Enzymes Flashcards
What are enzymes?
Proteins which act as biological catalysts produced by living things
What is a catalyst?
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
What is the only thing the body has to speed up chemical reactions?
Enzymes
Enzymes are all ……….. (in the body) ?
Proteins
What are proteins made up of?
Long chains of amino acids
What 3 things do proteins act as as well as catalysts?
Structural components of tissues, hormones and antibodies
An enzyme is a…..?
Biological catalyst
What does every enzyme have?
A unique shape which fits onto the substance involved in a reaction
How many reactions do enzymes usually catalyse?
Just one
What has to be right for the enzyme to work?
The substance has to match the enzymes shape, otherwise the reaction will not be catalysed
What does an enzyme have?
An area where other molecules can fit
What is the area of an enzyme called where other molecules can fit?
The active site
What happens to the substrate in a reaction?
It is held in by the active site and either connected to another molecule or broken down
What 3 things can enzymes do?
Build large molecules from many smaller ones, change one molecule into another molecule, or break down large molecules into smaller ones
What is an example of enzymes building large molecules from many smaller ones?
Building starch from glucose molecules
What is an example of enzymes changing one molecule into another?
Converting one type of sugar into another
What is an example of enzymes breaking down large molecules into smaller molecules?
The digestive system
What do enzymes need in order to work properly?
The right temperature and the right pH
What prevents an enzyme from working?
Factors which alter the shape of the active site
If the temperature gets too hot what happens to the active site of an enzyme?
It changes shape
What is an example of an enzyme that works best in acidic conditions?
The enzymes in the stomach: pepsin breaks down proteins in the stomach
What happens to an enzyme if the pH is too acidic or alkaline for it?
The active site changes shape
What does the term ‘denatured’ mean?
When the enzyme changes shape and stops working
What happens if the temperature gets too hot?
Some of the bonds holding the enzyme together break which destroys its special shape
