Lipids, Proteins & Amino Acids Flashcards

Question

Essential Fatty Acids

Answer 1

* PUFA (Polyunsaturated Fatty Acids * Essential b/c required for normal funcioning, but cannot be created by the body * Omega-6 - Lioleic acid (LA) - Gamma linolenic acid (GLA) - Arachidonic acid (AA) • Omega-3 - Alpha linolenic acid (ALA) - Eicosapentaenoic acid (EPA) - Docosahexaenoic acid (DHA)

Answer 2

• **Cell membrane components** - Incorporated into phospholipids - Affect flexibility, fluidity • **Vision (DHA)** - Retinal development - Possibly involved in sight • **Nervous system (DHA, AA)** - Cell membrane of glial cells (myelin) and neuronal cells (grey matter) **• Cell to cell communication** - Omega-6's: highly inflammatory - Omega-3's: less inflammatory - Modulate inflammation - Regulate blood pressure - Regulate blood clotting

Answer 3

• Plants / Phytoplankton are primary sources - Synthesize basic molecules (ALA & LA) • Animals synthesize remaining - EPA, DHA, AA from basic molecules • EFA's are concentrated up the food chain

Answer 4

* LA - Corn oil, soybean oil, safflower oil, sunflower seeds, and pecans * GLA - Safflower oil, hemp oil, primrose oil, oats, barley, spirulina * AA - Meat, poultry, eggs (especially corn-fed)

Answer 5

* ALA - Flaxseeds, canola oil, soybean oil, pumpkin seeds, tofu, walnuts, marine phytoplankton, chia seeds, designer eggs (fed with ALA source) * EPA - Cold water fish, grass-fed beef / game * DHA - Cold water fish, grass-fed beef / game, marine microalgae

Answer 6

• Cis unsaturate fatty acids - **Hydrogens** on **SAME SIDE** of double bond - 99% of naturally occurring MUFA & PUFA - Fatty acid has bent shape - Liquid at room temperature

Answer 7

• Trans unsaturate fatty acid - **Hydrogens** on **OPPOSITE SIDES** of double bond - Predominantly manufactured - Few occur naturally (animal fats, breast milk) - Fatty acid has straight shape - Solid at room temperature

Answer 8

* Adds hydrogens to unsaturated fatty acids * Makes liquid fats solid * Decreases the reactivity, increases shelf life * Most dangerous dietary fat - Cause increase in LDL, make LDL more atherogenic - Make cell membranes more sucseptable to damage

Answer 9

* Trans-fat added to nutrition fatcts panel (2006) * Look for "hydrogenated oils" in trans fats

Answer 10

Saturated fatty acid

Answer 11

Monounsaturated fatty acid

Answer 12

Polyunsaturated fatty acid

Answer 13

Omega-3 / Omega-6 --\> PUFA

Answer 14

Un- / Monounsaturated fats --\> Cis

Answer 15

• **Triglycerides ** --- Un- / Saturated fats - 3 fatty acids + 1 glycerol **• Phospholipids** - In cell membranes - Starting material **• Sterols** --- Cholesterol - In cell membranes - Starting material

Answer 16

* 3 fatty acids * Attached to a molecule of glycerol

Answer 17

* Primary storage form of fat in the body * Created by body to store fatty acids * Fatty acids removed and used to meet energy needs

Answer 18

* Fatty foods, fats, oils, meat, dairy * High sugar / CHO foods

Answer 19

• Glucagon - fasting stage hormone --\> When excess energy is consumed, it is stored as triglycerides in adipose tissue. • Insulin - fat stage hormone --\> When no food has been eaten for a while, triglycerides from adipose tissue are broken down, releasing fatty acids as an energy source.

Answer 20

**• Structure** - 2 fatty acids - Attached to a molecule of glycerol - Attached to a phosphate group **• Hydrophilic head and hydrophobic tail** **• Functions** - Component of cell membranse - Emulsifier **• Sources** - Synthesized by the body - Food: egg yolks, soy, wheat germ + peanuts

Answer 21

• Phospholipid Bilayer - Allows aqueous environment inside cell and flexible structure of membrane • Phospholipid = Emulsifier

Answer 22

* Ring structure * Cholesterol, steroid hormones, vitamin D * Functions: - Hormones, fat absorption (bile, chylomicrons), cell memnbranes • Sources: - Synthesized by the body - Animal fats, vegetable

Answer 23

• **Non-essential nutrient** - Produced by liver - Heavily regulated and recycled • **Dietary sources** - Animal fats • **Plant sterols** - Similar to animal cholesterol - May act to reduce human cholesterol levels • **Functions** - Cell membranes - Used to make: - ex: estrogen, testosterone, cortisol

Answer 24

• **Digestion** - Minimal in mouth and stomach - Majority occurs in the duadenum - Triglycerides and phospholipids broken down by pancreatic lipase

Answer 25

• **Bile** - Produced by the liver - Stoerd in the gallbladder - Released into the duadenum - Emulsifies dietary fat - Dietary fat becomes more accessible to lipases

Answer 26

**• Micelle** - Lipid droplets formed in the duodenum when bile emulsifies dietary fat

Answer 27

**• Water (blood) and oil (fat) are incompatible** **• Need unique system of transport** **• Lipidproteins** - Water soluble mechanism for transporting fat + cholesterol throughout the body - Lipid core - Shell composed of protein, phospholipids and cholesterol

Answer 28

**• Chylomicrons** - Transport of dietary triglycerides **• VLDL - very low density liver protein** - Produced by liver - release triglycerides **• LDL - low density liver protein** - Formed form VLDL they contain mostly cholesterol **• HDL - high density liver protein** - Pick up and recycle or dispose of cholesterol

Answer 29

Once absorbed into enterocyte: **• Micelles** - Re-packed into chylomicrons **• Chylomicrons** - Travel thorugh the lymph to the liver & deliver fat to cells **• Liver** - Reprackages chylomicrons into lipoproteins **• Lipoproteins** - Deliver fat to cells

Answer 30

**• LDL particles transport cholesterol fromt the liver to body cells** - Recommendation for decreasing blood levels of LDL **• HDL particles transport cholesterol from body cells to the liver so they can be excreted** - Recommendations for incresing blood levels of HDL

Answer 31

4. LDL delivers cholesterol to the cells

Answer 32

**• Leading cause of death in US** **• Diseases of the cardiovascular system** - Heart and blood vessels **• Most common outcomes** - Myocardial infarction (Heart Attack) - Cerebrovascular Accident (CVA, Stroke)

Answer 33

**• Inflammation** - Contributes to atherosclerotic plaque formation - Omega-3 fatty acids may reduce CVD risk **• High LDL cholesterol** - Contributes to atherosclerotic plaque formation **• Hypertension** - Increses chance of atherosclerotic plaque formation - Contributes to damage of blood vessels

Answer 34

**LDL Oxidation:** * Blood vessel injury + inflammation cause oxidation of LDL * Ox-LDL forms: foam cells * Foam cells form plaques in blood vessel walls * LDL is leathal * Antioxidants may limit oxidation of LDL **Narrows blood vessels** * Limit blood flow to tissue * Fewer nutrients / oxygen delivered **Plaques break free from the blood vessel walls** * Stimulate: * Block blood flow * Without blood flow: - Myocardial infarction in heart - Cerebral vascular accidents in brain

Answer 35

**• Non-modifiable** - Age, gender, race - Family history - Genetics (specific gene mutation) **• Modifiable** - Diet - Smoking - Physical activity

Answer 36

**• Total fat:** - 20 - 35% of total calories **• Saturated fat:** - Less than 10% of total calories - Less than 7% of total calories if at risk for heart disease **• Cholesterol:** - Less than 200 mg per day **• Avoid:** - Trans-fat, added sugar, high salt **• Increase:** - Fruits, vegetables, fiber, potassium, omega-3s

Answer 37

* One cup of **milk**: 8 g protein * One **egg**: 7 g protein * 3 oz **meat**: over 20 g protein

Answer 38

* 1 silce of bread: 2 g protein * ½ cup legumes: 6-10 g protein * ½ cup rice, pasta or cereal: 2-3 g protein * ½ cup nuts or seeds: 5-10 g protein

Answer 39

**• Food sources** - Meat, eggs, dairy products **• Benefits** - B vitamins - Heme-soluble iron - full compliment of essential amino acids **• Drawbacks** - High in saturated fat - High in cholesterol - Low in phytochemicals

Answer 40

**• Food sources** - Grains, nuts, legumes **• Benefits** - Low in saturated fat - Low in cholesterol - High in fiber - High in phytochemicals - High in unsaturated fat **• Drawbacks** - Must combine foods to achieve complete protein - Minerals have lower bioavailability

Answer 41

**• Consumption in the US** - Generally protein intake \> protein needs - Average consumption = 70 g of protein / day **• The dietary transition:** - US has higher protein diet + majority of protein comes from animal sources - Developing countries: individuals have better/more access of what is considered "high quality" protein --\> animal protein **• Needs increase with:** - Physical stress (Infection, burns, fevers, surgery) - Exercise (weight training, endurance sports) - Pregnancy and brest feeding

Answer 42

**• RDA** - 0.8 g / kilogram of body weight for adults **• AMDR** - 10-35% of calories **• Dietary Guidlines 2010** - Choose variety of protein foods - Include seafood, lean meat and poultry, eggs, beans, and unsalted nuts and seeds **• ^ weight = ^protein (needed for maintenance + repair)** • Ex: 70 kg (154 lb) adult = 56 g of protein / day

Answer 43

* Protein RDA = 0.8 g / kilogram of body weight * 163 lbs adult * Kilogram = lbs / 2.2 * 163 ÷ 2.2 = 74.09 kg 74. 09 x 0.8 = 59.27 - -\> this person needs 59.27 g of protein

Answer 44

**• Metabolism** - Enzymes regulate metabolic reactions **• Stucture** - Of cells, organs, tissues, body **• Energy** - Can be broken down, turned into glucose, and used for fuel **• Chemical signals** - Hormones, cytokines **• Transportation of substances** - Movement of molecules into cells, oxygen **• Movement** - Skeletal muscles, smooth muscles **• Immunity** - B-cells, T-cells, antibodies **• Blood clotting** - Plateletes, cellular communication **• Fluid balance** - Maintaining osmolarity of plasma

Answer 45

**• Contains:** - Carobn, Hydrogen, Oxygen, Nitrogen, (Sulfur) **• Amino acids (basic unit)** - Nitorgen group (amino) - Acid group (carboxyl group) - Hydrogen - Side chain (R)

Answer 46

**• Non-essential** - Body can produce them - dispensable **• Essential** - Must be taken in via food - indispensable **• Conditionally essential** - Essential during infancy, disease, or trauma

Answer 47

• Body has ability to synthesize, but will lose this ability under certain conditions - Phenylketonuria (PKU) - -\> tyrosine becomes essential AA

Answer 48

**• Complete Proteins** - All of the essential AA present in adequate amounts - Animal proteins (exept gelatin) **• Incomplete Proteins** - Inadequate amounts of 1 or more essential AA - Plant proteins **• Complementary Proteins** - Combine plant proteins to acquire all essential AA - Legumes and grains eaten together

Answer 49

Important when essential AA needs are not met ## Footnote **• Determined by:** - Digestibility - Amount of amino acids absorbed - Amino acid composition **• Measures** - Biological Value (BV) - Protein Efficiency Ratio (PER) **• Chemical Score**

Answer 50

**• Biological Value (BV)** - Conversion of dietary protein to tissue protein - Similarity of food and body amino acids - Egg white is highest **• Protein Efficiency Ratio (PER)** - Weight gain (lab animal) in response to consumption - Compared to reference standard - Used in infant food labeling **• Chemical Score** - Ratio of amount of amino acids to "ideal" - Limiting amino acids - Protein Digestibility Corrected Amino Acid Score

Answer 51

**• No "storage form" of protein** - Body proteins are used, and recycled **• Amino acid pool in cells** - Constant breakdown, rebuilding, and repair - Constant protein turnover - Cellular response to environmental changes **• Dietary protein** - North America - -\> 70% supplied by meat, poultry, fish, milk, milk products, legumes and nuts - Worldwide - -\> 35% of protein from animals

Answer 52

• Transamination - Transfer of an amino group - From existing AA to a "carbon skeleton" - Forms non-essential amino acids

Answer 53

• Deamination - Amino acid loses an amino group - Amino group travels to liver - Incorporated into urea and excreted - Carbon skeleton used for energy

Answer 54

• Peptide bonds - Links amino acids together - Condensatin reaction - Dipeptides (2 linked amino acids) - Poly-peptides (many linked amino acids)

Answer 55

• Protein synthesis determined through gene expression **DNA ——► RNA ——► Protein** ** / \** **Transcription Translation** • DNA-coded instructions determine shape and function of proteins

Answer 56

• Transcription - DNA becomes accessible to enzymes - mRNA synthesized (transcription of genetic code) - mRNA travels fromt he nucleus into the cytosol • Translation - mRNA sequence read in "codons" - Sequences of 3 bases that code fo specific AA - tRNA and ribosomes necessary for this process

Answer 57

**Primary Structure** * Simple polypeptide chain * Order of amino acids will determine 3D shape **Secondary Structure** * Bonding between nearby amino acids form (H-H) * Helices / pleated sheet **Tertiary STructure** * S-S bonds * Form 3D shape * Shape - function **Quaternary Structure** • Subunits together

Answer 58

* Gene mutations lead to changes in DNA sequence * Changes in DNA sequence can change the sequence of the amino acids in a protein * Changes in amino acid sequence can change the protein shape * Changes in protein structure can change the protein function

Answer 59

* Altering protein's 3 dimensional structure * Acid, alkaline, heat, enzymes and agitation * Function? Digestion

Answer 60

• Cooking - Denatures protein • Stomach - Further denaturation - Hydrochloric acid + Pepsin • Small Intenstine - Pancreatic proteases are Typsin, chymotrypsin, carboxypeptidases

Answer 61

• In Small Intestine - Peptides and AAs absorbed - Many transport mechanisms - Intact proteins Not typically absorbed • In enterocytes - Peptides broken down to AAs • Transport - AAs released into blood stream - Sent to the liver via portal circulation

Answer 62

• Positive Nitrogen Balance - Intake: Training, Recovery, Growth, Pregnancy - Output: Urinary nitrogen • Negative Nitrogen Balance - Intake: Low dietary - Output: Increased protein catabolism, increased excretion

Answer 63

• Definition - Long-term protein and calorie deficiencies - Loss of and muscle, decreased immunity • Types - Kwashiokor: pure protein deficiency - Marasmus: overall energy deficiency

Answer 64

* Edema * Mild to moderate weight loss * Maintenance of some muscle and subcutaneous fat * Growth impairment (60-80% of normal weight for age) * Rapid onset * Fatty liver

Answer 65

* Severe weight loss * Waisting of muscle and body fat (skin and bones appearance) • Severe growth impairment (less than 60% of normal weight for age) • Develops gradually

Answer 66

**High protein:** * Burden on the kidneys & liver (sick people) * Increased calcium excretion in urine * Increased fluid excretion in urine **v fiber, vitamins phytochemicals** **^ meat, sat fat, cholesterol** * Increased risk for heart disease * ^^ red meat intake linked to colon cancer **Recommendation** • IOM: max 2x RDA for protein

Answer 67

**Anabolic window** * 2-3 hours after exercise * Muscles ready for protein anabolism **Dietary intake** * CHO and protein * CHO intake provides energy and restores glycogen * High glycemic CHO stimulates insulin secretion * Insulin stimulates protein uptake * 4 : 1 carb to protein ratio, recommended * 10-20 g high quality protein - Egg white, whey, casein, soy - rapidly absorbed (low fiber, low phytochemicals) • Especially essential amino acids

Answer 68

**Overall** • Minimal protein use vs. CHO and lipid **Early stages** • 3-5% of total energy production from protein **Later stages** • ~ 10% of total energy production from protein **--\>** Protein sparing effect of carbohydrates - Adequate glycogen stores inhibit protein breakdown in muscle - Low carb diet/no carb replacemetn during endurance exercise increases amount of protein used for energy

Answer 69

**Variety protein sources** * Usually naturl protein isolated from food * Milk, eggs, soy, rice, hemp, legumse Whey and casein * Processed from milk (cheese-making process) * Whey = liqid portion & Casein = curds **Vegan sources** • Use combination to get all essential amino acids

Answer 70

* Effectively increase protein content of diet * Other results supported by mixed data * Clinical trials often sponsored and conducted by manufactures * Safety regulation relies on reports of adverse affects * Labels are under-regulated - FDA maintains passive role • Myths often masquerade as facts

Answer 71

"... any training technique, mechanical device, nutritional practice, pharmacological method, or psychological technique that can improve exercise performance capacity and/or enhance training adaptions."

Answer 72

**Regulated as dietary supplements (not drugs)** * DHSEA, 1994 (Dietary Supplement Health and Education Act) * Contain "dietary ingredients" (including organ tissues and enzymes) * Must be labeled "dietary supplement" * If in food supply prior to 1994: - no need to submit safety evidence to FDA • After 1994: - Must submit notification to FDA and provide some evidence of safety * Can make structure function claims about the supplement * Must submit additional evidence for qualified health claims (treating illness/disease) * Since 2006: - Supplement manufacturers must make adverse events data available to FDA if audited • FDA must prove a supplement is unsafe

Answer 73

* Body is designed to handle whole proteins * Individual AAs manufactured for supplements * No ULs set due to lack of data * Possible effects - Inerfere w/ absorption of other AA - Affect metabolism of other AA - Risk for toxicity (especially with methionin and tyrosine) • Recommendation: - Take whole protein supplements

Answer 74

Leucine, isoleucine, valine * Essential amino acids * Essential amino acids * Approx. 18% dietary amino acids in muscle * Leucine supplementation may increse protin anabolism (results are mixed) * Proposed UL for leucine - 500 mg / kg / day - Prevents hig blood NH3 - Prevents imbalance of other AAs

Answer 75

* ~ 20% of protein in milk * High protein quality score * Whey proteins - ß-lactoglobulin, a-lactalbumin, lg, albumin, lactoferrin, growth factors * ~ 26% BCAA (rich n leucine * Rapidly apbsorbed (fast acting) * Generally positive resulst - Increased muscle protein synthesis & strength

Answer 76

**Concentrate** • Native whey, 29%-89% protein, contains some carbohydrate (lactose) and lipid **Isolate** • » 90% protein, purest form, majority of fat & carbohydrate removed (low in lactose) **Hydrolysate** • Partially digested, theory is that absorption is faster, however absorption appears to be the same

Answer 77

* High protein quality score * Contains immune, growth, and antimicrobial factors * Theory: - Growth factors increase muscle mass - Antibodies improve immune function • Mixed results - not banned, but little evidence to support claims

Answer 78

• ß-hydroxy-ß-methylbutyrate - Metabolite of leucine (BCAA) • Theory: - Inhibits protein degradation • Results - Somewhat effective in untrained individuals - May help with initial adaptation to exercise - In trained athletes: generally not effective at increasing muscle size or strenght

Answer 79

• Conditionally essential amino acid - essential in times of stress • Theory - Endurance exercise is a physiological stress, therefore, glutamine is needed • Results - Effectiveness has been mixed in research studies to date - 5-10 g of supplements glutamine seems to be safe - Classified as: "apparently ineffective" by ISSN

Answer 80

* Breakdown product of lysine & methionine * Transports fatty acids into the mitochondria for ß-oxidation * Theory - Due to metabolic role described above, increase fat metabolism and promotes weight loss • Results - Not effective: - -\> Does not affect muscle carnitine content, fat metabolism, aerobic or anaerobic metabolism, or weight loss

Answer 81

* Produced in kidneys and liver from arginine, glycine, and methionine * In brain & muscle, shuttles phospate groups out of mitochondria * Assists with ATP production in the cytosol * Results - Generally effective + safe - Improves high intensity exercise capacity, muscle strength and mass - Increases ability to store carb as glycogen - Requires some loading

Answer 82

**Types of Vegetarians** * Vegan (no animal) * Lacto-vegetarians (plant + dairy) * Lacto-ovo-vegetarian (plant + dairy + eggs) **Nutrient Concerns** • B12, calcium, iron, zinc, vitamin D, high-quality protein, riboflavin, omega-3 fatty acids **Special Concerns for Infants and Children**

Answer 83

* Limited land and / or resources * Health * Religion * Personal ethics * Environmental concerns

Answer 84

Pros: * Lower risk of CVD, obesity, HTN, cancer * Higher consumption of - Fiber, potassium, magnesium, folate, antioxidants • Lower consumption of - Cholesterol, sat fat Cons: * Requires preperation and planning * Specific nutrient concerns - B12, calcium, iron, zinc, vitamin D, high-quality protein, riboflavin, omega-3 fatty acids

Lipids, Proteins & Amino Acids Flashcards

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