BIOL 3P30 Lecture Notes - Lecture 11: Citrate Synthase, Sodium-Potassium Alloy, Genetic Predisposition
22 Aug 2015
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Document Summary
Mitochondrial abundance (% of cell volume occupied with mitochondria) lower in big animals. Citrate synthase activity of skeletal muscle scales with body mass: only occurs in mitochondria. On top is the liver, bottoms is kidney. Rate that oxygen is being consume is lowered. Liver proteasome activity negatively correlated with body mass. Protein cycling is slower and therefore have a greater half life. No mechanism here but we see slower leak. Activities of all the major contributors to cellular metabolic rates are reduces concomitantly with increasing body mass. We see that cancer incidents are about the same across animals, including humans. 1: as soon as you remove the tissue you should see a change in metabolic rate. Chronic difference in average work rate: think of muscle movement during running- takes longer for those muscles to contract in a large animal, cells adopt to reduced work loads inherent to bigger speicies. An ex vivo model of metabolic rate allometry.
