2. Nutrition, Body Weight and Homeostasis Flashcards
Define energy.
The capacity to work.
Define 1Kcal.
The amount of energy needed to raise temperature of one kilo gram of water by one degree Celsius.
What is the conversion rate of Kcal and kJ?
1 Kcal = 4.2 kJ.
What is intake of carbohydrate used for?
For supplying energy.
What is intake of protein used for?
Energy and amino acids.
What is intake of fat used for?
Energy and essential fatty acids.
What is intake of water used for?
Hydration.
What is intake of fibre used for?
Normal GI function.
What are the main dietary carbohydrates?
Starch (carbohydrate storage molecule in plants), sucrose (table sugar), lactose (milk sugar), fructose (from fruit), glucose (sugar in human blood).
How many different amino acids are used for protein synthesis?
20.
How many essential amino acids, that can’t be synthesis so must be obtained from diet, are there?
9.
What are the nine essential amino acids?
Isoleucine Lysine Threonine Histidine Leucine Methionine Phenylalanine Tryptophan Valine
Why does fat produce much more energy when oxidised?
It contains less oxygen than carbohydrates or proteins.
Which vitamins are fat-soluble?
A, D, E and K.
What are minerals used for in the body?
Establishing ion gradients across membranes and maintaining water balance.
Why are vitamins needed in the body?
A deficiency of them lead to diseases.
What can a low fibre intake lead to?
Constipation and bowel cancer.
What can a high fibre do?
Reduce cholesterol and diabetes risk.
What are dietary reference values (DRV)?
A series of estimates of the amount of energy and nutrients needed by different groups of healthy UK population.
What are nutrient requirements dependent on?
Age, gender and level of physical activity.
How are estimated average requirements (used for energy) estimated?
Requirement for 50% of the group, so half the group will need more than what the EAR suggests.
How are reference nutrient intakes (for mineral) estimated?
The level where the need of 97.5% are met, many in the group will need less.
How are lower reference nutrient intakes (LRNI) estimated?
The amount that is enough for only a small number of people (2.5%) so the majority need more than this.
What causes variation in the energy requirements of people?
Age, sex, body composition and physical activity.
What is daily energy expenditure the sum of?
Basal metabolic rate, diet-induced thermogenesis (energy required to process food) and physical activity level.
What is the basal metabolic rate?
The energy needed to maintain resting activities of the body, like maintenance of cells (ion transport and biochemical reactions), function of organs and maintaining body temperature.
What factors affect BMR?
Body size, gender, environmental temperature, endocrine status and body temperature.
What is energy used for during physical activity?
Contraction of skeletal muscle, cardiac muscle and respiratory muscle.
What is the order that the following stores of energy are used? Muscle protein, muscle, carbohydrate and adipose.
Muscle, carbohydrate stores, adipose, muscle protein.
What is the most noticeable difference between a 70kg and 100kg man in terms of body composition?
Lipid stores, approximately 12kg for the 70kg man but 40kg for the 100kg man.
Define obesity.
Excessive fat accumulation in adipose tissue that impairs health. BMI of over 30 kg/m2.
What is the formula for calculating BMI?
BMI = weight (kg) / height2 (m2)
What is an alternative measurement of weight classification to BMI?
Hip to waist ratio.
Name two complications that upper body fat increases the risk of.
Insulin resistance/type II diabetes, hyperinsulinism, hypertension, hyperlipidaemia, stroke or premature death.
What causes Kwashiorkor?
Low protein intake from malnutrition so resulting in insufficient blood protein synthesis and decreased plasma inciting pressure, which leads to oedema.
What are the 6 main functions of blood?
Transport (of oxygen, nutrients, waste products and hormones), coagulation, immune functions, regulating body pH, regulating body temperature and hydraulic functions.
Define homeostasis.
Mechanisms that counteract changes in the internal environment to maintain a dynamic equilibrium.
What is the general outline of a homeostatic response?
Receptor detects change, control centre sends signal to counteract change, effectors bring about the desired change, negative feedback corrects the deviation.
How are blood glucose levels maintained after eating?
Pancreas secretes insulin, insulting stimulates liver to take up glucose to store as glycogen and tissues take up glucose, plasma glucose levels decline back to normal.
How are blood glucose levels maintained in a fasted state?
Pancreas releases glucagon, glucagon stimulates liver to break down glycogen and real ease glucose into the blood, plasma glucose levels rise back to normal.
Explain the difference between catabolic and anabolic processes.
Catabolic processes break down molecules to release energy in the form of reducing power but anabolic processes use energy and raw material to make larger molecules for growth and maintenance.
