topic 5

Question 1

whats the diff between 1,2,3, and 4 proteins

Answer 1

-primary refers to the chain of AA
-the secondary is the formation of repeating functional structures due to the formation of HB between the C=O and NH groups along the same chain
-tertiary is the folding of a polypeptide chain due to the hydrophilic effect
-quaternary, is a large protein unit comprises of 2 or more tertiary proteins

Question 2

what are the important forces required for the formation of tertiary proteins?

Answer 2

HB
VAn der waals forces
ionic bonds
occasionally disulfide bonds

Question 3

what is a teritary protein?

Answer 3

the folding of a poly peptide chain due to the hydrophilic effect. this burning the nonpolar backbone and residues, stabilized through HB between and van der waals the C=O and NH while exposing the polar side residues

Question 4

what is a motif

Answer 4

a combination of secondary structures that serves a functional purpose in a tertiary protein. the presence of motifs is related to the overall function of the protein and may be found across proteins which have unrelated functions

Question 5

what is a super secondary structure?

Answer 5

a motif

Question 6

what is a domain?

Answer 6

a condensed region of a polypeptide chain that functions independently of the protein. these structures are only found in tertiary structures and are commonly only in related proteins

Question 7

what is a quaternary structure? what types of interaction occurs?

Answer 7

a protein that contains more than 1 polypeptide chain (subunit).
stabilized by HB, inoic and Van forces

Question 8

hetrodimer vs a homodimer?

Answer 8

hetero dimer is a protein that contains different subunits
homodimer is a protein that has multiple of the same subunit

Question 9

how does urea impact the weak interactions found in tertiary or quaternary proteins?

Answer 9

Urea is an HB donor due to its terminal NH2 groups. this disrupts the HB within a protein

Question 10

what is 2-mercaptoethanol

Answer 10

a reagent an enzyme which reversibly cleaves the disulfide bonds within a protein

Question 11

what determines the folding pattern of a protein?

Answer 11

the AA sequence derived from DNA

Question 12

what are some examples of a motif?

Answer 12

omega loops, helix turn helix, beta-turn, helix, loop helix

Question 13

when the disulifde bond is cleaved, is the S oxidized or reduced?

Answer 13

reduced. note that the cleaving is done by 2-mercaptoethanol