4- Enzymes Flashcards
(26 cards)
What is metabolism?
the sum of all chemical reaction within cells and organisms
What is an anabolic reaction?
one which builds a molecule or molecules
What is a catabolic reaction?
One which breaks down a molecule or molecules
Why do organisms need enzymes in their bodies?
To act as catalysts for their metabolic reactions
what are some benefits that enzymes provide tov organisms?
Mean the organism requires less energy to function, meaning it needs to consume less food and could maintain a lower body temperature. Would also save time
Where do intracellular enzymes act?
Inside cells
Where do extracellular enzymes act?
Outside of cells
What is the structure of catalyse?
A conjugated globular protein with 4 haem groups in its quaternary structure
Is catalyse intracellular or extracellular
Intracellular
What is the function of catalyse?
It breaks down toxic hydrogen peroxide into water and oxygen
What is the function of amylase?
breaks down starch into maltose
Where is amylase present? Is it intra or extracellular?
-mouth and small intestine
-extracellular
What is the function of trypsin?
It is a protease, and therefore breaks down proteins into peptides
Where does trypsin work? Is it intra or extracellular?
-Small intestine
-Extracellular
What is the lock and key hypothesis?
-an are within the tertiary structure of an enzyme which has a shape complementary to the shape of a specific substrate molecule
-this area is called the active site
-when the substrate is bound to the active site an enyme-substrate complex is formed
-the substrate is held in a way by the enzyme that the right atom-groups are close enough to react. The R-groups within the active site will also react with the substrate forming temporary bonds
-these put strain on the bonds within three substrate, which also helps the reaction along
What determines the shape of an enzymes active site?
It’s tertiary structure
What type of proteins are enzymes?
globular
What is the induced fit hypothesis?
-the substrate enters the active site of an enzyme, which os not complementary but a slightly different shape to the substrate
-the active site slightly changes shape to mould around the substrate, this puts pressure on the substrate via its R-groups and causing a reaction
-when the enzyme-substrate complex occurs it puts strain on the bonds and therefore lowers the activation energy
What is an enzyme-product complex?
When the substrate reacts and the products are formed (within the lock and key hypothesis)
What are enzymes?
-biological catalysts
-globular proteins that interact with substrate molecules causing them to react at much faster rates
What are the roles of enzymes in reactions?
-catalyse anabolic reactions which are required for growth
-catalyse catabolic reactions which release energy that is required for majority of living processes
-catalyse digestion to break down larger organic molecules
eg. starch
How is startch digested?
- Startch polymers are partially broken down into maltose by the enzyme amylase (which is produced by salivary glands and pancreas) in the mouth and small intestine
- Maltose is broken down into glucose by maltase present in the small intestine
- Glucose is small enough to be absorbed by the cells lining in the digestive system and subsequently absorbed into the bloodstream
What must occur for a reaction to take place?
-some or all chemical bonds in reactants must be broken so that new bonds can form
-molecules need to collide in the right orientation
-energy needs to be supplied , activation energy (the highest the activation energy the slower the reaction will be)
What the factors that affect enzyme activity?
-temperature
-pH
-enzyme concentration
-substrate concentration
