Gene Expression Flashcards
Which enzyme is responsible for transcription?
RNA polymerase
Which process produces a primary mRNA transcript?
Transcription
Which process takes place to turn a primary mRNA transcript into a mature mRNA molecule?
Splicing
Which process is when the mature mRNA is used to direct the synthesis of a protein?
Translation
Which process takes place after translation and can result in multiple different proteins being produced from one gene?
Post-translational modification
Where does transcription take place?
In the nucleus
Where does translation take place?
At the ribosome
Which molecule carries specific amino acids to the ribosome?
tRNA
What is the ribosome composed of?
rRNA and protein
What is the function of RNA polymerase?
Breaks the hydrogen bonds between strands of DNA to begin transcription and adds complementary nucleotides to build a molecule of mRNA.
Describe the complementary base pairing used to build a molecule of RNA.
A—U, C—G
Which bonds hold amino acids together to form a polypeptide?
Peptide bond
What happens during splicing?
Introns are removed and exons are spliced together.
Which codons begin and end translation?
START and STOP codons.
What is the function of tRNA?
Carries a specific amino acid and has an anticodon which is complementary to a codon.
What is the function of mRNA?
It carries a complementary copy of the DNA code from the nucleus to a ribosome in the cytoplasm.
What happens during post-translational modification?
The addition of phosphate or carbohydrate molecules, cleavage of polypeptide chains.
What is alternative splicing?
When introns are treated as exons or exons are treated as introns leading to different versions of the mature mRNA
How can one gene lead to the production of many proteins?
Post-translational modification, alternative splicing
Which bonds are responsible for the final shape of a protein?
Hydrogen bonds between amino acids and sulphur bridges.
What is an intron?
A non-coding region of mRNA
What is an exon?
Coding region of mRNA.
Which factors can regulate gene expression?
Intracellular and extracellular factors.
How is gene expression controlled?
By regulating transcription or translation.
What is the phenotype of an organism?
: The physical and chemical characteristics of an organism.
What happens during translation at the ribosome?
tRNA with complementary anticodons match with codons on the mRNA
What are the differences between RNA and DNA nucleotides?
RNA contains RIBOSE SUGAR and URACIL, DNA contains DEOXYRIBOSE SUGAR and THYMINE
Also, RNA is one strand whereas DNA has two strands
What is a codon?
A sequence of three bases on mRNA which codes for one amino acid.
