Activity and Temperature

Activity and Temperature

1. Identify the role of enzymes in metabolism, describe their chemical composition and use a simple model to describe their specificity on substances

   • Metabolism: refers to the countless chemical processes that are continually going on inside the body to keep it functioning properly.
     • Molecules are: 1. Broken down 2. Combined 3. Exchanged
     • This process is regulated by ENZYMES
   • Enzymes are lage protein molecules that can be used over and over again. They are made in a cell when they are needed.
     • They are biological catalysts They speed up the rate of reaction or slow it down but are not chemically changed at the end of the reaction.
   • Lock and Key model suggests that each enzyme is created for a certain reaction. The induced fit model sugegstis that enzymes are plactic-like and can mold to fit a reaction

2. Enzymes need certain conditions for maximum efficiency

   • PH
     • Identify the pH as a way of describing the acidity of a substance
       • Acidity is measured on the pH scale, which ranges from 0 to 14. Substances with a 7 pH are 'neutral'. Below 7 is 'acid' and above 7 is 'alkaline.'
   • Concentration
   • Temperature
   • Explain why the maintainance of a constant internal environment is important for optimal metabolic efficiency
     • All enzymes work best under optimum conditions. Cells need to maintain an optimum environment for their enzymes to function.
     • HOMEOSTASIS
       • Describe homeostasis as the process by which organisms maintain a relatively stable internal environment
         • Explain that Homeostasis consits of two stages Two stages: 1. detecting changes from the stable state 2. counteracting changes from the stable state.
           • Responses are brough about by effectors. In Mammals:
             • Muscles resond by contracting or relaxing, thus bringing about movement
             • Glands respond by secreting a chemical substance such as the salivary glands in the mouth produce saliva when food is detected.
       • Outline the role of the nervous system in detecting and responding to environmental changes
         • The human nervous system is made up of the central nervous system, the brain and the spinal chord. It recieves information, interprets it and initiates a response.
         • The Preipheral nervous system is a system of nerves branching out throughout the body to and from the receptors and effectors. These act a communication channels and pass messages rapidly to the central nervous system and back
         • The endorcine system produces hormones.
       • Identiify the broad range of temperatures over which life is found, compared with the narrow limits for individual species.

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