* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Topic One: Cell Membrane - Red Hook Central Schools
Survey
Document related concepts
Lipid bilayer wikipedia , lookup
Cytoplasmic streaming wikipedia , lookup
Cell culture wikipedia , lookup
Cell growth wikipedia , lookup
Cell encapsulation wikipedia , lookup
Extracellular matrix wikipedia , lookup
Cellular differentiation wikipedia , lookup
Cell nucleus wikipedia , lookup
Cytokinesis wikipedia , lookup
Organ-on-a-chip wikipedia , lookup
Signal transduction wikipedia , lookup
Cell membrane wikipedia , lookup
Transcript
Cells And Cellular Transport Where does the name “cell” come from? • “Cells” were named by Englishman Robert Hooke in 1665. • He observed that cork wood looked like monk’s cells in a monastery. The Cell Theory 1. The cell is the basic unit of structure and function. 2. All organisms are made of one or more cells. 3. All cells come from pre-existing cells. Exceptions to the Cell Theory 1. Viruses!! They have DNA and/or RNA inside a protein shell. They are capable of reproduction inside another living cell, but not on their own. 2. Mitochondria and chloroplasts have their own DNA and can reproduce inside a cell. 3. Obviously….the first cell. This is the human Herpes Virus! Levels of Organization…Continued Organs Organ Systems Organism Types of Cells Prokaryotic Cells Eukaryotic Cells • The first and most primitive cells • Lack a nucleus and other membrane bound organelles (mitochondria, etc) • Bacteria are the ONLY prokaryotes • Most organisms have eukaryotic cells (ex: all plant and animal cells!) • All genetic material is contained in a nucleus • Have many membrane bound organelles 1. 13. 12. 2. 11. 3. 4. 10. 5. 9. 6. 7. 8. 14. 1. 2. Lysosome 13. 3. 4. 12. 5. 11. 6. 10. 7. 8. 9. Cell Organelle Functions Cell Membrane: provides a barrier between the cell and the environment. Vacuole: stores water, minerals and sometimes food. Lysosome: a sac of digestive juices (acts like a stomach). Mitochondria: where cellular respiration takes place, our energy comes from here! Golgi Bodies: “packages” cell material, wraps a membrane around protiens and materials made in the cells. Cell Organelle Functions Centrioles: (ONLY in animal cells) help the cell undergo cellular division, or mitosis. Cytoplasm: jelly like material that fills in the extra space in a cell, also where most of our chemical rxns occur. Ribosomes: site of protein production. Endoplasmic Reticulum (ER): Transports materials around the cell. Nuclear Membrane: separates the nucleus from the rest of the cell. Cell Organelle Functions Nucleolus: dense part of a nucleus, where RNA is made. Nucleus: stores DNA, controls most cellular activities. Cell Wall: rigid structure around the outside of plant cells to give them structure and support. Chloroplast: site of photosynthesis, makes sugar molecules using sunlight, water and carbon dioxide. The Cell Membrane A barrier that separates a cell from its surroundings. Also called: The Lipid Bi-Layer, Fluid Mosaic Model, And The Plasma Membrane Cell membranes are “semi-permeable” because they allow some molecules to pass through, while others cannot. Components of the Cell Membrane MOVIE Just the lipids! Membrane Facts! The lipid bilayer consists of two (bi) layers of phospholipids. The ____________ hydrophilic heads point to the outside and the ____________ hydrophobic tails point to the inside of the membrane. Various _________ proteins molecules are embedded in the membrane as well Cell Membrane Cross Section This is one of many kinds on proteins embedded in the membrane. This is the Lipid Bilayer. Why does this name fit? Membrane Proteins Marker Proteins: They are like a “name tag” for the cell. Membrane Proteins Continued… Channel Proteins: These proteins reach through the membrane to both sides. It allows specific molecules to pass from one side of the membrane to the other. Transport Proteins: Proteins that physically move molecules across the membrane. There are a variety of types! YouTube - Cell membrane animation Cellular Transport Cellular Transport • Passive Transport does NOT require cellular energy (ATP) • Moves molecules from high to low concentration • Active Transport DOES require ATP Diffusion The movement of molecules from an area of HIGH concentration to an area of LOW concentration. The direction of diffusion is called the concentration gradient. This is a form of passive transport. _________ LARGE molecules CANNOT diffuse, regardless of concentration gradient! What types of molecules can NOT diffuse?? Even though all molecules seem small to us, they do vary in size a lot! Large molecules can NOT cross the cell membrane! Large molecules must rely on active transport. Cellular Transport • Passive Transport does • Active Transport NOT require cellular DOES require ATP energy (ATP) • Moves molecules from high to low concentration Examples: • Diffusion Osmosis Osmosis is a special name for the diffusion WATER across a of ________ semi-permeable membrane. Because this requires NO ATP, it is called Passive transport _____________. Water always moves from low to high SOLUTE concentration. This is osmosis! •If a cell is placed in a solution with a LOWER concentration of solute, it will _________ swell (water enter will _________ the cell) •If a cell is placed in a solution with a HIGHER concentration of solute, it will _________ shrivel (water will _________ the cell) leave Cellular Transport • Passive Transport does • Active Transport NOT require cellular DOES require ATP engery (ATP) • Moves molecules from high to low concentration Examples: • Diffusion • Osmosis Phagocytosis This is “cell eating”. A cell engulfs (or wraps itself around) a food particle thus creating a food vacuole. This is a type of ACTIVE TRANSPORT! Clip Cellular Transport • Passive Transport does • Active Transport NOT require cellular DOES require ATP engery (ATP) Examples: • Moves molecules from • Phagocytosis high to low concentration Examples: • Diffusion • Osmosis Pinocytosis This is “cell drinking”. The cell membrane pinches inward (like a pin poking a hole) and creates a vacuole of dissolved particles. This is a type of ACTIVE TRANSPORT! Clip Cellular Transport • Passive Transport does NOT require cellular engery (ATP) • Moves molecules from high to low concentration Examples: • Diffusion • Osmosis • Active Transport DOES require ATP Examples: • Phagocytosis • Pinocytosis Membrane Proteins Using Cellular Energy: The proteins we learned about in the membrane sometimes require energy! Cellular Transport • Passive Transport does NOT require cellular energy (ATP) Examples: • Diffusion • Facilitated Diffusion • Osmosis • Active Transport DOES require ATP Examples: • Phagocytosis • Pinocytosis • Use of membrane proteins (ex: transport proteins) Moving Molecules Against the Concentration Gradient •The sodium ions are more highly concentrated on the inside of the cell. •With the help of ATP, the sodium ions are still pumped back into the cell (against the concentration gradient). Cellular Transport • Passive Transport does NOT require cellular energy ATP) Examples: • Diffusion • Facilitated Diffusion • Osmosis • Active Transport DOES require ATP Examples: • Phagocytosis • Pinocytosis • Use of membrane proteins (carrier proteins, etc) • Moving molecules from low to high concentration