BIOSC 150 1nd Edition Lecture 21 Outline of Last Lecture I Non Mendelian II Human Genetics Outline of Current Lecture 1 Case Studies 2 Genetics of Cardiomyopathy Current Lecture The heart is essential for circulation of blood carrying oxygen nutrients and wastes The heart pumps blood through a vessel system of arteries veins and capillaries The heart is essentially two pumps sending blood to the lungs or systematically Left ventricle is thicker than the right ventricle because the left ventricle has to pump the blood throughout the whole body while the right simply pumps it to the heart Electrical signals tell cardiac muscle cells to contract There are three typed of muscle 1 Skeletal muscle voluntary 2 Cardiac muscle involuntary 3 Smooth muscle involuntary Contraction and relaxation cycles of cardiac muscle tissue is responsible for heart pumping Cardiac muscles are all connected through intercalated disks Desmosomes and adherens like junctions hold cell together while gap junctions electrically couple cell Gap junctions in intercalated discs coordinate contraction initiation via electrical signaling of ions Branching of cardiac muscle cells connects many together and coordinates contraction Muscle cells are specialized for contraction Muscle cells contain organized bundles of actin and myosin Cardiac muscle striations reflect sarcomere architecture Sarcomere proteins drive contractions and the sarcomere shortens Myosins pull antiparallel actin filaments Tropomyosin and troponin together control myosin access to actin These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Binding changed troponin structure and releases tropomyosin to expose myosin binding site on actin Proteins of the cardiac sarcomere drive contraction and relaxation Actin binding site on myosin is very sensitive to mutation ATPase enzyme region of myosin is sensitive to mutation Myosins motor proteins that use the energy of ATP hydrolysis to travel along actin The hinge is made of 3 proteins coded for by three different genes and is sensitive to mutation Single Nucleotide change in genes for sarcomere proteins can cause HCM
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