Transcript Chapter 1
Chapter 7: Cell Structure and Function Cell theory All living things are made up of cells Cells are the basic unit of structure and function All cells come from pre-existing cells Scientists Anton van Leeuwenhoek Discovered life in pond water. How did he discover life so small? He was credited for developing the first simple… 1674 present Robert Hooke Looked at a cork under a microscope and saw tiny chambers in it. He called those tiny chambers (small rooms)… Cells Robert Brown Saw a dark spot in the middle of the cell and called it a… Nucleus Schleiden All plants were made up of cells. Schleiden weedin’ Schwann All animals were made up of cells. Virchow All cells come from pre-existing cells. Structure of Cells What regulates what enters and exits the cell? Cell Membrane Lipid bilayer-protection Protein-act as a pump Carbohydrates-regulates what goes in and out (bouncer checks IDs) What is only found in plant cells (for added protection)? Cell Wall Protects cell Porous-allow material in and out Pectin-holds other cells together Cellulose-roughage, adds more protection Lignin-makes rigid (stronger from wind) What is the brain of the cell called? Nucleus Eukaryote- has a nucleus (eu=you, You have a nucleus) Prokaryote- does not have a nucleus (Pro=NO) (some single celled organisms) Nucleolus Nuclear membrane Nucleus Chromosomes-contains genetic info. pass from one generation to the next. ChromatIN- material IN chromosomes DNA-(DNA and protein found in chromatin) RNA and ribosomes- found in nucleolus Cytoskeleton Cyto=cell Skeleton=structure that supports and shapes Microtubules-help cell maintain shape Microfilaments-help function in cell mov’t and support Cytoplasmic streaming mov’t in the cytoplasm Organelles What is an organelle? How does it compare to an organ found in a human body? Organelle is a “tiny organ” found in cells. Has a specific job to do for the cell. Organelles in the Cytoplasm Ribosomes- make proteins. Free- in cytoplasm Attached- ribosomes attached to Rough ER. Endoplasmic Reticulum- assembles and modifies protein. Rough ER- has ribosomes on it Smooth ER- does NOT have ribosomes on it More organelles… Golgi apparatus- (UPS) packages, modifies, and distributes carbohydrates and lipids to proteins. Lysosomes- Enzymes that digest old and unused material within a cell. (Lysol) clean up crew. Vacuoles- stores water, salts, carbs., proteins Plants have one very larger vacuole Animals have smaller vacuoles Organelles still continued… Chloroplast- use NRG from the sun to make food. Only found in plants (photosynthesis) Mitochondria- cells use chemical NRG (from food) and converts it into NRG the cell can use for growth, mov’t, and development. Centrioles- aid in cell division. Mitochondia “Powerhouse” Animal Cell Plant Cell Cell City Project You and a partner will construct a 3-D model of a cell in comparison to a city. You will need to include the following organelles in your city. Type up a reason of what you chose to represent the organelles and why you chose it. Also include the definitions. Everything must be neatly typed. Cell membrane cytoplasm Nucleus Nucleolus Nuclear membrane Free Ribosomes Attached Ribosome Smooth Endoplasmic Reticulum Rough Endoplasmic Reticulum Golgi Apparatus Mitochondria Vacuoles Lysosome Centrioles Movement through Cell Membrane Diffusion- mov’t of molecules from an area of Higher concentration to Lower concentration. (DHL) Doesn’t require cell to use NRG Moves until reaches equilibrium (actually it keeps moving equally in both directions) Osmosis- diffusion of WATER through a selectively permeable membrane. Doesn’t require NRG Terms Permeable- substance can cross the membrane Selectively Permeable- some subs. are able to cross membrane while others cannnot Impermeable- subs. cannot cross membrane. Diffusion Diffusion Osmosis Osmotic Pressure What if too much water and pressure build up? The plant could internal explode. Typically doesn’t happen because of cell wall prevents cells from expanding too much. Facilitated Diffusion Does not require NRG Membrane Proteins “help” the diffusion process. Active Transport Active- requires NRG Acts like a pump Endocytosis- infold the membrane around food. Phagocytosis-when food is taken in by endocytosis, the cytoplasm engulfs particles. Exocytosis- removal of large amounts of material out of a cell. Endocytosis Phagocytosis Exocytosis Levels of Organization Cells Tissues-group of similar cells Organs-group of tissues that work together Organ system- group of organs Organism- all organ systems working together. Cell specialization- cell that perform a special funtion.