12 terms

E. Basic DNA and RNA Structure


Terms in this set (...)

What are the bases found in DNA?
Adenine (A), Cytosine (C), Guanine (G) and Thymine (T).
What are the four Bases found in RNA?
Adenine, Guanine, Cytosine. RNA and Uracil (U)
Which are purines?
Adenine (A) and guanine (G)
Which are pyrimidines?
Thymine (T) and Cytosine (C)
Who pairs up with who?
Purines and pyrimidines.
Which bases pair in DNA?
A with T: the purine adenine (A) always pairs with the pyrimidine thymine (T)
C with G the pyrimidine cytosine (C) always pairs with the purine guanine (G)
Which bases can pair in RNA when it is double-stranded?
Cellular organisms use messenger RNA (mRNA) to convey genetic information (using the letters G, U, A, and C to denote the nitrogenous bases guanine, uracil, adenine, and cytosine) that directs synthesis of specific proteins. Many viruses encode their genetic information using an RNA genome.
Which RNA bases can pair with which DNA bases?
When this base-pairing happens, RNA uses uracil instead of thymine to pair with adenine in the DNA template.
A sample section of RNA bases paired with DNA bases.
How is a single polynucleotide chain of DNA constructed?
A polynucleotide is a polymer, or chain, of nucleotides. Famous pair of polynucleotides DNA and RNA is also a polynucleotide.
What does a DNA chain consists of?
Nucleotides joined by bonds between phosphate and sugar (= phosphodiester bonds). One end of the chain ends with a phosphate linked to the 5' carbon of the sugar and is called the 5' end. The other end of the chain ends with an hydroxyl group linked to the 3' carbon of the sugar and is called the 3' end.
What holds the nucleotide chain together?
It's made of the sugar and phosphate parts of nucleotides, so we call it a sugar-phosphate backbone.

A polynucleotide strand has a sequence of bases. The bases have different chemical names. In DNA, the bases are adenine, guanine, cytosine, and thymine.
DNA is normally comprised of two polynucleotide chains. How are the two chains held together?