Nutrition exam #2

• *Transport fats:
• -carry fat-soluble vitamins: A, D, E, K along w. some phytochemicals & assist in their absorption
• *emergency reserves
• *maintain body temperature (padding)
• *muscle fuel

• *High Density Lipoproteins:
• -BAD cholesterol
• -primarily composed of protein
• -transport cholesterol from the cells to the liver for recycling or disposal
• -produced in the liver

• *Low Density Lipoproteins:
• -GOOD cholesterol
• -composed primarily of cholesterol
• -transport lipids to the tissues
• -carries lipids from liver into periphery & is readily available to cells
• -produced in the liver

• Very Low Density Lipoproteins:
• -composed primarily of triglycerides
• -produced in the liver
• -transport lipids to the tissues
• -get smaller and more dense as the triglycerides are removed (more protein= more dense)

• Chylomicrons:
• -made in the gut by villi into the lymphatic system to the thoracic duct, blood then carries these lipids to the rest of the body
• -represent food fat
• -only present after a meal is consumed
• -largest of the lipoproteins (least dense)

• BEST WAY to raise HDL is regular aerobic exercise
• -ideally for 30 mins

BEST WAY to lower LDL is a diet low in saturated fats

• -an organic ester consisting of 1 molecule of glycerol combined w. 3 molecules of fatty acids
• -98% of lipids in nature, food and the body are in this form
• -classified according to fatty acid characteristics

• -carbons contain all the H they can hold (no double bonds are between the carbon atoms
• -solid at room temperature
• *found in ANIMAL PRODUCTS (butter, eggs, milk, cheese, meat, and tropical oils, coconut, palm kernel and palm)
• ex: butyric, myristic, palmitic, stearic

** Increase blood cholestrol levels!!

• -Carbons are missing 2 hydrogen atoms (one double bond is present)
• -liquid at room temp
• -found in nuts, avocados, olive oil, peanut oil, canola oil
• -ex: oleic acid

*Lowers blood cholesterol

• -Carbons are missing 4 or more hydrogen atoms (two or more double bonds are present)
• -Liquid at room temperature
• -found in sunflowers, safflower, soybean, corn, cottonseed oils

• -contains glycerol and 2 fatty acids, plus a phosphate group and an "other molecule
• -has both fat and water soluble components
• -liver readily synthesizes these so they are not essential

• 3 types:
• -cephalin: in brain
• -sphingomyelin: in myelin sheath of neurons
• -lecithin: in cell membranes, in lipoproteins, serves as an emulsifier
• *needed for the absorption of fats and transport in blood;
• food sources: eggs, liver, soybeans, wheat germ, and supplements

• -most famous sterol
• -an alcohol of high molecular weight, having a complex ring structure, found free or esterified with fatty acids
• -synthesized by the liver and intestinal cells to meet body needs,
• *NOT ESSENTIAL
• -component of all cell membranes
• -precursor of vitamin D
• -precursor of hormones (adrenal & sex)
• *Food sources of cholesterol include ANIMAL products only
• *elevated serum cholesterol levels are a major risk factor for CVD

• -merged from monoglycerides and long chain fatty acids
• -has protein in the coating that allows these fats to cross the villous membrane
• -once in the villi the monoglycerides and long fatty acids are reassembled into triglycerides

Dietary saturated fats

• Total Fat: <30% kcal
• Saturated Fat: <10% kcal
• Monounsaturated Fat: <10%
• Polyunsaturated Fat: <10%
• Cholesterol: less than 300 mg
• * 1 egg (yolk)

-Needed by the body but are not made in sufficient amounts to meet physiological needs

• 2 Types:
• -linoleic acid (omega 3)
• -linolenic acid (omega 6)

less than 300 mg

*1 egg (yolk) has more than the needed cholestrol levels

• *precursor to:
• -Vitamin D
• -hormones (adrenal & sex)

• -a slow, progressive condition of thickening and hardening of the arteries
• -when the arteries that carry blood to the heart become blocked, the heart suffers damage known as Coronary Heart Disease (CHD)

*Fatty streaks- in the arteries are the first signs of atherolsclerosis- seen in teens

*Fibrous Plaque- occurs in response to artery wall injury

*forms in the inner arterial wall reducing blood flow

• plaque forms from:
• -diet high in saturated fat (major contributor)
• -inflammation of the artery wall
• from:
• -high LDL cholestrol
• -Hypertension
• -toxins from cigarette smoking
• -high blood levels of homocysteine
• -certain viral or bacterial infections

chest pain

Coronary Heart Disease

-when the arteries that carry blood to the heart become blocked, the heart suffers this damage


*falls under the umbrella of CVD (cardiovascular disease)

• Myocardial Infarction
• -when arteries are blocked in the heart

• Cerebrovascular accident
• -when the arteries are blocked in the heart

• -elevated serum cholestrol (blood cholestrol)
• -hypertension
• -cigarette smoking

• men:
• -left chest pain
• *will develop in 40's

• women:
• -nausea
• -lower back pain
• -indegestion
• -not feeling well overall
• *will develop in 50's
• **protected by estrogen
• -will begin development of CHD after menopause

• *switch to skim milk
• *trim visible fat from meals
• *remove skin from poultry
• *eat more poultry and fish instead of red meat
• *eat more meatless meals
• *low fat cooking techniques

*high polyunsaturated fat can promote cancer growth (omega 6)

*Fatty acids from fish may protect against some cancers and may support recovery during treatment for cancer (omega 3)

• *process by which hydrogens are added to monounsaturated or polyunsaturated fats to reduce the number of double bonds
• *makes the fat more spreadable and resistant to oxidation.
• -in this process the fat becomes more saturated and trans fatty acids are produced

*hydrogenation decreases PUFA, and increases MUFA, SFA and trans fatty acids

• PROBLEMS:
• *we force hydrogen into the molecules to make fats more spreadable
• -resistant to oxidation (dont break down readily)
• -can become a problem

bile emulsifies the fat so that the process of fat digestion can take place

• *contain plant sterols that decrease intestinal absorption and increases fecal excretion of cholesterol
• *OVERALL LOWER CHOLESTEROL

found in margarines, mayonnaise, salad dressings, and cream cheese type spread

*products are safe, FDA approved, and well tolerated

• Simplesse
• -protein base artificial fat used in frozen desserts (cant heat)
• -comes from skim milk protein
• -fat free foods may contain more sugar which still contain high amounts of calories

• Olestra
• an artificial fat that the body cant digest or absorb
• -so complex that it is consumed and leaves the body in one piece (unchanged)
• -not absorbed at all

• CONS:
• -vitamin losses
• -phytochemical loss
• -possible anal leakage

• *stay away from ingredients that are hydrogenated or contain saturated/trans fats
• -liquid must be listed as first ingredient
• ex: whipped, bottled, spray butter

• *central body fat stores
• -drives a lot of hormones
• -a person with more fat cells is more likely to gain excess weight leading to many types of cancer and heart disease

• our body makes the needed amount already so it is unnecessary to buy dietary supplements
• -found in cell membranes, in lipoproteins, serves as an emulsifier, surfactant in lungs, needed for the absorption of fats and transport in blood

Food sources: eggs, liver, soybeans, wheat germ, and supplements

• MOUTH:
• -lingual lipase is present for fat digestion
• -this enzyme is only significant for infants where it digests the short and medium chain fatty acids found in milk

• STOMACH:
• -gastric lipase is present
• -it accesses and hydrolyzes a very small amount of fat

• SMALL INTESTINE:
• -fat in the small intestine signals the release of CCK which causes the gallbladder to contract and release bile into the small intestine
• -bile emulsifies the fat so that the process of fat digestion can take place

• *fat digestion takes place due to pancreatic lipase and intestinal lipase
• *triglycerides are broken down into fatty acids, glycerol, and monoglycerides

*glycerol (short, 2-4 carbons) are absorbed directly into the capillaries of the villi

• *monoglycerides and long chain fatty acids emerge into Michelles which has protein in the coating (that allows these fats to cross the villi membrane)
• -once inside the villi, the monoglycerides & long-chain fatty acids are reassembled into TG

*contains: C, H, O as well as Nitrogen & usually Sulfur

*an amino acid that is required by animals but that they cannot synthesize; must be supplied in the diet

• 9 Essential Amino Acids:
• -isoleucine
• -leucine
• -valine
• -theronine
• -lysine
• -tryptophan
• -phenylalanine
• -methonine
• -histidine

an essential amino acid supplied in less than the amount needed to support protein synthesis

• 4 Limiting amino acids:
• *lysine
• *methionine
• *threonine
• *tryptophan

Phenylketonuria

• -inborn error of metabolism (genetic disorder)
• -1 in 2500 live births
• -lacking enzyme phenylalanine hydroxlyase which is needed to convert phe to tyrosine
• -need to restrict phe and supplement tyrosine
• *diet for life!

w.out phenylalanine hydroxylase, tyrosine becomes conditionally essential

• Essential a.a. when PKU is present:
• -taurine
• -cysteine
• -tyrosine

• *contain all 9 essential aa in the correct proportions to support life and growth
• -fish
• -eggs
• -beef (MEAT!)
• -milk
• -cheese
• -soy

*are lacking one or more of the essential a.a.

• -nuts
• -legumes
• -seeds
• -vegetables
• -grain

*PLANT PROTEINS!

apart of protein synthesis

• *process of removal of the amino group (NH2)
• *occurs in the liver, where the amino groups are converted to urea
• -urea is then excreted by the kidneys in the form of urine

• wt. in lbs
• 2.2 lb/kg

ex:

• 140 lbs
• 2.2 = 63.63 kg

63.63 kg x 0.8 gm pro/kg = 50.90 gm protein

7 gms of protein per exchange

• *Building materials for growth and maintenance
• -a matrix of collagen is filled w. minerals to provide strength to bones and teeth
• -replaces tissues including skin, nails, hair, and GI tract lining

• *Enzymes:
• -are proteins that facilitate anabolic (building up) and catabolic (breaking down) chemical reactions

• *Hormones:
• -regulate body processes and some hormones are proteins
• Ex: Insulin or Glucagon

• *Regulators of fluid balance
• -plasma proteins attract water
• -maintain the volume of body fluids to prevent edema (which is excessive fluid)
• -maintain the composition of body fluids

• *acid/base regulators:
• -act as buffers by keeping solutions acidic or alkaline

• *Transporters
• -carry lipids, vitamins, minerals and oxygen in the body
• -act as pumps in cell membranes

• *Antibodies
• -fight antigens such as bacteria and viruses that invade the body

*Source of energy and glucose (IF NEEDED)

• *Blood clotting
• *Vision
• -opsin:protein needed in eyes

• *enlarged liver and kidneys (possible kidney disfunction later in life)
• *depletion of vitamin B6
• *loss of zincfrom tissues in urine
• *promotes calcium excretion
• *protein foods are high in fat

• -excess protein is NOT stored
• -deamination (in liver)
• -urea is sent to kidneys
• -vitamin B6 is used to make different unessential amino acids

• -many reasons for supplements
• -protein powders have not been found to improve athletic performance
• -whey protein is a waste product of cheese manufacturing
• -purified protein preparations increase the work of the kidneys

DAIRY PRODUCTS (eggs) are good protein supplements!

• AMINO ACID SUPPLEMENTS:
• -are NOT beneficial and can be harmful
• -branched amino acids provide little fuel and can be toxic to the brain
• -lysine appears safe in certain doses
• -tryptophan has been used experimentally for sleep and pain, but may result in a rare blood disorder

• ***MOST INDIVIDUALS DO NOT NEED PROTEIN SUPPLEMENTS!
• -we get protein by foods

eats dairy products and eggs, but no animal flesh

eats dairy products but no eggs or animal flesh

eats eggs but no dairy products or animal flesh

eats no animal flesh and no animal products

eats fruits, nuts, seeds, and sometimes honey

• -Lack of availability
• *many people dont choose to be vegetarian (dont have access)
• -religious reasons
• -ethical reasons
• -ecological reasons
• *1 acre of wheat feeds 15 people
• *1 acre of rice feeds 24 people
• *10 acres/one cow feeds 1 person

• Staples of a vegan diet
• *putting two incomplete protein foods together at the same time to get a complete protein

• -grains
• -legumes
• -nuts
• -seeds
• -vegetables
• -fruits

• Ex:
• -Beans and rice
• -hummus and bread
• -corn and black eyed peas
• -butgur and lentils
• -tofu and rice
• -corn and lima beans
• -tortilla and refried beans
• -pea soup and bread

• *Vitamin B12
• -comes only in animal products
• -deficiency shows in long term
• presents: anemia, breakdown of mylein sheaths (nervous system)
• ** MUST TAKE A SUPPLEMENT OR FORTIFIED FOOD!

• *Vitamin D:
• -dairy products

• *Calcium
• -soy products dont have alot of these

• -objective of these methods is to identify high-quality proteins
• *easily digestible and contain all essential amino acids in correct proportions!

** Support life and growth

protein synthesis is limited depending on which amino acids are present/lacking


-protein syntheis is unique for each human being and is determined by the amino acid sequence

• -is a reflection of protein status (protein is 16% N)
• -normal, healthy individuals are N Balance (zero N balance or equilibrium)
• -N intake (protein in foods)= N output (urinary and fecal excretion)

• *determined by calculating nitrogen intake- nitrogen output

• -N intake (protein in foods) is greater than N output (urinary and fecal excretion)
• -signifies growth and repair of body tissue
• -ex:
• *infants
• *pregnancy (to grow fetus)
• *tissue repair/recovery (wound healing)
• *all developments of growth

TO MAKE BODY MORE POSITIVE GIVE MORE NITROGEN!

• -N intake (protein in foods) is less than N output (urinary and fecal excretion)
• -signifies tissue wasting
• -Ex:
• *Cancer
• *HIV/AIDS
• *Elderly
• *muscle atrophy (bed ridden, wheel chairs, etc)
• *catabolic state (wasting away)

• Kwashirokor:
• -protein deficiency
• "the evil spirit that infects the first child when the second child is born"
• -baby is weaned off breast milk and forced to eat watery cereal
• -can take about a week (rapid onset)
• *REVERSIBLE

• Marasmus:
• -severe calorie deficiency
• *STARVATION
• *become VERY obsessed w. food
• *slow onset
• *reversible (slowly!)

• *Kwashiorkor:
• -older infants and young children (18 months to 2 years of age)
• -some muscle wasting, some fat retention
• -growth is 60-80% weight for age
• -edema and fatty liver
• -apathy, misery, irritability and sadness
• -loss of appetite
• -hair and skin problems

• Marasmus:
• -infancy (6 to 18 months of age)
• -severe deprivation or impaired absorption of protein, energy, vitamins and minerals
• -develops slowly
• -severe weight loss and muscle wasting, including the heart
• -<60% weight for age
• -anxiety and sympathy
• -good appetite is possible
• -hair and skin problems

• STOMACH:
• -HCl denatures protein and activates pepsinogen to pepsin
• (activate pepsin when needing to break down protein in stomach)
• -Pepsin breaks down large polypeptides to smaller polypeptides and some amino acids

• SMALL INTESTINE:
• -pancreatic and small intestinal enzymes hydrolyze polypeptides to short peptide chains, tripeptides, dipeptides, and amino acids
• -enteropeptidase converts pancreatic trypsinogen to trypsin.
• -Trypsin cleaves peptide bonds next to the amino acids lysine and arginine, converts pancreatic chymotrypsinogen to chymotrypsin, and converts pancreatic procarbboxypeptidases to carboxypeptidases

• PROTEASE ENZYMES:
• Chymotrypsin:
• -Cleaves peptide bonds next to the amino acids- phenylalanine, tyrosine, tryptophan, methionine, asparagine, and histidine
• Carboxypeptidases:
• -Cleave amino acids from the carboxyl end of peptides

• *Aminopeptidases and tripeptidases on the surface of the intestinal mucosa cleave the remaining peptides to amino acids
• -amino acids are absorbed through villi into the circulatory system

• *small head size
• *narrow, receding forehead
• *short, upturned nose
• *flattened nose bridge
• *underdeveloped jaw
• *receding chin
• *receding or flattened upper jaw
• *extra skins folds on eyelids
• *drooping eyes/downward slant of eyes
• *shortsidedness
• *uneven ears in placement and size
• *poorly formed outer ear
• *absence of growth in upper lip, flat upper lip
• *thin lower lip

• *Thiamin (Vitamin B1)
• -needed for metabolism of alcohol (tpp-coenzyme)
• -needed for normal nervous function
• (can lead to brain encephalopathy near the end of heavy drinking)

• *Magnesium
• -needed for nervous function/stimulation

• *deficiency in both:
• -will develop uncontrollable shaking if lacking both enzymes!! DT's (Delerium Tremens)

• *B1
• *Magnesium

• *alcohol does damage indirectly via malnutrition
• -not likely a person will eat enough food if they drink alot
• -provides empty calories
• -disrupts tissue's metabolism of nutrients
• -wernicke-korsakoff syndrome- thiamin deficiency
• -pellagra, beriberi, scurvy, protein-energy malnutrition

• *no more than 1 drinks a day for the average woman
• (have lower body weight & LDH levels)
• *no more than 2 drinks a day for the average male

**tolerance differs among individuals

• *Alcohol Dehydrogenase (ADH)
• -removes hydrogens
• -handles about 80 percent of alcohol
• *RATE LIMITING ENZYME

• *Microsomal Ethanol Oxidizing System (MEOS)
• -a group of enzymes that handles about 10 percent of alcohol

** people who drink a lot have a different metabolizing system

• METABOLISM:
• -physical and chemical changes that take place within cells

• ANABOLISM:
• -synthesis of complex molecules from simpler compounds
• -formation of enzymes, hormones, tissue protein, glycogen, fats
• -requires ATP

• CATABOLISM:
• -breaking down of complex molecules to simpler compounds to generate ATP

• new glucose being created from noncarb source
• -mainly being glycerol from triglycerides

making glycogen during fasting when body needs it

breakdown of glycogen into glucose

when there are too many fats it will package fats into storage in tissues

• creating ketones when glucose is lacking as an energy source
• -when carbs are lacking

• glucose ---> pyruvate (2 pyruvates)
• under anerobic conditions