Question

Given the R-groups in the peptide, ALA-GLN-ARG-SER-HIS, it would likely be:
Very water soluble
Somewhat water soluble
Not very water soluble
Not soluble at all
You cannot tell from the sequence

need explanation. thx

Answer 1

is this at pH 7? i would start by drawing it, then find the charges on each ionizable group

Answer 2

is it safe to assume at ph7 if not stated?

Answer 3

i suppose so

Answer 4

so we would only pay attention to the amino acids that are positively and negatively charged??

Answer 5

nope, also the R groups. Polar groups allow for better dissolution in water, while non-polar dont.

Treat this like any other organic molecule

Answer 6

ok so it has 2 + charged, 2 polar/uncharged and 1 nonpolar/aliphatic aa.

Answer 7

so it is soluble to a degree right?

Answer 8

yes soluble to a degree

Answer 9

so how do u determine between somewhat soluble and very soluble?

Answer 10

i would say that there is no non-polar or uncharged groups it's very soluble.

this has gly and ala which are non-polar.

This distinction is not great, usually you have to quote a number

Answer 11

ok thx