Question

How obesity link with glucose metabolism?

(i) What is glucose metabolism? Is it include glycolysis, TCA cycle, oxidative phosphorylation and electron transport chain? Explain the process.

(ii) What is the effect of obesity?

(iii) How obesity affects metabolism?

iv) What is the cause of obesity?

(v) Regulation of energy homeostasis and obesity.

Answer 1

i) glucose metabolism is a process of interconversion of glycogen into glucose and vice-versa. When blood glucose level is low, glyvogen breaks down to glucose by the process of glycogenolysis. When blood glucose level is more than sufficient, glucose gets converted into glycogen and gets stored in adipose tissue. When sufficient glycogen is not present in the body, because of prolonged starvation, glucose can be produced into the body from non carbohydrate source such as pyruvate, amino acids, glycerol etc by the process known as glyconeogenesis. All the process happens to maintain the body homeostasis.

It includes glycolysis, TCA, oxidative phosphorylation and ETC ultimately to produce ATP to provide energy for the body to work.

In glycolysis the glucose is broken down to pyruvate which undergoes TCA cycle to produce NADh, GTP and FADH2. The NADG and FADH2 passes electrons to electron transport chain (ETC) to create proton motive force across the which helps in the production of ATP across the inner mitochondrial membrane. the process of ATP production is known as oxidative phosphorylation. In ETC the terminal electron acceptor O2 accepts electrons and produce H2O.

glucose (66) glycolysis 2x Pyruvate (31) NADA 22 NADHE Acetyl GOA (26) Citrate (60) oxaloacetate NADH 140 Isou trate (66) e coz NADT Malate 14) TCA x-ketoglutanate (56 Hot fumarate (40) CADH 7 согласс О р (4) succinyl CoA Succinate . GTP GDP ATX ) ATP

intermembrane space inner mitoch meint oamen ogspot geconcenelopment pre 26bbt. Jame bedbe bo od dubbebbe 689969ggera be better 1999 seco NADH NADH nutoch. NACH / matrix APP ATP é (50) © t

ii) Obesity is associated with insulin sensitivity. It leads to excessive amount of body fat due to abnormal fat accumulation. In obesity, the Insulin receptor become insensitive to high level of blood glucose and don't let the glycogen to be broken down even if blood glucose is low followed by fat accumulation even if no more blood glucose is available. If glucose is not present in the blood the amino acids, glycerol, pyruvate etc use to get converted into glucose by the process glyconeogenesis which ultimately leads to accessive fat acuumulation in te body and the patient becomes overweight.

iii) It affect metabolism because it doesn't allow the glycogen to be broken down to glucose, glycogenolysis. Thus it aid in maintaining homeostasis. It cause Insulin resistance leads to type2 diabetes. It also cause hypertension and high cholesterol in the body. Heart attack, stroke, congestive heart failure, cancer are the main diseases caused by the homeostasis produced due to obesity.

iv) Causes of obesity:

• physical inactivity causing very less calories to burn.
• overeating, especially high in carbohydrate and fat, cause more calories to get stored as fat
• genetics: if parents are obese then there is high chances of the child to be obese because of regulation of genes by hormones
• disease: insulin resistance. hyperthyroidism, PCOD (polycystic ovarian disease) which leads to hormonal imbalance contribute to obesity
• stress: it also has significant effect in obese poeple.