amino acids/proteins biological information

what are proteins composed of?

amino acids act as building blocks to form the polypeptide

what is a zwitterion?

a compound that contains a + and - charge

what trend do we observe with non-polar hydrophobic amino acids?

contain lots of carbons and hydrogens in side chain with less EN elements

what trend do we see with the polar (hydrophilic) amino acids?

polar amino acids contain more EN groups such as oxygen, sulfur, nitrogen (dont have charges)

what trend do we see with the charged amino acids?

the side chain has + or - charge

acidic and basic groups?

acidic group: donates a proton (H+)

basic group: accepts a proton (H+)

which functional group acts as a base and which functional group acts as an acid in the amino acid backbone?

amine group (NH2) acts as base and accepts a proton to become RNH3+

carboxylic acid (RCOOH) donates a proton to become (RCOO-)

how can naturally occurring amino acids be classified?

L, NH2 is on the left

what does essential amino acid mean?

essential amino acid means they must be obtained from your diet, your body cannot make these amino acids

primary structure of proteins

sequence of amino acids in a polypeptide chain

does the backbone change amongst amino acids?

no

do the R groups change amongst amino acids?

yes

secondary structure of proteins

refers to local folded structures that form within a polypeptide due to interactions between atoms of the backbone

how do the alpha and beta pleated sheets differ?

alpha helix: coiled shaped, H-bonding between hydrogens of NH group in backbone

beta pleated sheets: short zigzagging lengths of polypeptide chain, H-bonding with NH of backbone

what interaction is holding the secondary protein structure together?

H-bonding between Hs of the NH group with the C=O of the backbone

does this interaction holding the secondary protein together occur between the backbone or the R groups?

backbone

tertiary structure of proteins

interactions between the R groups of the amino acids that make up the proteins

does this tertiary protein interaction occur between the backbone or R groups?

occurs between R groups

what would undergo ionic bonds?

charged R groups

what would undergo hydrophobic interactions?

non-polar R groups

what would undergo hydrophilic interactions?

polar R groups

what would undergo disulfide linkage?

cysteine (CH2-SH)

what would undergo H bonding?

serine, asparagine, glutamine

which groups would prefer to fold to the exterior of the protein?

hydrophilic (polar) groups

which groups would prefer folding to the interior of the protein?

hydrophobic (non-polar) groups

what are quarternary protein structures?

they contain two or more protein subunits combined to form an active protein

a single protein subunit in a quarternary structure is what type of protein structure?

tertiary structure

hemoglobin is composed of how many protein subunits?

4