2a. NUCLEIC ACIDS Flashcards
What is a nucleotide?
The basic building block of nucleic acids
Describe the three-part structure of a nucleotide
All nucleotides are made up of phosphate, a sugar and a nitrogenous base
Describe the structure of ATP
One ribose sugar, adenine, and three phosphtes
Describe which part of the nucleotides form the genetic code
The nitrogenous bases form the genetic code
Recall the five DNAnitrogenous bases
Adenine, guanine, cytosine, thymine and uracil
Recall which bases are purines, and which are pyrimidines
Purines – adenine and guanine. Pyrimidines – cytosine and thymine
Recall the structure of purines
Purines – two ringed structure (hexose and pentose)
Recall the structure of pyrimidines
Pyrimidines – one ring structure (hexose)
Describe the structure of an RNA nucleotide
A phosphate group, a ribose sugar and a nitrogenous base (either Adenine, Guanine, Cytosine or Uracil)
What is the function of mRNA?
Transfers genetic information from the DNA to the ribosomes
Describe the structure of a DNA nucleotide
A phosphate group, a deoxyribose sugar and a nitrogenous base (either Adenine, Guanine, Cytosine or Thymine)
What is the function of DNA?
To hold the genetic information
Describe the difference between ribose and deoxyribose sugars
Deoxyribose has one less oxygen (on carbon 2)
Describe three similarities between a DNA and RNA nucleotide
DNA and RNA both contain a pentose sugar, have bases A, C and G, and contain a phosphate.
Describe two differences between a DNA and RNA nucleotide
DNA uses thymine whereas RNA uses uracil. DNA contains a deoxyribose sugar, whereas RNA contains a ribose sugar
What are the similarities between an ATP nucleotide and a DNA nucleotide?
Both contain a sugar, both contain a nitrogenous base, both contain phosphate
What are the differences between an ATP nucleotide and a DNA nucleotide?
ATP contains ribose, whereas DNA contains deoxyribose. ATP only contains adenine, whereas DNA can contain A, C, T & G. ATP contains 3 Pi, whereas DNA only contains one
What are the similarities between an ATP nucleotide and an RNA nucleotide?
They both contain a ribose sugar, they both contain a nitrogenous base, and they both contain phosphate
What are the differences between an ATP nucleotide and an RNA nucleotide?
ATP only contains adenine, whereas RNA can contain A, U, C & G. ATP contains 3 Pi, whereas RNA only contains one
Which two types of nucleotides can polymerise?
DNA and RNA
Name the reaction that bonds nucleotides together
Condensation (& polymerisation)
What is the molecule called when many nucleotides bond together?
Polynucleotide / Nucleic Acid
Name the reaction that breaks polynucleotides down
Hydrolysis
Recall complementary base pairing rules in DNA
Adenine & Thymine, Cytosine & Guanine
Recall the number of bonds each base pair makes. What type of bonds form?
There are 2 hydrogen bonds between adenine and thymine
There are 3 hydrogen bonds between cytosine and guanine
If a DNA molecule has 24% of adenine, calculate the percentage of cytosine, guanine and thymine?
If there is 24% of A there is also 24% of T
100% - 24% – 24% = 52% (C and G)
so there is 52/2 = 26% of G and 26% of C
Recall complementary base pairing rules in RNA
Adenine & Uracil, Cytosine & Guanine
Describe the structure of an RNA molecule
Small and single stranded (therefore no base pairs and no hydrogen bonds)
Describe the structure of a DNA molecule.
DNA is two strands of DNA, held together by hydrogen bonds between the bases
In which structural part of a polynuleotide do the phosphodiester bonds exist?
The sugar-phosphate backbone
Name the shape of a DNA molecule
Double Helix
