nucleic acids and their functions Flashcards
what is a nucleotide?
the basic unit which nucleic acids are formed from
what are nucleotides composed of?
a phosphate group, a pentose (five-carbon) sugar and an organic nitrogenous base
what is a nucleic acid?
polymers of nucleotides, for example DNA or RNA
pentose (five-carbon) sugar in DNA
deoxyribose
pentose (five-carbon) sugar in RNA and ATP
ribose
what are the possible organic bases in DNA?
adenine, thymine, guanine, or cytosine
what are the possible organic bases in RNA?
adenine, cytosine, guanine or uracil
what is the main function of DNA?
replication and providing the code for protein synthesis
what is the function of RNA?
transfers genetic information from DNA to ribosomes made from RNA and proteins
what is the function of ATP?
involved in the transfer of energy
how do nucleotides join together to form nucleic acids?
nucleotides join together by phosphodiester bonds formed in condensation reactions
describe a DNA molecule
a DNA molecule is a double helix composed of two polynucleotides joined together by hydrogen bonds between complementary bases
describe an RNA molecule
an RNA molecule is a short polynucleotide chain
why is ATP known as the universal energy currency?
because it is used in all energy requiring reactions in all cells in all living organisms
what is the nucleotide ATP made up of?
adenine (nitrogenous base) joined to ribose (five-carbon sugar) and three phosphate groups
what energy-requiring reactions is ATP involved in?
active transport, protein synthesis, nerve transmission and muscle contraction
how is ATP formed?
ATP is formed when phosphate is added to adenosine diphosphate (condensation reaction)
what is a pyrimidine base?
bases with a single ring structure
what is a purine base?
base with a double ring structure
examples of pyrimidine (single ring) bases
cytosine, thymine, uracil