More Biological Molecules Flashcards
mRNA
Messenger RNA, encodes amino acid sequence of a polypeptide
tRNA
Transfer RNA, brings amino acids to ribosomes during translation
rRNA
Ribosomal RNA, with ribosomal proteins, makes up the ribosomes, the organelles that translate the mRNA.
RNA main function
Transfer genetic information from DNA to ribosomes where ribosomes read RNA to make polypeptides in translation
Nucleotide structure
Pentode sugar
Nitrogen containing base
Phosphate group
Bond between nucleotides
Phosphodiester
Hydrogen bonds between A and T
2
Hydrogen bonds between C and G
3
Bond between sugar and phosphate
Ester bond
DNA and RNA difference
RNA is single stranded, a smaller molecule and has no base pairing
Sugar phosphate backbone
Chain of sugars and phosphates
DNA replication
DNA helicase breaks hydrogen bonds in polynucleotide strands making it unwind
Each single strand acts as template for new strand. Complementary base pairing means free floating DNA nucleotides are attracted to complementary exposed base pair
Condensation joins nucleotides of the new strands catalysed by DNA polymerase
Water structure
Slightly positive and slightly negative
Slightly negative oxygen attract slightly positive hydrogen, hydrogen bonding
High latent of vaporisation
Takes a lot of energy to break hydrogen bonds between water molecules, a lot of energy used when water evaporates
Used to cool down
Good solvent
Slightly positive and negative will attract positive and negative ions surrounding it and dissolving it
Strong cohesion
Attraction between molecules of same type
Helps water to flow and means high surface tension when in contact with air
So droplets form and evaporate to to cool skin
ATP structure
Adenine combined with ribose sugar and 3 phosphate groups
ATP being used
Broken down into ADP and Pi in hydrolysis reaction. Phosphate Bond broken and energy released catalysed by ATP hydrolyse
Re-synthesised between ADP and Pi
Iron Ions
Haemoglobin is large protein that carries oxygen around body in red blood cells
Fe2+ binds to oxygen in haemoglobin and becomes Fe3+ until oxygen released
Hydrogen ions
pH calculated based on concerntration of H+ ions
Sodium ions
A molecule of glucose or an amino acid can be transported into a cell alongside sodium ions in co-transport
Phosphate ions
Bonds between phosphate groups that store energy in ATP
Phosphates in DNA and RNA allow nucleotides to join up to form polynucleotides
