Biochemistry Flashcards
What process allows the genetic code to be able to be moved out of the nucleus, and what molecule does this form?
Transcription forms mRNA
Describe the process of transcription
DNA helicase unwind and unzip the DNA
hydrogen bonds break between the bases
RNA polymerase catalyses the formation of temporary hydrogen bonds beteeen RNA nucleotides and the DNA bases
The RNA strand is now complimentary to the ‘template strand’
mRNA moves out the nucleus and joins a ribosome
Where are tRNA molecules made
The nucleolus
What is the name of the three bases at the top of the loop on a tRNA molecule
The anticodon
What joins three bases at the straight tip of a tRNA molecule?
Amino acid
What causes the ribosome to stop moving along the mRNA chain
The stop codon
What happens to the mRNA chain after translation
It breaks down into free nucleotides again
Describe the structure of a nucleotide
Pentose sugar
A phosphate group attached to the sugar
A nitrogenous base (A,T,C OR G)
How is dna stored in prokaryotic
DNA is in a loop within the cytoplasm (no nucleus)
DNA is described as naked as it has no histine
What enzyme catalyses the unwinding process
DNA gyrase
What stage if the cell cycle does DNA replication take place
Interphase
What is semi conservative replication
DNA replication where one strand in the new molecule is from the original molecule and one strand is newly formed
Why is it important that the amino acid sequence (primary structure) is correct
Because it allows the chain to food and be held in its tertiary structure giving its specific 3D shape
Having a specific 3D shape is vital to a proteins function
What is the name for a diffferent variation of a gene
An allele
What specifically does DNA code for
Amino acids sequence
