.... Transport In active transport a cell moves materials from an area of low concentration to an area of high concentration, this process is the opposite of osmosis or diffusion. Active transport requires energy because it is moving against the concentration gradient. In active transport the cell uses ATP to remove unwanted materials and to receive needed ones. For example a muscle cell wants potassium and wants to get rid of a sodium, the cell releases ATP to the pump proteins which results in the cell ejecting the sodium ion and at the same time another receptor cell accepts a potassium which is then released into the cell and the process is re .....

.... theories; and the theory advanced in the 5th century BC by Empedocles—that all things are composed of air, earth, fire, and water—was influential in . The Roman emperor Caligula is said to have instituted experiments for producing gold from orpiment, a sulfide of arsenic, and the emperor Diocletian is said to have ordered all Egyptian works concerning the chemistry of gold and silver to be burned in order to stop such experiments. Zosimus the Theban (about AD 250-300) discovered that sulfuric acid is a solvent of metals, and he liberated oxygen from the red oxide of mercury. The fundamental concept of stemmed from the Aristotelian doctrine that all thi .....

.... p. 392). It has been found after many research , that new memory is stored in a section of the brain called the hippocampus (Loftus p. 392). Memory is acquired by a series of solidifying events , but more research is still needed to discover and fully understand (Loftus p. 392). Memory is broken down into three systems or categories . These different systems are sensory memory , short-term , and long-term memory. Sensory memory is the shortest and less extensive of the others. It can hold memory for only an instance (Memory p. 32). Suppose you see a tree , the image of the tree is briefly held by the sensory memory and quickly disappears unless you transfer i .....

.... by-product the quickest, by the addition of the yeast solution. The best results came from galactose, which produced .170 ml/minute of carbon dioxide. Followed by glucose, this produced .014 ml/minute; finally, sucrose which produced .012ml/minute of Carbon Dioxide. The test solutions water and glycine did not release Carbon Dioxide because they were not a food source for yeast. The results suggest that sugars are very good energy sources for a cell where amino acid, Glycine, is not. INTRODUCTION Fermentation is an anaerobic process in which fuel molecules are broken down to create pyruvate and ATP molecules (Alberts, 1998). Both pyruva .....

.... tunnel is a machine used to fly aircraft's, missiles, engines, and rockets on the ground under pre-set conditions. With a wind tunnel you can chose the air speed, pressure, altitude and temperature to name a few things. A wind tunnel is usually has a tube like appearance with which wind is produced by a large fan to flow over what they are testing (plane, missiles, rockets, etc.)or a model of it. The object in the wind tunnel is fixed and placed in the test section of the tunnel and instruments are placed on the model to record the aerodynamic forces acting on the model. Types of Wind Tunnels There are four basic types of wind tunnels. Which are low subs .....

.... years these single celled organisms have changed and evolved into many different species including humans. This theory also states that humans and other species continue to evolve today and as a result of all these changes they will eventually become a totally different species then what they are now. Evolutionists believe that evolution has created many organisms spread across the globe, some of which have become extinct and some of which are the plants and animals which live today. The theory that groups of organisms can be transformed into different organisms has been suggested many times since the early 1800s, when scientists began looking for evide .....

.... radio channel and watching various televisions for important activity. Inside the Apollo 4 there was a metal door with a sharp edge. Each time the door was open and shut, it scraped against an environmental control unit wire. The repeated abrasion had exposed two tiny sections of wire. A spark alone would not cause a fire, but just below the cuts in the cable was a length of aluminum tubing, which took a ninety-degree turn. There were hundreds of these turns in the whole capsule. The aluminum tubing carried a glycol cooling fluid, which is not flammable, but when exposed to air it turns to flammable fumes. The capsule was filled with pure oxygen in an .....

.... of portland cement is around 700 million metric tons (Danbury). Many people use the words concrete and cement interchangeably, but they're not. Concrete is to cement as a cake is to flour. Concrete is a mixture of ingredients that includes cement but contains other ingredients also (Day 6- 7). Portland cement is produced by pulverizing clinker consisting essentially of hydraulic calcium silicates along with some calcium aluminates and calcium aluminoferrites and usually containing one or more forms of calcium sulfate (gypsum) as an interground addition. Materials used in the manufacture of portland cement must contain appropriate proport .....