Nucleic acids Flashcards
(19 cards)
What is the structure of DNA?
Polymer of nucleotides
deoxyribose, phosphate, nitrogenous base
A complementary to T and G to C
Nucleotides joined by phosphodiester bonds
Bases joined by H bonds
Antiparallel strands
How does DNA being a stable molecule due to sugar-phosphate backbone protecting more reactive bases relate to its function?
Code remains unchanged so mutations are rare
The consistent codes to produce functional proteins
How do strands being held together by H bonds relate to its function?
can easily separate strands for transcription + replication
How does DNA being large relate to its function?
Stores lots of information
How do base-pairs within sugar-phosphate backbone relate to its function?
protecting from reactive chemicals that might cause mutation
How do base pairing relate to its function?
Allows DNA replication to produce two identical copies
How is a nucleic acid formed?
condensation reaction between nucleotides forms a nucleic acid
What are the characteristics of genetic code?
degenerate
universal
non-overlapping
What does degenerate mean?
more than one codon for a single amino acid
reduces the effect of mutation
What does universal mean?
codons code for all the same amino acids in all species
What does non-overlapping mean?
each base only belongs to one triplet when the sequence is read
What is the structure of tRNA?
clover leaf shape
H bonding in structure
single anticodon
has amino acid attachment site
What is the structure of mRNA?
linear
no H bonding in structure
many codons
no amino acid attachment site
What is the structure of rRNA?
ribosomal
sphere shape
How does single stranded structure relate to its function?
easily binds to other molecules
e.g. for translation
How does shorter structure relate to its function?
only provides code for 1 protein
What is the use of mRNA?
transfers genetic info from DNA to ribosomes (copy used in translation)
What is the use of tRNA?
transfers specific amino acids to ribosomes to form a polypeptide
(codon/anticodon have complementary sequences)
What is the use of rRNA?
ribosomes formed from rRNA proteins
