Key food molecules Flashcards
zwittierion/ dipolar ion
ion containing an equal number of positive and negative charges.
-amino acids this way due to the amine and carboxyl acid groups (NH3+, COO-)
peptide links
carboxyl group and amine group = H2O
this portion then becomes an amide.
effect of pH on amino acids
- amino acids are zwitterions
- therefore, it is amphiprotic (acid or base)
amino acids basic environment
- acts as an acid.
- due to it losing the H+ when the concentration of H+ ions is lowered.
- NH2 = COO-
- therefore overall negative charge
- anionic form
amino acids in acidic environments
- acts as a base
- due to it combining with the increasing concentration of H+.
- COOH= NH3+
- therefore overall positive charge
- cationic form
amphoteric
can act as an acid or base
formation of proteins
-condensation reactions to for di or poly-peptide bonds. therefore water is released.
primary structure
-chain
secondary structure
-alpha helix and beta pleated-sheets
tertiary structures
- overall three-dimensional structure
- shape depends on the properties of the R group (polarity).
Quaternary structure
-two or more polypeptide chains
enzymes
provide an alternitive pathway with a lower activation energy.
lock-and-key model
the substrate can only react with an enzyme that has a complementary active site. This can be related to a key and a lock, as only a key with a particular shape.
induced-fit model
the active site may change tp fit the substrate’s shape.
coenzyme what?
organic non-proteins based molecules that assist the enzyme by binding to the active site.
-chemmical structure can change during reaction.
temperature on enzymes
cooler temps= not much energy therefore the enzymes move slowly.
high temps= the enzymes denature (the active site is permenantly changed)
pH on enzymes
-determines whether the protein acts as an acid or base.
-
denaturation
the collapse of intra- and intermolecular bonds that maintian the shape in quaternary, tertiary, and secondary structures of an enzymes, hence altering the ennzymes catalytic activity.
hydrolysis of primary vs denaturation
hydrolysis involves the breaking of strong covalent bonds (intramolecular), whereas denaturation involves the breaking of weak intermolecular bonds.
