Gene-environment interaction and its effect on obesity disease
Unlike what is usually portrayed on media, obesity is not just a problem of unhealthy lifestyle but in fact influenced by genetic factor as well. Genetic factor is believed to attribute 40 – 70% in the development of obesity (Shawky & Sadik, 2012). In other words, environment, genotypes and the association of these two factors play roles in the phenotype expression, which, in this case, is obesity. With regards to environmental influence, obesity can be the result of many external factors such as energy imbalance caused by oversized food portions, physically inactive lifestyle, consumption of unhealthy food, smoking, emotional factor or improper sleep time (Marti et al., 2013). …show more content…
With a high carbohydrate and sugar diet, the energy produced in the form of ATP increase rapidly because these are the types of food that undergo catabolism most easily. When energy expenditure does not correspond with energy intake, excessive ATP molecules will play the role of a feedback signal to inhibit isocitrate dehydrogenase enzyme in citric acid cycle. Normally, this enzyme convert D-Isocitrate to α-ketoglutarate, followed by a cyclic cascade of biochemical reaction to complete the citric acid cycle. However, when this enzyme is inhibited, D-Isocitrate concentration increase, which leads to the increase of Citrate in Mitochondria. Simultaneously, during the fed phase with high-carb and high sugar diet, insulin hormone also elevate significantly and induce citrate lysase enzyme to split citrate into oxaloacetate and acetyl coA. Acetyl coA carboxylate enzyme combine acetyl coA with carbon dioxide to produce malonyl-coA. Malonyl-coA will undergo a serial reaction of fatty acid elongation until palmitoyl coA is formed. This fatty acyl coA is subsequently hydrolyzed into palmitate. After esterification reaction, this palmitate molecule is converted to triacylglyceride. Triacylglyceride is the main constituent stored in the lipid droplet of adipose tissue. The biogenesis of lipid droplet can happen gradually through direct diffusion of fatty acids, endocytosis of sterols or by fusion of smaller droplet containing
Unlike what is usually portrayed on media, obesity is not just a problem of unhealthy lifestyle but in fact influenced by genetic factor as well. Genetic factor is believed to attribute 40 – 70% in the development of obesity (Shawky & Sadik, 2012). In other words, environment, genotypes and the association of these two factors play roles in the phenotype expression, which, in this case, is obesity. With regards to environmental influence, obesity can be the result of many external factors such as energy imbalance caused by oversized food portions, physically inactive lifestyle, consumption of unhealthy food, smoking, emotional factor or improper sleep time (Marti et al., 2013). …show more content…
With a high carbohydrate and sugar diet, the energy produced in the form of ATP increase rapidly because these are the types of food that undergo catabolism most easily. When energy expenditure does not correspond with energy intake, excessive ATP molecules will play the role of a feedback signal to inhibit isocitrate dehydrogenase enzyme in citric acid cycle. Normally, this enzyme convert D-Isocitrate to α-ketoglutarate, followed by a cyclic cascade of biochemical reaction to complete the citric acid cycle. However, when this enzyme is inhibited, D-Isocitrate concentration increase, which leads to the increase of Citrate in Mitochondria. Simultaneously, during the fed phase with high-carb and high sugar diet, insulin hormone also elevate significantly and induce citrate lysase enzyme to split citrate into oxaloacetate and acetyl coA. Acetyl coA carboxylate enzyme combine acetyl coA with carbon dioxide to produce malonyl-coA. Malonyl-coA will undergo a serial reaction of fatty acid elongation until palmitoyl coA is formed. This fatty acyl coA is subsequently hydrolyzed into palmitate. After esterification reaction, this palmitate molecule is converted to triacylglyceride. Triacylglyceride is the main constituent stored in the lipid droplet of adipose tissue. The biogenesis of lipid droplet can happen gradually through direct diffusion of fatty acids, endocytosis of sterols or by fusion of smaller droplet containing