U1 KA3 - Gene Expression Flashcards
What does Gene Expression involve?
The transcription and translation of DNA sequences
How many types of RNA are involved in transcription and translation?
3 types: mRNA, tRNA, and rRNA
What is the structure of RNA?
Single stranded, composed of nucleotides containing Ribose sugar, phosphate, and 1 of 4 bases: Cytosine, Guanine, Adenine, and Uracil
What replaces Thymine in RNA?
Uracil
What are Ribosomes made of?
Ribosomal RNA (rRNA) and Proteins
What is the function of Messenger RNA (mRNA)?
Carries a copy of the DNA code from the nucleus to the Ribosome
What is a CODON?
A triplet of bases on the mRNA molecule that codes for a specific amino acid
How does tRNA function?
It folds due to complementary base pairing and carries a specific amino acid to the ribosome
What is at one end of a tRNA molecule?
An anticodon (an exposed triplet of bases)
What does RNA POLYMERASE do during transcription?
Moves along DNA, unwinding the double helix and breaking hydrogen bonds between bases
What is synthesized by RNA Polymerase?
A primary mRNA transcript from RNA nucleotides by complementary base pairing
What is Uracil in RNA complementary to?
Adenine
What must be removed from the Primary mRNA Transcript?
Non-coding introns
What are the coding regions of mRNA called?
Exons
What happens during RNA Splicing?
Non-coding introns are removed and coding exons are spliced together
What does Alternative RNA Splicing allow?
Different proteins to be expressed from one gene
What initiates translation?
Start codon
What terminates translation?
Stop codon
How do anticodons bond to codons?
By complementary base pairing
What joins amino acids together during translation?
Peptide bonds
What are proteins formed from?
Polypeptides
What holds together the 3-dimensional shape of a protein?
Hydrogen bonds and other interactions between individual amino acids
What determines the functions of proteins?
Their large variety of shapes
What is phenotype determined by?
The proteins produced as a result of gene expression
