Enzymes - C5 Flashcards
What are enzymes?
Biological catalysts
What are four uses of enzymes?
Digestion, photosynthesis, cellular respiration, DNA replication
What is the active site of an enzyme?
The substrate binding site
What gives an active site its’ shape?
The unique folding of polypeptides
What are the three levels of specificity of enzymes?
Substrate (absolute - lactase only works on lactose) Bond (peptidase only works on peptide bonds), Group (Trypsin only works on peptide bonds next to basic amino acids - lysine and arginine)
Three characteristics of enzymes
Most often proteins, Globular, typically water soluble, 1 or more polypeptide chains
Is the enzyme consumed by the reaction?
No
How does an enzyme work?
Lowers activation energy by positioning substrates so that bonds can be made/broken more easily
Describe the Locke and Key model
1894, claimed Activation Site is exactly complimentary of substrate
Describe the Induced Fit model
1958, Active Site changes and molds around substrate to make a tight fit
Define Enthalpy
The energy given off/absorbed in producing products
What is an exothermic reaction?
negative, products in lower energy state than reactants
What is an endothermic reaction?
positive, products in higher energy state than reactants
breakdown _
What is an a catabolic reaction?
A breakdown of chemicals, releases energy
builds _
What is an Anabolic reaction?
A building of chemicals, requires energy
