Hard flashcards
What occurs during aerobic exercise?
Increase production of ATP and increase uptake of glucose. Adrenalin increases rate of glycolysis by increasing rate of gluconeogenesis and release of fatty acids from adipocytes.
What occurs during anaerobic exercise?
Where there is a high demand for ATP, glucose transport from the blood can’t keep up with the high demand for glucose. Glycogen is therefore broken down. Lactate increases to allow continuation of glycolysis. Liver uses lactate to form glucose (gluconeogenesis lactate to pyruvate to glucose).
What happens during prolonged fasting?
Glucagon/insulin ratio increases further. Adipose tissue hydrolyses triglycerides. TCA Cycle intermediates are reduced so they can be used for gluconeogenesis. Protein is broken down to provide amino acid substrates for gluconeogenesis. Ketone bodies are produced to partially substitute brain requirement for glucose.
Where does oxidative phosphorylation take place?
Inner membrane.
What does cyanide and azide target?
Haem group in cytochrome oxidase complex (Complex IV).
What happens during non shivering thermogenesis?
UCP-1 is activated. ATP synthase is bypassed and energy from H+ gradient is released as heat instead of producing ATP.
How does malonate act as a metabolic poison?
Acts as a competitive inhibitor of complex II. Slows flow of electrons from succinate to ubiquinone.
How does a g protein coupled receptor specifically work?
Ligand binding causes conformational change in 7tm receptor. This allows heterotrimeric g protein to bind to 7tm receptor. GDP is exchanged for GTP and g protein is seperated into alpha and beta sub unit. Each sub unit binds to its target protein.
How can g protein be deactivated?
Dephosphorylation of GTP to form GDP. Alpha unit leaves target protein and rejoins with beta unit.
What deactivates 7tm receptor?
Unbinding of ligand. Receptor remains active as long as ligand is bound and can activate further heterotrimeric g proteins.
How do enzyme linked receptors work specifically?
Ligand binding causes receptors to cluster. This leads to enzyme activity within the cell. Enzymes phosphorylate the receptor. This leads to binding of signalling proteins to cytoplasmic domain of receptor. These signalling proteins lead to a signal cascade within the cell.
How do type 1 intracellular receptors work specifically?
Receptor located in cytoplasm. Hormone passes through cell membrane and bind to receptor which leads to heat shock protein dissociation which results in 2 hormone bound receptors join together and form a hormodimer that passes through nucleus and bind to DNA.
Explain the fibrillar collagen synthesis pathway?
Pro alpha chain synthesis. Hydroxylation and glycosylation occurs. Three of these form triple helix. Secretion out of cell. Cleavage of propeptides to form collagen. Assembled into fibril and then into fiber.
What do fibril associated collagens do? Give an example?
Regulate organisation of collagen fibrils. Collagen type IX and XII.
What occurs in Alport syndrome?
Mutations in collagen IV result in an abnormally split and laminated glomerular basement membrane.
