BIO 101 1st Edition Lecture 9 Outline of Last Lecture I Water Balance in Cells a Hypertonic b Hypotonic c Isotonic II Facilitated Diffusion III Active Transport a Ion Transport b Co Transport IV Traffic of Large Molecules a Exocytosis b Endocytosis i Phagocytosis ii Pinocytosis iii Receptor mediated endocytosis Outline of Current Lecture I Main Kinds of Cells a Prokaryotic b Eukaryotic II Cell Size III Eukaryotic Cell Components IV Endomembrane System V Other Organelles Current Lecture Chapter 6 Tour of the Cell Remember the cell theory all living things are made of cells all cells come from other cells The cell is the basic unit of life 2 main kinds of cells Prokaryotic smaller simpler cells Bacteria and blue green algae No true nucleus No membrane bound organelles Eukaryotic larger more complex True nucleus membrane bound Membrane bound organelle Fungi plants and animals BIO 101 1st Edition Cell Size Most are small visible only under microscope Small size is because the surface area volume ration Needs to be large transport reasons getting things in and out Nuclear control close proximity to nucleus Eukaryotic cells are approx 10x larger than prokaryotic cells How do they compensate They have developed a system of membrane bound structures called organelles These organelles are used to compartmentalize incompatible processes keep them separate The abundant complex internal membranes effectively increase surface area of eukaryotic cells Eukaryotic Cell Components Nucleus source of genetic material DNA surrounded by double membrane with nuclear pores big enough for large molecules and ribosomes to pass through Nucleolus place inside nucleus where ribosomes are assembled looks like a dark spot in nucleus Cytoplasm everything between nucleus and plasma membrane includes semi fluid cytoplasm and organelles Ribosomes site of protein synthesis made of RNA and proteins Endomembrane system complex system of interrelated membranes that are either DIRECTLY CONNECTED to one another or INDIRECTLY CONNECTED by vesicles membrane sacs which are pinched off and move from one membrane site to another Summary of Endomembrane System Nuclear membrane is directly connected to the ROUGH ENDOPLASMIC RETICULUM RER which is directly connected to the SMOOTH ER SER ER is connected via vesicles to GOLGI APPARATUS which is connected via vesicles to LYSOSOMES VACUOLES and PLASMA MEMBRANE Functions 1 RER network of membranes with ribosomes attached like tubes with inner space called cistemae membranes are made on RER phospholipids are made by enzymes in the RER membrane membrane proteins are made by ribosomes on the RER and embedded in newly made phospholipid bilayer 2 SER connected to RER but without ribosomes synthesizes fat steroids sex hormones DETOXIFIES drugs and poisons 3 Golgi Complex stacked flattened membrane sacs modify store and route products of ER BIO 101 1st Edition a Forming face vesicles from ER fuse here b Maturing face gives rise to new vesicles Often carbohydrates are added and modified to proteins these direct the protein to correct destination 4 Lysosomes sac of hydrolytic enzymes single membrane clean up garbage in cell digest food particles destroy invading bacteria role in cell suicide part of development 5 Vacuoles like transport vesicles but bigger storage space garbage dump plant cells have large central vacuole very versatile storage toxic compounds Other Organelles NOT part of Endomembrane System membranes not made on ER increase by dividing microbodies sacs that contain specialized teams of enzymes for a specific metabolic task ex peroxisome breakdown fats detoxify alcohol process produces H2O2 hydrogen peroxide which is toxic so also contain catalase and enzyme that turns H2O2 toxic H2O O2 harmless Energy Transducers Mitochondria and chloroplasts captured prokaryotic cells Produce energy for the cell Surrounded by double membrane Not part of endomembrane system not made by ER Grow and divide Have their own ribosomes Code for some of their own proteins contain own DNA Mitochondria site of cellular respiration found in nearly ALL eukaryotic cells Chloroplasts site of photosynthesis PLANTS ONLY make sugar using CO2 and H2O
View Full Document
Unlocking...