Gene Expression Flashcards
Gene expression
Involves transcription and translation of DNA sequences. Only a fraction of the genes in a cell are expressed.
Transcription
Process of synthesising RNA from a DNA template
Translation
Synthesising proteins from from an mRNA template at a ribosome
RNA
Single stranded molecule composed of nucleotides containing: ribose sugar, phosphate and A-U G-C bases
mRNA
Carries a copy of the DNA code from the nucleus to the ribosome
tRNA
Carries a specific amino acid to the ribosome and has an anti codon at one end that base pairs with a codon on the mRNA
rRNA
Forms the ribosome along with proteins
Codon
Triplet of bases on the mRNA molecule that code for a specific amino acid
Anti codon
Found on a tRNA molecule. Sequences of nucleotides that are complementary to codons
RNA Polymerase
Enzyme that synthesises RNA from RNA by complementary base pairing with DNA
RNA splicing
Process of removing non-coding introns from the primary transcript and joining coding exons to form a mature transcript
Intron
Non coding regions in the primary transcript
Exon
Coding regions of the primary transcript
Alternative RNA splicing
Different mature transcripts are produced from the same primary transcript. Depending on what exons are retained
Protein
3 dimensional formed by the folding pollypeptide chains. Which determines there functions
Hydrogen bonds
Bonds that hold amino acids together with a protein
Phenotype
Observable characteristics of an organism determined by gene expression and environmental factors
What is a gene?
A section of DNA coding for a trait.
What is an allele?
Different forms of a gene.
What is a genotype?
Genetic makeup (e.g., BB, Bb, bb).
What is a phenotype?
Physical trait (e.g., tall, short).
What does homozygous mean?
Two identical alleles (BB or bb).
What does heterozygous mean?
Two different alleles (Bb).
What is a dominant allele?
Masks recessive allele (B).
