Presentation on theme: "Cells Under the Microscope"— Presentation transcript:
1Cells Under the Microscope Chapter 3Section 1 Looking at CellsCells Under the MicroscopeMeasuring Cell StructuresMeasurements taken by scientists are expressed in _____ units. The official name of the metric system is the ____________ ____________ of Measurements, abbreviated SI. The table below summarizes the SI units used to measure length.
2Cells Under the Microscope, continued Chapter 3Section 1 Looking at CellsCells Under the Microscope, continuedMagnification is the ________ of making an image appear _________ than its actual size.Resolution is a measure of the ___________ of an image.Both high magnification and good resolution are needed to view the ________ of extremely small objects _________.
3Cells Under the Microscope, continued Chapter 3Section 1 Looking at CellsCells Under the Microscope, continued__________ microscopes have much higher ___________ and __________ powers than light microscopes.
4Chapter 3 Types of Microscopes Section 1 Looking at CellsTypes of MicroscopesLight microscopes form an image when _______ passes through one or more ________ to produce an enlarged image of a specimen.
5Types of Microscopes, continued Chapter 3Section 1 Looking at CellsTypes of Microscopes, continuedElectron MicroscopesElectron microscopes form an image of a specimen using a beam of ____________ rather than light.The electron beam and specimen must be in a _________ so that the electron beam will not bounce off of gas molecules.________ organisms ________ be viewed with an electron microscope.
6Types of Microscopes, continued Chapter 3Section 1 Looking at CellsTypes of Microscopes, continuedTransmission Electron MicroscopeAn electron beam is directed at a very thin slice of a specimen stained with metal ions. Some structures become more ________ stained than others.The heavily stained parts _________ electrons, those that are lightly stained allow electrons to pass through.The electrons that pass through strike a fluorescent ________, forming an image.
7Types of Microscopes, continued Chapter 3Section 1 Looking at CellsTypes of Microscopes, continuedScanning Electron MicroscopeAn electron beam is focused on a specimen coated with a very thin layer of _______.The electrons that ________ off the specimen form an image on a fluorescent screen.The image shows ____________________ details of the surface of a specimen.
8Types of Microscopes, continued Chapter 3Section 1 Looking at CellsTypes of Microscopes, continuedScanning Tunneling MicroscopeA needle-like probe measures differences in ___________ caused by electrons that leak, or tunnel, from the surface of the object being viewed.A __________ tracks the movement of the probe across the surface of the object.The image shows three-dimensional details of the surface of a specimen.________ specimens and objects as small as ________ can be viewed.
9Chapter 3 The Cell Theory The Cell Theory has three parts: Section 2 Cell FeaturesThe Cell TheoryThe Cell Theory has three parts:1. All _________ things are made of one or more cells.2. Cells are the basic units of ________ and ___________ in organisms.3. All cells arise from _____________ cells.
10The Cell Theory, continued Chapter 3Section 2 Cell FeaturesThe Cell Theory, continuedCell SizeSmall cells ___________ more ____________ than large cells. If a cell’s surface area–to-volume ratio is too low, substances cannot ________ and _________ the cell well enough to meet the cell’s needs.
11The Cell Theory, continued Chapter 3Section 2 Cell FeaturesThe Cell Theory, continuedCommon Cell FeaturesCells share common structural features, including:an outer boundary called the cell ________________,interior substance called _________________,structural support called the __________________,genetic material in the form of _________cellular structures that make proteins, called __________
12Chapter 3Section 2 Cell FeaturesProkaryotesProkaryotes are single-celled organisms that lack a ____________ and other internal compartments. They have a cell wall, may have cilia or flagella, and have a single ___________ molecule of DNA.
13Chapter 3 Eukaryotic Cells Eukaryotic cells have: Section 2 Cell FeaturesEukaryotic CellsEukaryotic cells have:A ____________ which contains the cell’s DNAOther internal compartments called ___________.
14Eukaryotic Cells, continued Chapter 3Section 2 Cell FeaturesEukaryotic Cells, continuedThe cytoskeleton provides the interior _____________ of a cell. There are three basic kinds of cytoskeletal fibers.________________: long slender filaments made of the protein actin________________: hollow tubes made of the protein tubulin.Intermediate fibers: thick ropes made of protein.
15Eukaryotic Cells, continued Chapter 3Section 2 Cell FeaturesEukaryotic Cells, continuedThe cytoskeleton’s network of _________ fibers ___________ the cell’s organelles and other components of the cytoplasm.
16Chapter 3 The Cell Membrane Section 2 Cell FeaturesThe Cell MembraneThe cell membrane is a ______________ permeable barrier that determines which substances enter and leave the cell.The ______________ permeability of the cell is mainly caused by the way phospholipids interact with water.A phospholipid is a lipid made of a phosphate group and two fatty acids.
17The Cell Membrane, continued Chapter 3Section 2 Cell FeaturesThe Cell Membrane, continuedCell membranes are made of a ____________ layer of phospholipids, called a bilayer.
18Chapter 3Section 3 Cell OrganellesThe NucleusThe nucleus is an internal compartment that houses the cell’s DNA. Most ____________ of a eukaryotic cell are ______________ by the cell’s nucleus.The nucleus is surrounded by a ______________ membrane called the nuclear envelope.Scattered over the surface of the nuclear envelope are many small channels called nuclear ________.
19Chapter 3 The Nucleus, continued Section 3 Cell OrganellesThe Nucleus, continuedRibosomal proteins and RNA are ______ in the nucleus.Ribosomes are partially assembled in a region of the nucleus called the ________________.
20Ribosomes and the Endoplasmic Reticulum Chapter 3Section 3 Cell OrganellesRibosomes and the Endoplasmic ReticulumRibosomes are the cellular structures on which ____________ are made.The Endoplasmic Reticulum or ER is an extensive system of internal membranes that ________ proteins and other ____________ through the cell.
21Ribosomes and the Endoplasmic Reticulum, continued Chapter 3Section 3 Cell OrganellesRibosomes and the Endoplasmic Reticulum, continuedThe part of the ER with attached ribosomes is called the ___________ ER.The rough ER helps transport proteins that are made by the attached ribosomes.New proteins enter the ER.The portion of the ER that contains the completed protein pinches off to form a ___________.A vesicle is a small, membrane-bound sac that transports substances in cells.
22Ribosomes and the Endoplasmic Reticulum, continued Chapter 3Section 3 Cell OrganellesRibosomes and the Endoplasmic Reticulum, continuedThe ____ moves proteins and other substances within eukaryotic cells.
23Ribosomes and the Endoplasmic Reticulum, continued Chapter 3Section 3 Cell OrganellesRibosomes and the Endoplasmic Reticulum, continuedPackaging and Distribution of ProteinsVesicles that contain newly made proteins move through the cytoplasm from the ER to an organelle called the Golgi _________________.The ________ apparatus is a set of flattened, membrane-bound sacs that serve as the _______________ and _____________ center of the cell.
24Chapter 3Section 3 Cell OrganellesMitochondriaMitochondria are organelles that harvest ____________ from organic compounds to make ATP.ATP is the main energy currency of cells. Most ATP is made inside the mitochondria.
25Mitochondria, continued Chapter 3Section 3 Cell OrganellesMitochondria, continuedMitochondria have ____ membranes. The outer membrane is smooth. The inner membrane is greatly folded, and has a large __________ area.Mitochondria have their own DNA. Mitochondria reproduce independently of the cell. Mitochondrial DNA is similar to the DNA of prokaryotic cells.Mitochondria are thought to be descendents of primitive prokaryotes.
26Mitochondria, continued Chapter 3Section 3 Cell OrganellesMitochondria, continuedMitochondria have an ______ and an _________ membrane.
27Structures of Plant Cells Chapter 3Section 3 Cell OrganellesStructures of Plant CellsPlants have three unique structures that are not found in animal cells:Cell _____________________Central __________
28Structures of Plant Cells, continued Chapter 3Section 3 Cell OrganellesStructures of Plant Cells, continuedThe cell membrane of plant cells is surrounded by a thick cell wall, composed of _________ and _____________.The cell wallhelps _____________ and maintain the _________ of the cell____________ the cell from damage_______________ the cell with adjacent cells
29Structures of Plant Cells, continued Chapter 3Section 3 Cell OrganellesStructures of Plant Cells, continuedChloroplasts are organelles that use _______ energy to make carbohydrates from carbon dioxide and water.Chloroplasts, along with _____________________, supply much of the energy needed to power the activities of plant cells.Chloroplasts, like mitochondria, have their own DNA and reproduce independently of the plant cell.Chloroplasts, like mitochondria, are thought to be descendents of ancient prokaryotes.
30Structures of Plant Cells, continued Chapter 3Section 3 Cell OrganellesStructures of Plant Cells, continuedCentral Vacuole:Most of a plant cell’s __________ is taken up by a large, membrane-bound space called the central vacuole.The central vacuole stores ____________ and may contain ions, nutrients, and wastes.