8.0 Protein Synthesis Flashcards
What is a locus?
the position of a gene on a chromosome
What does it mean that the genetic code is degenerate?
Most amino acids are coded for by more than one triplet
What does it mean that the genetic code is universal?
The same triplet code codes for the same amino
acid in pretty much all organisms. This feature
allows for genetic engineering to occur
What is DNA wrapped round in prokaryotes?
Not histones
What is a homologous pair?
Two chromosomes that cary the same genes,e ach one from a different parent.
What are the differences between DNA and mRNA?
MRNA is single stranded, MRNA has Uracil, has
no hydrogen bonds. Pentose sugar in MRNA is
ribose, mRNA is smaller than DNA
Give one way that tRNA is like DNA?
Both have hydrogen bonds
What are the two enzymes involved in transcription and their function?
DNA helicase which seperates the two strands by
breaking hydrogen bonds. RNA polymerase
which ads RNA nucleotides together by joining
the sugar phosphate back bone together.
Describe the process of transcription
- DNA Helicase breaks the hydrogen bonds
between complementary bases in the gene. the
double strand of the gene unwind. leaves 2
separate strands (1 coding strand and 1 template
strand). complementary RNA nucleotides bind to
exposed bases on the template strand. RNA
Polymerase joins the sugar-phosphate backbone
of the RNA strand (Phosphodiester bonds).
leaves pre-mRNA (contains introns and exons).
the copies of the introns are removed by splicing.
leaves mRNA
What process happens between transcription and translation?
Splicing of pre-mRNA. This removes the
introns.
When does transciption stop?
When the RNA polymerase reaches a stop codon
Where does translation take place?
In the ribosomes
How many tRNA molecules bind to the mRNA transcript at any one time?
2
What bond forms between the amino acids?
Peptide bond
What is the role of a tRNA molecule?
Carry amino acids, bind to the complementary
codon sequence
