enzymes 1 Flashcards
How does gibs energy determine the spontanaoty of enzyme reactions
G<0 then the reaction = spontaneous
required for life
doesnt mean reaction is fast (determined by kenetics)
What is the main function of enzymes
To reduce the activation enegry of a reaction overall,
Can be done by providing a network to keep the raction out of equilibirum and/or coupling non-spontaneous with spontaneous reactions
How does a reaction proceed
Via a higher energy transition state (AE)
AE can be lowered with enzymes
Enzymes enable backwards and forwards reaction to occur via coupling
What enzyme is used to break down glycogen and how
Glycogen phosphorylase, binds a phosphate to a glucose monomer of glycogen, breaking this off.
3*10^14 faster than ‘normal’ sponetaneous reaction
what are the 6 clases of enzymes
oxidoreductase = redox
transferase = transfer functional group
hydrolase = hydrolysis
lyase = non-hydrolic bond cleavage
isomerase = transfer groups within atom
ligase = joint two molecules together
What are the two types of cofactors and cofactor jobs
help catylise of enzymes
metal ions
co-enzymes
what are metal ions good at
Lewis acids = electron aceptors - oarticipate in acid base chem
For very specific geometric arrangments around them good for arrangment around central metal ion
what are some examples of metal ions and enzymes which use them
Mg++ : DNA pol, Hexokinase, pyrovate kinase
Ca++: Alcohol dehydrogenase, carbonic anhydrase
Fe++/+ : cytochrome oxidase, pereoxidase
What is the benifits on co enzymes
small organic moleculees
co-substrates
are carriers - electrons, atoms, functional groups
often dirrived from vitamine residues
tipically regenerated (not used in reaction)
What is an example of a co enzyme
PLP - helps with glycogen phosphorylase, carries a protein to donate in the reaction
