Nutrition* Flashcards
What is a macronutrient?
Chemical element which is large and essential to growth and health
What is a micronutrient?
Substance, essential to proper growth and metabolism
Act of enzyme components or coenzymes
Energy terms in food - GE, DE and ME?
Gross energy is the total chemical energy in food
Digestible energy is the energy available after digestion
Metabolisable energy is DE minus urinary and faecal energy losses (energy available to the body)
Calculation of % of energy from a specific source?
8000 kJ
Fat intake of 94g per day
94g x 37 kJ = 3478 kJ
3478/8000 = 43.5%
Energy expenditure:
- male 3000 kcal.day
- female 2100 kcal.day
Macronutrient protein overview - uses, basic structure and storage?
Structural components - collagen and fibrin Growth and repair Haemoglobin Hormones Osmotic Pa Immunity Energy
R-CH(NH2)-COOH
Skeletal muscle
Essential vs Non-essential aas?
Essential:
- leucine, isoleucine, lysine, phenylalanine, methionine, threonine, tryptophan and valine
Non-essential:
- arginine, proline, glutamine, glycine, glycine, aspartate, and serine
Nitrogen balance - protein relation and intake?
Dietary intake must exceed daily losses
During prot breakdown, loss of nitrogen
0.8kg protein/kg/day intake
Quality and quantity of protein sources?
Quality of sources depends on the specific amino acids present in the source
Quantity is the amount of protein needed
Protein deficiency - limiting factor, consequences and risk groups?
Limiting factor is related to energy requirements, if one fulfilled so will the other will be
Muscle wasting
Diarrhoea
Oedema
High prot can cause bone demineral and impaired renal function
Low food intake Impaired absorption Liver disease Kidney disease Low prot diet
Carbohydrate overview - uses, basic structure and store?
Energy source
Essential for the brain, NS and developing RBCs
Production of glucose from prots and fats
(CH2O)n
mono, di and polysaccharides
Liver and skeletal muscle
Minimum carb requirements?
29% of energy intake
150-180g per day
Increased during exercise and pregnancy
50% of total caloric intake
The glycaemic index (GI)- what is it? different types of food? calculation of GI?
The amount of change the food produces to the blood sugar
Fast producing such as sugar creating a high rise of blood sugar
Slow producing such as pasta that is longer lasting
GI = (AUC B/AUC A) x 100
Lipids overview - uses? basic structure and storage? FA?
Include oils, fats and waxes Largest energy store Structural Protection Insulation Vit carrier groups: simple, compounded and derived FA: COOH + HC chain Sat: no double bond Unsat: double bond Cis: H on top of C of DB Trans: H on opposite Cs of DB
Simple lipids - chain? example? structure? conversion? store?
C between 14-22 long always even
Triacylglycerol: most efficient fat form, glycerol and 3 FAs, stored in muscle fibres and can be converted to cholesterol and phospholipids
Compound fats - definition? examples and roles?
SImple fats in combo with other chemicals
Phospholipids: combo of 3 FAs with phospho head, forms membrane bilayer
Lipoproteins such as VLDL, LDL, HDL and chylomicrons
LDL carry cholesterol to muscles
HDL remove cholesterol away from arteries to liver
Derived fats - definition? example?
Substances derived from simple and compound fats
Cholesterol: no FAs but has similar physical and chem properties, formation of bile acid and hormones and synth by liver
Essential FAs - role? example? sources?
Formation of prostaglandins, leukotrienes and thromboxanes (eicosanoids) Linoleic acid and linolenic acid Plant/seed oils Vegetables Breast milk
Lipid deficiency - recommended intake?
Rarely occurs
Important for growth and development
Excess greater problem causing obesity and CHD
< 35% of total energy intake
What are vitamins - definition? types of vitamins? examples? excretion of each vitamin type? influence vit intake?
Organic compounds required in very small amounts to prevent deficiency, many are not able to be synthesised
4 fat soluble and 9 are soluble
Fat sol: A, D, E and K
Water sol: thiamin, riboflavin, niacin, B6, B12, folic acid, biotin, pantothenic acid and C
Fat sol are harder to excrete as they bind to body fats
Water sol are readily excreted
Vitamin density
Bioavailability
Body losses
Vit A - active form? converted from? source? function? def? tox?
Retinol
Can be converted from alpha/beta carotene
Carrots
Growth, development, night vision and immune function
Night blindness, dry eyes, reduced taste, defective bone formation
Joint/bone pain and hair loss
Vit D - store? function? def? intake? tox?
Stored in liver Involved in regulation of CA turnover Rickets 3 ug.d-1 Hypercalcaemia, anorexia and soft tissue calcification
Vit E - function? store? def?
Major chain breaking lipid soluble antioxidant in mem and for immune function Stored in liver Def rare (bioavailability)
Vit K - function? def? source?
Functions as a procoagulant - enhances osteocalcin function
Def results in bleeding disorders
Source from green vegetables and vegetable oils
B1 Thiamin - function? def? body stores? intake?
Metabolism of carbs (pyruvate to acetyl CoA)
Def leads to Beri-Beri - cardiac and nerve damage
Body stores of 30mg
Intake of 0.4mg/1000kcal
B2 Riboflavin - function? def? tox?
Oxidative process (glycolysis and FA oxidation)
Def: dermatitis and oral sores
Tox rare due to low solubility
B12 Cyanocobalamin - function? folate? def? absorption? tox?
Required for nerve myelination (cause irreversible neural damage)
Involved in folate coenzyme recycling
Def cause megaloblastic anaemia
Absorbed by binding to an intrinsic factor a protein cofactor secreted by parietal cells
Low tox
Folate - function? def? pregnancy? source?
Single carbon transfer reactions - purines and pyrimidines
Def results in impaired cell division and altered prot synthesis
Green leafy vegetables
Pregnancy needs established folate store to ensure a healthy foetus
Pantothenic acid - function? source? tox? def?
Forms part of CoA for energy metabolism
Many plant sources
No tox
Def rare but fatigue and nausea
Biotin - function? def? source?
Involved in lipogen, gluconeo and catabolism of BCAA and enzymes for TCA
Def v rare - red scaly skin rash
Source many plant food and also GI flora
Vit C - function? source? def? tox?
Citrus fruits
Scurvy >10mg
Tox <40mg
What is a mineral?
An inorganic compound required in the body for bone, body fluids and tissue formation
minerals and trace elements
Ca - abundance? source? function? def?
99% in skeleton
Source from nuts and veg
Function for bone formation, neural transmission and maintenance of cell membrane potential
Def causes osteoporosis, rickets and cramps
Fe - source? function? def?
Pulses, grain, beg, dried fruit and iron cookware
Function to produce haem, electron transfer and oxidative processes
Def common causing fatigue, anaemia, reduced infection resistance and impaired temp regulation
Na and K - source? function?
Na from salt and K from bananas
Function for osmolarity of ECF and cell mem pot
P and Mg - source? functions? def?
P from grains and soft drinks, function for bone formation , def rare but cause bone pain and muscle weakness
Mg from green vegetables, cereals and legumes, integral to bones, RNA and prot synth, def rare causes muscle weak and cramps
Cu and Zn - source? function? def?
Cu source from nuts, bran and bananas, function for proteins and CT formation, def rare but anaemia
Zn from nuts, bran and bananas, cofactor for enzymes in energy metabolism, for prot synth and immune function, def causes depressed immune function and impaired wound healing
F and Se - source? function? def?
F in water, reduces caries, def dental caries
Se in grains and nuts, needed for selenoproteins, def rare but cardiac damage
