Nuclear structures Chromosomes 46 in humans (23 pairs) 22 pairs of autosomes, 1 pair of sex chromosomes contains DNA and RNA Deoxyribonucleic acid (DNA) Thymine, adenine, guanine, and cytosine (TAGC) adenine linked to thymine (A-T) guanine linked to cytosine (G-C) double stranded strands linked together by phosphate groups 2' hydrogen group regulates cell division mRNA is produced from DNA an exon is portion of gene that codes for mRNA exon is expressed Gene segment of DNA that contains the information needed to synthesize a protein determines the unique biologic qualities of a cell exon coding information intron does not code for mRNA Ribonucleic acid (RNA) usually single stranded but can be double stranded double stranded RNA found in some viruses certain interactions between single stranded RNA in human cells can form double stranded RNA has ribose sugar Uracil, adenine, guanine, and cytosine (UAGC, no thymine) less stable than DNA 2' hydroxyl group can be located in either the nucleus or cytoplasm messenger RNA (mRNA) translates DNA information into protein ribosomal RNA (rRNA) major part of ribosome, which helps synthesize a protein transfer RNA (tRNA) transfers amino acids to mRNA Genetic Terms Nucleotides thymine, adenine, guanine, and cytosine Codon sequence of three nucleotides each codon correlates to one of the 20 amino acids linking of the amino acids create a protein Gene promotor regulatory portion of DNA that controls initiation of transcription Gene enhancers site on DNA that transcription factors bind to regulate transcription Transcription DNA => mRNA Translation mRNA => protein Haploid Haploid is the amount of DNA in a human egg or sperm cell (half the amount of DNA in a normal cell) Whole-genome sequencing Whole-genome sequencing (WGS) is the process of determining the entirety, or near entirety, of the DNA sequence of an organism's genome, including coding and non-coding DNA Whole-exome sequencing Whole-exome sequencing (WES) allows sequencing of only the protein-coding regions of genes in a genome (known as the exome) Genome-wide association sequencing Genome-wide association sequencing (GWAS) uses single-nucleotide polymorphisms (SNPs) to evaluate mutational variability among patients with a phenotype (or disease) of interest. Cell Cycle Phases G0 represents a "stable" phase cells are diploid (2N) in the G0 and G1 phases G1 initial growth phase cells are diploid (2N) in the G0 and G1 phases S DNA replication/synthesis phase cells become tetraploid (4N) at the end of S and for the entire G2 phases G2 gap phase cells become tetraploid (4N) at the end of S and for the entire G2 phases M mitosis phase Apoptosis Defined as programmed cell death Requires a series of intracellular signaling events Different from cell lysis - where a cell releases its contents into the surrounding area One hallmark of cancer is the cell's loss of apoptosis Research techniques Agarose gel electrophoresis separates DNA based on size DNA is negatively charged gel exposed to electric field smaller pieces moves through gel faster Southern blotting restriction enzymes cut up DNA separate on agarose gel identifies DNA sequence Northern blotting restriction enzymes cut up RNA separate on agarose gel identifies RNA sequence Western blotting SDS-PAGE gel identifies protein DNA ligation combining different DNA fragments not found together naturally to create recombinant DNA Plasmid vector an extrachromosomal element, often circular, that can replicate and be transferred independently of the host chromosome one example of the function of a plasmid is antibiotic resistance can be introduced into bacteria in the process of transformation Polymerase chain reaction (PCR) DNA => DNA a molecular biology tool used to generate many copies of a DNA sequence uses "primers" specific to a segment of DNA requires temperature-mediated enzyme DNA polymerase Reverse transcription polymerase chain reaction (RT-PCR) RNA => DNA variant of polymerase chain reaction (PCR) used in molecular biology to generate many copies of a DNA sequence from fragments of RNA RNA strand is first reverse transcribed into its DNA complement amplification of the resulting DNA proceeds using polymerase chain reaction