Nutrition, Diet and Body Weight Flashcards
What do catabolic processes do?
Break down molecules to release energy in the form of reducing power
What do anabolic processes do?
Use energy and raw materials to make larger molecules for growth and maintenance
What do living things require energy for?
Biosynthetic work, transport work, mechanical work, electrical work and osmotic work
What type of energy is used by cells?
Chemical bond energy
What is the SI unit of food energy>
Kilojoule
What does ‘calorie’ actually mean?
Kilocalorie
How many kilojoules per calorie?
4.2 kJ
What does the carbohydrate in our diet provide?
Mostly energy
What does the protein in our diet provide?
Amino acids and energy
What does the fat in our diet provide?
Energy and essential fatty acids
What is fibre necessary for?
Normal GI function
What are some major dietry carbohydrates?
Starch, sucrose, lactose, fructose, glucose, maltose, glycogen
What is lactose?
Glucose & galactose disaccharide
What is sucrose?
Table sugar!
Glucose & fructose dissacharide
What is maltose?
Glucose-glucose dissacharide
What is glycogen?
Polymer of glucose, carbohydrate storage molecule in animals
Why can’t we get energy from cellulose?
We lack enzymes that break the b1-4 glycosidi bonds
How many amino acids cannot be synthesised by the body and are therefore essential?
9
What are the essential amino acids?
Isoleucine Lysine Threonine Histidine Leucine Methionine Phenylalanine Tryptophan Valine
Mnemonic = If Learned This Huge List May Prove Truly Valuable
What other amino acids may children and pregnant women require from the diet?
Arginine, tyrosine and cysteine
What are lipids composed of?
Triacylglycerols (3 fatty acids esterified to one glycerol)
Why do fats yield more energy?
Contain much less oxygen than carbohydrates or protein, more reduced so yield more energy when oxidised
What are the fat soluble vitamins?
A, D E and K
What are some essential fatty acids?
Linoleic and linolenic
What state do saturated fats tend to be in at room temperature?
Solid
What state do unsaturated fats tend to be in at room temperature?
Liquid
What are some essential minerals and why?
Calcium and phosphorus (structural)
Magnesium, manganese, cobalt, copper, zinc, molybdenum (enzyme co factors)
Iron (haemoglobin)
What can a deficiency of vitamin A result in?
Xerophthalmia
What can a deficiency of vitamin D result in?
Rickets
What can a deficiency of vitamin E result in?
Neurological abnormalities
What can a deficiency of vitamin K result in?
Defective blood clotting
What can a deficiency of vitamin B1 result in?
Beriberi
What can a deficiency of vitamin B12 result in?
Anaemia
What can a deficiency of vitamin B6 result in?
Dermatitis, anaemia
What can a deficiency of biotin result in?
Alopecia, scaly skin, CNS defects
What can a deficiency of vitamin C result in?
Scurvy
What can a deficiency of choline result in?
Liver damage
What can a deficiency of folate result in?
Neural tube defects, anaemia
What can a deficiency of niacin result in?
Pellagra
What can a deficiency of pantothenic acid result in?
Fatigue, apathy
What can a deficiency of riboflavin result in?
Ariboflavinosis
What is low fibre intake associated with?
Constipation and bowel cancer
What is a high fibre intake associated with?
Reduced cholesterol and risk of diabetes
What is RNI and what is it used for?
Reference Nutrient Intake - used for protein, vitamins and minerals
What is EAR and what is it used for?
Estimated Average Requirement - used for energy
What is the RNI enough to ensure?
Enough to ensure the needs of 97.5% are being met, many within that group will need less
What is the LRNI only enough for?
Only enough for the small number of people (2.5%) who have low requirements - the majority will need more
What is the EAR the requirement for?
Around 50% of group - 50% require more
What is daily energy expenditure the sum of?
Basal metabolic rate, diet-induced thermogenesis and physical activity level
What factors affect basal metabolic rate?
Body size, gender, environmental temperature, endocrine status and body temperature
How much does an increase of 1 degree of body temperature increase BMR?
By 12%
How does environmental temperature affect BMR?
Increases in cold
Define obesity
Excessive fat accumulation in adipose tissue whih impairs health - BMI > 30
What are the units of BMI?
Kg/m^2
What is the equation to calculate BMI?
BMI = Weight (kg) / Height^2 (m^2)
What is a greater proportion of fat in the upper body associated with?
Increased risk of insulin resistance, hyperinsulinism, type 2 diabetes, hypertension, hyperlipidaemia, stroke, premature death
What is the main sign of Kwashiorkor?
Too much fluid in tissues causing oedema
Why does malnutrition often lead to oedema?
Low protein intake results in insufficient blood protein synthesis leading to a decrease in plasma oncotic pressure and therefore oedema
What is the normal fasting plasma concentration of glucose?
3.3-6.0 mmol/L
How does phosphocreatine provide initial bursts of energy?
Phosphocreatine can anaerobically donate a phosphate group to ADP to form ATP during the first 2 to 7 seconds following an intense muscular or neuronal effort.
