Energy and Metabolism Overview

This set of flashcards covers key concepts related to energy, metabolism, dietary energy sources, hormonal regulation, and factors influencing energy expenditure.

What is the first law of thermodynamics in relation to energy?

Energy cannot be created or destroyed, only transformed from one form to another.

What does 1 calorie equal in terms of heat energy?

1 calorie is the amount of heat energy needed to raise the temperature of 1 gram of water by 1 degree Celsius.

How is food energy measured using a bomb calorimeter?

A food sample is burned inside a bomb calorimeter, and the rise in temperature of the surrounding water measures the energy content.

What is the caloric value of 1 gram of fat?

1 gram of fat provides 9 Calories of energy.

What are the three main macronutrients and their caloric values per gram?

1 gram of carbohydrates and protein provide 4 Calories each, while 1 gram of fat provides 9 Calories.

What is the Basal Metabolic Rate (BMR)?

BMR is the energy expenditure at rest.

What factors influence the Basal Metabolic Rate (BMR)?

Factors include age, muscle mass, gender, fasting, hormone activity, stress, disease, environmental temperature, pregnancy, and lactation.

What is Diet Induced Thermogenesis (DIT)?

DIT is the amount of energy required to digest and absorb food molecules.

Which hormone is released after meals and promotes energy storage?

Insulin is released after meals and stimulates glycogenesis and lipogenesis.

What is the function of glucagon in the body?

Glucagon is released in between meals and stimulates gluconeogenesis and glycogenolysis, increasing blood glucose levels.

What are ketone bodies and when are they produced?

Ketone bodies are produced in the liver from fatty acids during prolonged starvation when glucose availability is low.

What is leptin and what role does it play in appetite regulation?

Leptin is a hormone released from adipose tissue that inhibits hunger signals and regulates energy balance.

What is the relationship between sleep and appetite hormones such as ghrelin and leptin?

Sleep deprivation increases ghrelin (appetite hormone) and decreases leptin (satiety hormone), leading to increased hunger.

What is gluconeogenesis?

Gluconeogenesis is the formation of glucose from non-carbohydrate sources, primarily occurring in the liver.