ENZYMES PMT Flashcards
What are enzymes
biological catalysts that increase the rate of a chemical reaction without being permanently altered themselves.
what is an advantage of enzymes in the body?
They enable cellular reactions to take place at lower temperatures
what is the active site?
The region of an enzyme to which a substrate molecule binds and the reaction takes place
why are enzymes described as having a ‘high specificity’ for their substrate?
Only substrates with a specific complementary shape can fit into a enzymes active site
describe the lock and key model
1) substrate collide with the active site of an enzyme
2) substrate binds, enzyme substrate complex forms
3) substrate converted to products
4) product released from the active site which is now free to bind with another substrate
what factors affect the rate of an enzyme controlled reaction?
-Temperature
-pH
-Substrate concentration
Explain how increasing temperature initially affects the rate of an enzyme controlled reaction
-as temperature increases molecules have more kinetic energy
-Movement of molecules increases
-Probability of a successful collision increases
-Rate of reaction increases
-More enzyme substrate complexes form
explain how increasing temperature above the optimum, affects the rate of an enzyme controlled reaction
-Temperature increases above the optimum
-Increased vibrations break bonds in enzymes structure
-Rate of reaction decreases
-Active site changes shape enzymes denatured
explain how pH affects the rate of an enzyme controlled reaction
-Enzymes have an optimum pH
-pH shifts from the optimum
-Rate of reaction decreases
explain how the substrate concentration affects the rate of an enzyme controlled reaction
-Substrate concentration increases
-Number of substrate molecules in the same volume increases
-Rate of reaction increase
-Probability of a successful collision increases
-More enzymes substrate complexes form
what type of molecules are proteins and carbohydrates?
Polymers
what are the monomers of carbohydrates?
Simple sugars
which enzyme catalyses the breakdown of carbohydrates?
Carbohydrates
which type of carbohydrates catalysts the breakdown of starch?
amylase
what are the monomers of proteins?
Amino acids
which type of enzyme catalyses the breakdown of protein
Protease
What is the function of lipase?
enzymes which catalyse breakdown of lipids into fatty acids and glycerol
why are small molecules synthesised into larger organic molecules in the body?
Large molecules are used for storage or are used to build structures
which enzyme catalyse a formation of glycogen from glucose?
Glycogen synthase
