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Introducing your stars of the day…. CELLS!. The Dynamic Duo!. There are two types of cells: Cells w/internal, membrane-bound structures Cells without! PROKARYOTES -Form unicellular organisms (bacteria) -No membrane-bound structures (Remember what the root “ pro ” means?) 2) EUKARYOTES
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The Dynamic Duo! • There are two types of cells: • Cells w/internal, membrane-bound structures • Cells without! • PROKARYOTES -Form unicellular organisms (bacteria) -No membrane-bound structures (Remember what the root “pro” means?) 2) EUKARYOTES -Form multicellular organisms (plants and animals) -Contain membrane-bound structures called ORGANELLES
Setting the Stage for Cell Activities! • The cell has to maintain a balance (homeostasis) of nutrients and wastes. It has to keep its audience happy! • In comes the PLASMA MEMBRANE! • Boundary between cell and environment • Allows nutrients in and waste out • Regulates levels of nutrients/wastes in cell
Behind the Scenes: Plasma Membrane! SELECTIVE PERMEABILITY! Do you have a backstage pass? • The plasma membrane of a cell allows some molecules into the cell, but keeps others out. • Some molecules are allowed in freely, like water, whereas others have limited access, like sodium. • Limited access molecules have to enter through special doors called PROTEIN CHANNELS.
Building the Set! Structure of the Plasma Membrane THE INFAMOUS PHOSPHOLIPID BI-LAYER! • Remember that a lipid is what makes up a fat! • Phospho- refers to a Phosphate group from the element Phosphorus • Bi- means 2 so it must be 2 layers!
Building the Set! Structure of the Plasma Membrane • BRRRR! Polar and Non-Polar ends! • The fatty acid (lipid) tails are NONPOLAR. • NONPOLAR means they hate water and prevent certain water-insoluble molecules from entering the cell! • The head is POLAR. • POLAR means it loves water and helps to bring water into the cell!
The Pre-Show Act…The Fluid Mosaic Model! • The movement of molecules in and out of the plasma membrane is described by the FLUID MOSAIC MODEL. • It is fluid because the membrane is flexible! • The membrane moves with the currents, just like waves on a lake. • The imbedded proteins move like boats on the surface of the lake (above and below) • These proteins form a pattern or mosaic on the surface of the membrane. • TRANSPORT PROTEINS are the proteins that move the nutrients/wastes through the membrane.
The Tech Crew! General Cell Organelles • What does organellesound like? • ORGANS! Each organ serves a purpose in your body. • Likewise, each organelle has its own function in the cell. • The organelles work together to help the cell function properly.
The Tech Crew CELL WALL • Found in plant cells, fungi, & bacteria • Rigid structure located outside plasma membrane • Provides additional protection and support • Inflexible barrier, yet porous • Made of CELLULOSE in plants • Not selectively permeable
The Tech CrewNUCLEUS • The leader of the cell! • Contains directions to make proteins which run the cell functions • Directions are found in CHROMATIN (DNA strands) • BRAIN of the cell!
The Tech CrewNUCLEOLUS • Located within the nucleus • Makes RIBOSOMES • RIBOSOMES are the sites at which enzymes and proteins are made • Ribosomes move out of the nucleolus and the nucleus through nuclear pores to the cytoplasm • There is a nuclear envelope outside the nucleus that contains these pores.
The Tech CrewCYTOPLASM • Clear, gelatinous (Jello-like) fluid in cell • Proteins are made in the cytoplasm
The Tech Crew!ENDOPLASMIC RETICULUM • Site of cellular chemical reactions Highly folded membranes in cytoplasm • Large workplace in cell for protein synthesis • Folds allow for a large surface area to be stored in a small space in the cell • Ribosomes attach to ER and it is called ROUGHER • Area of ER without ribosomes are called SMOOTH ER
The Tech CrewGOLGI APPARATUS • Flattened system of tubular membranes • After proteins are made in ER they are transported to Golgi apparatus • Sorts proteins and packages them to be sent throughout the body (Like mail!)
The Tech CrewVACUOLES • Stores materials temporarily • Sac surrounded by membrane • Store food, enzymes, & wastes
The Tech CrewLYSOSOMES • Contain digestive enzymes • Digest excess or worn out organelles, food particles, viruses or bacteria • Membrane protects lysosomes from digesting itself! (like the lining of your stomach!) • The Garbage Men of the cell!
The Tech CrewCHLOROPLASTS • Capture light energy and produce food for storage • Have a membrane • Found in plant cells only!
The Tech CrewMITOCHONDRIA • Transforms energy for cell • POWERHOUSE of cell! • Has an outer and highly folded inner membrane to fit large surface area into a small space
The Tech CrewCYTOSKELETON • What does CYTE mean? • So CYTOSKELETON is a CELL SKELETON! • Composed of tiny rods and filaments to form a framework to help support cell • Constantly changing structure
