HLSC 2P09 Endo control of metabolism 2015 Question and Answer Flashcards

What are the two main pancreatic hormones involved in metabolism regulation?

Insulin and glucagon.

What cells in the pancreas secrete insulin?

Beta (β) cells.

What cells in the pancreas secrete glucagon?

Alpha (α) cells.

How does insulin affect glucose levels in the body?

Insulin decreases blood glucose levels by promoting the uptake and storage of glucose.

What is the primary effect of glucagon in the body?

Glucagon increases blood glucose levels by promoting glycogen breakdown and gluconeogenesis.

In which part of the body does insulin primarily act to affect blood glucose levels?

Liver, muscle, and adipose (fat) tissue.

What effect does insulin have on muscle cells?

Insulin increases glucose uptake and storage in muscle cells.

What is gluconeogenesis?

The formation of glucose from non-carbohydrate sources, such as amino acids.

What is the role of GLUT4 transporters?

GLUT4 transporters are responsible for the insulin-mediated uptake of glucose into cells, particularly in muscle and adipose tissue.

What happens to GLUT4 transporters in muscle and fat cells in the absence of insulin?

There are no GLUT4 transporters in the membrane, preventing glucose from entering the cells.

What metabolic process does insulin inhibit in the liver?

Gluconeogenesis.

How does insulin affect fat metabolism?

Insulin promotes fat synthesis and storage while inhibiting the breakdown of fat.

What condition results from insufficient insulin production?

Diabetes Mellitus.

What is the key difference between Type 1 and Type 2 diabetes?

Type 1 is due to destruction of pancreatic beta cells leading to insulin deficiency; Type 2 is characterized by insulin resistance.

Which hormone is primarily responsible for glycogenolysis?

Glucagon.

What triggers the secretion of glucagon?

A decrease in blood glucose levels.

What is the role of the enzyme glucokinase in relation to insulin?

Glucokinase facilitates the uptake of glucose in the liver by phosphorylating it to glucose-6-phosphate.

What is the typical structure of insulin?

A small protein comprising 51 amino acids.

How does insulin exert its effects at the cellular level?

By binding to its receptor, which has tyrosine kinase activity, initiating a signaling cascade.

What are the major target cells affected by insulin?

Liver, muscle, and adipose tissue.

What happens to protein synthesis in the presence of insulin?

Insulin increases protein synthesis in many tissues, especially muscle and liver.

What is the main action of insulin on fat cells?

Insulin increases the transport of glucose into fat cells and promotes the synthesis of fatty acids.

How does insulin affect glycogen levels in the liver?

Insulin promotes the synthesis and storage of glycogen in the liver.

During fasting, which hormone predominates to regulate blood glucose levels?

Glucagon.

What effect does low insulin have on lipid metabolism?

Low insulin activates hormone-sensitive lipase, leading to fat breakdown for energy.

What is a serious complication of unmanaged diabetes?

Diabetic coma.

What happens to blood glucose and insulin levels between meals?

Insulin secretion decreases leading to an increase in blood glucose.

What is the significance of the half-life of insulin in circulation?

The half-life of insulin is about 5 minutes, indicating its rapid action.

What role does the sympathetic nervous system play in insulin secretion?

It inhibits insulin secretion.

What two processes does glucagon stimulate in the liver?

Glycogenolysis and gluconeogenesis.

What physiological conditions increase glucagon secretion?

Low blood glucose and elevated blood amino acids.

How does protein metabolism change in response to insulin?

Insulin increases amino acid transport into cells and protein synthesis.

What diabetes-related issue can high blood glucose lead to in the kidneys?

Glucosuria, or glucose spilling into the urine.

What is the effect of insufficient insulin on fat metabolism?

Enhanced fat breakdown and abnormal fat metabolism.

What are the risks associated with diabetes?

Arteriosclerosis, heart attacks, strokes, retinopathy, nephropathy, and neuropathy.

What dietary strategy is currently used in diabetes management?

Allowing a normal carbohydrate diet while providing enough insulin to manage glucose levels.

What happens to the body's metabolism when insulin levels are low?

Increased mobilization of fats and decreased utilization of glucose.

What metabolic change occurs due to the absence of insulin?

Enhanced fat breakdown and ketogenesis.

What characterizes diabetic complications over time?

Long-term damage to organs and systems if diabetes is not well managed.

What is the counter-regulatory hormone to insulin?

Glucagon.

What happens to protein catabolism in diabetes?

Increased catabolism leading to depletion of protein reserves.

What is the primary source of glucose during fasting?

Gluconeogenesis in the liver from amino acids.

What happens to neurotransmitter function with prolonged hyperglycemia?

It can lead to neuropathy and impaired nerve function.

What therapeutic approach is effective during diabetic emergencies?

Rapid administration of insulin and fluids.

What impact does chronic high glucose have on blood vessels?

It leads to vascular damage and complications like atherosclerosis.

In addition to glucose metabolism, what else does insulin affect?

It also regulates fat and protein metabolism.