Transcript Do Now
Do Now • What are cells? • Why do we need them? • List different types of cells that you know of… Objective • Describe how cells were discovered and named. • Identify the scientists that discovered and observed cells. • List the 3 parts of the cell theory. LETS CELLEBRATE! Chapter 1 What are Cells? a) Basic structural and functional unit of all living organisms! b) They come in all shapes and sizes Lets take a look… How were they discovered? a) The light microscope led to the discovery of cells. Who discovered cells? i. Observed dead cork cells. ii. Said boxes looked like tiny rooms or cells, that is where they get their name. iii. Used a microscope at 30x magnification Who discovered cells? i. Observed pond water. ii. 1st to observe living cells. iii. Used a microscope at 300x magnification But WHERE do they come from???? Hmmmm… What happens when you leave meat out? Fransisco Redi Experiment He placed meat in both an open container, and a closed container to see what happened… Redi’s Conclusion… -Maggots come from FLIES, not meat. -Life must come from life, not spontaneous generation right? -Nobody believed him! Do Now • What organisms/materials did Redi work with? • What did he discover? Objective • Compare and contrast a scanning electron microscope vs. a transmission electron microscope. • Describe prokaryotic and eukaryotic cells. Where do cells come from? i. Discovered that cells must come from other cells. ii. He disproved the theory of “spontaneous generation”- theory that life can just appear out of nowhere. Pasteur’s Experiment Pasteur’s Experiment • Control group• Experimental group- Pasteur’s Results • flask that was exposed to the air contained bacteria in it from the air. Flask that wasn’t exposed did not contain anything. The cells must come from living things in the air!! 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! Cell Theory! Cells come only from other living cells. Every living thing is made of 1 or more cells. Cells carry out the functions needed to support life. Section 1.2 - MICROSCOPES • How small are cells? – We use micrometers (μm )= 1 millionth of a meter! – Range from 1 μm to 1000 μm Types of Microscopes A) Compound Light Microscrope (LM) B) Scanning electron microscope (SEM) C) Transmission electron microscope (TEM) Compound Light Microscope i. Uses light. ii. Thin specimen. iii. Total magnification=40100x iv. Used to see cells, but not organelles inside. Scanning Electron Microscope (SEM) i. ii. iii. iv. v. Uses electrons that bounce off the speciment. 3-D image, must be dead Specimen is coated in metal Total magnification= 100,000x See details of OUTSIDE of cell (cell membrane, cilia) Transmission Electron Microscope (TEM) i. Uses electrons to deflect through specimen. ii. Thin specimen iii. Total magnification=300, 000x iv. Allows us to see INSIDE the cell. DO NOW What do you notice that is different between these 2 cells? Objective • List the different organelles of a cell. • Explain the function of each organelle. • Identify each organelle in a diagram of a cell. Microscope Quiz A. Parts of the microscope: 1. labeling 2. what they do B. Types of microscopes (compare and contrast): 1. Light 2. SEM 3. TEM C. How to properly use the microscope for 1. focusing 2. Carrying 3. Safety D. Calculating total magnification Prokaryotic Cells i. Have circular DNA ii. No Nucleus! iii. Doesn’t have membranebound organelles iv. Most unicellular organisms are prokaryotes. Example: Bacteria Eukaryotic Cells i. Multicellular Eukaryote Unicellular Eukaryote Have linear DNA that is in a double helix shape. ii. Has a nucleus! iii. Have membranebound organelles. iv. Mostly multicellular although there are some unicellular eukaryotes. Think – Pair - Share • 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? Activity Organelle Jigsaw Activity! Each of you will become an expert on 2 or 3 organelles and fill out the information in your chart for those particular organelles. After you have completed this part, we will separate into different groups and each of you will be the teacher of that group for those organelles! Do Now • What are the differences between prokaryotic and eukaryotic cells? • Why do we need so many more organelles than bacteria do? Explain. Objective • To list and explain the different organelles found in all eukaryotic cells. • To compare and contrast animal vs. plant cells. • To create flash cards for the next test • The wall!- protects the internal structures of the cell. • Determines what comes in and out of the cell. Cytoplasm- clear fluid that contains the organelles CytoskeletonProvides the framework for the cell, holds organelles in place. Nucleus- controls the cell. Nucleolus- produces ribosomes. Nuclear Pores- allow things in and out of nucleus. Makes polypeptide chains of amino acids, producing Proteins. Rough- contains ribosomes and synthesizes proteins. Smooth- No ribosomes, synthesizes lipids (fats). Modifies proteins and fats and gets them ready for export! Large water “bubble” in a plant cell. Maintains the shape of the cell, without it, the plant cell would shrink and the plant would wilt. Contain enzymes, break down cellular waste product and debris. Involved in cell division ( we will talk about this more later when we do mitosis!) Convert oxygen into energy (we will talk about this more when we do cellular respiration!) Used in cells for movement Used in stationary cells for moving substances around the outside of the cell. • Capture light energy and convert it to chemical energy (sugar). Rigid structure Provides strength for the cell. Works with vacuole to maintain “turgor pressure” Index Cards! Front: Name of Organelle Drawing Back: Location Function Do Now: Classify the organelles as plant, animal, or both Plant Both Animal Objective • SWBAT compare and contrast plant and animal cells. • SWBAT observe plant and animal cells under a microscope. Do Now • What are the differences between prokaryotic and eukaryotic cells? Objective • Compare and contrast the 3 Domains. • Understand multicellular organization. • Explain the significance of models in science. i. prokaryotic (cell wall and ribosomes) ii. Unicellular iii. Can survive harsh environments. i. prokaryotic ii. Unicellular iii. Normal living environments. i. all other organismseukaryotic cells. ii. Can be unicellular or multicellular • *Each cell is specialized to do a certain job very well for the overall well being of the organism. • Ex: muscle cell for the heart. • Organisms are organized: • cell tissue organ organ system organism • Plant organization: • A. organs= stems, roots, and leaves • Build models to study small parts. • A. how could you creatively build a 3-D model of a cell? • Ex: • B. How would you represent DNA? • Rosalind Franklin, James Watson and Francis Crick• A. modeled DNA with sticks • B. now done with computers