Gene Expression Flashcards
(34 cards)
What determines phenotype?
The proteins produced as a result of gene expression
What can influence phenotype?
Environmental factors
How many genes from the genome are expressed?
Only a fraction
What does gene expression involve
Hint: 2 Ts
Transcription and translation of DNA sequences
Transcription and Translation involves three types of rna: name them
mRNA
tRNA
rRNA
Describe RNA in comparison to DNA
Single stranded
Ribose sugar
Uracil instead of Thymine
In RNA what base is complementary to Adenine
Uracil
What does mRNA do?
Carry a copy of the DNA code from the nucleus to the ribosome
mRNA is transcribed from DNA where?
In the nucleus
mRNA is translated into proteins by ribosomes, where?
In the cytoplasm
What is a triplet of bases called?
A codon
What does a codon do?
Codes for a specific amino acid
Why does tRNA fold?
Due to complementary base pairing
Where does tRNA carry its specific amino acid to?
Ribosome
What does tRNA have?
An anticodon at one end
Attachment site for specific amino acid at the other end
What forms the ribosome?
rRNA and proteins
What is the role of RNA polymerase in transcription?
RNA polymerase moves along DNA unwinding the double helix and breaking the hydrogen bonds between bases.
RNA polymerase synthesises a primary transcript of mRNA from what?
RNA nucleotides by complementary base pairing
What does RNA splicing form?
A mature RNA transcript
What are introns of the primary transcript, and what happens to them?
Non-coding regions that get removed
What are exons?
Coding regions that join to form the mature transcript
During splicing what happens to the order of exons?
Unchanged during splicing
tRNA is involved in the translation of mRNA into what, where?
A polypeptide at the ribosome
Translation begins at a start codon and ends where?
Stop codon
