Nucleic Acids

What are nucleic acids?

• biological macromolecules

• store and transmit genetic info

What are the two main types of nucleic acids?

• DNA (Deoxyribonucleic acid)

• RNA (Ribonucleic acid)

What are the building blocks of nucleic acids?

Nucleotides

What are the three parts of a nucleotide?

1. A phosphate group

2. a 5-carbon sugar (ribose or deoxyribose)

3. a nitrogenous base

What is the difference between DNA and RNA in terms of sugar?

• DNA contains deoxyribose

• RNA contains ribose.

What are the nitrogenous bases found in DNA?

Adenine (A), Thymine (T), Cytosine (C), and Guanine (G).

What are the nitrogenous bases found in RNA?

Adenine (A), Uracil (U), Cytosine (C), and Guanine (G).

Which nitrogenous bases pair together in DNA?

• A–T (w. 2 hydrogen bonds)

• C–G (w. 3 hydrogen bonds)

What is the shape of DNA?

• A double helix

  • Looks like a twisted ladder

• 2 strands wound around each other

• The sides of the ladder are made of sugar and phosphate

• rungs are pairs of nitrogen bases (A-T and C-G) held together by hydrogen bonds.

What kind of bond connects nucleotides in a single strand?

• Phosphodiester bonds

  • between the phosphate of a nucleotide + the sugar of the next

How is the sequence of bases important in DNA?

• determines the genetic code

  • which instructs cells how to build proteins

What is complementary base pairing?

rule: A pairs w T (or U in RNA)

C pairs w G

What is the difference between purines and pyrimidines?

• Purines (2 rings): Adenine & Guanine

• Pyrimidines (1 ring): Cytosine, Thymine, and Uracil

What is a gene?

• section of DNA

• contains instructions for making a specific protein

What is the central dogma of molecular biology?

• DNA → RNA → Protein

• Replication → Transcription → Translation