Zusammenfassung der Ressource
Activity and
Temperature
- 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.