Exam 2 Flashcards
Essential Amino Acids
Body can’t make on its own
Has to be gotten through the diet
9 out of 20 a.a.’s are essential
Provide a source of nitrogen for other compounds
Nonessential Amino Acids
Body can make
But can still be gotten through diet
11 out of 20 a.a.’s are nonessential
Provide a source of nitrogen for other compounds
Structure of amino acid
1) amine group:
always has a nitrogen
2) carbon skeleton:
central carbon with hydrogen(backbone), acid group, r-group(sidechain)
Function of a.a. r-group
1) differentiates one a.a. from another
2) determines the structure
3) determines the function of the a.a.
Some a.a.’s have similar r-groups which affects where they are absorbed
Dipeptide
2 a.a.’s linked together
Polypeptide
many a.a.’s linked together
Denaturation
straightening or uncoiling protein so the enzymes can get in and break apart the bonds
Transamination
transfer of an amine group (nitrogen group) to the carbon skeleton to form a different nonessential a.a.
Deamination
removal of the amine group from an a.a.
Could create glucose with C, H, O (if no carbs available)
Nitrogen excretion
Nitrogen goes to liver where it is converted to urea and sent to kidneys to be excreted
Complete protein
all 9 essential a.a.’s in the optimal ratios
Ex: meat, dairy, seafood
Incomplete protein
missing or has a low amount of one or more essential a.a.’s
Ex: nuts, grains, vegetables, beans
Complementary protein
combining 2 incomplete proteins to get all 9 essential a.a.’s
Ex: beans and rice
Animal protein vs plant protein
Animal protein:
more saturated fat and calories, less fiber
Plant protein:
less saturated fat and calories, more fiber
Kwashiorkor (protein malnutrition)
getting calories (mainly carb) but not protein Ex: child in third world country that relies on rice impaired growth, mental retardation, impaired immune system, edema, intestinal malabsorption
Edema
swelling due to lack of protein
Protein pulls fluid back into the blood
Marmasmus (protein-energy malnutrition)
not getting calories (they’re starving)
Ex: starving child in third world country or anorexic child in U.S.
Also deficient in all other nutrients
Vitamin B6
1) Water soluble
2) Functions in a.a. metabolism, heme synthesis (RBC, hemoglobin)
3) Deficiency symptoms: anemia (deficiency is rare)
4) Dietary sources: meat, fish, poultry, nuts, potatoes, green vegetables, purple fruits, bananas
Anabolism
Building body compounds
Ex: making muscle, gaining fat
Catabolism
Break down the basic building units for energy and excretion
Ex: breaking down fat/muscle for energy (losing weight)
Glucose
only carb we get energy from
six carbons
Vitamin B1 (thiamin)
1) Water soluble
2) Coenzyme (works with an enzyme) for energy metabolism/plays a role in metabolism or neurotransmitter
3) Deficiency symptoms: Beriberi, dementia and amnesia, weakness
Alcoholics are at high risk for deficiency
4) Dietary sources: whole grains, enriched grains, green leafy vegetables, legumes, pork
Water soluble vitamins
sensitive to light, air and heat
1) B1, B2, B6, niacin, biotin, C
Vitamin B2 (riboflavin)
1) Water soluble
2) transfer of energy to ATP
3) Deficiency symptoms: weakness, dry skin
4) Dietary sources: enriched flour products, milk, green leafy vegetables
Very sensitive to light (can be lost in glass milk bottles)
Niacin
1) Water soluble
2) transfer of energy from ATP, formation of fatty acids
3) Deficiency symptoms: Pellagra (4 D’s)-dermatitis, diarrhea, dementia, death
4) Dietary sources: whole grains, enriched flour/grains, protein with tryptophan
Pantothenate
Pan=everywhere Found in almost all foods 1) Water soluble 2) aerobic energy metabolism 3) Deficiency symptoms: weakness 4) Dietary sources: whole grains, meat, milk
Biotin
1) Water soluble
2) energy metabolism
3) Deficiency symptoms: weakness
4) Dietary sources: meat, milk, egg yolks, nuts
Groups at risk=people that eat a lot of raw egg whites
Chromium
1) Trace mineral
2) enhances ability of insulin to move glucose from blood into cells (works with insulin to move glucose out of blood)
3) Deficiency symptoms: rise in blood glucose levels
4) Dietary sources: whole grains, mushrooms, nuts, cereals
Iodine
1) Trace mineral
2) synthesis of thyroid hormones (regulate body temperature and metabolic rate)
3) Deficiency symptoms: goiter
4) Dietary sources: iodized salt, seafood, dairy foods, some vegetables (depending on soil content)
Groups at risk=lack of iodized salt intake, people who live in places with low iodine content (in the soil)
Basal metabolic rate
calories your body burns to keep you alive
Ex: heartbeat, kidney filtering waste
The more muscle you have, the higher your metabolic rate
60-75% of total energy expenditure
Physical activity
we have the most control over this
15-35% of the total energy expenditure
Thermic effect of food (TEF)
About 100 calories/day
Energy costs associated with digestion, absorption, and metabolism of food
5-10% of daily energy expenditure
Android
Apple shape
Lots of visceral fat
More common in men
Gynecoid
Pear shape
Excess hip/femoral fat
More common in women
Harder to lose
Measures of body fat (technology)
1) skinfold measurements
2) under water weighing (hydrostatic)
3) BOD POD (air displacement)
4) bioelectric impedance
5) dual-energy x-ray absorptiometry (DXA)
Thrifty gene theory
hypothesis suggesting that some people have a gene that causes them to be energetically thrifty (thrifty gene) and expend less energy at rest and during physical activity
Set-point
each person is “programmed” to weigh a certain amount of to have a particular level of body fat
Body fat
the number of fat cells times the amount of fat in fat cell
Energy regulating hormones (hunger hormones)
1) Leptin-made by fat cells, decreases appetite
2) Ghrelin-made in stomach (is a protein that acts as a hormone), stimulates appetite
What is the energy deficit to lose 1 lb/week
500kcal/day
Xenical
limits fat absorption by inhibiting the release of fat digesting enzyme
Neoplasm
new growth
Benign neoplasm
Pose no problems (except locally)
Cells adhere to one another
Do not invade into other tissues
Malignant neoplasm
Cancerous
Resists treatment
Harmful cells don’t adhere, they invade surrounding tissue
Carcinogen
Initiators
Cancer causing substance (initiates cancer)
Promoter
increases cell division, does not cause cancer
Dietary fiber
Anti-promoter and anti-carcinogen
Fiber dilutes things and keeps them moving through the GI tract to be excreted
Antioxidants
Vitamins A, C, E
beta-carotene and selenium
Donate an electron to free radicals and neutralizes them
Phytochemicals
Act as antioxidants
NOT NUTRIENTS
Free radical
A molecule that is missing an electron
They bounce around the body looking for another electron and can damage cell DNA (and LDL) causing cancer long term
Oxidation produces free radicals
Vitamin C (ascorbic acid)
1) Water soluble
2) immune functions, collagen formation, increases iron absorption
3) protects the lungs, LDL cholesterol, regenerates vitamin E
4) Deficiency symptoms: scurvy
5) Dietary sources: citrus fruits, tomato, dark green vegetables
Groups at risk=smokers, alcoholics, physical stress
Easily destroyed by air and heat
Vitamin E
1) Lipid soluble
2) Protects cell membrane
3) Deficiency symptoms: anemia (fragile RBCs)
4) Dietary source: plant oils
Groups at risk (same for all fat soluble vitamins): preterm infants, people eating little fat, people with fat malabsorption
Vitamin A
1) Lipid soluble
2) Vision-especially night vision
Plays a role in the cells surrounding the eye and create moisture and mucus to keep the eye from drying out
3) Deficiency symptoms: night blindness, Xeropthalmia (disintegration/drying out of eye)
Stored in liver
VISION
Beta-carotene
Phytochemical
Can be converted into inactive form of vitamin A
Osteoblasts
build bones
Osteoclasts
chew away at bone tissue
Bone turnover
Build bone density in first 30 years of life
34-45yrs bone density stays the same
Over 45 yrs-start to lose bone density
After menopause-estrogen levels drop, bone density decreases at a higher rate
Blood calcium
If not enough in blood (from diet) we get it from the breaking down bones
Functions requiring blood calcium: nerve transmission, muscle contraction, blood clotting, vascular control (blood pressure)
Osteoporosis
Loss of bone mineral and protein
Hard but very brittle bone tissue that breaks easily
Fluoride
1) Water soluble
2) Health of teeth
3) Found in drinking water (not bottled water) and toothpaste
Vitamin D
Produced by body when exposed to sunlight
1) Lipid soluble
2) Acts as a hormone-enhances calcium levels
3) Deficiency symptoms: rickets-bones aren’t strong enough to hold up body weight so they bow
CALCIUM
Osteomalacia
soft bones
not the same as osteoporosis
osteo=bone, malacia=soft
Lipid soluble vitamins
A, D, E
