DNA and RNA Flashcards
What does DNA do?
Deoxyribose nucleic acid (DNA) codes for the sequence of amino acids in the primary structure of a protein, which in turn determine the final structure and function of a protein.
What monomer makes up DNA?
A nucleotide
What is a DNA molecule made up of?
- Deoxyribose (pentose sugar)
- A nitrogenous base
- Phosphate group
What is the polymer of a nucleotide called?
Polynucleotide
How is a polynucleotide made?
It is created via a condensation reaction between the deoxyribose sugar and the phosphate group, creating a phosphodiester bond
How is the double helix held together?
Hydrogen bonds between the base pairs
What is RNA?
It is a polymer of a nucleotide formed of ribose, a nitrogenous base and a phosphate group
Features of DNA?
- In the nucleus
- Large
- Deoxyribose
- C,G,A,T
- Double helix
Features of RNA?
- Small
- Ribose
- Nucleus, cytoplasm, ribosome
- C,G,A,U
- Single stranded
What is the function of RNA?
The function of RNA is to transfer the genetic code from DNA in the nucleus to the ribosomes. Some RNA is also combined with proteins to create ribosomes
What is DNA replication?
Before cells divide all the DNA must replicate to provide a copy for the new cell
The process of DNA replication is semi- conservative replication (in the parental DNA and one strand is newly synthesised)
What is semi- conservative replication?
- DNA helicase breaks the hydrogen bonds between the complementary base pairs between the 2 strands within a double helix, this causes the double helix to unwind.
- Each of the separated strands of DNA act as a template. Free floating DNA nucleotides within the nucleus are attracted to their complementary base pairs on the template strands of the parental DNA.
- The adjacent nucleotides are joined together (to form a phosphodiester bond) by a condensation reaction. DNA polymerase catalyses the joining together of adjacent nucleotides.
- The 2 sets of daughter DNA contains one strand of the parental DNA and one newly synthesised strand.
Who discovered the structure of DNA?
Watson and Crick in 1953 with the help of Rosalind Franklin
Who conducted the experiment which proved DNA replication must be semi- conservative?
Meselson and Stahl
What is ATP?
It is an immediate source of energy for biological processes.
How is ATP made?
ATP is made during respiration from ADP + Pi using enzyme ATP hydrolase. This releases a small amount of energy.
What is released during the hydrolysis of ATP?
An inorganic ion
What bond forms between water molecules?
Hydrogen bonds
The 5 key properties of water
- It is a metabolite (in condensation and hydrolysis reactions)
- An important solvent in reactions
- Has a high heat capacity, it buffers temperatures
- Has a large latent heat capacity of vaporisation, providing a cooling effect with loss of water through evaporation
- Has strong cohesion between water molecules, this supports water columns and provides surface tension
What does solvent mean?
It means to dissolve
What is latent heat?
How much heat to change a liquid to a gas. It cools the body down (sweating)
What is high specific heat?
Energy required to raise temperature by 1 degree C
What does cohesion mean?
Molecules stick together
What are inorganic ions?
Inorganic ions occur in solution in the cytoplasm and body fluids of organisms
