DNA & Genomes Flashcards
What is the Genome?
Entire genetic (haploid) component of an organism
What is the Proteome?
Complement of proteins expressed by a genome
What is Genome Sequencing?
Identity and assembly of entire sequence of bases in each chromosome
What is Genome Annotation?
Provides information on location and function of genes and other important DNA sequences
How is the genome related to the complexity of the organism?
Weakly (or not at all)
What percentage of human DNA encodes proteins?
~1.5%
How many genes do humans have?
~20,000
What percentage of DNA exists as repetitive sequences?
50%
What are single base variations in DNA sequences known as?
Single Nucleotide Polymorphisms
(SNPs)
What do SNPs cause?
Subtle differences in phenotype
What is an inherited group of SNPs known as?
Haplotype
What are Haplotypes used for?
Define different populations
What are INTRONS?
Long stretches of non-coding DNA
(but have regulatory functions)
What are EXONS?
Stretches of protein coding DNA
How is DNA stored?
VERY tightly packed
(Cruciform)
What enzymes enable DNA supercoiling?
Catalysed by Topoisomerases I & II
What are some Topoisomerase Inhibitors and where are they used?
Etoposide & Doxorubicin
Used in anti-cancer drugs
(cause severe DNA damage & death in proliferating cells)
Which antibiotics target bacterial Topoisomerases?
Coumarins & Quinolones
What are the proteins called that DNA is packed around to make nucleosomes?
Histones
How many classes of Histone are there?
5
(H1, H2A, H2B, H3, H4)
What is Chromatin?
A string of nucleosomes that form chromosomes
How is epigenetic information encoded in Chromatin?
Due to covalent modifications of histones e.g. methylation, acetylation
(passed from generation to generation but not encoded in DNA sequences)
