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level: enzyme

Questions and Answers List

level questions: enzyme

Question	Answer
- proteins that allow chemical reactions to take place at normal body temperature - without enzymes, these reactions would be too slow to be of any use to the body	enzymes
- chemical reaction requires energy to get started - enzymes reduce the activation energy needed to begin a reaction - enzymes allow reactions to occur at a rate suited to body's requirements	activation energy
- substrate molecules on which an enzyme acts on - enzymes are specific - each enzyme will combine with only one particular substrate - enzyme and substrate have a shape and structure that allow them to fit together - lock and key model - active site: part of the enzyme that combines with the substrate	enzyme-substrate complex
- increase the rate of chemical reaction - by regulating type and amount of enzyme present, the body is able to control which reactions occur and what rate they proceed	higher concentration
- increases reaction rate - there will be more substrate coming into contact with enzyme molecules - beyond a certain concentration, the increasing substrate will cease to have an effect because all enzyme molecules will be fully occupied (saturation)	increased substrate concentration
- otherwise rate of reaction will be slow because it becomes more difficult for substrate molecules to make contact with enzyme molecules	products are continually removed
- rate of most chemical reactions increases as temperature increases - only within a limited temperature - enzymes are proteins, beyond 40 degrees, their structure changes and they are denatured - optimum temperature is around 37 or 38 degrees	temperature
- each enzyme has an optimal pH at which it works most effectively	pH levels
- change the shape of the active site so the enzyme can combine with substrate	co-factors
- substrates that slow or even stop enzyme activity - inhibitors may be used by cell to control reaction so that products are produced in specific amounts - many drugs are enzyme inhibitors	enzyme inhibitors