Question

Bio -> Cell Biology

1.

a) A sugar-phosphate backbone connected to a base/nucleotide is essential for which of the following macromolecules:

1. Starch
2. Cellulose
3. Glycogen
4. Nucleic acids
5. Triglycerides

b) Which of the following bonds are typically required for amino acid to amino acid bonding to form a peptide bond:

1. Hydrogen bonds
2. Covalent bonds
3. Non-covalent bonds
4. Electrostatic interactions

Answer 1

Question 1 a

Answer - Option 4- Nucleic acids.

Nucleic acids like DNA and RNA, are made up of nucleotides, which are made up of Ribose sugar, Phosphate group and Nitrogen base. In the case of DNA the sugar is 2- Deoxy ribose and in RNA it is Ribose. In a DNA or RNA strand, the back bone is made up of Sugar and Phosphate group and nitrogen bases are projected form the sugar phosphate back bone. The nucleotides are connected together by means of Phosphodiester bonds. During the formation of Double straned DNA, the nitrogen base can bind to the complementary base present in the next strand through hydrogen bonding. The remaining choices like Starch, Glycogen and cellulose are purely made up of sugar, it does not have any phosphate group or nitrogen base. The triglycerides are made up of fatty acids, it also have no nitrogen base.

Question 1 b

Answer - Option 2

In the protein, amino acids are connected together with the help of Peptide bonds, which is an example for covalent bond. Covalent bond, otherwise called as molecular bond formed by the sharing of electrons. The peptide bond is formed by the dehydration reaction, in which Peptide group of an amino acid and the amino group of adjuscent amino acid is involved. Hydrogen bonds, Non covalent interaction and electrostatic interactions are also present in the proteins, but it helps in the higher conformation of proteins like in Secondary, Tertiary or Quarternary conformations.