introduction to nutrition the adventure of ingested food
DESCRIPTION
Introduction to Nutrition The Adventure of Ingested Food. To obtain nutrients in food!. • • • • • •. • • • •. ENERGY. Carbohydrates Proteins Lipids (fats) Water Vitamins Minerals. Survive Growth Physical activities Maintenance: - constant body temp. - biological processes. - PowerPoint PPT PresentationTRANSCRIPT
Introduction to NutritionThe Adventure of Ingested Food
To obtain nutrients in food!
ENERGY••••••
CarbohydratesProteinsLipids (fats)WaterVitaminsMinerals
••••
SurviveGrowthPhysical activitiesMaintenance:- constant body temp.- biological processes
Metabolism: chemical reactions that the body needs to perform in order to stay aliveThere are two (2) types of chemical processes:
Catabolism – breaking down of materials in an organism (e.g. digestion of food)Anabolism – building of large and complex molecules from simpler ones
Factors determine how much an animal needs to eat: Body size: larger body needs more energy to stay alive Physical activity: muscle burns more energy when activity is more rigorous Gender: males typically are larger in size &have greater amount of muscle mass Age: metabolic rate decrease with age (loss of muscle mass) Heredity factors: some individual have a naturally high metabolic rate
Basal metabolic rate: the minimum amount of energy required to keep you alive
Male:BMR = [66 + (13.7 x mass in kilograms)
+ (5 x height in centimeters)– (6.8 x age in years)] x 4.18
BMR = unit is kJ1000 calories (C) = 4180 J
Female:BMR = [655 + (9.6 x mass in kilograms)
+ (1.8 x height in centimeters)– (4.7 x age in years)] x 4.18
To account for the level of activity:a. Little or not exerciseb. Some (1-3 days/week)c. Moderate (3-5 days/week)
BMR x 1.2BMR x 1.375BMR x 1.55
2007 StatisticsCanada
2007 StatisticsCanada
Carbohydrates: are sugars and their derivatives (i.e. other forms of sugars) main source of energy of the human body made up carbon, hydrogen and oxygen three main types: monosaccharides, disaccharides & polysaccharides
Monosaccharides: are simple sugars examples include glucose, fructose, galactose the molecular formula is C6H12O6 the molecular structure is either linear or ring form
glucose
Disaccharides: when simple sugars pair up forming sugar derivatives examples include maltose, sucrose, lactose
glucose + glucose = maltose + H2Oglucose + fructose = sucrose + H2Oglucose + galactose = lactose + H2O
amylose (some branching)
Polysaccharides: are long chains of sugar units example include cellulose, amylose (starch), glycogen
cellulose – very long chain of glucose units, provide structure for plant cell wallsstarch – polysaccharides of mostly glucose units, store energy in plant cellsglycogen – polysaccharides of glucose units, store energy in animal cells
glycogen(highly branched)
cellulose(no branching)
Proteins: are chains of amino acids; they are variable in shape, size, function examples include hormones, organelles, hemoglobin, antibodies there are 20 amino acids from which proteins are built human body can make twelve (12) of these amino acids, so we need to
obtain the other eight (8) from food sources
Animal sources: meat, eggs, fish, cheesePlant sources: beans, lentils, seeds, nuts
molecular structure:
Peptide bond – H2O is created/released
Lipids: are concentrated source of chemical energy
functions: insulate the body, absorb vitamins, form cell membranescommon types of lipids are fats and oilsmolecular structure: glycerol + 3 fatty acids = triglyceridethere are two (2) forms of triglyceride: saturated and unsaturated
triglyceride
Saturated:single bonds = straight chainsolid at room temperature
Unsaturated:double bonds = kinksliquid at room temperaturehealthier
Bolus
ChymeChemical Digestion Absorption
Food
Ingestion
Mechanical Digestion(physical breakdown of food)• chewing (mouth)• churning (stomach)• segmentation (intestine)
Propulsion
• swallowing (oropharynx)• peristalsis (esophagus &
intestines)
Via blood vessels (capillaries)• nutrients, vitamins• water
FecesDefecation / Egestion
(chemical breakdown of food)• lipids, starches• large molecules• proteinsare broken down furtherinto tiny molecules by
enzymes & body chemicals
mouth
tongue
Mechanical breakdown of food:• teeth, tongue
Chemical breakdown of food:• saliva, amylase
oral cavity
salivary glands
Function of your teeth:••••
incisors: slicing & grippingcanines: ripping & tearingpremolars: bitting & tearingmolars: grinding
lipgingiva
caninesincisors
wisdomtooth
crown
root
enameldentin
premolars
molars
uvula
periodontal membrane
tongue
frenulum
Swallowed Food bolus
Peristalsis pushes the bolustowards the stomach via musclecontraction of the esophagus
mouth
tongue
oral cavity
pharynx
esophagus
oral cavity
pharynxmouth
tongue
gastric pitsesophagus
stomach
Gastric glandsecrete mucus &gastric juices todigest bolus
mouth
tongue
oral cavity
pharynx
esophagus
stomach
small intestine
large intestine
mouth
tongue
oral cavity
pharynx
esophagus
stomach
small intestine
large intestine
anusrectum
oral cavity
pharynx
esophagus
stomach
small intestinelarge intestine
anusrectum
mouth
tongue
livergall bladder
Liver secretes bile• bile digest fat
commonbile duct
mouth
tongue
oral cavity
pharynx
esophagus
anus
livergall bladder
pancreas
rectum
stomachspleen
small intestine
large intestine
Pancreas- digest large molecules,- neutralize stomach acid
Spleen- removes old RBC- stores WBC that guardagainst invaders