1.3 Gene Expression Flashcards
What are the three types of RNA?
mRNA, tRNA and rRNA
Describe 3 structural differences between mRNA and DNA
RNA:
- Single stranded
- Ribose sugar
- Uracil base
DNA:
- Double stranded
- deoxyribose sugar
- Adenine
What is the role of mRNA?
Messenger RNA carries a copy of the DNA code from the nucleus to the ribosome where it is then translated
What is the role of tRNA?
Transfer RNA translates mRNA into a polypeptide at the ribosome
What is the role of rRNA?
Ribosomal RNA and proteins form the ribosome
What is the role of RNA polymerase in the transcription of DNA into primary mRNA transcripts?
RNA polymerase moves along DNA unwinding the double helix and breaking the hydrogen bonds between bases. It also makes a primary transcript of mRNA from RNA nucleotides
What is RNA splicing?
RNA splicing forms a mature mRNA transcript
What is an intron?
The introns of the primary transcript are non-coding regions and are removed
What is an exon?
The exons are coding regions and are joined together to form the mature transcript. The order of exons is unchanged during splicing.
Describe the process of translation
-Anticodons bond to codons by complementary base pairing,
-Translating the genetic code into a sequence of amino acids.
-Peptide bonds join the amino acids together
What is alternative RNA splicing?
Different proteins can be expressed from one gene. Different mature mRNA transcripts are produced from the same primary transcript depending on which exons are retained.
What is the bond between amino acids?
Peptide bond
How do polypeptides fold?
Polypeptide chains fold to form the three-dimensional shape of a protein, held together by hydrogen bonds and other interactions between amino acids.
What is phenotype determined by?
Phenotype is determined by the proteins produced as the result of gene expression.
