Nucleic Acids and Nucleotides Flashcards
What are nucleotides?
Subunits of Nucleic Acids
How do nucleic acids exist?
They exist as polymers = polynucleotides
What do polynucleotides consist of?
They consist of monomers called nucleotides
What three things are nucleotides composed of?
Nitrogenous base
Pentose (5 carbon sugar)
Phosphate group (s) (1-3)
What are nucleosides?
Molecules composed of nitrogenous base linked to 5-carbon sugar (no phophate)
What are the base components of nucleotides?
Nitrogen-containing rings (bases)
2 families
What are the 2 families of nucleotides?
Pyrimidines
Purines
What are the three pyrimidines?
Cytosine
Thymine
Uracil
What are the two purines?
Guanine
Adenine
What is the sugar component of nucleotides?
5-carbon sugar is either ribose or deoxyribose
What is the phosphate component of nucleotides?
2
Nucleotides have 1,2 or 3 phosphate groups
They are attached to the C5OH part of the ribose or deoxyribose (the 5’ position)
What are nucleotides containing ribose called?
Ribonucleotides
What are nucleotides containing deoxyribose called?
Deoxyribonucleotides
What are the two main types of nucleic acid?
Ribonucleic acids
Deoxyribonucleic acids
What are genes?
Portions of DNA
How does RNA differ from DNA?
2
RNA is single stranded
RNA does not have to stay in the nucleus
Why is RNA not found in chromosomes?
RNA does not carry the genetic code
What can RNA do to DNA?
RNA can read the DNA code and take the information out of the nucleus
What is RNA’s main job?
To build proteins
What are the 4 nitrogen bases in DNA?
Adenine
Guanine
Cytosine
Thymine
What are the two types of biochemical bonds that link monomer nucleotides into polymers of DNA or RNA?
Phosphodiester bonds
Hydrogen bonds
What are phosphodiester bonds?
Covalent bonds that link adjacent nucleotides together in both DNA and RNA
What are hydrogen bonds?
2
They join nitrogen bases of nucleotides together in complementary base pairs in the centre of DNA
This holds the 2 antiparallel strands together
Why are hydrogen bonds not required on RNA?
RNA is single stranded
What do phosphodiester bonds form?
They form a backbone with a repeating pattern of sugar-phosphate units
Where exactly are phosphodiester bonds formed?
Between the OH group on the 3’ C of one nucleotide and phosphate on the 5’ C of the next nucleotide
How many hydrogen bonds does adenine form with thymine?
Two
How many hydrogen bonds does guanine form with cytosine?
Three
