64 terms

Nutri Sci 132 Exam 1

Study of the flow of nutrients and energy through the environment
Essential nutrients
Necessary, but must be taken into body, can't be synthesized
Most essential nutrient; forms cells, cools us, flushes wastes, dissolves chemicals,
Needed in large quantities-Carbs, fats, and protein
CHO-supplies energy, powers mvmt and nervous activity, brain can use it,
Simple carbs
Sugars-rapidly absorb in bloodstream
Complex carbs
Starch and Fiber- made of sugar polymers; provides long-lasting energy, less difficult for blood sugar regulation
Burned for energy in low intensity exercise (cals), most energy dense nutrient
Forms dry wt of body, forms muscles, CT, bones, & skin
Functions of Nutrients
Structure, Energy, Regulates Metabolism, Fluid Balance, & Acid/Base Balance
Process of releasing energy from food, converting substance into other substances, and preparing end products for excretion; Sum of all biochemical reactions in the body
The energy required to raise the temp of 1 g water, 1 degree centigrade
Carbs, Fats, and Proteins energy values
Carb=4 kcal/g; Fats=9 kcal/g; Proteins=4 kcal/g
Needed in small quantities; Prevent deficiencies; Aid in optimal functioning- vitamins and minerals
Phytochemicals and Alcohol
Chemicals made by plants which have physiological effect on body, and may be important in chronic disease prevention
Structure function of nutrients
Water: Cell rigidity; Lipids: Cell membranes; Proteins: muscles, CT, skin, organs; Minerals: bones and teeth
Energy function of nutrients
Provides fuel, calories are fuel
Metabolism regulation by nutrients
Synthesizes body tissue, hormones, proteins, and other substances-Enzymes are catalysts; Release of energy from nutrients-vitamins and minerals serve as cofactors
Fluid balance by nutrients
Sodium, Potassium, and Proteins maintain balance
Acid/Base balance by nutrients
Proteins and minerals maintain acid/base
Nutrient Density
Ratio of a food's nutrient composition to its energy value (low cal=low density)
Anecdotal Evidence
Personal experiences that help generate questions that may lead to a hypothesis.
Scientific Method
Question, Hypothesis, Experiment, Evaluate
Epidemiological study
Natural study that proves correlation not cause
Animal Studies
Interventional study; Experimental and control group, fast, cheap, may not generalize to humans
Human Studies
Interventional study; Experimental and control groups, expensive, long time, difficult control
Case-control studies
Compare those with condition vs. those without
Double-blind studies
Researchers and control group do not know who receives treatment vs. who receives placebo
Food Guide Pyramid
Created by USDA to emphasize proportionality;• Greatest proportion to least: grains, veges, fruits, dairy, meat/beans, fats
3 leading causes of death in U.S.
Heart disease, cancer, and stroke-have strong nutritional components
Dietary Guidelines for Americans
1-Adequate nutrients within caloric needs; 2-Weight mgmt.; 3-Physical activity; 4-Encourage certain food groups (fruits/veges, whole grains, milk); 5- Limit fat intake (20-35% of cals); 6- Eat carbs often; 7-Eat Potassium rich foods, limit Na intake; 8-Drink alcohol sensibly and moderately; 9-Food safety
Requirements on food labels
Total kcals, Kcals from fat, total fat, sat. fat, cholesterol, Na, total carbs, dietary fiber, sugars, portein, vit A and C, Calcium and iron
First type of diets- hunt animals, fish, forage, subsistence farmers, pastoralists; Ex- Inuits of Alaska, Plains Indians
Generate their own foods from planting
Industrial Revolution
Processed food became abundant
Main differences between traditional and modern diets
Today's diet has more fat, more refined sugar, less starch and less fiber
Food security in past
There was food, but frequent shortages occurred, caused our bodies to store fat and slow metab in shortage
Diseases of poverty
Like ancient diets- nutritional deficiencies and infectious disease
Diseases of affluence
Modern diets- nutritional excess and chronic disease
4 functions of digestion
Motility, secretion, digestion, and absorption
Small intestine
10 ft long, includes duodenum, ilium and jejunum; peristalsis; segmentation (ton of water used); Microvilli and villi for absorption
Churning-mix/break down food; secretes HCl (has mucus barrier); Reservoir for slow release of food into SI
Creates bile (an emulsfier of fat), which is stored in gall bladder
Neutralizes acids, enzymes for chemical reactions to break down stuff
Pushes food from throat to stomach using peristalsis
Large Intestine (colon)
Mucosa further breaks down sugars with disaccharides (sucrose/lactase); Water reabsorption
Reservoir for elimination
Villi draining system
1: Portal system (directly to liver)-proteins, carbs, small fats, water solubles; 2: lymphatic system- fatty acids
Functions of Water
50-60% body wt., 1: Solvent for chem reactions, 2: Dissolve solute particles, 3: Maintain acid-base balance, 4: Hydrolysis of large molecules, 5: Transport, 6: Lubrication, 7: Temp regulation
Passive transfer of water across a semipermeable membrane
Increase water excretion
# of oz in a cup?
8 oz
# of cups in a pint
2 cups (16 oz)
# of cups in quart
4 cups (32 oz)
Produces carbs: 6CO2+6H2O+sun--->C6H12O6+6O2
Glucose function
Major blood sugar, supplies energy to body (RBC and brain); Building block of body
Glucose regulation
1-Breakdown liver glycogyn to glucose; 2-Gluconeogenesis (glucose from a.a.); 3-Exercise; 4-Hormonal control (glucogen triggers glycogen, insulin drives glucose into cells
Glucose, Galactose, Fructose
Sucrose (glucose+fructose); Maltose (glucose+glucose); Lactose (glucose+galactose)
Raffrinose and Stachynose
Complex carbs, Fibers, Starches- Amylose and Amylopeptin; Glycogen (storage form)
Insoluble fiber
Cellulose, Hemicellulose; Whole grains, seedy fruits, veges; stim peristalsis, prevent constipation, increase bulk
Soluble fiber
Pectin, Guar gum, Carrageham; grains legumes fruits; decrease blood cholesterol, increase excretion