11) for this question i got it right, but how would you know whether the value would be negative or not?

21) im not understanding how we got the answer for this. if its asking for work shouldn't it be in J/s and where the 600 sec came from

23) i thought one of the aa residues had to be a cysteine since the structure involved S-H bonds and im not getting how D is the correct answer

24) how were we able to choose between Thr and Ser if they can both be phosphorylated ( i ruled out tryptophan because i didn't see any phenol groups). was it not Thr since in the structure you don't see a methyl and H attached to same chiral carbon as OH?

32) why is the answer not B since it is phosphorylated by rhodopsin kinase so wouldn't that be the source of phosphate groups?

45) not really getting how we solved this

56) if resistance is negligible then why was it included in the equation of the solution?