Genes and genome Flashcards
What is the genome?
An organism’s complete set of DNA, contains all the information needed to build and maintain an organism.
What are some examples of the non-coding parts of the genome?
Telomeres, centromeres, introns.
What is a gene?
Basic unit of heredity, linear sequence of nucleotides along a segment of DNA that provides the coded instructions for synthesis of RNA which is translated to proteins and leads to the expression of hereditary character.
What is the structure of a typical human gene?
Promoter, 5’UTRs, ATG start site, axons, introns, stop codon and 3’ UTRs.
What recognises the sequences at 5’ and 3’ ends to start splicing?
snRNP which allows ens to interact with each other to loop out the intron.
What happens during the process of splicing?
Spliceosome allows 5’ exon cleavage which interacts with 3’ and form loop. Splices other end and forms lariat loop. RNA ligase to put ends together.
What are the other methods of alternative splicing?
- Consitutive splicing, all exons present.
- Exon skipping.
- Mutually exclusive exons, 1 of 2 exons.
- Alternative 5’/3’, spliced into internal region of the gene.
What is RNA editing?
Discrete changed made after RNA has been transcribed, usually at single nucleotide level. Carried out by editosome complex, which uses RNA to guide it to right sequence.
What is DNA editing?
Recombination associated with differentiation of somatic cells/sex determination.
What are the 2 types of DNA editing?
Chromatin dimunition and chromosome elimination.
What is gene clustering?
A gene cluster is a group of two or more genes found within an organism’s DNA that encode similar polypeptides, or proteins, which collectively share a generalized function and are often located within a few thousand base pairs of each other. Similar to operons in bacteria, so they are controlled together.
What are 2 other genomes which can be found in eukaryotic cells?
Mitochondrial and chloroplast genome.
