DNA Flashcards
what is DNA made from and what does it code for
codons (3 nucleotide bases in DNA) codes for the sequence fo amino acids in the primary structure of a protein white in turn determines the final 3D structure and function of the protein
- essential that cells contain this genetic code, can be passed onto new cells w/o being damaged
- DNA polymer forms a double helix
- deoxyribose (pentose sugar), a nitrogenous base (adenine, cytosine, thymine or guanine) and one phosphate group
what is the monomer that makes up DNA called
nucleotide
how are polynucleotides formed
via condensation reactions between the deoxyribose sugar and the phosphate group of another nucleotide (=sugar phosphate backbone), creating a phosphodiester bond
between the two polymer chains - hydrogen bonds formed between complementary base pairs (c and t or a and t)
what is RNA and its structure
a polymer of a nucleotide formed from ribose, nitrogenous base (adenine, uracil, guanine, cytosine)
- relatively short polynucleotide chain
- single stranded
describe DNA replication
- DNA helicase breaks hydrogen bonds between complementary base pairs between the 2 strands within a double helix
- double helix strands unwind and become free floating
- parental DNA strands act as a template
- free floating DNA nucleotides are attracted to complementary base pairs on the template strands of parental DNA
- DNA polymerase joins adjacent nucleotides via condensation reactions, forming phosphodiester bonds
PRODUCING 2 sets of daughter DNA which contain one strand of parental (original) DNA and one newly synthesised strand
what is the role of rRNA
binds to proteins to create ribosomes
why must DNA be replicated
in order to create new cells, every new cell needs their own copy of the entire genome (all of DNA)
who did research on x-ray diffraction
Rosalind Franklin
who discovered the structure of DNA in 1953
Watson and Crick only because of the research Rosalind Franklin did
who proved DNA replication was semi- conservative
Meselson and Stahl
what is the structure of ATP
pentose sugar (ribose)
3 phosphate groups
adenine
how is ATP formed
made during respiration via condensation reaction from ADP + Pi using the enzyme ATP synthase
what catalyses the hydrolysis ATP
ATP hydrolase
what are the 5 key properties of water
metabolite (used in chemical reactions within the body such as condensation and hydrolysis reactions)
solvent (dipolar) - solutes can easily be transported around body
- high heat capacity (takes a lot of energy to increase temp - BUFFER TEMP)
- large latent heat of vaporisation (large amount of energy needed to turn water to gas) - provides cooling effect with loss of water through evaporation
- strong cohesion (H bonds between water molecules, sticking together) - can provide surface tension
what is the importance of hydrogen ions
alter pH of solution - impact on enzymes
chemiosmosis
- pH is calculated based on concentration of H ions
- more H ions present the lower the pH (more acidic) - enzyme controlled reactions are affected by pH
