Answer:
(a) Ala; (b) Tyr; (c) Ser; (d) His
Explanation:
The general formula for an amino acid is NH₂-CH(R)-COOH
The differences among the different amino acids is caused by the side groups R.
(a) Ala, Leu
Ala: R = CH₃-
Leu: R = (CH₃)₂CHCH₂-
Leucine has a larger hydrophobic side group. It should be the less soluble of the pair,
Alanine is the more soluble amino acid.
(b) Tyr, Phe
Tyr: R = HOC₆H₄CH₂-
Phe: R = C₆H₅CH₂-
Tyrosine has a polar OH group. It can form hydrogen bonds with water.
Tyrosine is the more soluble amino acid.
(c) Ser, Ala
Ser: R = HOCH₂-
Ala: R = CH₃-
Serine has a polar OH group. It can form hydrogen bonds with water.
Serine is the more soluble amino acid.
(d) Trp, His
Trp: R = Indole-CH₂-
His: R = Imidazole-CH₂-
Tryptophan has a large aromatic hydrophobic side chain.
Histidine is a basic amino acid. At pH 7 it exists mainly as the anion NH₂CHRCOO⁻, which is hydrophilic.
Histidine is the more soluble amino acid.
There’s no choices to pick from
it allows plants to survive and continue to reproduce
Answer: SiCl₄(s) + 4 H₂O(l) → H₄SiO₄(aq) + 4 HCl(aq)
Explanation:
You can pretend there is an imaginary line splitting the chemical equation into two on the arrow to help balance the equation.
Balance out chlorine on both sides, add the coefficient 4 to HCl
now there are 4 chlorines on the left and the right side.
Then, balance out Hydrogen on both sides, add the coefficient 4 to H₂O
now, there are 4*2=8 hydrogens on the left and 4+4=8 hydrogens on the right.
Counting the total number of atoms on both sides of the arrow, the equation is balanced
1 Si = 1 Si
4 Cl = 4 Cl
4 O = 4 O
8 H = 8 H
Living: biotic
Non-loving: abiotic
