Slides in this set
Nucleotides Coding Molecules
· The monomer of all nucleic acids is called a Nucleotide.
· A single nucleotide is made up of...
· A phosphate group Always the same
· A sugar molecule 5-carbon sugar (either dioxyribose or ribose)
· One organic base adenine, thymine, guanine, cytosine and uracil.
· These 3 subunits are joined together by covalent bonds.
· A condensation reaction between the phosphate group of one nucleotide and
the sugar of another joins the two together.
· The nucleotides form a chain with the repeating sugar phosphate `backbone'
and the organic bases projecting out.
· Only nucleotides with the same sugar can join together to make Nucleic
An Example…read more
DNA Base Pairing
· The two DNA strands run
`antiparallel' because the
strands run in the opposite
· A pyrimidine always pairs up
with a purine.
· More specifically in DNA,
adenine always pairs up
with thymine and guanine
pairs up with cytosine. (
· In a complete DNA
molecule, the antiparallel
chains twist which is known
as a double helix.…read more
· The DNA replication takes place in the interphase stage of
mitosis and is the process that creates two identical sister
· To make a new copy...
· The double helix is untwisted
· The hydrogen bonds between the bases are broken and
the DNA is `unzipped'
· Free DNA nucleotides hydrogen bond onto the exposed
bases according to the base pair ruling.
· Covalent bonds are formed between the phosphate and
sugar to seal the background.
· This continues all away along the DNA molecule until two new
DNA molecules are formed
· This is called `Semi Conservative Replication' as each new
molecule is made from one conserved strand and a newly built