2.1.3: Nucleotides And Nucleic Acids Flashcards
(14 cards)
What are nucleotides?
Nucleotides are the monomers from which nucleic acids, like DNA and RNA, are formed.
Nucleotides consist of a pentose sugar, a nitrogenous base, and one phosphate group.
What is the structure of a nucleotide?
A nucleotide consists of a pentose sugar, nitrogenous base, and one phosphate group.
The pentose sugar in DNA is deoxyribose, while in RNA it is ribose.
What are the nitrogenous bases found in DNA?
The nitrogenous bases in DNA are adenine, cytosine, guanine, and thymine.
In RNA, thymine is replaced by uracil.
What are the two categories of nitrogenous bases?
The two categories of nitrogenous bases are purines and pyrimidines.
Purines include adenine and guanine; pyrimidines include cytosine, thymine, and uracil.
What is the complementary base pair for adenine?
Thymine (in DNA) or uracil (in RNA).
Guanine is the complementary base pair to cytosine.
What is a phosphodiester bond?
A phosphodiester bond is a strong covalent bond that forms between the pentose sugar and phosphate of different nucleotides.
It helps ensure that the genetic code is not broken down.
What is the polymer of nucleotides called?
The polymer of nucleotides is called a polynucleotide.
Polynucleotides are formed through condensation reactions that create phosphodiester bonds.
Fill in the blank: DNA contains the pentose sugar _______.
deoxyribose
Fill in the blank: RNA contains the pentose sugar _______.
ribose
True or False: Both DNA and RNA have thymine as a nitrogenous base.
False
RNA contains uracil instead of thymine.
What type of reaction do DNA and RNA nucleotides undergo to form polymers?
Condensation reactions.
What is the significance of complementary base pairing?
It helps maintain the order of the genetic code when DNA replicates.
What are the nitrogenous bases categorized as purines?
Adenine and guanine.
What are the nitrogenous bases categorized as pyrimidines?
Cytosine, thymine, and uracil.
