Enzymes and metabolism Flashcards
What conditions needs to happen for chemical reactions to occur
For particles to react and break their bonds in a chemical reaction, the particles need to be at either a high enough temp. (optimum temp) or have a catalyst
What is a catalyst
a substance that decreases the amount of energy needed to break bonds, which increases the rate of reaction
what are catalysts in living organisms called
in living organisms catalysts are proteins called enzymes
what are enzymes
biological catalysts that speed up chemical reactions by lowering the activation energy
what has the shape of proteins got to do with reactions
the shape of proteins means that the enzymes are specific for a particular reaction
what is a substrate
a molecule on which an enzyme acts
what is the relationship between enzymes and substrates
- enzymes will combine with only one particular substrate, which means its involved in only one specific reaction
- the enzyme and its substrate have characteristics that are complementary to one another
What is the active site
part of the enzyme molecule that combines with the substrate
What is the Enzyme Substrate Complex
Structure formed when enzyme and substrate combine
What is the lock and key model
the shape of the enzyme is complementary to the shape of the substrate which means they fit perfectly into each other
what is the induced fit model
when the substrate joins to the enzyme, the enzyme changes shape so that to substrate fits
What are the factors affecting enzyme activity?
- concentration of enzyme
- concentration of substrate
- removal of products
- temperature
- PH levels
- presence of co-factors
- enzyme inhibitors
how does the concentration of the enzyme affect the enzyme activity
Higher concentration = increased rate of reaction
how does the concentration of substrate affect the enzyme activity
Higher concentration = increased rate of reaction (however, increasing the substrate beyond a certain point will cease to have any affect on the rate of reaction
how does the removal of products affect the enzyme activity
products of reaction need to continually be removed otherwise the rate of reaction will slow
how does temperature affect the enzyme activity
rate of reaction increases as the temperature increases. But if the temp is to high the enzyme becomes denatured (the temp must be optimum)
how do PH levels affect the enzyme activity
each enzyme has an optimum PH at which it works most effectively
how does the presence of co-factors affect the enzyme activity
they change the shape of the active site so that enzymes can combine with the substrate
how do enzyme inhibitors affect the enzyme activity
- substances that slow down or stop enzymes activity
- this may be used so that cells only produce specific amounts of products
