Structure of DNA and RNA (3.1.5.1) Flashcards
what are DNA and RNA polymers of?
nucleotides
what are DNA and RNA and what is their role in living cells?
they are important information-carrying molecules
in cells, DNA holds genetic information and RNA transfers genetic information from DNA to ribosomes
what are ribosomes formed from?
RNA and proteins
what are the nucleotides in DNA and RNA formed from?
a phosphate group, a pentose and a nitrogen-containing organic base
what are the specific components of a DNA nucleotide?
a phosphate group, deoxyribose and one of the organic bases (adenine, cytosine, guanine or thymine)
what are the specific components of an RNA nucleotide?
ribose, a phosphate group and one of the organic bases (adenine, cytosine, guanine or uracil)
what does a condensation reaction between two nucleotides form?
a phosphodiester bond
what does the condensation of many nucleotides form?
a polynucleotide
what is the structure of a DNA molecule?
a double helix with two polynucleotide chains held together by hydrogen bonds between specific complementary base pairs
what is the structure of an RNA molecule?
a relatively short polynucleotide chain
what does antiparallel mean?
the two DNA strands in a double helix run in opposite directions (essential for DNA replication)
why didn’t scientists believe that DNA carried the genetic code?
because of its relative simplicity compared to other molecules like proteins
what are the purine bases?
adenine and guanine
what are the pyrimidine bases?
cytosine, thymine, uracil
