Cells and Chemistry
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NOVA | How Cells Divide
By Rick Groleau Posted 10.09.01 NOVA Most of the time, when a cell in our bodies divides, each new cell carries a complete set of chromosomes. The cells involved with human reproduction, however, carry only half after division occurs. In this step-by-step explanation, learn about mitosis and meiosis, the two types of cell division. This feature originally appeared on the site for the NOVA program 18 Ways to Make a Baby .
Cell Size and Scale
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Interactive tutoring on the toughest topics in biology Have you ever wished for an effective tool to help your students visualize tough topics like a tour of the plant and animal cell, cellular respiration, photosynthesis, mitosis, meiosis, protein synthesis, or how neurons work? Our new 3-minute animations allow instructors to show 3D, fluid movement and dramatic "zoom" sequences that bring difficult-to-teach biological concepts to life during lectures. Each animation is accompanied by a PowerPoint® slideshow with screenshots identifying the main components of the animation. Students can prepare for exams by completing the tutorial, printing a personal review sheet, and taking a quiz.
Small Movies of Cell Bio Topics
The Cytoskeleton
Cells contain elaborate arrays of protein fibers that serve such functions as: establishing cell shape providing mechanical strength locomotion chromosome separation in mitosis and meiosis intracellular transport of organelles The cytoskeleton is made up of three kinds of protein filaments: Actin filaments (also called microfilaments ) Intermediate filaments and Microtubules Actin Filaments Monomers of the protein actin polymerize to form long, thin fibers. These are about 8 nm in diameter and, being the thinnest of the cytoskeletal filaments, are also called microfilaments .Membranes organize proteins and other molecules enabling the cell to run much more efficiently than if everything were floating freely. Mitochondrial membranes, for example, keep protein assembly lines together for efficient energy production. And the lysosome safely holds enzymes that would destroy essential proteins if released into the cytoplasm.
Membranes Organize Cellular Complexity
Page Topics Brownian movement , Osmosis , Elodea Osmosis , Elodea Hypertonic , Elodea Hypotonic , Blood Isotonic , Blood Hypertonic , Blood Hypotonic ,
Transport Videos
DNA-RNA-Protein
DNA carries the genetic information of a cell and consists of thousands of genes. Each gene serves as a recipe on how to build a protein molecule. Proteins perform important tasks for the cell functions or serve as building blocks. The flow of information from the genes determines the protein composition and thereby the functions of the cell.
From Nobelprize.org, an introduction to DNA-RNA-Protein pathway. by Sep 5
Interactive Concepts-Catalysis
I recommend the one on catalysis for understanding how an enzyme catalyzes a reaction. by Sep 4
Water Movie
Water Movie, via YouTube. About the importance of water to life. by Sep 4
It's All About Carbon
If you have questions about climate change, please e-mail them to All Things Considered or call the show at 202-898-2395. When the subject is global warming, our mood is usually "uh-oh." Which makes sense, because a warmer Earth will lead to all kinds of disruptions and expensive adjustments that we could do without.
It's All About Carbon, All Things Considered, NPR. Cute video, but listen to the audiocast, especially from start at 2:24 to 6 min or so for a discussion on the importance of carbon for life. by Sep 4
ChemHealthWeb
National Institutes of Health site on Chemistry of Health. Lots of interactive units on the importance of chemistry to the human body. by Sep 4
Elements, Compounds & Mixtures Elements Note that an element: consists of only one kind of atom, cannot be broken down into a simpler type of matter by either physical or chemical means, and can exist as either atoms (e.g. argon) or molecules (e.g., nitrogen). A molecule consists of two or more atoms of the same element, or different elements, that are chemically bound together.
Elements, Compounds & Mixtures
CHEMICAL BONDS Song
The CHEMICAL BONDS Song - Mr. Edmonds - Rock with Abba's "Dancing Queen" music theme ! I laughed...but wonderfully accurate and makes it easy to remember. by Sep 4
Chemical Bonds
Selected by the SciLinks program, a service of National Science Teachers Association. Copyright 2001. For an explanation of the significance of this logo go to: http://www.scilinks.org/certificate.asp Because of the tendency of atoms to complete their outer energy shells with the stable number of electrons for each shell, atoms with incomplete shells have a tendency to gain electrons, lose electrons or share electrons. Atoms that have gained or lost electrons become ions.
Custom Search Bonding Links <-- Back to electronegativity Electronegativity Differences between atoms can be used to determine the type of bonding that occurs.
Types of Bonds
Animation about halfway down on this page does a good job explaining the different type of chemical bonds. by Sep 4