Question

Which statement about RNA is not true? Uracil is found in RNA as one of the two pyrimidine nitrogenous bases. RNA possesses catalytic activity, which earned it the name "ribozyme." RNA is thought to have dominated early life on earth, serving as both genetic information and as a catalyst. RNA is a more stable molecule than DNA. RNA typically consists of a single polynucleotide strand with distinct secondary structures.

Answer 1

RNA is a more stable molecule than DNA

Step-by-step explanation:

This is a false statement. DNA is far more stable than RNA.

This is because of the stability provided by the presence of double helix strands held by hydrogen bonds holding the purine and pyrimidine bases is shape,which releases free energy for thermodynamic stability.

it is also stable because of the interaction of the hydrogen bonds with the surrounding water molecules in the cells.

The presence of Thymine instead of Uracil in DNA is additional factor to DNA stability, because Thymine has resistance to photochemical mutations compare to U in RNA. Thus genetic code encoded in DNA molecule is more stable against mutation compare to RNA.

Furthermore, the phosphodiester bonds holding the alternate backbone of phosphate and sugar further provided needed stability.

RNA is made up of single strands, made up of Uracil base of low resistance to photochemical mutations, OH-groups in position 2 of its ribose sugar which makes it to easily hydrolysed in alkaline solution. These factors makes it less stable compare to DNA.

Answer 2

Answer: RNA is a more stable molecule than DNA

Step-by-step explanation: DNA (deoxyribonucleic acid) is much stable than RNA (ribonucleic acid) for many reasons; Frist of all its because of the double strand of the DNA versus the single-stranded RNA. This is thanks to the Hydrogen bonding between bases since those bondings release free energy that allows the molecule to be provided by more thermodynamic stability.

Also the lack of 2′ OH groups makes DNA more stable since the OH groups are very reactive by themselves. In the DNA sugar molecule there is not a spare OH group that could start reacting on its own. So this is why DNA is immune to chemical reactions, while RNA (having an extra OH group) is more chemically "promiscuous".