1. Option D1: Human Nutrition

2. Components of the Human Diet
Nutrients are chemical substances found in food that are used in the body
Nutrition Information:
Food energy: from carbohydrates, proteins, fats.
Units: food calories (kcal) or kilojoules (1kcal = 4.18kJ)
daily needs vary by individual based on gender, age, size and activity.
Fats (lipids) can be saturated or unsaturated.
Trans fats are particularly unhealthy.
Sodium (salt): keep it low.
Carbohydrates are polymers of sugars (an energy source).
Sugars are absorbed easily into the blood
Dietary fibre (cellulose) cannot be digested (healthy).
Proteins are polymers and sources of amino acids.
They are used to build new proteins in cells.
Vitamins are organic compounds that are essential in small amounts in the diet.
Minerals are mineral ions (elements) that are also essential.

3. Nutrient: a chemical substance found in foods that used in the body.
Essential Nutrients
Cannot be replaced or synthesised by the body, so must be taken in the diet.
Water
Minerals
Some vitamins
Some unsaturated fatty acids
Some amino acids
Dietary fibre is also necessary, though as it is not absorbed it is technically not a nutrient.
Non-essential Nutrients
Can be replaced or synthesised by the body, so are not necessary in the diet.
Carbohydrates/ sugars (energy could come from proteins or fats)
Other minerals and some vitamins
Saturated fatty acids
Some amino acids.
Dietary fibre is also necessary, though as it is not absorbed it is technically not a nutrient.
Image: 'La Boqueria'
Found on flickrcc.net

4. phenylalanine
hydroxylase

5. Protein-deficiency malnutrition
Kwashiorkor: “The disease of the first child when the second is born.”
Link: NCBI PubMed Health
Caused by a lack of essential amino acids as a result of extremely low protein intake (such as when breastfeeding ceases for one child and the diet switches to low-protein sources of energy).
Essential amino acids are therefore not available to make new proteins - enzymes, pumps, antibodies – that are necessary for normal cell function, growth and immunity.
Edema (severe swelling) results as fluids gather in tissues and cannot be returned to the blood effectively. Growth is severely stunted and mental development can be impaired.
Risk factors:
Extreme poverty, overpopulation, large family sizes
Drought, war, poor infrastructure

6. Phenylketonuria (PKU)
Inherited, progressive, degenerative.
Genetics Review
Is this disorder autosomal or sex-linked?
What is a mis-sense base-substitution mutation?
What is the chance of a child having PKU if both parents are asymptomatic carriers?

7. Phenylketonuria (PKU)
Inherited, progressive, degenerative.
Cause
Autosomal recessive, disease-causing allele:
mis-sense base-substitution mutation on the gene for the enzyme phenylalanine hydroxylase.
Result
Phenylalanine (Phe) cannot be metabolised into tyrosine. Phe builds up in the brain, and competes with other amino-acids related to transport.
Effect
Mental development is retarded.
Detection
Heel-prick (Guthrie test) of newborns to test concentration of Phe and Phe:Tyr ratio.

8. Phenylketonuria (PKU)
Inherited, progressive, degenerative.
Detection
Heel-prick (Guthrie test) of newborns to test concentration of Phe and Phe:Tyr ratio.
Treatment
Strict low-Phe diet: no dairy, meat, breastmilk, nuts or aspartame (artificial sweetener).
Lots of medication.
There is no cure for PKU.
Genetic counseling would be sought by prospective parents who suffer from or are suspected carriers of the disease-causing PKU allele.

9. Fatty Acids CH3(CH2)nCOOH High-density energy storage
Usually solid at room temp
Animal products, palm and coconut oil
High contribution to coronary heart disease (CHD)
Usually oils at room temp
Usually plant sources, e.g. olive oil
Lower contribution to CHD
Image: 'Öl 2'
Found on flickrcc.net

10. Fatty Acids CH3(CH2)nCOOH High-density (efficient) energy storage
Metabolism of fatty acids in cell respiration skips glycolysis.
Coenzyme A* cuts off carbon atoms from the fatty acid in the link reaction and carries them to the Krebs cycle.
Therefore: longer chains are a greater store of potential energy.
*Coenzymes assist enzymes and are made using vitamins. It’s all connected!

11. Fatty Acids Important components of the plasma membrane

12. Fatty Acids CH3(CH2)nCOOH fatty acids glycerol Lipid Hormones
Have other diverse functions.
Triglycerides are efficient energy stores.
glycerol
fatty acids
saturated
mono-unsaturated
poly-unsaturated
“Good Cholesterol”: High Density Lipoproteins
Transport triglycerides out of the blood and so reduce the risk of CHD.
“Bad Cholesterol”: Low Density Lipoproteins
Raise blood triglyceride levels and blood pressure, increasing risk of CHD.
Lipid Hormones
Steroid hormones, such as testosterone and cortisol, are made using lipids.
Hormones are chemical messengers.

17. Describe these fatty acids
Saturated, mono-unsaturated or poly-unsaturated?
If they’re unsaturated, what’s their omega-number?
Are the unsaturated fatty acids cis- or trans-fats?
Describe these fatty acids O H H H H H H H H H H H C C C C C C C C C C C C H H H H H H H H H H H H HO O H H H H H H H H H H C C C C C C C C C C C C H H H H H H H H H H H HO H H H H H H H H H H H O H C C C C C C C C C C C C H H H H H H H H H OH

18. Describe these fatty acids
Saturated, mono-unsaturated or poly-unsaturated?
If they’re unsaturated, what’s their omega-number?
Are the unsaturated fatty acids cis- or trans-fats?
Describe these fatty acids O H H H H H H H C C C C C C C C C C C C H H H H H H H H H H H H HO O H H H H H H H H C C C C C C C C C C C C H H H H H H H H H H H HO H H H H H H H H H H H O H C C C C C C C C C C C C H H H H H H H H OH

21. Vitamins & Minerals Minerals are elemental ions found in food.
Vitamins are complex organic compounds (contain C, H and O). Some can be made by the body, but others are essential in the diet.

23. Understanding Vitamin D
Understanding Vitamin D

24. http://www. mja. com. au/public/issues/175_05_030901/grover/grover