Why are free ionic bonds of little relevance and relatively…

Why are free ionic bonds of little relevance and relatively unlikely to form in living organisms?   Cells are composed mostly of water, which interferes with ionic bonds between free ions. Cells are largely hydrophobic and exclude ions. Cells incorporate ions into larger molecules and prevent the formation of ionic bonds.

The image shown below displays amino acid side chains (shown…

The image shown below displays amino acid side chains (shown in sticks) represented as numbers. Choose the statement(s) below that is/are correct. Serine is represented by label 3. Tryptophan is represented by label 2. Alanine is represented by label 4. Cysteine is represented by label 7. Disulfide bonds formed by two cysteine residues are represented by label 5.