organisation Flashcards
Are most chemical reactions fast or slow?
Slow
One way to increase the rate of chemical reactions is to increase the temperature
Give two reasons why we can’t just make our cells warmer to increase the rate of reactions?
-Heating our cells more would require a lot of energy
-Higher temperature could damage cells
-Higher temperature would also speed up non-useful reactions
What is a Catalyst?
A catalyst is a substance that increases the speed of a chemical reaction without being used up or changed in the process.
What is an enzyme?
An enzyme is a special type of catalyst that is made by a living organism. Sometimes we call the biological catalysts. Enzymes are large proteins, so made up of a long chain of amino acids
What is the name of the special region of an enzyme that binds to the substrate?
Active site
In order for an enzyme to catalyse a reaction, What must the active site of the enzyme be to the substrate?
Complementary
At first scientists thought that in order for an enzyme to catalyse a reaction, the substrate had to fit perfectly into the active site, What was the name of this model?
The lock and key model
We now know that in order for an enzyme to catalyse a reaction, the enzymes active site actually changes shape slightly as it binds to the substrate. What do we call this model?
The induced fit model
Why do organisms need enzymes?
As most chemical reactions are naturally very slow.
What do we call the complex that is formed when an enzyme binds to a substrate?
Enzyme-substrate complex
