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
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.