Flashcards in Energy metabolism Deck (88)
Name two things failure of energy metabolism can lead to?
2. protein-energy malnutrition and cachexia (anorexia, cancer, infections).
What is the first law of thermodynamics?
Energy cannot be created or destroyed, but it can be only transformed from one form to another.
How do plants depend on energy?
From the sun to synthesise proteins, carbohydrates and fats.
What are 3 different forms of energy?
1. Chemical (synthesis of new macromolecules)
2. Mechanical (muscular contraction)
3. Electrical (maintenance of ionic gradients across membranes)
What is the basic concept of energy balance?
Energy intake+Energy stores-Energy expenditure
What do we call the heat energy that is no longer available for work?
What is a colorie?
The amount of heat required to raise the temperature of 1g of water by 1 degree.
What are the 3 forms of energy storage in our body?
1. Fat (major energy storage)
2. Glycogen (short-term energy/carbohydrate reserve)
3. Protein (rarely used for energy except in severe cases of starvation and wasting conditions)
What is the '494' rule used to calculate energy from food?
1g of carb - 4 kcal
1g fat - 9kcal
1g protein - 4 kcal
What is the Basal Metabolic Rate (BMR)?
The energy to maintain basic physiological functions (heartbeat,respiration).
How can the BMR be measured?
After a 12 hour fast with no stimulation.
What is the difference between BMR and Resting Metabolic Rate (RMR)?
3% higher energy expenditure in RMR than BMR.
What type of people have a higher RMR?
Physically active people.
what is diet induced thermogenesis (DIT)?
The thermic effects of food.
What percentage of DIT is burnt off as heat?
Which two types of macronutrients contain the highest DIT?
Protein and carbohydrate
What is the most variable part of energy expenditure?
Name two other types of energy expenditure?
1. Drug induced thermogenesis (smoking, caffeine)
2. Psychological thermogenesis (stress/anxiety)
Name three factors to take into account in energy requirements?
1. Disease/injury (burns,cancer)
2. Physical activity (impaired/reduced)
3. Underfeeding/overfeeding critically ill patients
What is the glucostatic theory about?
Food consumption is triggered by decreased glucose availability to the tissues.
Describe the three factors regulating food intake?
1. Appetitie (psychological desire to eat)
2. Hunger (subjective feeling that determines when food consumption is initiated)
3. Satiety (state of inhibition over eating that leads to the termination of a meal)
How does the CNS regulate food intake?
Hypothalamus regulates feeding behaviour.
Which hormone is released by the duodenum for feeling satiety?
Which hormone suppresses appetite and carbohydrate cravings?
Which hormone might be involved in food cravings?
What hormone levels are elevated in obese people and what is it produced by?
Name the 4 external factors influencing appetite and hunger.
1. Meal pattern (composition, smell, sight)
3. Emotional factors stress)
4. Disease states (anorexia, trauma, infections)
Name 4 external factors influencing appetite?
1. Specific learned likes and dislikes
2. Taste, palatability of foods
3. Cultural practices
4. Drugs, hormones
Suggest 4 factors that can stimulate people to eat when they are not hungry.
1. Eating in front of TV
2. Eating with people