DNA and RNA Flashcards
What does DNA stand for?
deoxyribonucleic acid
What does DNA store?
Genetic information
What does RNA stand for?
Ribonucleic acid
What is the main function of RNA?
To transfer genetic information from the DNA to the ribsosomes
What components make up a nucleotide?
A phosphate group
A pentose sugar
A nitrogen containing organic base
What is a nucleotide?
The monomers which make up DNA and RNA
What forms when many nucleotides join together?
Polynucleotide chain
How do the nucleotides join together?
Through a condensation reaction
Where do the nucleotides join together?
Between the phosphate group of one nucleotide and the pentose sugar of another
What bond forms between the phosphate group and the pentose sugar?
Phosphodiester
What makes up a phosphodiester bond?
Phosphate group
2 ester bonds
What is the chain of phosphate and sugar called?
sugar-phosphate backbone
What structure does DNA have?
Double helix
Describe the double helix structure.
Two separate antiparallel polynucleotide strands which wind around each other to form a spiral, joined by hydrogen bonds
Why can DNA store a lot of genetic information in a small space?
The DNA molecules are long and tightly coiled up
What makes up a DNA nucleotide?
Phosphate group
Deoxyribose sugar
Base
What are the 4 bases in DNA?
Adenine
Thymine
Cytosine
Guanine
What type of bond joins the two polynucleotide strands together to form a DNA double helix?
Hydrogen bonds
Which bases pair together in DNA?
Adenine and Thymine
Cytosine and Guanine
How many hydrogen bonds form between adenine and thymine?
2
How many hydrogen bonds form between cytosine and guanine?
3
The two polynucleotide strands are antiparallel, what does this mean?
They run in opposite directions
What makes up an RNA nucleotide?
Phosphate group
Ribose sugar
Base
What are the 4 bases in RNA?
Adenine
Uracil (instead of thymine)
Cytosine
Guanine
What do the nucleotides form in RNA?
a single polynucleotide strand
Is RNA shorter or longer than DNA?
Shorter
Why did scientists doubt that DNA could carry the genetic code?
They thought it was too simple