Biochem - Nucleic Acids Flashcards
What bond forms when nucleotides are polymerised?
Phosphodiester bonds
tRNA anticodon sequence is the same as….
The template strand (With thymine switched to uracil)
Helicase…
Helicase unzips and unwinds the DNA
The template DNA is…
The DNA complimentary to the coding strand; it is the strand which complimentary nucleotides bond to the recreate the sequence of the coding strand
Purine bases pair with…
Pyrimidine bases
Phosphodiester bonds link…
adjacent nucleotides.
Explain how nitrogenous bases allow identical copies of DNA to be made.
Adenine pairs with Thymine because of hydrogen bonding; Purine can only bond with pyrimidine because of their different sizes and-so bases can only pair with their one complimentary base.
Outline protein synthesis:
mRNA transported out of nucleus.
mRNA transported to ribosome, where translation occurs.
tRNA brings specific amino acids, based on the complimentary anticodon on the tRNA.
Amino acids form peptide bonds - form polypeptide.
Polypeptide processed by golgi apparatus.
What substance can be used to release DNA from nuclear envelope?
Detergent, because it works as an emulsifier (Attracts phospholipid molecules) and breaks open the nuclear membranes.
True or False: Genetic code overlaps
True
Helicase….
Unwinds the DNA molecule and breaks hydrogen bonds between base pairs.
DNA polymerase…
Links new nucleotides together in DNA replication.
RNA polymerase…
Links mRNA nucleotides in transcription
How many nucleotide bases that code for a single amino acid.
3
There is a maximum of….. different base combinations.
64
Why are not all base combinations used to code for amino acids?
Some amino acids can be made from multiple base combinations.
Some amino acids are stop/start codons.
What nucleotide bases are in both DNA and RNA
Adenine, Cyrosil and guanine
What nitrogenous base changes between DNA and RNA?
Thymine is replaces with Uracil.