Nucleic Acids and Inorganic Ions Flashcards
what is DNA made up of?
DNA (mono)nucleotide
Components of a nucleotide
A pentose sugar
A phosphate group
A nitrogen containing organic base (Cytosine, Uracil, Thymine, Guanine)
Bond formed between the sugar of one nucleotide and phosphate group of another
phosphodiester bond
Difference between RNA and DNA nucleotide
Ribose sugar
Uracil instead of thymine
Base pairs, what type of bond and how many?
C and G (3 Hydrogen bonds)
A and T (2 Hydrogen bonds)
Adaptations of DNA
Stable, passed from generation to generation and rarely mutates
2 separate strands only bound by hydrogen bonds (easy to separate for DNA replication)
large molecules carrying its of genetic information
base pairs are protected by backbone (from outside chemical and physical forces)
Base pairs allow replication and transfer (as mRNA)
DNA helicase
Breaks hydrogen bonds between bases during semi conservative replication
Template strand
the strand to which complimentary free nucleotides join during semi conservative replication
DNA polymerase
joins the free nucleotides (to each other) during semi conservative replication, to form the complimentary polynucleotide strand
what is semi conservative replication?
DNA replication where an original strand acts as a ‘template’ to form a new complimentary polynucleotide strand. The new DNA is made up of one original stand and one new strand.
components of ATP
Adenine (nitrogen containing organic base)
Ribose sugar (5C)
chain of 3 phosphates
how is ADP formed
hydrolysis of ATP by ATP hydrolase
ATP + water –>ADP +Pi (+Energy)
why is water a DIPOLAR molecule and why is it important
Oxygen is slightly negative
Hydrogen is slightly positive
(but no overall charge)
Forms hydrogen bonds (between + of one molecule and - of another)
Makes water slightly cohesive:
1. allows transpiration and movement through xylem in plants.
2. creates surface tension in bodies of water (strong enough to support small organisms)
Roles of ATP
1)Metabolic processes (e.g. building molecules)
2)Movement (e.g. energy for muscle contraction)
3)Active transport (changes shape of carrier proteins)
4)Secretion (needed to form lysosomes)
5)Activation of molecules (phosphorylates other compounds to make them more reactive (adding a phosphate group))
What is specific heat capacity of water and why is it important
high specific heat capacity
so a lot of energy needed to heat a given mass
so water acts as a buffer against temperature variations :
1. in aquatic environment
2. in living organisms (as they are made up of water)
What is latent heat of vaporisation of water and why is it important
surface water molecules can gain enough kinetic energy to break off and evaporate.
This is important in mammals sweating to cool the body down.
Water in metabolism
breaking molecules by hydrolysis
major raw material for photosynthesis
produced in condensation
chemical reactions take place in cytoplasm (in water)
Hydrogen Ions
More H+ ions -> Lower pH
Enzymes have an optimum pH. If too many H+ ions are present they interact with side chains of amino acids in active site of enzymes changing their tertiary structure and denaturing the enzyme
Iron Ions
Each of the 4 polypeptide chains in haemoglobin contain one Fe2+ ion.
It makes up part of the haem group which binds to the oxygen molecule.
Necessary for oxygen transport around the body.
Sodium Ions
Sodium potassium pump is necessary for the absorption of glucose and amino acids into the blood from the lumen of the ileum.
Sodium ions active transport out of epithelial cells into blood, creates concentration gradient higher to lower form lumen to epithelial cells, sodium ion diffuse in and glucose and amino acids are co-transported in, they then enter the blood via facilitated diffusion
Phosphate Ions
Component of DNA and ATP.
ATP: hydrolysis of phosphate group form ATP to form ADP releases a large amount of energy.
DNA: forms phosphodiester bonds with pentose sugar of a different nucleotide to form a phosphate sugar backbone, which protects the bases in DNA
