Nucleic acids

• What does DNA stand for?

  deoxyribonucleic acid
• What does RNA stand for?

  ribonucleic acid
• What is the function of DNA?

  store genetic information
• What is the function of RNA?

  To transfer genetic information from the DNA to the ribosomes
• DNA and RNA are polymers, what are the monomers called?

  nucleotides
• Generally what are nucleotides made up of?

  a pentose sugar, a nitrogenous base, a phosphate group
• What is a DNA nucleotide made up of?

  - A Deoxyribose sugar

  - A phosphate group

  - A nitrogenous base (Adenine, thymine, cytosine or guanine)
• What is an RNA nucleotide made up of?

  - A ribose sugar

  - A phosphate group

  - A nitrogenous base (Adenine, cytosine, guanine or uracil)
• What are the key differences between DNA and RNA?

  ♦ RNA has a ribose sugar, DNA has a deoxyribose sugar

  ♦ RNA is single stranded, while DNA is double stranded

  ♦ RNA has Uracil, while DNA has Thymine

  ♦ RNA transports genetic information , DNA stores genetic information
• What is a polynucleotide?

  polymer of nucleotides ( can be formed by DNA or RNA)
• How do the nucleotides join together?

  A condensation reaction between the phosphate group on one nucleotide and the sugar on another.
• What bond is formed between two nucleotides?

  phosphodiester bond
• What is the chain of sugars and phosphates known as?

  sugar-phosphate backbone
• What is the structure of DNA?

  double helix
• What bonds hold together 2 DNA polynucleotides?

  Hydrogen bonds between complimentary base pairs
• What are the complimentary base pairs?

  Adenine - Thymine

  Cytosine - Guanine
• How many hydrogen bonds are between A and T?

  2 hydrogen bonds
• How many hydrogen bonds are between C and G?

  3 hydrogen bonds
• How is the double helix formed?

  2 anti parallel (running in the opposite directions) polynucleotide strands twist due to the hydrogen bonding between base pairs to from the double helix
• When was DNA first discovered and what was believed?

  1800s - many scientists doubted it could carry the genetic code because of its relatively simple chemical composition - some argued genetic information must be carried by proteins as they are much more chemically varied
• When was it proven that DNA carried genetic information and who made this discovery?

  1953- Watson and Crick
• What is the structure of an RNA polynucleotide?

  A single strand much shorter than a DNA polynucleotide.