Nucleic Acids Flashcards
What does DNA contain
A
T
C
G
Adenine
Thymine
Cytosine
Guanine
What does RNA contain
A
U
C
G
Adenine
Uracil
Cytosine
Guanine
What does 2 nucleotides formed together through a condensation reaction form
Dinucleotide and forms a Phospho-diester bond
DNA chains
A DNA molecule is a double helix with 2 strands of polynucleotides (the 2 strands are antiparallel) and the are held together by hydrogen bonds
Specific complementary base pairings
A=T
C- G. (3 lines)
=
RNA chains
Relatively short polynucleotide chains (1 strand of DNA)
DNA replication (semi conservative )
Semi-conservative =
Half the original nucleotides are used to ensure genetic continuity between generations
What are the 3 stages of semi conservative replication of DNA
Stage 1 =
The DNA unwinds by the enzyme DNA Helicase by breaking the hydrogen bonds, holding the base pairings together
Stage 2=
Free nucleotides that have been activated from the nucleus, bind to their complementary bases, the original bases acts as a template, this is to form a new DNA molecule
Stage 3=
Once the nucleotides have bound, they forms the bond : PHOSPHODIESTER BOND by DNA polymerase which helps the nucleotides join together through a condensation reaction
Energy and ATP
A single molecule of ATP is a nucleotide derivative and is formed from a molecule of ribose, molecule of adenine and 3 phosphate groups
What is the formula for ATP and water
ATP + water = ADP + Pi ( inorganic phosphate + energy
^ this is ATP Hyrdolase as it is hyrdrolysis
Or you can have
ADP + Pi + energy = ATP + water
^ this is ATP synthase as it is a condensation reaction
Water= is a major component of cells. It’s has several properties that are important in biology
It’s METABOLITE in many metabolic reactions including condensation and hydrolysis
It’s an IMPORTANT SOLVENT in which metabolic reactions occur. As polar molecules attract other polar molecules so water can dissolve manny ionic compounds such as salts and polar molecules like sugar
Had a relatively high heat capacity as water doesn’t change temperature easily, so it acts as a buffer against sudden changes in temperature
Has a relatively large latent heat of vaporisation, providing a cooling effect with little loss of water through evaporation
Had a strong cohesion between water molecules which supports columns of water in the tube-like transport cells of plants and produces surface tension where water meets air
Inorganic ions
These occur in solutions in the cytoplasm and body fluids or organisms, some in night concentration and some in very lore concentrations
Each ions have a specific role, depending on its properties
What are the roles of ions
Hydrogen ions and pH = determines pH levels of functions of enzymes
Iron ions as a component of haemoglobin = transports oxygen
Sodium ions in the co-transport of glucose and amino acids = transports of glucose and amino acids across a plasma membranes
Phosphate ions as components of DNA and ATP = structural role of DNA and role in storing energy for ATP
What is the structure of DNA and RNA
Both are polymers of nucleotides and each nucleotide is formed from a PENTOSE, NITROGEN - CONTAINING ORGANIC BASE, and A PHOSPHATE GROUP
DNA phosphate is a deoxyribose sugar
RNA phosphate is a ribose sugar
