Structure of DNA and RNA Flashcards
What are the components of a nucleotide?
- Pentose sugar
- Phosphate group
- Nitrogenous base
What bonds form between ajdacent nucleotides?
Phosphodiester bonds
How are phosphodiester bonds formed between adjacent nucleotides?
A phosphodiester bond will form between the deoxyribose/ribose sugar of a nucleotide and the phosphate group of an adjacent nucleotide via a condensation reaction
The pentose sugar and phosphate in polynucleotides create a…
sugar-phosphate backbone
What is DNA?
Deoxyribonucleic acid (DNA) is a type of nucleic acid that contains the instructions needed to make proteins
What are the components of a DNA nucleotide?
- Deoxyribose sugar
- Phosphate group
- A nitrogenous base
What are the four bases that can be found in a DNA nucleotide?
- Adenine (A)
- Thymine (T)
- Guanine (G)
- Cytosine (C)
What nitrogenous bases pair together?
Adenine with thymine
Guanine with cytosine
How are the two strands of DNA held together?
They are held together by hydrogen bonds between bases
- A & T bond via 2 hydrogen bonds
- G & C bond via 3 hydrogen bonds
What features allow DNA to pass genetic information from one generation to another?
Sugar-phosphate backbone - ensures the molecule is stable
Double stranded - allows for replication by using one strand as a template
Weak hydrogen bonds between bases - easy unzipping of the two strands for replication
Large molecule - carries a lot of genetic information
Complementary base pairing - maintains the order of the genetic code when DNA replicates allowing identical copies to be made
What is RNA?
Ribonucleic acid (RNA) is a type of nucleic acid that uses information from DNA to synthesise proteins
What are the components of an RNA nucleotide?
- Ribose sugar
- Phosphate group
- A nitrogenous base
What are the two types of RNA?
- Messenger RNA (mRNA)
- Transfer RNA (tRNA)
What are the four bases found in an RNA molecule?
- Adenine (A)
- Uracil (U)
- Guanine (G)
- Cytosine (C)
What are purines?
Larger bases that contain two carbon ring structures
- E.g Adenine and Guanine
What are pyrimidines?
Smaller bases that contain one carbon ring structure
- E.g Thymine, Cytosine and Uracil
What are the differences between DNA and RNA?
Difference between the monomers
- DNA contains a deoxyribose sugar, RNA contains a ribose sugar
- DNA contains Thymine, RNA contains Uracil
Difference between the polymers
- DNA is double stranded, RNA is single stranded
- DNA is longer as it contains the entire genome, RNA is shorter as it is the length of one gene
