Enzymes Flashcards
Why do chemical reactions need to be carefully controlled?
to get the right amounts of substances in the cells
How can you ‘‘usually’’ make a reaction happen more quickly?
by raising the temperature
there’s also a limit to how far you can raise the temperature inside a living creature before its cells start getting damaged
Living things have thousands of what (going on inside them all the time)?
different chemical reactions
Enzymes
act as biological catalysts
Catalysts
a substance which increases the speed of a reaction, without being changed or used up in the reaction
What do enzymes reduce?
the need for high temperatures
Metabolic reactions
enzymes speeding up the useful chemical reactions in the body
Are enzymes proteins?
Yes
What are proteins made up of?
chains of amino acids
A substrate
a molecule that is changed in a reaction
Active site
(every enzyme molecule has it) the part where a substrate joins on to the enzyme
How does an enzyme work?
a substrate has to be the correct shape to fit into the active site
Lock and key model
the substrate fits into the enzyme just like a key fits into a lock
What happens when the rate of a reaction increases (when the temperature is high)?
the enzymes and substrate have more energy so they move more and are more likely to collide and form enzyme substrate complexes
What happens if the temperature is too high?
some of the bonds holding the enzyme together break which changes the shape of the enzyme’s active site. Therefore, the substrate won’t fit anymore and the enzyme is denatured
