BIO 243 1st EditionLecture 5Outline of Last Lecture I.Proteins ctda.EnzymesII.Nucleic Acidsa.Nucleotidesb.DNAc.RNAd.ATPIII.Cellsa.OrganellesOutline of Current Lecture I. Organelles Ctd.a. Ribosomesb. Endoplasmic Reticulumc. Golgi Apparatusd. Lysosomese. VesiclesII. PathwayIII. Cytoskeletona. FilamentsIV. NucleusV. Plasma MembraneCurrent Lecture1. Organelles Continueda. Ribosomesi. Contain protein and ribosomal RNAii. Involved in the synthesis of proteins from messenger RNA template b. Endoplasmic Reticulumi. A series of membranes that generate space, lumen ii. Smooth endoplasmic Reticulum (SER)1. Phospholipid synthesis2. Detoxificationiii. Rough Endoplasmic Reticulum (RER)1. Ribosomes are attached 2. Secreted proteins, membrane protein, lysosomal protein, Golgi and endoplasmic reticulum proteinsa. Only synthesized in the RERc. Golgi apparatus i. Membrane adjacent to the RERii. Proteins are modified, cleavediii. Set to be Packagedd. Lysosomesi. Membrane boundii. Acidic environmentiii. Hydrolytic enzymes e. Vesicles i. Pinches off from the Rough ERii. Transports to the Golgiiii. Packed with proteins hat determine their ultimate destination 2. Pathway a. Cell surface b. Golgi Apparatus  Lysosomes c. Rough ER3. Cytoskeleton a. Consists of a series of filamentsb. 3 types of filamentsi. Microfilaments1. Comprised of a protein known as actin2. Maintain the cell shape 3. Involved in cell motility 4. They can polymerize (get longer) and depolymerize (get shorter)ii. Intermediate filaments1. Bigger than microfilaments2. Multiple typesa. Keratini. in epithelial cellsii. most commonb. Neurofilamentsi. in nervous tissue3. Rope like, very strong4. Resist mechanical stressiii. Microtubules1. Made of tubulin subunits2. Can polymerize and depolymerize3. Motor moleculesa. Can attach to receptors on organelles or vesicles and can move the organelles along microtubules b. ATP powered c. Can also cause cytoskeleton elements to slide over other elementsi. Muscle contractionii. Cilia movementiv. Cilia and Flagella1. Assist with movement2. Comprised of microtubulesa. Comprised in a 9 + 2 arrangement3. Ciliaa. Small hair like structures b. Ciliary motioni. Traveling wave created by the activity of many cilia acting together to propel things across cell surfaces 1. Ex. Propels mucus down throat 4. Flagellaa. Tail of a sperm cellv. Nucleus1. Contains DNA 2. DNA is synthesized and replicated3. RNA synthesis 4. RNA processing 5. Encased by the nuclear envelope/membrane a. Double layered membraneb. Nuclear pores act as holes in the nuclear envelope 6. Contains a nucleolusa. Ribosomal RNA is synthesizedb. Ribosome assembly occurs here7. Chromatina. DNA + proteinvi. Plasma Membrane1. Terminologya. Hydrophobic – water fearingi. Lipids and other non polar moleculesb. Hydrophilic – water lovingi. Polar molecules2. Phospholipid bilayera. Backbone of the plasma membraneb. Semipermeablec. Heads are hydrophilicd. Fatty acid tails are hydrophobici. Provides a barrier 1. Separates cell from the rest of the world2. Only nonpolar molecules can pass through the hydrophobic region e. Cholesterol i. Stabilize ii.