Pitch: the use of notes in voice range. Speak in a voice range that is comfortable and move up or down Pause: Give you time to catch your breath and the audience time to collect your ideas. Articulation and Pronunciation: Articulation is the art of expressing words distinctly. Pronunciation is the ability to say words correctly. Length: Length of your presentation is crucial.
Enzyme. Photo by: fotohunter. An enzyme is a biological catalyst. A catalyst is a chemical compound that speeds up the rate of some chemical reaction. When that chemical reaction occurs in a living organism, the catalyst is known as an enzyme.hemical reaction: Any change in which at least one new substance is formed. Lock-and-key model: One of the ways in which enzymes bring about chemical reactions. Product: A compound that is formed as the result of a chemical reaction.
An enzyme lowers the activation energy of a chemical reaction. c. Most enzymes are proteins. d. An enzyme is consumed during the reaction it catalyzes. e. An enzyme is very specific in terms of which substrate it binds to.. Enzymes react with their substrate (form chemical bonds), forming an enzyme-substrate complex, which irreversibly alters the enzyme. c. Enzymes increase the rate of a reaction by raising the activation energy for reactions. d. Enzymes speed up the rate of the reaction without changing the DG for the reaction.