Polymers and Life - Polymers and Enzymes Flashcards
what is an amino acid residue?
an amino acid when it is in a polypeptide chain/dipeptide
what are the interactions between side chains in proteins?
id-id bonds
hydrogen bonds
ionic
covalent
how are addition polymers formed?
electrophillic addition
starting material must contain a double bond
what is the primary structure of proteins?
polypeptide chain of amino acids
what holds the secondary structure of proteins together?
hydrogen bonds between N-H and C=O
what are fibrous proteins usually made up of?
helices
what are globular proteins usually made of?
both sheets and helices
what are some examples of condensation polymers?
polyesters
polyamides (nylons)
polypeptides
what must the monomers contain for condensation polymerisation?
two functional groups each
a carboxyl group
what are polyamides typically formed from?
dicarboxylic acid + diamine
what are polyesters usually made from?
carboxylic acid + alcohol
how are nylons named?
nylon - number of carbon in diamine, number of carbon in dicarboxylic acid
what is another name for a polyamide?
a nylon
what reaction breaks down an ester?
hydrolysis
which bond breaks in an ester during hydrolysis?
the C-O bond
how quick is the hydrolysis of esters?
very slow without a catalyst
why does the C-O bond in an ester break in hydrolysis?
it is a weak bond as the carbon is delta positive because of the C=O as well as the C-O
what are the 2 conditions that esters can be hydrolysed in?
aqueous solution
aqueous alkaline solution
what happens in the hydrolysis of esters in aqueous conditions?
carboxylic acid is formed
reversible reaction
water is the electrophile
what happens when an ester is hydrolised in aqueous alkaline conditions?
a carboxylate salt is formed
not reversible
OH- is the electrophile
what is the functional group of a carboxylate salt?
carboxylic acid but O- instead of OH
what is the breakdown of amides called?
hydrolysis
what are the 2 conditions that amides can be hydrolysed in?
alkaline solutions
acidic solutions
what are the products of amide hydrolysis in acidic conditions?
amine salt + anion
what acids are used in the hydrolysis of amides?
moderately concentrated hydrochloric or sulfuric
what are the products of alkaline hydrolysis of amides?
carboxylate ion + amine formed
what alkali is used in the hydrolysis of amides?
usually moderately concentrated NaOH
why do the bonds formed between an enzyme and substrate need to be weak?
so that the substrate can leave the complex once the breakdown in complete
what can affect the activity of enzymes?
pH
temperature
competition
substrate conc
what bonds are usually formed between an enzyme and substrate at the active site?
hydrogen bonds or interactions between ionic groups
what is the strength of the bonds formed between an enzyme and substrate?
relatively weak
why are the bonds formed between an enzyme and substrate relatively weak?
so the products can leave the complex
which type of inhibition do you need to know for chem?
competitive inhibition
how do competitive inhibitors affect enzymes?
they bind to the active site but do not leave when the products are formed, denaturing the enzyme
what are the two ways that pH can affect enzymes?
ionisable groups in the active site can react with or donate H+ ions, meaning it can’t interact with substrate the same
bonds in tertiary structure of the protein affected, shape breaks down and enzyme is denatured
what is molecular recognition?
the way in which molecules interact in terms of intermolecular and non-covalent bonds
what is a pharmacophore?
the part of a medicine molecule that allows it to have the desired effect
what is the receptor site?
the part of the active site that forms bonds with the substrate
what are some examples of molecular recognition?
antibodies + antigens
enzymes + substrates
