nucleic acids Flashcards
draw simple structure of a nucleotide
how is ATP synthesised
by the condensation of ADP and Pi
catalysed by enzyme ATP synthase
photosynthesis, or during respiration.
what is the bond for nucleotides
phosphodiester bonds
differences between DNA and RNA
- DNA has thymine whereas RNA has uracil
- DNA has the pentose sugar deoxyribose, RNA has the pentose sugar ribose
- DNA found in the Nucleus vs RNA found in cytoplasm of prokaryotes
- DNA is very long, RNA is very short
what is a double ring base and single ring base called
why do these exist
Adenine + Guanine = Purines (double ring)
Thymine + Cytosine + Pyrimidines (single ring)
pyrimidine always pairs with a purine (complementary) so that the distance of two bases is equal along whole chain.
how many hydrogen bonds do C and G have vs A and T
adenine + Thymine - 2 hydrogen bonds
cytosine + guanine - 3 hydrogen bonds
causes different strengths
Watson–Crick model of DNA replication process of science
- take sample of bacteria with N14 and N15 and extract the DNA
- spin the N14 and N15 isotopes in centrifuge separately
N14 is high (light)
N15 is low ( heavy) - scientists transfer the N15 DNA to N14 DNA where it replicates once
4.scientists extracted DNA sample and spun it in centrifuge. band form in between N14 + n15 bands (semi - conservate)
- scientists allowed it to replicate another time where 2 bands form, same as last + band of pure N14 isotopes
the process of DNA replication
1) DNA helicase enzyme attaches to hydrogen bonds of complementary base pairs, causing them breaking + separation
2) Free ACTIVATED NUCLEOTIDES line up with complementary base. however ONLY linked by hydrogen bond NOT phosphodiester bonds
3) now DNA polymerase attaches and makes phosphodiester bonds (CONDENSATION REACTION). activated nucleotides lose their extra two phosphates that gives energy needed for reaction
what is ATP structure like
triphosphate - 3 phosphates
adenine - sugar + base
what is the reaction for the hydrolysis of ATP phosphate molecule
ATP + H20 —————> ADP + Pi + energy
ATP hydrolase
ADP = adenosine diphosphate
