8Eukaryotic Cell Organelles and Function Cell MembraneNickname: “The Gatekeeper”Function: forms outer boundary of the cell allows only certain materials to move into and out of the cellParts: made up of a double layer of fats with some proteins scattered throughout
9Animal Cell Figure 7-5 Plant and Animal Cells Cytoplasm Cell Membrane Section 7-2CytoplasmCell MembraneGo to Section:
11Eukaryotic Cell Organelles and Function CytoplasmGel-like material inside the cell membrane and outside the nucleusFunction: contains water, chemicals, and the various cell organellesCytoplasm constantly moves or streams
12Animal Cell Figure 7-5 Plant and Animal Cells Cytoplasm Nucleolus Section 7-2CytoplasmNucleolusNucleusCell MembraneNuclear MembraneGo to Section:
14Eukaryotic Cell Organelles and Function NucleusNickname: “The Control Center”Function: holds the DNAParts:Nucleolus: dark spot in the middle of the nucleus that helps make ribosomesNuclear envelope/membrane: surrounds nucleus in eukaryotic cells, has pores to let material in and out of the nucleus
15Eukaryotic Cell Organelles and Function NucleusParts:Chromatin: Strands of genetic material found in the nucleus, made of protein and DNA
26Eukaryotic Cell Organelles and Function Endoplasmic Reticulum (ER)Nickname: “Roads”Function: The internal delivery system of the cell
27Endoplasmic Reticulum 2 Types:Rough ER:Rough appearance because it has ribosomes on its surfaceFunction: helps make proteins, that’s why it has ribosomesSmooth ER:NO ribosomesFunction: makes fats or lipids
30Eukaryotic Cell Organelles and Function Golgi Complex (Golgi Body)Nickname: The shippersFunction: packages, modifies, and transports materials to different location inside/outside of the cellAppearance: stack of pancakesStructure: stack of membrane-covered sacs
35Eukaryotic Cell Organelles and Function Lysosomes: circular, but bigger than ribosomesNickname: “Clean-up Crews”Function: to break down food into particles the rest of the cell can use and to destroy old cells
40Eukaryotic Cell Organelles and Function CentriolesFunction: Help with cell divisionOnly found in animal cellsLook like two small bundles of spaghetti arranged perpendicular to each other
41Now let’s talk about structures only found in PLANT Cells!!
42Plant Cell Figure 7-5 Plant and Animal Cells Vacuole Cell Membrane Section 7-2VacuoleCell MembraneGo to Section:
43Eukaryotic Cell Organelles and Function VacuolesFunction: stores waterThis is what makes lettuce crispWhen there is no water, the plant wiltsAnimal cells have vacuoles to provide temporary storageVacuoles in animal cells are smaller than plant vacuoles
56It’s a question of control. Cell TransportIt’s a question of control.
57Who’s in control? Cells get nutrients, etc. from environment Release waste into same environment
58Moving along…or not!Selective permeability: property of a cell membrane which allows some materials to pass through while keeping others out.
59Diffusion Molecules move constantly Move from crowded conditions to less crowded conditionsParticles diffuse in liquids and in gases
60Diffusion cont’dEquilibrium: molecules of a substance are spread evenly throughout a spaceMolecules continue to move during equilibrium
61Osmosis—Diffusion of H2O The diffusion of water through a cell membraneMost cells surrounded by water molecules and contain water molecules
62Osmosis Cont’d What happened to egg cells in lab? If cells aren’t surrounded by pretty pure water, they’ll lose the water.No water molecules in corn syrup around eggs—so ….
63Water tended to move out of the cells and dilute the corn syrup Cells became shriveled and yolks became firm
64Place eggs in pure water and the process is reversed The eggs swell up and the yolks slosh around inside
65Moving on…Particle movement across cell membrane by diffusion is called passive transport because…Cell doesn’t use energy to move the materials
66Active transport: energy required to move large molecules through cell membrane Need help of transport proteins
67Active transport is required to move substances from where there are small amounts to where there are large amounts
68Cell membraneCell membrane is composed of a double layer (bilayer) of phospholipids with protein molecules scattered throughoutPhospholipids make a bilayer with polar heads facing out and hydrophobic tails facing in