Cell Size and Scale Some cells are visible to the unaided eye The smallest objects that the unaided human eye can see are about 0.1 mm long. That means that under the right conditions, you might be able to see an ameoba proteus, a human egg, and a paramecium without using magnification. A magnifying glass can help you to see them more clearly, but they will still look tiny. Smaller cells are easily visible under a light microscope. It's even possible to make out structures within the cell, such as the nucleus, mitochondria and chloroplasts. 3-D Biological Molecules Listed below are links to pages containing 3-dimensional displays of models of molecules of Biological interest. These may be moved in an intuitive way using the computer mouse or touchscreen. In the explanatory text are links which highlight features of the molecule or give extra information.
Interactive Eukaryotic Cell Model Nucleolus: The prominent structure in the nucleus is the nucleolus. The nucleolus produces ribosomes, which move out of the nucleus and take positions on the rough endoplasmic reticulum where they are critical in protein synthesis. Cytosol: The cytosol is the "soup" within which all the other cell organelles reside and where most of the cellular metabolism occurs. Though mostly water, the cytosol is full of proteins that control cell metabolism including signal transduction pathways, glycolysis, intracellular receptors, and transcription factors.
Chapter 8: Biology: Photography through the microscope Photography through a microscope Amateur microscopes and cheap cameras A simple toy microscope and a disposable camera can team up to make stunning photographs of very tiny things. Histology Tutor Background: A complex organism, such as a human, is made of collections of cells working together in performing a specific function. These groups of cells are called Tissues. The study of tissues is called Histology. Objectives: The PCR Method - a DNA Copying Machine Lists of Nobel Prizes and Laureates The PCR Method - a DNA Copying Machine Play the Eye of the Donkey Game Cell - humans, examples, body, used, water, process, plants, type, chemical, characteristics, form, energy, animals, system, carbon, oxygen, cells, parts, cause Photo by: Mopic The cell is the basic unit of a living organism. In multicellular organisms (organisms with more than one cell), a collection of cells that work together to perform similar functions is called a tissue. In the next higher level of organization, various tissues that perform coordinated functions form organs.
Nuclear reactor and power plant simulation Introduction This is not a lesson like the others in Radioactivity and Atomic Physics Explained but it fits in well with the lesson on nuclear power. It is a very sophisticated simulation of a pressurised water reactor (PWR), which is the most common type of nuclear power reactor in the US but not in Europe, though the principles are very similar. Using the tour There is a comprehensive tour which goes through the workings of the reactor, starting from a consumer of electrical energy and working backwards to the reactor core itself. You can restart the tour at any time using the button at the top left of the screen.
audio et texte en anglais sur le tabac (laura et philippe) Tobacco by Claire Powell and Dave Collett What’s in a cigarette? Activation Energy and Enzymes TITLE: Activation Energy and EnzymesSOURCE: Freeman, S, Biological Science, Second Edition, Pearson Prentice Hall, Inc.© 2006 Pearson Prentice Hall, Inc.KEYWORDS: Activation energy, enzymes, exergonic reactions, ATP, activation energy, catalysts, lock-and-key model, induced-fit model 1ère ES/L : Food Preservation Methods: Canning, Freezing, and Drying (Nico&Camille) You can preserve foods inexpensively by using canning, freezing, or drying techniques. Modern-day food preservation methods, such as water-bath canning, help you can and preserve with ease. After you understand the basic procedures for a food preservation method, you'll just need to concentrate on preparing your recipe. About canning food