... membrane. An example would be glucose molecules which are not able to cross the cell membrane independently due to the lipid bilayer. Osmosis is another form of passive transport, whereby water moves from an area of low concentration of solutes to an area of high concentration, the two areas are separated by the semi permeable cell membrane. So if a cell uses ... up water in chemical reactions the cytoplasm will become more concentrated so more water will move across the membrane to restore the balance. An isotonic environment is where a cell neither gains nor loses ... mitochondria du...

• Word Count: 1603
• Approx Pages: 6
• Has Bibliography
• Grade Level: Undergraduate

... through natural process. Monomers of all classes of macromolecules form larger molecules by dehydration synthesis, a chemical reaction in which one monomer donates a hydroxyl and the other a hydrogen, thus forming a water molecule. A polymer's properties depend on its size, it monomers, the strength of its bonds, and whether links form between different parts of the molecule. Synthetic polymers include the plastics polystyrene ... different kinds of nitrogenous bases. Lipids make up the most structurally heterogeneous class of macromolecules, but all share the property of being wholly o...

• Word Count: 728
• Approx Pages: 3
• Grade Level: Undergraduate

... other. "Muscle fibers, though, are just the building blocks for whole muscles- (6). "In chemical composition the fibers may be said, in round numbers, to consist of seventy five percent of water, about twenty percent of proteids, two percent of fat, one percent of nitrogenous extractives and carbohydrates, and two percent of salts, which are mainly potassium phosphate and carbonate-(3). The Actin ... depend on three principal types of protein filaments: Actin filaments, microtubules and inter mediate filaments. Muscle fibers are huge single cells formed from many separate cells whose nu...

• Word Count: 1417
• Approx Pages: 6
• Has Bibliography