-
Describe the function of fats
- *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
-
Differentiate between the various types of proteins:
-HDL
-LDL
-VLDL
-Chylomicrons
- *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)
-
Describe effective ways to raise HDL's and lower LDL's
- 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
-
Describe triglyceride
- -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
-
Describe Saturated Fat
- -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!!
-
Describe Monounsaturated Fat
- -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
-
Polyunsaturated Fat
- -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
-
Describe Phospholipid
- -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
-
Define Cholesterol
- -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
-
Define Michelle
- -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
-
Describe food sources for each of the types of dietary fats
-
Which food factor is the most influential in raising blood cholesterol?
Dietary saturated fats
-
Dietary guideline recommendations for:
-Total Fat
-Saturated Fat
-Monounsaturated Fat
-Polyunsaturated Fat
-Cholestrol
- Total Fat: <30% kcal
- Saturated Fat: <10% kcal
- Monounsaturated Fat: <10%
- Polyunsaturated Fat: <10%
- Cholesterol: less than 300 mg
- * 1 egg (yolk)
-
Define Essential Fatty Acid
-name 2 essential fatty acids
-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)
-
Describe the desirable blood cholesterol levels
less than 300 mg
*1 egg (yolk) has more than the needed cholestrol levels
-
Name the compounds that cholestrol is a precursor to
- *precursor to:
- -Vitamin D
- -hormones (adrenal & sex)
-
Define Atherolsclerosis
- -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
-
Define Plaque
*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
-
-
Define CHD
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)
-
Define MI
- Myocardial Infarction
- -when arteries are blocked in the heart
-
Define CVA
- Cerebrovascular accident
- -when the arteries are blocked in the heart
-
Risk factors for the development of CHD
- -elevated serum cholestrol (blood cholestrol)
- -hypertension
- -cigarette smoking
-
Compare & Contrast the development of CHD in men vs. women
- 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
-
Describe specific ways to lower fat intake
- *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
-
Describe the role that dietary fat plays in the development of cancer
*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)
-
Describe hydrogenation
-what are the problems associated w. the consumption of trans fatty acids?
- *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
-
Identify the function of bile in fat digestion
bile emulsifies the fat so that the process of fat digestion can take place
-
List the active ingredient in Benecol and Take control
-health benefits associated with these products?
- *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
-
Describe Olestra and Simplesse
-what are the potential problems associated with their use?
- 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
-
Describe the characteristics of margarine that decrease the risk of CHD
- *stay away from ingredients that are hydrogenated or contain saturated/trans fats
- -liquid must be listed as first ingredient
- ex: whipped, bottled, spray butter
-
Describe the type of obesity that increases the risk of many types of cancer and heart disease
- *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
-
Explain why lecithin need not be taken as a dietary supplement
- 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
-
Describe fat absorption, transport, and storage (metabolism)
*mouth, stomach
- 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
-
Describe fat absorption, transport, and storage (metabolism)
*small intestine, large intestine
- 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
-
Name the elements found in proteins, but not in CHO or lipids
*contains: C, H, O as well as Nitrogen & usually Sulfur
-
Define essential amino acids
*name the 9 essential amino acids
*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
-
Define limiting amino acid
-name the 4 common limiting amino acids
an essential amino acid supplied in less than the amount needed to support protein synthesis
- 4 Limiting amino acids:
- *lysine
- *methionine
- *threonine
- *tryptophan
-
Define PKU
-identify which amino acids become conditionally essential when PKU is present
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
-
give examples of food sources for complete proteins
- *contain all 9 essential aa in the correct proportions to support life and growth
- -fish
- -eggs
- -beef (MEAT!)
- -milk
- -cheese
- -soy
-
give examples of food sources for incomplete proteins
*are lacking one or more of the essential a.a.
-legumes- -seeds
- -vegetables
- -grain
*PLANT PROTEINS!
-
Define foods with no protein
-
Define Deamination
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
-
-
-
Calculate an individual's RDA for protein, following the formula given in class
ex:
63.63 kg x 0.8 gm pro/kg = 50.90 gm protein
-
Calculate the gms of protein in a menu using the diabetic exchanges
7 gms of protein per exchange
-
Identify the functions of proteins
- *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
-
Describe problems associated with high protein diets
- *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
-
identify problems associated with protein or amino acid supplements
- -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
-
Define lacto-ovo vegetarians
eats dairy products and eggs, but no animal flesh
-
Define Lacto vegetarians
eats dairy products but no eggs or animal flesh
-
Define Ovo vegetarians
eats eggs but no dairy products or animal flesh
-
Define vegan
eats no animal flesh and no animal products
-
Define fruitarian
eats fruits, nuts, seeds, and sometimes honey
-
Describe the reasons why someone may become vegetarian
- -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
-
Define protein complementation or mutual supplementation
- 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
-
identify nutritnts that may be lacking in the strict vegetarian diet
- *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
-
Describe methods of assessing protein quality
- -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
-
explain what happens to protein synthesis when an amino acid is lacking
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
-
Define and give examples of Nitrogen Balance
- -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
-
Define and give examples of Positive N Balance
- -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!
-
Define and give examples of Negative N Balance
- -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)
-
Differentiate between kwashirokor and marasmus
- 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!)
-
Define common symptoms of protein calorie malnutrition (PCM or PEM)
- *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
-
Describe protein digestion and absorption
- 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
-
Identify calories per gm of alcohol
-
Describe characteristic signs of fetal alcohol syndrome
- *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
-
identify which nutrient deficiencies most often result from alcohol abuse
- *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)
-
which nutrients play a role in delerium tremens
-
Describe why nutrient deficiencies are common in alcoholics
- *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
-
Identify recommended levels of alcohol intake
- *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
-
List enzymes involved in alcohol metabolism
- *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
-
Identify which chemical reactions occur in various parts of the cell
- 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
-
Define gluconeogenesis
- new glucose being created from noncarb source
- -mainly being glycerol from triglycerides
-
Define glycogenesis
making glycogen during fasting when body needs it
-
glycogenolysis
breakdown of glycogen into glucose
-
Define lipogenesis
when there are too many fats it will package fats into storage in tissues
-
Define ketogenesis
- creating ketones when glucose is lacking as an energy source
- -when carbs are lacking
-
glycolysis
- glucose ---> pyruvate (2 pyruvates)
- under anerobic conditions
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