CHAPTER 6: NUTRITION 6.1 TYPE OF NUTRITION Nutrition = process by which org anisms obtain nutrients and energy from food. Ty pe of nutr it ion Defi ni tio n Exap!e " Autotrophic Nutrition Living organisms that are capable of producing its own food from simple inorganic compounds • Plants • Bacteria Photosynthesis Organisms that synthesis food from inorgan ic compounds such as water and carbon dioxide using sunlight as source of energy • reen plants •Algae !hemosynthesis Organisms that syn the si"e foo d from simple inor gani c comp ound s usin g ener gy rele ased from oxidi"ing minerals li#e nitrates$ car bon dioxide and sulphides • %ulphur bacteria &eterotrophic Nutrition Living organisms that feed on other living things &olo"oic Nutrition %aprophytism Parasitism 1
Notes for the first part of the Nutrition chapter.
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Nutrition = process by which organisms obtain nutrients and energy from food.
Type of nutrition Definition Exap!e"
AutotrophicNutrition
Living organisms that are capable of producingits own food from simple inorganic compounds
• Plants
• Bacteria
PhotosynthesisOrganisms that synthesis food from inorganiccompounds such as water and carbon dioxideusing sunlight as source of energy
• reen plants
• Algae
!hemosynthesisOrganisms that synthesi"e food from simpleinorganic compounds using energy releasedfrom oxidi"ing minerals li#e nitrates$ carbondioxide and sulphides
'. A balanced diet contains the main nutrients which include carbohydrates$ fats$ proteins$vitamins$ minerals$ water and roughage in the correct proportions to meet the body(s dailyre)uirements.
*. +he importance of a balanced diet,-a to allow the organism to function efficiently by providing daily energy re)uirement-b for metabolism and maintain a healthy life-c for growth and repair damage tissues-d to supply essential nutrients
Dai!y ener&y re'uireent'. /nergy can be obtained from carbohydrates and fats. Proteins are only used if there is ashortage of carbohydrates and fats.
*. /nergy re)uirement vary according to,
-a Age 0 !hildren and teenagers re)uire more energy because they
have a higher metabolic rate
-b %ex 0 A male adult need more energy because they usually have
relatively less fatty tissues as heat insulator and a higher rate
-c Body si"e and weight 0 People with bigger body si"e and weight will re)uire more
energy for their basal metabolism
-d Occupation and
lifestyle
0 A person who does heavy wor# will need more energy than a
person who only moderately active$ and thus re)uires more
energy than a sedentary wor#er.
-e Pregnancy and
lactation
0 Pregnant women and breast0feeding mothers re)uire more
energy.
-f !limate 0 A person who lives in a cold country needs more energy to
maintain his body temperature than a person living in the
tropics.
Deterination of ener&y (a!ue in foo) "ap!e"
/nergy value of food = 1efined as the energy produced when ' gram of food is completely
burned. +he unit for energy value of food is 2oule per gram -34g or#ilo2oules per gram -#24g
• /nergy value if food can be measured through the use of either simple calorimeter or
• /ach day about *.;4<.9 litre of water is lost in the body through sweating$ excretion$
defecation and respiration.
• 5unctions of water includes,
a %olvent for various biochemical reactionsb +o transport hormones$ ingested food$ heat and gases.c !oolant that carries away heat to be eliminated.d Providing structure and supporte /ssential component of the blood$ digestive 2uices and lubricant in 2oints.
itamin ! 1!P@P test Percentage of itamin ! in fruit 2uice
=
!oncentration of itamin ! in fruit 2uice
=
6./ -A%NUTRITION
'. >alnutrition is failing health that results from not eating a balanced diet over a longperiod of time.
*. >alnutrition refers to,-a undernutrition, resulting from inade)uate consumption or excessive loss of nutrients-b overnutrition, resulting form overeating or excessive inta#e of specific nutrients
<. /ffects on malnutrition
-a Cwashior#or
• caused by protein deficiency
• symptoms,
-i swelling legs-ii underweight-iii ?moon face(-iv swollen abdomen-v thin muscles but fat present-vi dry$ sparse$ thin hair -vii apathetic$ little interest in his surrounding
-viiistunted growth
-b >arasmus
• caused by deficiency of energy and protein foods in children