Nucleic Acids Flashcards
What are the two functions of nucleic acids?
Pass information between generations
Code for protein production
What are RNA and DNA composed of?
They are made up of individual units called nucleotides that are composed of one four nitrogen containing bases, a sugar molecule, and a phosphate group.
Why are viruses not considered to be alive?
They cannot survive without a host cell and there are no chemical reactions occurring within the virus when its outside the host.
What are the five nitrogenous bases?
Adentine, thymine, cytosine, guanine and uracil.
Which pentose sugars do DNA and RNA have?
DNA has a polymer formed by condensation of deoxyribose nucleotides (H group on the carbon 2) (GCAT)
RNA has a polymer formed by condensation of ribose nucleotides (OH group on the carbon 2) (GCAU)
How do nucleotides connect?
They link via condensation reactions. The phosphate group (turtle head) of one nucleotide connects to the OH group on the 3 carbon of the sugar. This is a phosphodiester bond.
What is the structure of DNA?
The sugar phosphate backbone is on the outside and the bases are on the inside. The two strands are linked by hydrogen bonds through complimentary base pairing. The turtle heads are the 5’ end, and they build on the 3’ end.
Complementary base pairing in DNA replication
The two strands separate and build complementary strands to each, being semi conservative. This creates two identical DNA molecules.
Why do the two strands of DNA run opposite to each other?
That way the bases can face each other and thus pair. Their optimal energy configuration is a double helix with approximately 10 - 15 bases per twist.
Location of DNA in eukaryotic cells
Located in the nucleus, small amounts can be found in the mitochondria
Location of DNA in prokaryotic cells
In a central area called the nuceloid
Location of RNA in eukaryotic cells
Made in the nucleus during transcription and transported out of the nuclear pores ti the cytoplasm
Location of RNA in prokaryotic cells
In the cytoplasm
