DNA & RNA Structure Flashcards
Nucleotide
The basic building block of nucleic acids (DNA and RNA)
-Consists of a phosphate group, nitrogenous base, sugar
Purines: double ring structure (Adenine and Guanine)
Pyrimidines: single ring structure (Cytosine, Uracil, Thymine)
The base pairs are held together by hydrogen bonds
-A & T have two hydrogen bonds
-C & G have three hydrogen bonds
DNA (Deoxyribonucleic acid)
Primary source of heritable information
(genetic information is stored in and passed from one generation to the next through DNA)
Double stranded helix
-Backbone (outside): sugar-phosphate
-Center (inside): nucleotides pairing
Strands are antiparallel
-One strand runs 5’ to 3’ and other strand runs 3’ to 5’ upside direction
-5’ end: free phosphate group
-3’ end: free hydroxyl group
Codons: Cytosine, Guanine, Adenine, Thymine
RNA (Ribonucleic acid)
Primary source of heritable information in some viruses
Single stranded
Codons: Uracil, Adenine, Guanine, Cytosine
Prokaryotic DNA
-Found in the nucleus
-Linear chromosomes (contains terminal ends)
Eukaryotic DNA
-Found in nuclei of region
-Circular chromosomes
Plamids
Small, circular DNA molecules that are separate from the chromosomes
-Prokaryotes (some eukaryotes) contain plasmids
-Plasmids replicate independently from chromosomal DNA
-Contains genes that may be useful to prokaryote when it is in a particular environment, but may not be required for survival
Conjugation: Bacteria can exchange genes found on plasmids with neighboring bacteria