Structure Of RNA and DNA Flashcards
What is a nucleotide made up of?
A pentose sugar
A phosphate group
Organic base-Adenine, Thymine, Cytosine, Guanine
How are the pentose sugar, phosphate group and organic base joined together?
Condensation reactions
How can 2 nucleotides be joined together? What bond is formed between them?
A result of a condensation reaction between the deoxyribose sugar of one of the nucleotides and a phosphate group of another
Phosphodiester bond
What is a polynucleotide?
The continued linking of nucleotides forms a long chain called a polynucleotide
What is the pentose sugar always in rna
Ribose
What are the organic bases in RNA?
Adenine, Uracil, Guanine, Cytosine
In DNA what is the pentose sugar?
Deoxyribose
What are the organic bases in DNA
Adenine, thymine, guanine, cytosine
DNA is made up of 2 strands of nucleotides. What are they joined together by?
Hydrogen bonds
Which bases are complimentary to each other?
Adenine and Thymine
Guanine and Cytosine
How many hydrogen bonds are there between adenine and Thymine and Cytosine and guanine?
2 between T and A
3 between C and G
What makes DNA a stable molecule?
The phosphodiester backbone protects the more chemically reactive bases inside the double helix
Hydrogen bonds link the organic base pairs forming bridges between the phosphodiester uprights, as there are 3 bonds between C and G, the higher the proportion of C-G pairings, the more stable the DNA molecule
How is the DNA molecule adapted to carry out its functions?
Very stable structure, which normally passes from generation to generation without change. Only rarely does it mutate.
Two separate strands are joined only with hydrogen bonds, which allow them to separate during DNA replication and protein synthesis
It’s an extremely large molecule and therefore carries an immense amount of genetic information
By having the base pairings within the helical cylinder of the deoxyribose phosphate backbone, the genetic info is to some extent protected from being corrupted by outside chemical and physical forces
Base pairings lead to DNA being able to replicate and to transfer information as mRNA
List 3 basic components of a nucleotide
pentose sugar, phosphate group, organic base
suggest why the base pairings of adenine and cytosine and guanine and thymine do not occur
the bases are linked by H bonds. the molecular structures could be such that H bonds do not form between adenine and cytosine and between guanine and thymine
