1. DNA and RNA Flashcards
What is RNA and DNA?
Types of nucleic acid found in all living cells.
Both carry information.
Function of DNA.
simple
Used to store genetic information.
All the instructions needed to grow and develop from a fertilised egg to a fully grown adult.
Function of RNA.
simple
Transfer genetic information from the DNA to the ribosomes.
Ribsomes read RNA to make polypeptides in a process called translation.
What are ribsomes made of?
From RNA and proteins.
What does DNA and RNA stand for?
Deoxyribonucleic acid.
Ribonucleic acid.
What is a nucleotide?
Biological molecule made from 3 different components.
Pentose sugar.
Nitrogenous base.
Phosphate group.
Why are nucleotides important|?
They start the monomers that make up DNA and RNA.
What does the joining of many nucleotides form?
Polynucleotide strands.
Where do the nucleotides join up?
Between the phosphate group of one nucleotide and the sugar of another.
Bond that forms between them is known as the phosphodiester bond - formed by condensation reaction.
What is the chain of phosphates and sugars known as?
The sugar-phosphate backbone.
What is the structure of DNA?
Double helix structure.
DNA molecules formed from 2 separate strands which wind around each other to form a spiral.
Long molecules coiled up tightly, lots of genetic information fit into small space.
What are the 2 strands in the DNA?
Polynucleotides.
What is the structure of DNA nucleotide?
Consists of phosphate group, pentose sugar deoxyribose and nitrogenous base.
Each molecules has the same sugar and phosphate but the base can vary.
Adenine - A.
Cytosine - C.
Guanine - G.
Thymine - T.
2 DNA polynucleoctides strands join together by what?
Hydrogen bonds between the bases.
Each base joins with only one particular partner - complementary base pairing.
Whats are the pairs in complementary base pairing?
Adenine and thymine - 2 hydrogen bonds.
Guanine and cytosine - 3 hydrogen bonds.
Always equal amounts of the molecules.
How is the DNA a double helix?
As two polynucleotides stands are anti parallel - they run in opposite directions.
How are the 2 ends of a polynucleotide strand different?
One end - phosphate group.
Other end - hydroxyl group attached to sugar.
How is the structure of RNA different to the structure of DNA?
Sugar in RNA is ribose.
Uracil replaces thymine as a base.
Nucleotide forms single polynucleotide strand.
RNA strands are much shorter.
What does the base uracil pair with?
Ademine in RNA.
COMPARISON BETWEEN RNA AND DNA.
Shape.
DNA - double stranded into double helix and held together by hydrogen bonds.
RNA - single stranded.
COMPARISON BETWEEN RNA AND DNA.
Pentose sugar.
DNA - deoxyribose sugar.
RNA - ribose sugar.
COMPARISON BETWEEN RNA AND DNA.
Bases.
DNA - A,T,C,G
RNA - A,U,C,G
COMPARISON BETWEEN RNA AND DNA.
Size.
DNA - long.
RN - short.
When was DNA first observed?
In the 1800’s.
Scientists doubted it could carry genetic code due to its simple composition.
Some argued it must be carried by proteins.
