Nucleic acids Flashcards
Nucleotide
The monomer of DNA and RNA contains a pentose sugar, a
phosphate group and a nitrogenous base
nitrogenous base
part of a nucleotide
adenine, guanine, cytosine, thymine and uracil
DNA nucleotide
monomer of DNA
contains a deoxyribose sugar, a phosphate group and a nitrogenous base
complementary base pairs
the base pairs that align opposite each other and form hydrogen bonds
adenine and thymine/ uracil
guanine and cytosine
Polynucleotide
DNA polymer
many nucleotides joined via a condensation reaction
joined by phosphodiester bond
phosphodiester bond
Bond joining 2 nucleotides together
forms between a phosphate group and the pentose sugar
are strong covalent bonds, and
therefore help ensure that the genetic code is not broken down
ribose
pentose sugar
found in RNA nucleotide and ATP
mRNA
a copy of a gene
single-strand polymer
Uracil
Nitrogenous base
found in RNA instead of thymine
tRNA
found only in the cytoplasm
single-stranded but folded to create a clover-like shape
held in place by hydrogen bonds
rRNA
rRNA combines with protein to make ribosomes
DNA template strand
a DNA strand that is used to make a new DNA copy from
both DNA strands in the double helix are used as a template in DNA replication
DNA polymerase
an enzyme in DNA replication
joins together adjacent nucleotides
semi-conservative replication
DNA replication is semi-conservative replication
one strand is from the parental DNA and one strand is newly synthesised
DNA helicase
enzyme that breaks hydrogen bonds between two chains of DNA in a double helix
causes the 2 template strands to separate
involved in DNA replication and transcription
Large latent heat of vaporisation
a lot of energy is required to convert water from its liquid state to a gaseous state
due to the hydrogen bonds, as energy is needed to break these to turn it into a gas
means water can provide a cooling effect
high specific heat capacity
a lot of energy is required to raise the temperature of the water
because some of the heat energy is used to break the hydrogen bonds between water molecules
important so water can act as a temperature buffer
metabolite
water is involved in many reactions
such as photosynthesis, hydrolysis and condensation reactions
what are the 5 key properties of water?
It is a metabolite
An important solvent in reactions.
Has a high heat capacity, and it buffers temperature.
Has a large latent heat of vaporisation
Has strong cohesion between water molecules
solvent
water is a good solvent
many substances dissolve in it
polar molecules dissolve readily in water due to the fact water is polar
strong cohesion
water molecules ‘stick’ together due to hydrogen bonds
results in water moving up the xylem as a continuous column of water
provides surface tension, creating a habitat on the surface of water for small invertebrates
ATP synthase
enzyme that catalyses the synthesis of ATP from ADP and Pi
ATP hydrolase
enzyme that catalyses the hydrolysis of ATP into ADP and Pi
Phosphorylation
the addition of a phosphate group to a molecule
making the molecule more reactive
structure of water
water is a polar molecule
the oxygen atom is slightly negative
the hydrogen atoms are slightly positive
Dipeptide
2 amino acids bonded together by a peptide bond
formed by a condensation reaction
RNA nucleotide
monomer of RNA
composed of a phosphate group, ribose and nitrogenous base
has the base uracil instead of thymine
Role of hydrogen ions
determine the pH
the more hydrogen ions, the more acidic the conditions are
an important role in chemiosmosis in respiration and photosynthesis
role of iron ions
a compound of haemoglobin
involved in oxygen transport
Role of sodium ions in co-transport
involved in co-transport for absorption of glucose and amino acids in the ileum
Role of phosphate ions
as a component of DNA, RNA and ATP
phosphodiester bond in DNA and RNA forms between the phosphate group and the pentose sugar
fatty acid structure
carboxyl group and a long hydrocarbon chain
can be saturated or unsaturated
