2.1 - Nucleic Acids: DNA & RNA Flashcards
The structure of nucleotides The reactions that synthesise and breakdown nucleic acids The role and structures of DNA and RNA The similarities and differences between DNA and RNA
What are nucleotides?
The singular base units of nucleic acids
What are the three components of a nucleotide?
- A pentose sugar - Contains 5 carbon atoms.
- A nitrogenous base - Contains carbon and nitrogen.
- A phosphate group - Contains phosphate
How do nucleotides join together?
Via phosphodiester bonds
What is the sugar-phosphate backbone?
A chain of phosphates and sugars in a polynucleotide
What is DNA?
A nucleic acid that contains instructions to make proteins
What are the components of a DNA nucleotide?
- Deoxyribose - A pentose sugar
- A, T, G, or C base - Adenine, thymine, guanine, or cytosine
- A phosphate group
What type of helix is DNA?
Double helix
What are the purines in DNA?
Adenine and guanine
What are the pyrimidines in DNA?
Thymine and cytosine
Which bases pair together in DNA?
Adenine-thymine via 2 hydrogen bonds
Cytosine-guanine via 3 hydrogen bonds
What type of bonds hold DNA strands together?
Hydrogen bonds
What is RNA?
A nucleic acid that uses DNA information to synthesise proteins
What are the components of an RNA nucleotide?
- Ribose - A pentose sugar.
- A, U, G, or C base - Adenine, uracil, guanine, or cytosine.
- A phosphate group
How many strands does RNA have?
Single-stranded
What are the differences between the pentose sugar of DNA and RNA?
DNA = Deoxyribose
RNA = Ribose
What are the differences between the bases of DNA and RNA?
DNA = A, T, G, C
RNA = A, U, G, C
What are the differences between the size of DNA and RNA?
DNA = Long
RNA = Short
What are the differences between the number of strands of DNA and RNA?
DNA = 2
RNA = 1
What are the differences between the helix of DNA and RNA?
DNA = Double helix
RNA = Single helix
How does having a sugar-phosphate backbone relate to the function of DNA
Protects coding bases on the inside of the helix
How does being double stranded relate to the function of DNA
Allows strands to act as templates in DNA replication
How does being a large molecule relate to the function of DNA
It stores lots of information
How does having a double helical structure relate to the function of DNA
Makes the molecule compact
How does complementary base pairing relate to the function of DNA
Allows accurate DNA replication
