Option D

• essential nutrients 


  A chemical substance found in foods and used in the human body, but they can’t be produced by human therefore are needed within our diet.
• examples of essential nutrients:

  • Essential Amino acid
  • Essential fatty acids
  • minerals
  • most vitamines
• Six classes of nutrients

  • carbohydrates
  • proteins
  • lipids
  • vitamins
  • minerals
  • water
• non-essential nutrients 


  can be made in the body or have replacement nutrients which serve the same dietary purpose
• malnutrition 


  a health condition caused by a deficiency, imbalance or excess of nutrients in the diet.
• causes of malnutrition…


  • improper dietary intake of nutrients ( to much or to little nutrients )
  • due to inadequate utilisation of nutrients by the body ( due to illness, disease… )
• symptoms of malnutrition 


  • stunted growth
  • obesity ( over nutrients )
  • wasting (to thin for their height )
• Determining energy content


  Through the use of calorimetry
• equation to calculate energy content:

  energy = mass of water x 4.2 x temperature increase
• Source if error in calorimetry

  unwanted heat loss to the surrounding environment
• type of energy sources

  carbohydrates and lipids
• Short term energy store

  Carbohydrates as they easier and faster to digest and transport
• long term energy store

  lipids as they can store more energy per gram but are harder to digest and transport.
• amino acids


  monomeric building blocks from which proteins are constructed
• how many amino acids

  20 amino acids
• phenylketonuria (PKU)


  a genetic condition that results in the impaired metabolism of the amino acid phenylalanine. (recessive disease cause by mutation in the enzyme coding gene)
• Phenylalanine hydroxylase (PAH) use in the body


  PAH converts Phenylalanine into tyrosine.
• Phenylketonuria (PKU) effect in the body


  excess phenylalanine is instead converted into phenylpyruvate rather than thyroxin causing a toxic build up of this compound in the blood and urine.
• symptoms of phenylketonuria 


  untreated can cause brain damage and mental retardation
• treatment of PKU


  • low protein diet
  • precise quantities of essential amino acids
  • strict diet
• lipids 


  synthesised by fatty acids from carbohydrates.
• what fatty acids cannot be synthesized in the body

  alpha-linolenic acid ( omega 3 )and linoleic acid ( omega 6 )
• Fat and Cholesterol in blood

  Fat and cholesterol cannot be dissolved in the blood stream therefore it’s packaged into a protein for transport. ( this forms lipoproteins )
• Low density lipoproteins (LDL)


  carry cholesterol from the liver to the body ( increasing blood cholesterol levels )
• High density lipoproteins (HDL)


  carry excess cholesterol back to the liver for disposal ( lowering blood cholesterol levels )
• cause of LDL levels increase


  
  

  • saturated fats increase LDL levels and therefore increase the cholesterol levels in the blood
  • Trans fast increase LDL level and lower HDL levels ( therefore increasing cholesterol levels in the blood )
• causes of HDL levels increase


  Cis-polyunsaturated fats raise HDL levels, lowering cholesterol levels in the blood
• narrowing of arteries caused by…


  • When there is a high level of LDL, particles form a deposit on the walls of the arteries.
  • the accumulation of fat within the arteries wall leads to plaque development.
  • this overal causes restricted flow in the arteries which can lead to CHD.
• water soluble vitamines 


  vitamin B and C
• Fat soluble vitamins 


  Vitamin A, D, E, K
• Ascorbic acid (vitamin C)


  • functions as a potent antioxidant as well as playing a role in the immune functions
  • involved in the collagen synthesis and lipoprotein synthesis
• deficiency in ascorbic acid 


  scurvy
• scurvy symptoms 


  • skin discolouration and bruising
  • haemorrhaging
  • Anaemia
  • dental issues
  • fatigue
  • edema
• vitamin D


  • involved in the absorption of calcium and phosphorus in the body.
  • stored in the liver when levels are low
• deficiency in vitamin D


  rickets
• Rickets symptoms 


  • Bone fragility
  • muscle weakening
  • dental problems
  • growth problems
  • enlarged spleen/liver
  • skeletal deformation
• minerals in the body

  calcium, magnesium, phosphorus, iron, sodium, potassium and chlorine
• minerals important for body fluids

  sodium, potassium and chlorine
• minerals important for for teeth or/and bones

  calcium, phosphorus and magnesium
• minerals which act as con factor for specific enzymes or components of proteins and hormones

  iron, phosphorus and iodine