Molecular Genetics Introduction PDF

Molecular Genetics The study of the structure of DNA, its cellular activities (including its replication), and its influence in determining the overall makeup of an organism. Britannica.com...

Molecular Genetics The study of the structure of DNA, its cellular activities (including its replication), and its influence in determining the overall makeup of an organism. Britannica.com 1 13 mins* Crash Course Stop at transcription and come back to it There is a distasteful remark in the transcription part of the video : ( 2 Activity: the history of DNA 3 LUCA, last universal cellular ancestor last universal cellular ancestor LUCA We are at the molecular DNA level: DNA is a nucleic acid molecule, it is a polymer of nucleotides Nucleic acids are the “nuclein” of Miescher DNA carries the instructions for all cell processes. DNA is in the nucleus of eukaryotic cells and in the cytoplasm of prokaryotic cells. A chromosome is a coiled molecule of DNA. the coil structure is supported by histones (proteins). A nucleosome is 8 histones wrapped by DNA (allows for compact packing) fig. 1 p291 Genes are sections of the DNA molecule that contain the coded instructions to make proteins. Genes vary in size from a few hundred to more than 2 million DNA bases. 6 The nucleus → The chromosomes → DNA → The genes Deoxyribo- ACTG nucleic acid Watson and Crick(1952) - DNA 7 structure was finally determined A genome is an organism’s complete set of DNA. A karyotype: The complete set of chromosomes in a species/individual of a species. Shows the number and appearance of chromosomes in the nucleus of a eukaryotic cell. The first chromosome is the biggest. It is a DNA molecule with 247 million base pairs! Uncoiled DNA of all the chromosomes is about 2 m! This is the human genome. Finally completely mapped in 2020! Humans have almost 20 000 genes! 8 Let’s zoom in to the molecular level 6 mins* Worksheet: 9 The nucleic acid is a polymer of nucleotides held by phosphodiester bonds. The phosphate group is also phosphoric acid. So, DNA is an acid. 10  Notice the 3 What do you see? phosphates. It is a Write it down. nucleoside Be molecular, be triphosphate. gr. 12 specific! 6 mins The E from the bonds is used in replicating the DNA and in DNA synthesis. 11  5 mins* An Introduction to the Human Genome: We are 99.9% the same. 0.1% differences; SNVs, single nucleotide variants and SNPs (snips), single nucleotide polymorphisms (deletions, duplications or rearrangements). Alleles are a specific variant of a gene 12 Epigenetics refers to the functional Epigenome means changes to the genome that alter gene above the genome. expression but do not change the DNA It controls when, sequence. how and how much the genome should work. These functional changes might be rapid and dynamic or long lasting and inheritable. It is not necessarily permanent but explains differences in identical twins. 13  Article of interest Textbook material Page 279 #2, 4, 6 & 7 Answers p730 14