2.1.3 nucleic acids + ATP Flashcards
(20 cards)
describe the structure of nucleotides
pentose sugar
nitrogen containing base
phosphate group
what is the difference between ribose and deoxyribose
have different amount of oxygen
ribose has an OH on C2 and deoxyribose has only H on C2
what are the types of nitrogenous bases
purine bases = adenine and guanine
pyrimidines = thymine, cytosine, and uracil
why do purines always pair with pyrimidines
its the only was the keep a regular
maintain an equal distance between backbones
how are nucleic acids (polynucleotides) formed
condensation reaction
phosphate group (C5) bonds with OH group on C3
forms a phosphodiester bond
what reaction breaks down polynucleotides
hydrolysis reactions
describe the structure of DNA
made of deoxyribose sugar
2 polynucleotides bonded by complementary base pairings
forms a double helix structure with anti-parallel strands
which bases pair together in DNA and what bonds hold them togehter
Adenine and Thymine held by 2 hydrogen bonds
Cytosine and Guanine held by 3 hydrogen bonds
describe the structure of RNA
single strand
made of ribose sugar and has different bases
has uracil (pyrimidine) instead of thymine
describe the structure of ATP
adenosine triphosphate
made of nitrogenous base, ribose, + 3 phosphate groups
phosphorylated nucleotide
describe the structure of ADP
adenosine diphosphate
nitrogenous base, ribose, and 2 phosphate groups
explain the synthsis of ATP
ADP molecule is phosphorylated
a mol of inorganic phosphate (Pi) added
consensation reac = release water
how does ATP release energy
hydrolysis: ATP mol loses a Pi = releases a little bit of energy = ADP
condensation: Pi reforms with ADP = a lot of E released
what is meant by reactions being ‘coupled’
hydrolysis of ATP can only occur when a reac what needs E is also occuring
must happen simultaneously
explain whether or not ATP is a good E store and why?
not a good long term E store
= due to P groups being unstable (easily lost)
however it is a good short term store
= ATP forms rapidly by phosphorylation
= occurs constantly; always being supplied
describe and explain the properties of ATP
small = easily moves in and out of cells
soluble in water = good as most E requiring processes happen in aq environment
bond between phosphates = provide immediate E when formed; enough to be used in cellular respiration
small amount of E = good for most needs; not lots of E wasted in heat
easily regenerated = recharged with E by breaking bonds
what is meant by the genetic code having triplet codes
3 nucleotides make a codon each codon
each codon instructs for an AA
what is meant by the genetic code being non-overlapping
the codons do not overlap
if 3 nucleotides code for 1 AA the a separate 3 will code for another AA
bases are NOT shared in a codon
what is meant by the genetic code being degenerate
different codons can code for the same AA
means sometimes a mutation wont cause an effect on DNA (silent mutation)
what are start and stop codons
start codon = comes at beginning of gene; ensures full gene is read in frame; wont code for an AA if at start of gene
stop codon = stops the gene from being read
