1 Identify the role of enzymes in metabolism, describe their
chemical composition and use a simple model to describe
their specificity on substances
1.1 Metabolism: refers to the countless chemical processes
that are continually going on inside the body to keep it
1.1.1 Molecules are:
1. Broken down
1.1.2 This process is regulated by
1.2 Enzymes are lage protein molecules that can be used over and over
again. They are made in a cell when they are needed.
1.2.1 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.
1.3 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
2.1.1 Identify the pH as a way of describing the acidity of a substance
184.108.40.206 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.'
2.4 Explain why the maintainance of a constant internal
environment is important for optimal metabolic efficiency
2.4.1 All enzymes work best under optimum conditions. Cells need to maintain
an optimum environment for their enzymes to function.
220.127.116.11 Describe homeostasis as the process by which organisms maintain a relatively stable internal
18.104.22.168.1 Explain that Homeostasis consits of two stages Two stages: 1. detecting changes from the stable
state 2. counteracting changes from the stable state.
22.214.171.124.1.1 Responses are brough about by effectors. In
126.96.36.199.1.1.1 Muscles resond by contracting or relaxing, thus bringing about movement
188.8.131.52.1.1.2 Glands respond by secreting a chemical substance such as the
salivary glands in the mouth produce saliva when food is detected.
184.108.40.206 Outline the role of the nervous system in detecting and
responding to environmental changes
220.127.116.11.1 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
18.104.22.168.2 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
22.214.171.124.3 The endorcine system produces hormones.
126.96.36.199 Identiify the broad range of temperatures over which life is found, compared with the narrow
limits for individual species.