Proteins and Enzymes Flashcards
amino acids
- total of 20
- differ due to unique R group
- four groups bonded to a single carbon (Alpha carbon)
structure of amino acid
NH3 group
CH
R grourp
COO- (carboxyl) group
What is a protein
- chain of amino acids joined by peptide bonds
- formed via condensation reactions
joining two amino acids together
- amino and carboxyl group of two amino acids join together to form a peptide bond
- molecule of water is formed as a by-product
primary structure
linear sequence of amino acids
secondary structure
changes in primary structure due to formation of hydrogen bonds between nearby amino acids
- forms alpha helix coils
- beta pleated sheets
tertiary structure
irregular folding of structure due to interactions between r groups that are relatively far away from each other
quaternary structure
consists of two or more polypeptide chains
- ie haemoglobin
denaturation
disruption of the secondary and tertiary structure of the protein and destroys protein’s biological function
characteristics of enzymes
- catalysts
- typically protein
- increase reaction rate by lowering Ea
- do not alter final eqm
- regulated (body controls action of enzyme as required)
- not used up
What are the different types of enzyme regulators?
- competitive/non-competitive inhibitor
- allosteric inhibitor
- allosteric co-operativity
- feedback loops
Competitive inhibitor
where the inhibitor and substrate compete over the active site.
Both are identical shapes and only one can bind.
Non-competitive inhibitor
Inhibitor binds to a site away from active site and changes the enzyme’s shape so that the substrate can no longer bind to the active site.
What are the types of enzyme partners?
- cofactors - fe2+, cu+
- coenzymes - NAD, FAD, ATP
- prosthetic groups - Heme, retinal
- vitamins - vitamin C (in a collagen forming enzyme)
