1.5 Nucleic acids Flashcards
what are the monomers of nucleic acids?
nucleotides
state the three components of nucleotides.
pentose sugar
organic base
phosphate group
what are the two types of organic base?
purine and pyrimidine
what is a purine?
class of organic bases
double ring structure
includes adenine (A) and guanine (G)
what is a pyrimidine?
class of organic bases
single ring structure
includes cytosine (C), thymine (T), uracil (U)
describe the structure of a DNA nucleotide.
deoxyribose
organic base (A, T, C or G)
phosphate group
describe the structure of an RNA nucleotide
Ribose
organic base (A, U, C or G)
phosphate group
describe the structure of an ATP nucleotide.
Ribose
Adenine
three phosphate groups
what is an endergonic reaction?
a non-spontaneous reaction that requires an input of energy, e.g. ATP formation.
what is an exergonic reaction?
a spontaneous reaction that overall releases energy, e.g. ATP hydrolysis
describe the role of ATP
Universal Energy Currency. Hydrolysed to release energy:
ATP + Water ⇌ ADP + Pi + Energy
what is complementary base pairing?
describes how hydrogen bonds form between complimentary purine and pyrimidine bases
two bonds form between A and T (or U)
three bonds form between G and C
describe the structure of DNA
Double-stranded polymer of nucleotides twisted to form a double helix
nucleotides joined by phosphodiester bonds
hydrogen bonds form between complementary base pairs, A and T, C and G
anti parallel strands
describe the structure of RNA
single-stranded polymer of nucleotides
nucleotides joined by phosphodiester bonds
hydrogen bonds form between complementary base pairs, A and U, C and G
compare and contrast DNA and RNA
DNA/RNA
double stranded/ single stranded
long chain of nucleotides/ short chain of nucleotides
contains deoxyribose sugar/ contains ribose sugar
contains bases A, T, C, G/ contains bases A, U, C, G
storage of genetic info/ role in protein synthesis
both phosphodiester bonds to join nucleotides
name the 3 types of RNA found in cells
transfer RNA (tRNA)
messenger RNA (mRNA)
ribosomal RNA (rRNA)
what is the function of tRNA?
it carries specific amino acids to the ribosomes
describe the structure of tRNA.
80 nucleotides
single helix
clover leaf shape
anticodon on one end, amino acid binding site on the other
what is the function of mRNA?
carries genetic information from the nucleus to the ribosomes for protein synthesis.