enzymes Flashcards
define catalyst
a substance which increases the speed of a reaction without being changed or used up in the reaction
what are enzymes?
They are large proteins made up of chains of amino acids. Enzymes act as biological catalysts which reduce the need for high temperatures to increase rates of reaction
what speeds up useful reactions in the human body?
ONLY enzymes
draw the lock and key method
look in textbook for answer
describe the structure of an enzyme
The enzyme has an active site with a unique shape the fits onto the substrate involved in a reaction. Enzymes only catalyse one specific reaction. This is because the substrate has to fit into its active site for the enzyme to work. If the substrate doesn’t match the enzymes active site, the reaction won’t be catalysed.
what is the optimum temperature for enzymes?
about 37°C
what is the optimum pH for enzymes?
All enzymes have a different optimum pH, however pH 7 is most common. Pepsin (in the stomach) best works at pH 2.
what happens if the temperature of an enzyme is too high?
Some of the bonds holding the enzyme together break. This changes the shape of the enzyme’s active site, so the substrate won’t fit anymore. The enzyme is said to be denatured when the happens.
what is an optimum temperature?
the conditions where something works best at, where the enzyme is most active
what happens when the pH is too high or low?
It interferes with the bonds holding the enzyme together. This changes the shape of the enzyme’s active site, so the substrate won’t fit anymore. The enzyme is said to be denatured when the happens.
draw the graphs for optimum pH and optimum temperature
look in textbook for answer
explain the lock and key theory
-enzymes bind to the substrate because they are complementary
-the substrate is broken down into products
-products are released
role of enzymes in digestion
act as biological catalysts which speed up the rate of biological reactions without being used up
how does the shape of an enzyme affect its function?
enzymes have a specific active site which is complementary to their substrate
what types of metabolic reactions do enzymes catalyse?
-building larger molecules from smaller molecules
-changing one molecule to another
-breaking down larger molecules into smaller molecules
