Nucleic Acids Flashcards
Desribe nucleic acids
Informational macromolecules that store hereditary information. They are the only molecules in existence that can produce identical copies of itself
Describe DNA
Contains the stored information in its digital code made up of the nitrogenous bases adenine, thymine, guanine, and cystine
Describe RNA
Ribonucleic acid, it is made by the DNA and is involved in protein synthesis
What are the differences between DNA and RNA?
DNA is double-stranded (double helix), while RNA is single-stranded (single helix). DNA uses deoxyribose sugar whereas RNA uses ribose sugar. And RNA uses uracil instead of thymine as a nitrogen base
Describe nucleotides
Made of three parts: a phosphate group, pentose sugar (deoxyribose or ribose), and a nitrogenous base. These bases are divided into two during the formation of DNA, the two strands are held together hydrogen bonds between the purines and pyramidines. There is a triple hydrogen bond between cytosine and guanine and a double bond between adenine and thymine
What word describes how the two strands of DNA run with respect to the other?
Antiparallel
Why do DNA strands run antiparallel?
The hydrogen bonds can only be created when the bases are upside down from one another
What are the two categories of nitrogenous bases?
Purines and pyramidines
Describe purines
Larger with two fused rings. Adenine and guanine (“pure silver”)
Describe pyramidines
They have only one fused ring and are smaller. Cytosine, thymine, and uracil (“cut pyramid”)
Draw a diagram of a nucleotide
What differentiates a nucleotide of RNA from a nucleotide of DNA?
A hydroxyl group on the carbon-2 makes the pentose sugar a ribose, found in RNA. A hydrogen makes it a deoxyribose, found in DNA
Describe hydrogen bonding in DNA
Acts like a zipper, opening small portions at a time to transmit information
What chemical bond holds nucleotides together?
Phosphodiester bonds
Describe a phosphodiester bond
Occurs in the formation of nucleic acids. Condensation synthesis reaction between the phosphate group of one nucleotide and the carbon-3 hydroxyl group of another
Describe the ladder-like structure of nucleic acids
The rungs are the nitrogen bases connected by hydrogen bonds. The handles are the phosphodiester bonds
What type of nitrogen bases are longer?
Purines (adenine and guanine)
Draw a detailed diagram of DNA strands including hydrogen and phosphodiester bonds
What term is given to the chemical structure of a nitrogenous base and a sugar?
Nucleoside
