowthrepairrenewal
6Proteins do all the work! cellsDNARepeat after me…Proteins do all the work!organism
7Cells functions Building proteins read DNA instructions build proteins process proteinsfoldingmodifyingremoving amino acidsadding other moleculese.g, making glycoproteins for cell membraneaddress & transport proteins
9What kind of molecules need to pass through? histone proteinchromosomeDNANucleusFunctionprotects DNAStructurenuclear envelopedouble membranemembrane fused in spots to create poresallows large macromolecules to pass throughnuclearporesporenuclear envelopenucleolusWhat kind of molecules need to pass through?
10production of mRNA from DNA in nucleus nuclearmembrane1production of mRNA from DNA in nucleussmallribosomalsubunitlargecytoplasmmRNAnuclear pore2mRNA travels from nucleus to ribosome in cytoplasm through nuclear pore
12Nucleolus Function ribosome production build ribosome subunits from rRNA & proteinsexit through nuclear pores to cytoplasm & combine to form functional ribosomessmallsubunitlarge subunitribosomerRNA &proteinsnucleolus
13Ribosomes Function Structure protein production rRNA & protein smallsubunitlargeRibosomesFunctionprotein productionStructurerRNA & protein2 subunits combine0.08mmRibosomesRoughERSmoothThe genes for rRNA have the greatest commonality among all living things. There is very little difference in the DNA sequence of the rRNA genes in a humans vs. a bacteria.Means that this function (building of a ribosome) is so integral to life that every cell does it almost exactly the same way.Change a base and this changes the structure of the RNA which causes it to not function.
14Types of Ribosomes Free ribosomes Bound ribosomes suspended in cytosol synthesize proteins that function in cytosolBound ribosomesattached to endoplasmic reticulumsynthesize proteins for export or for membranesmembrane proteins
15Endoplasmic Reticulum Functionprocesses proteinsmanufactures membranessynthesis & hydrolysis of many compoundsStructuremembrane connected to nuclear envelope & extends throughout cellaccounts for 50% membranes in eukaryotic cell
17Smooth ER function Membrane production Many metabolic processes synthesissynthesize lipidsoils, phospholipids, steroids & sex hormoneshydrolysishydrolyze glycogen into glucosein liverdetoxify drugs & poisonsex. alcohol & barbiturates
18Membrane Factory Build new membrane synthesize phospholipids builds membranesER membrane expandsbud off & transfer to other parts of cell that need membranes
19Which cells have lot of rough ER? Rough ER functionProduce proteins for export out of cellprotein secreting cellspackaged into transport vesicles for exportWhich cells have lot of rough ER?Which cells have a lot of ER?protein production cells like pancreas = production of digestive enzymes (rough endoplasmic reticulum from a cell of exocrine pancreas (88000X))