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48 Cards in this Set
- Front
- Back
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Fx of Ocular Lens
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Further magnifies and projects image
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Fx of Objective lens
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Enlarges and projects image
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What is a microscope's resolving power?
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0.1-0.2 micro meters
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Fx of Condenser
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Collects and focuses light
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How do you use a microscope?
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Place sample on "specimen slide", adjust objective lens and see through ocular lens.
Light comes from illuminator, reflects off mirror and then the prism, and then comes out of ocular lens. |
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When preparing tissues for viewing in a light microscope, explain what the process "fixation" means.
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To preserve tissue morphology and molecular composition as close as possible to normal living state.
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When preparing tissues for viewing in a light microscope, explain what the process "embedding".
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To replace organic solvent with a wax or resin in order to make the tissue more amenable to sectioning by a knife's blade.
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When preparing tissues for viewing in a light microscope, what are the different methods used to "fix" a sample tissue?
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(1) Chemical Crosslinking: using formaldehyde or glutaraldehyde.
(2) Oxidizing Agents: Osmium tetroxide (3) Precipitating agents: Using ethanol, methanol, Acetic Acid, or Acetone. |
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What is "parafin"?
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A type of wax used to embed sample tissues.
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What is "resin"?
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A type of plastic used to embed sample tissues.
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What are some challenges associated with preparing tissue samples for viewing?
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Fixation - changes in cell or tissue structure due to the fixative.
Embedding - heat from wax or the process of freezing can cause distortions. Sectioning - 2D sections through a 3D object. |
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What are the 2 most commonly used histological stains?
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Hematoxylin - basic dye used to stain acidic substances (i.e. nucleic acids)
Eosin - acidic dye used to stain basic substances (i.e. proteins in cytoplasm) |
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Define histochemistry.
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Staining technique where a dark stain identifies a particular component of a cell or tissue.
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Define autoradiography.
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A method of visualizing molecules within cells using radioactivity.
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What is the resolving power of an electron microscope?
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1 - 2 nano meters
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What are the 4 basic types of tissues?
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Connective, Muscular, Epithelial, and Nervous tissue
(C-MEN) |
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Where can you find epithelium tissue?
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Epithelial tissue covers the body surface and forms the lining for most internal cavities.
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What is the function of the epithelium tissue?
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The major function of epithelial tissue includes Protection, Secretion, Absorption, and Filtration.
(Abs Pros Fill Secretly) |
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What are the various shapes that epithelial cells can assume?
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Cells can be thin, flat to cubic to elongated.
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What is the function of connective tissues?
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Support and protection
(Connect S and P) |
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What are the 3 types of muscle tissues?
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Skeletal, smooth, and cardiac.
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Describe the fx of the 3 types of muscle tissues.
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Skeletal muscle - a voluntary type of muscle tissue that is used in the contraction of skeletal parts.
Smooth muscle - involuntary muscle tissue; found in the walls of internal organs and blood vessels. Cardiac muscle - involuntary; found only in the walls of the heart. |
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What is the function of nerve tissues?
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Nerve tissue - composed of specialized cells which (1) receive stimuli and (2) conduct impulses to and from all parts of the body.
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Describe the fx of cell membranes.
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Cell membranes (1) define the borders of the cell and (2) transport molecules between the inside and outside of the cell.
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Describe the different modes of cellular transportation.
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(1) Passive diffusion
(2) Facilitated diffusion (3) Active transport (4) Endocytosis-pinocytosis |
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Where are heterochromatin and euchromatin found?
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In the nucleus, as part of the chromatin.
Heterochromatin lies against the nuclear envelope in patches and is broken up at the site of the nuclear pore. On a slide, heterochromatin are densely packed together (and thus appear dark) whereas euchromatin are lightly packed together (and thus appear light/transparent). |
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Describe Heterochromatin.
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Heterochromatin are:
(1) transcriptionally inactive, (2) enriched in centromeric repeats, and (3) contains trimethylated lysine 9 of histone H3. Their function ranges from gene regulation to the protection of the integrity of chromosomes. |
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Describe Euchromatin.
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Euchromatin are:
(1) transcriptionally active (to become mRNA), (2) enriched in genes, (3) contains acetylated histones. |
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What is the function of the nucleolus?
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It is the site of rRNA synthesis and initial assembly of ribosomes.
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What is the function of the Endoplasmic Reticulum?
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The ER forms an interconnected network of tubules, vesicles, and cisternae within cells.
It facilitates protein folding and the transport of synthesized proteins in sacs called cisternae. |
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What is the function of the rough ER?
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The surface of the rough ER is studded with ribosomes that synthesize proteins (site of protein synthesis).
Synthesized proteins are destined for plasma membrane or secretion. |
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What is the function of the smooth ER?
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Synthesis of lipids and steroids.
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What is the function of the Golgi?
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The Golgi apparatus is integral in modifying, sorting, and packaging macromolecules synthesized in the cell for either exocytosis (it forms secretory granules to facilitate this process) or use within the cell.
It primarily modifies proteins delivered from the rough endoplasmic reticulum but is also involved in the transport of lipids around the cell, and the creation of lysosomes. The Golgi complex can be thought of as a "post office"; it packages and labels items which it then sends to different parts of the cell. |
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What is the fx of cholesterol in the cell membrane?
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Breaks up close packing of lipids and increases fluidity of cell membrane.
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What are integral proteins? Peripheral proteins? Transmembrane proteins?
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Integral proteins are proteins within the membranes.
Peripheral proteins are proteins on the inner or outer surface of cell membrane. Transmembrane proteins are integral proteins that span the membrane one or more times |
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Describe a key feature of the fluid mosaic model.
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Proteins can move laterally in the plane of the membrane.
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What is the fx of cell receptors?
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Cell receptors are molecules involved in cell adhesion, recognition, and response to hormones; typically have oligosaccharide chain on outer surface.
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Compare and contrast passive diffusion, facilitated diffusion, and active transport.
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Passive diffusion is transport dependent upon concentration gradient.
Facilitated diffusion is passive transport but requires carrier protein. Active transport is transport independent of concentration gradient and requires energy. |
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Compare and contrast endocytosis and pinocytosis.
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Endocystosis – bulk transport
Pinocytosis – invagination of smaller molecules |
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What is the fx of the cytoskeleton?
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1. Provides strength and structure to cells
2. Transport of molecules and organelles found around the cell 3. Facilitates movement of certain cell types |
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How are newly synthesized proteins transported from the RER to the Golgi complex?
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Through shuttle vesicles.
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Compare and contrast heterophagy and autophagy.
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Heterophagy - breakdown of materials taken into the cell from its external environment.
Autophagy - breakdown of intracellular substances |
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What is the components and the fx of the mitochondria?
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Basic Components: Inner and outer membranes, matrix, and cristae.
Fx: Produces ATP from glucose |
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What is the fx of lysosomes?
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Lysosomes are membrane-bound vesicle that contains enzymes that can breakdown large molecules of living tissue at acidic pH.
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Where are mitochondrion found?
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They are found in large numbers at sites where large amounts of energy are being expended.
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What are microfilaments?
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They are thin, twisted, flexible helical rod polymers, 5-7 nm diameter.
Made up of actin (hence, also known as actin filaments). Microfilaments interact with myosin during muscle contraction. They are also involved in cell shape changes and motion. |
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What are intermediate filaments?
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Intermediate filaments have an average diameter of 10 nanometers, which is between that of actin (microfilaments) and microtubules.
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What are microtubules?
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Microtubules are the thickest polymers, 24 nm diameter; made of tubulin.
Microtubules are hollow rods that form the mitotic spindle, cilia and flagella. Microtubules also transport organelles around the cell. |
