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1. Which cells do we 11-11 suspect are older eukaryotes or prokaryotes? Why? REVIEW 11-11 Cell Nucleus DNA Phospholipid Ribosome Prokaryote Eukaryote Mitochondria Bacteria Proteins How to remember prok vs euk cells It’s all in a hand bag: Girls…when going to a wedding / fancy occasion describe your purse – Small, compact, just the stuff you NEED The rest of the time, what are most of your purses like? – Big. Lots of room, extra stuff you may not need Cell Organelle Review Plant Cell 1. The cytoskeleton is 11-12 made up of ______ + ______. (the answers are also organelles from your packet) Describe and interpret 11-12 relationships between structure and function at various levels of biological organization. TODAY: How are animal and plant cells different? adding to what we already know Assignment Read section 4.3 and complete section review Organelles Plasma membrane – Made of 2 layers of phospholipids (a bilayer) – Allows transport of molecules into / out of the cell – Helps protect cell from bacteria, etc – Chemical communication with other cells – (Review) Phospholipid – contains hydrophobic tails and hydrophilic head – Membrane contain lipids called sterols (cholesterol) - help make membrane more firm and prevent freezing at lower temperatures Membrane Proteins: Integral proteins – – Proteins in the plasma membrane that are embedded or pass all the way through the membrane – Have carbohydrate attached to act as marker or label – Function: Communication Transporting materials into cell Peripheral proteins – proteins found only on one side of the membrane Fluid Mosaic Model – Idea that the phospholipids / lipids / proteins can “flow” around each other – Plasma membrane is more of a fluid than a solid Cytoplasm – – part of the cell including the fluid, the cytoskeleton and all organelles except nucleus Cytosol – – the cytoplasm that includes the ribosome's but not the membrane bound organelles – 20% protein Nucleus – – control center of cell– controlled by the code in your DNA Nuclear Membrane / Envelope – – double membrane that surrounds the nucleus Nuclear Pore – – protein lined holes in the nuclear membrane that allow RNA to enter / leave nucleus Nucleolus – – where DNA concentrates to create ribosomal RNA (ribosome's) Chromosome – – DNA coils to form chromatin – chromatin coils to form chromosomes – Chromatin is how the cell’s genetic material is stored when not replicating – Chromatin coils to for chromosomes when replication is occurring Ribosome – – proteins that direct protein synthesis – Consist of two subunits Mitochondria – – takes organic molecules and makes ATP (adenosine triphosphate) – Phospholipid Membrane bound organelle Inner membrane has many folds for reactions to occur (called cristae) Which cells would you think have the most mitochondria? – Muscle cells Endoplasmic reticulum (ER) – “intracellular highway” – Has a membrane and is composed of tubes and sacs – Rough ER – contains ribosome's Thus produces proteins (some phospholipids) Proteins produced then surrounded by vesicle from the ER and then transported around / out of cell – Smooth ER – lack ribosome's Produce lipids and hormones in sex cells (estrogen & testosterone) Golgi Apparatus – Flattened membranes and sacs – Receive vesicles from ER and modify them as the move through the Golgi (get “address labels”) – Vesicles then are sent to various locations – Create lysosomes Vesicle – – Used to carry contents around, into / out of cell – Vary in type – Spherically shaped – Surrounded by a membrane Lysosome – vesicle that contains digestive enzymes produced by Golgi – Digest organic materials, bacteria, etc – Break down glycogen to get glucose – Cytolysis or autolysis – lysosomes release enzymes to destroy the cell (old or malfunctioning cells) Cytoskeleton – Microtubule – Microfilament - – network of thin tubes / filaments that supports the cell – hollow tubes made of protein that hold organelles in place and give the cell shape – Smaller threads that contribute to changes in cell shape – Made of protein Intermediate filaments – – Rods that anchor nucleus and other organelles in place – Maintain internal shape of the nucleus – Make up most of your hair Cilium – Flagellum – Hair like structures that extend from the surface of cells – Assist in cell movement – Very numerous – Whip like structure that assist in movement – Usually less in number Centriole – – short cylinders that organize microtubules for cell division – Not found in plant cells Cell wall – Central vacuole – large organelle that stores water, enzymes, wastes etc – rigid layer found outside plasma membrane – Contain cellulose – Take up a large amount of the plant cell – If filled with water, how will plant stand? Upright – if they are lacking water, plant will droop Plastid – – plant organelles that have their own DNA and perform specific functions Chloroplast – – plastid example – use light energy to make carbohydrates Thylakoids – – flat membranous sacs that contain chlorophyll (where photosynthesis takes place) Chlorophyll – – green pigment that absorbs light energy in plants Cellular Organization Organelle Tissue Organ Organ system – Intracellular structures with specific functions – Group of similar cells with a specific funtion – A groups of tissues with a particular job – A group of organs that accomplish a task – IE: Digestive system Respiratory System Nervous System Endocrine System Cardiovascular System Warm Up 11-11 What are two differences between prokaryotic and eukaryotic cells? Today: – Get out your microscope packets and get a partner (or you can work by yourself) – Microscope practice and questions Warm Up 11-12 What is depth of focus? Today: – Observing cheek cell and Elodea cells Warm Up 12-12 What is the maximum total magnification if the ocular lens is 10 x and the objective lens is 40x Warm Up 11-17 What is the function of the ER? Today: – Go over “Microscope Practice” lab – Finish Observing Cells - Elodea, Onion Cell, Cheek Cell Lab MAKE SURE YOUR DRAWINGS ARE DETAILED ENOUGH Warm Up 11-18 Draw either a Elodea (in pen or pencil) and label the following: chloroplasts, plasma membrane, cell wall, cytoplasm Today: – Cheek, Elodea and Onion cell labs due – Looking at living protists under the microscopes Warm Up 11-19 Get out worksheet packet – answer questions on pages 17 & 18. Today: – Review how organelles look – Prepare for the test – Homework: Finish Protist Lab Complete the pages of the worksheet packet Warm Up 11-20 What is the function of the Golgi complex? Today: – Prepare for test Monday – Review sheets due Monday – Complete multiple choice on pages 21 and 23 of the new packet Warm Up 11-23 Get out both your worksheet packets Turn in your protist lab Practice test: – #17 – 20 we didn’t discuss, but try them anyway – Short answer questions: Skip #24, 25 and 29. Today 11-24 Test! Get out review sheets Get out a pencil 11-25 Check the grade sheet coming around – Are you missing anything? – Find it! Turn it in! Missing a lab? – Today is the day to make it up Go over tests (maybe) Warm Up 12-01 Explain how our cells get food (make this explanation in some detail – you will see a similar question again Light Microscopes and Cell Stains A typical light microscope allows light to pass through a specimen and uses two lenses to form an image. The first set of lenses, located just above the specimen, produces an enlarged image of the specimen. The second set of lenses magnifies this image still further. Because light waves are diffracted, or scattered, as they pass through matter, light microscopes can produce clear images of objects only to a magnification of about 1000 times. Light Microscopes and Cell Stains Another problem with light microscopy is that most living cells are nearly transparent, making it difficult to see the structures within them. Using chemical stains or dyes can usually solve this problem. Some of these stains are so specific that they reveal only compounds or structures within the cell. Light Microscopes and Cell Stains Some dyes give off light of a particular color when viewed under specific wavelengths of light, a property called fluorescence. Fluorescent dyes can be attached to specific molecules and can then be made visible using a special fluorescence microscope. Fluorescence microscopy makes it possible to see and identify the locations of these molecules, and even to watch them move about in a living cell. Electron Microscopes Light microscopes can be used to see cells and cell structures as small as 1 millionth of a meter. To study something smaller than that, scientists need to use electron microscopes. Electron microscopes use beams of electrons, not light, that are focused by magnetic fields. Electron microscopes offer much higher resolution than light microscopes. There are two major types of electron microscopes: transmission and scanning. Electron Microscopes Transmission electron microscopes make it possible to explore cell structures and large protein molecules. Because beams of electrons can only pass through thin samples, cells and tissues must be cut first into ultra thin slices before they can be examined under a transmission electron microscope. Transmission electron microscopes produce flat, two-dimensional images. Electron Microscopes In scanning electron microscopes, a pencil-like beam of electrons is scanned over the surface of a specimen. Because the image is of the surface, specimens viewed under a scanning electron microscope do not have to be cut into thin slices to be seen. Scanning electron microscopes produce three-dimensional images of the specimen’s surface. Electron Microscopes Because electrons are easily scattered by molecules in the air, samples examined in both types of electron microscopes must be placed in a vacuum in order to be studied. Researchers chemically preserve their samples first and then carefully remove all of the water before placing them in the microscope. This means that electron microscopy can be used to examine only nonliving cells and tissues. b._________ a._________ c._________ d._________ e.___________ f.___________ ____________ ____________ g._________ h._________ ___________ i.___________ ____________ ___________ k.__________ ___________ j.____________ Describe and find an illustration of these 25 organelles Cytoskeleton Plasma membrane Microtubule – Phospholipids bilayer Microfilament Cytoplasm Cilium Cytosol Flagellum Nucleus Centriole – Nuclear Pore Cell wall – Nuclear Membrane – Nucleolus Central vacuole Chromosome Plastid Nuclear envelope Chloroplast Ribosome Mitochondrion Chlorophyll Endoplasmic reticulum Golgi Apparatus Lysosome ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ ___________ PERIPHERAL PROTEIN INTEGRAL PROTEIN INTEGRAL PROTEIN PERIPHERAL PROTEINS