Transcript The Cell
DO NOW … What four characteristics are common to all living things? What are cells? Name different types of cells you know of... What is a difference between living and non-living things? THE CELL Chapter 1 Objectives Describe how cells were discovered and named. Identify the scientists that discovered and observed cells. List the 3 parts of the cell theory. What is a cell? Basic structural and functional unit of all living organisms! They come in different shapes + sizes Unicellular vs. Multicellular Unicellular – a single cell Multicellular – made up of many cells Who discovered the cell? ROBERT HOOKE Observed dead cork cells Said boxes looked like tiny rooms or jail “cells”. Used a microscope at 30x magnification How were cells discovered? The light microscope helped discover cells! Cork cells! *Cork is from tree bark (dead cells) Animalcules Who else discovered the cell? ANTON VAN LEEUWENHOEK Observed pond water 1st to observe “living” cells Used a microscope at 300x magnification Do you have these recipes at home? People thought organisms grew from non-living materials! Fransisco Redi Experiment Placed meat in both an open container and a closed container to see what happened. Redi’s Conclusion Maggots come from flies, NOT the meat! Life must come from life, which proved that spontaneous generation is not real! People still did not believe him but he was right. Louis Pasteur Experiment Showed that bacteria are present in air and do not appear spontaneously. Louis Pasteur Conclusions Discovered that cells MUST come from other cells Disproved “Spontaneous Generation” and said life cannot just appear out of no where. Helped verify Redi’s research! Pasteurization Pasteur came up with the idea of Pasteurization after discovering bacteria could contaminate milk from the air. This process kills the bacteria so that it does not harm us! Used in milk, cheese, yogurt, etc. http://bcs.whfreeman.com/thelifewire/content/chp03/0302003.html Cell Theory = Every living thing is made of one or more cells Cells carry out the functions needed to support life Cells come only from other living cells Do Now What are the differences between prokaryotic and eukaryotic cells? Why do we need so many more organelles than bacteria do? Explain. Objectives Compare and contrast a scanning electron microscope vs. a transmission electron microscope. Describe prokaryotic and eukaryotic cells. Bill Nye!! https://www.youtube.com/watch?v=UHjsQeXjc2g Section 1.2 - Microscopes How small are cells? Unit used = micrometer (um) One millionth of a meter Most cells range from 1 um to 1000 um. Types of Microscopes 1. Light Microscope 2. SEM Microscope 3. TEM Microscope Light Microscope Uses light Looks at thin specimen Total Magnification = 40x-100x Use to see cells, but NOT detailed organelles SEM vs. TEM SEM “Scanning electron microscope” Beams of electrons bounce of the surface of the coated cell. Images appear 3D- Outside Specimen TEM “Transmission electron microscope” Electrons pass through the think section. Images appear 2D Total Magnification = 100,000x Must be dead . Specimen coated in metal Total Magnification = 300,000x Allows us to see organelles inside the cell SEM TEM http://www.udel.edu/biology/ketcham/microscope/scope.html Prokaryotic vs. Eukaryotic cells What are the differences you can see? Prokaryotic Cells Have circular DNA NO nucleus Does not have membrane bound organelles ex: snow globe Most unicellular organisms are prokaryotes Example: Bacteria Eukaryotic Cells Have linear DNA – double helix shape Has nucleus Have membrane bound organelles Most multicellular organisms are eukaryotic cells. Some are unicellular though. Example: You! Do Now What is found INSIDE a cell? Do plant cells and animal cells have the same stuff inside? What do plants need to do that animals do not? Objective To compare and contrast animal vs. plant cells. Identify each organelle in a diagram of a cell. Explain the function of each organelle To create flash cards for the next test CELL ORGANELLES Plasma membrane Cilia and Flagella Cytoplasm/cytoskeleton Mitochondria Nucleus Central Vacuole Ribosomes Chloroplasts Endoplasmic Reticulum Cell Wall Golgi Apparatus Lysosomes Centrioles **Each organelle has its own purpose and fucntion! Plasma Membrane THE WALL – protects the internal structures of the cell. Selective permeability Determines what comes in and out of the cell A.K.A- Cell Membrane! Found in: Animal and Plant cells Cytoplasm/Cytoskeleton Cytoplasm- Clear FLUID that contains the organelles. Cytoskeleton- Provides the FRAMEWORK for the cell, holds organelles in place. Found in: Plant and Animal Cells Nucleus Nucleus- CONTROLS the cell Nucleolus- produces ribosomes Nuclear Pores- Allows things in and out of the nucleus. Nuclear Evelope- Membrane surrounding the nucleus Found in- Plant and Animal Cells Challenge Question Where do you find the DNA or a eukaryotic cell? If prokaryotes do not have a nucleus, where is their DNA? Ribosomes Produces Proteins! Proteins are made up of one or more polypeptide chains of amino acids. Found in: Plant and Animal Endoplasmic Reticulum Rough- Contains ribosomes and synthesizes PROTEINS Smooth- No Ribosomes, synthesizes LIPIDS (fats) Found in: Plant and Animal Index Cards!! Front: Drawing Name of Organelle Back: Location Function Gogli Apparatus Modifies proteins and fats and gets them ready for export! (proteins are eventually released to outside of cell) Found in: Animal and Plant Lyosomes Contains ENZYMES break down cellular waste product and debris Found in: Animal Cells Centrioles Organelles made of microtubules involved in cell division (located in cytoplasm) (will talk about this later when we do mitosis) Found in: Animal Cells Cilia and Flagella Flagella- Used in cells for movement (longer & less numerous than cilia) Cilia- Used in stationary cells for moving substances around the outside of the cell (look like hairs) Found in- Animal and Prokaryote Mitochondria Convert oxygen into ENERGY (ATP) Powerhouse of the cell! (we will talk about this more when we do cellular respiration!!) Found in: Animal and Plant Cells Index Cards!! Front: Drawing Name of Organelle Back: Location Function Central Vacuole LARGE WATER “bubble” in the plant cell Maintains the SHAPE of the cell, without it, the plant cell would shrink and the plant would wilt Stores water, along with ions, nutrients, and waste. Found in: Plant Chloroplasts Captures light ENERGY and convert it to chemical energy (sugar) Found in: Plant Cell Wall Supports the cell and maintains its shape Works with central vacuole to maintain “Turgor Pressure” Found in: Plant Challenge Question! How can chloroplast, a structure found in plant cells but not in animal cells, provide energy for both plants and animals? Index Cards!! Front: Drawing Name of Organelle Back: Location Function Do Now: Classify the organelles as plant, animal, or both Plant Both Animal Quick Refresher! Endosymbiotic Theory Explains the origin of chloroplasts and mitochondria and their double membranes. Theory: Chloroplasts and Mitochondria were once prokaryotes that were engulfed!! Theory = Evidence!! •Have circular DNA like bacteria •Replicates(reproduces) like bacteria separate from the host cell •Make their own proteins •Two membranes (one from the host cell and one from their own cell membrane) Specialization •Specific cells perform specific functions. Ex: Blood cells can only be blood cells. Muscle cells cannot be turned into blood cells. Organization Organisms are organized (what was the order again?) Cells Tissue Organ Organ System Organism Plants are organized too! What do you think could be their level of organization?? Cell → Tissue → Organ (leaf) → Organ system (leaves, stems, roots) → Organism Objectives Compare and contrast the 3 Domains. Understand multicellular organization. Explain the significance of models in science. Section 1.3 - Domains 3 domains of life: 1. Eukarya – Have a nucleus. Plants, animals, and fungi. 2. Bacteria – prokaryotics. 3. Archaea – “ancient”. Genetically different from bacteria. Archaea •Prokaryotic (Cell wall and ribosomes) •Unicellular •Can survive HARSH environments Bacteria •Prokaryotic •Unicellular •NORMAL living environments Eukarya •All other organismsEukaryotic cells •Can be unicellular OR multicellular