nucleic acids Flashcards
what is the structure of a nucleotide?
phosphate group
pentose sugar
organic base
what bond is formed between nucleotides?
phosphodiester bonds
what is different about RNA compared to DNA?(3)
ribose instead of deoxyribose
uracil instead of thymine
single stranded
what bonds are between the two DNA strands?
hydrogen
what are the 2 stages of cell division?
nuclear division
cytokinesis
what are the 4 requirements of semi conservative replication?
four types nucleotide bases
both strands act as template strands
DNA polymerase and DNA helicase
source of chemical energy
what are the 5 stages of semi conservative replication?
- DNA helicase breaks hydrogen bonds between base pairs
2.double strand unwinds into 2, exposing base pairs
3.each strand is used as a template strand that complementary free nucleotides bind to
- condensation reaction catalysed by DNA polymerase joins nucleotides together, forming phosphodiester bonds
5.each new DNA molecule contains one of the original DNA strands
describe the structure of ATP
a derivative of a nucleotide with a molecule of ribose, a molecule of adenine and three phosphate groups.
what is the role of ATP
immediate energy source of cell as it is released in smaller, manageable amounts
what processes use ATP?(5)
metabolic processes
movement
active transport
secretion
activation of molecules
what is the importance of water being dipolar?
allows opposite charges to attract and form hydrogen bonds which allow water molecules to stick together
what is the importance of water having a high specific heat capacity?
can be used as a buffer against sudden temp changes as it takes a lot of energy to break the hydrogen bonds between water molecules
what is the importance of water having a high latent heat of vaporisation?
evaporation of sweat in mammals is effective for cooling down as body heat is used to evaporate the water
what is the importance of cohesion and surface tension?
cohesion allows water to be pulled up vessels such as xylem
surface tension means water can support small organisms
what are examples of important ions?
iron ions
hydrogen ions
phosphate ions
sodium ions
