UF FOS2001 Exam 2

carbon, oxygen, hydrogen

-Structural lipid found in animal fat -Cheese, egg yolk, beef, pork, poultry, fish

Liver

-Pigments -Terpenes -Waxes -Sterols (Cholesterol) -Phospholipids -Triglycerides

-Soluble in organic solvents -Associated with flavor -Oxidizes naturally when exposed to air -Excellent heat transfer -Hydrophobic (does NOT mix with water) -High calorie -Energy storage for plants and animals

Antioxidants

make the lipid a more liquid oil

makes a more solid fat

-primary form of lipid found in food and in the body -Chemically composed of a three-carbon compound called glycerol in which fatty acids are bonded to each of the carbons

Chemically have a three-carbon glycerol backbone; the first two carbons of the glycerol molecule have fatty acids bound to them, and the third carbon has a phosphate group bonded to it

Molecules in the blood that help transport cholesterol and fatty acids to tissues

-Oxidation of fats, such as those in food products, results in rancidity -Tocopherols are often added to products to prevent oxidation of oils and to extend their shelf life (consuming these products can increase your vitamin E intake)

body makes them by reusing the nitrogen groups of essential amino acids and from proteins that have been broken down (process is called transamination)

nonessential amino acids that cannot be made by the body in the quantities needed

protein in the blood that helps keep balance between fluids inside and outside cells and blood vessels, prevents swelling.

Aroma of food and sight of food

Swallows chewed food mixed w saliva

-ring of muscles between esophagus and stomach; can cause heartburn or vomiting if it doesn't work properly -happens to pregnant women often

between stomach and small intestine; regulates how quickly food leaves our stomach and moves into small intestine

-Cytosol -Mitochondrion -All macronutrients are used for production of citric acid cycle -then they can be pushed into the electric transport chain -When exiting the electric transport chain, then they can convert ADP to ATP

-produces little energy -produced with glucose and only if there is enough oxygen in the cell

amino acids, fatty acids and glucose can be converted to acetyl-CoA if there is enough oxygen in cell and mitochondria

glucose

Amino acids

End product of fat digestion and absorption inside the cell

-Results in temporary weight loss -Carb restriction/increases protein intake -Multibillion dollar industry but 95% fail to achieve results -Should focus on balanced diets and life style changes

-Most important micromineral -Helps deliver oxygen to tissues and cells -Vitamin C can enhance absorption from non-meat sources in the liver -if deficiency occurs, it can lead to anemia.

Meats, poultry, fish, beans, dark leafy greens, dried fruits.

retinol, retinal, retinoic acid -found in animal tissue

Antioxidant found in plants -can be converted to Vitamin A if needed in the small intestine -measured in RAE (retinol activity equivalents) -spinach, dark green leafy vegetables, and broccoli

The bacteria in the large intestine

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ADENOSINE TRIPHOSPHATE (ATP): A high-energy molecule that can be broken down to a usable form of energy.

The first step in the process of converting food to energy; it is a complex series of chemical reactions and interactions combined with muscular movements that break the food down into smaller compounds.

The movement of the smaller products of digestion across the lining of the intestinal tract, into our bodies, and ultimately into our cells.

The period of time it takes food to travel the length of the digestive tract.

The sum of biochemical reactions that occur in the cells of the body, which includes both catabolic and anabolic reactions.

The storage form of glucose; it is stored in the liver and the muscles.

STEARIC ACID: 70°C (158°F) OLEIC ACID: 16°C (60.8°F) LINOLEIC ACID: -5°C (23°F)

The hydrogenation of fatty acids TRANS FORM: The hydrogens attached to the carbon atoms are on either side of the double bond.

Fully hydrogenated oils remove all double bonds from all fatty acids - Makes hard fat / hard stock

Advanced lipid oxidation endproducts (ALEs): - May oxidize lipoproteins in human serum - Potentially injurious to human organs • Liver • Kidney • Lung • Gut - May cause inflammatory responses

Conjugated Fatty Acids - Dairy products - Dietary supplements - Claims to reduce risk of: • Colorectal cancer and breast cancer in women - May decrease body fat and a "fuller" feeling after eating - More research needed...

calories consumed versus calories expended doing physical activities.

RESTING ENERGY EXPENDITURE (REE): The energy expended by the body for heartbeat, breathing, nerve impulse transmission, kidney function, growth and repair, and other basic functions.

THERMIC EFFECT OF FOOD (TEF): The energy expended by the body in digesting, absorbing, transporting, storing, metabolizing and otherwise processing food; it amounts to about 10 percent of calories consumed.

BASAL METABOLISM RATE (BMR): Body processes involving involuntary activities only, such as heartbeat, breathing, and chemical reactions.

BODY MASS INDEX (BMI): A height-weight relationship used to assess obesity; it equals (weight in kilograms)/(height in meters squared), or (weight in pounds × 704.5)/(height in inches squared).

APPETITE: The psychological mechanisms that determine how much we eat HUNGER: The physiological mechanisms that determine how much and when we eat.

*Watch module 9 lecture, slide 19

A protein contained in the red blood cells that carries oxygen throughout the body.

A protein that provides all of the essential amino acids in the amount that the body needs and is easy to digest and absorb. Also called a high-quality protein.

A form of PEM characterized by a swollen appearance, especially in the abdo- men. Historically, kwashiorkor was thought to be caused by a lack of protein, but in fact there may be other contributors to its development.

Two or more foods whose amino acid content, when combined, provides all of the essential amino acids.

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MOUTH: Mechanically digests food by chewing and grinding; begins chemical digestion of carbohydrates with salivary amylase ESOPHAGUS: Moves food from the mouth to the stomach STOMACH: Mechanically digests food by churning and mixing; releases hydrochloric acid (HCl) to denature proteins; begins chemical digestion of proteins with pepsin SMALL INTESTINE: Releases enzymes; completes chemical digestion of carbohydrates, fats, and proteins; releases bile to emulsify fats; is the primary site of absorption LARGE INTESTINE: Absorbs water; prepares indigestible wastes (feces) for defecation RECTUM: Temporarily stores feces ANUS: Eliminates feces from the body ACCESSORY ORGANS: TONGUE: Helps mix food with saliva; assists in swallowing; provides the sense of taste; helps with the initial swallowing process SALIVARY GLANDS: Produce saliva, which contains the enzyme salivary amylase that starts digestion of carbohydrates LIVER: Produces bile, which emulsifies fats; receives nutrients after ab- sorption; major site for metabolism GALLBLADDER: Stores bile, then releases it into the small intestine PANCREAS: Produces digestive enzymes that are released into the small intestine, where they help digest carbohydrates, fats, and protein

What it is--What it does--Why it's important MUCUS--Protects the lining of the stomach from HCl--Without it, the stomach would be damaged by HCl and pepsin HYDROCHLORIC ACID (HCl)-- Denatures proteins; liquefies foods; activates the enzymes pepsin and lingual lipase; helps prepare iron for absorption--It helps neutralize bacteria and assists in digestion of proteins INTRINSIC FACTOR--Is essential for the absorption of vitamin B12-- You need vitamin B12 to prevent a form of anemia called pernicious anemia PEPSINOGEN--Is a proenzyme (inactive) that is converted to an active form called pepsin by stomach acid--It aids in protein digestion by breaking protein into shorter chains HORMONES (20 different chemical messengers)--Control movement of the stomach and secretion of HCl; communicate with the pancreas, liver, gallbladder, small intestine, and the rest of the body--Hormones regulate digestive processes and ensure that the right enzyme is released at the right time

CARBOHYDRATES: -When food enters your mouth, the enzyme called *salivary amylase* in the saliva breaks carbohydrates into smaller glucose links. -Amylase continues to work until it reaches the stomach where hydrochloric acid inactivates it. -Once food is in the stomach, no further carbohydrate break down occurs. -Once they enter the small intestine, carbohydrates are broken down by an enzyme released from the pancreas called *pancreatic amylase* into smaller chains of glucose. -Next, several enzymes from the lining of the small intestine continue the breakdown. -The end products of carbohydrate digestion are single sugars (monosaccharides) ready for absorption -The single sugars glucose and galactose are transported across the wall of the small intestine. -Depending on these factors, the absorbed glucose can be used to maintain blood glucose, used to replace glycogen stores in the liver and muscle, or made into triglycerides and stored as fat.

FATS: -In the mouth *lipase*, an enzyme that breaks down fats is released in the saliva. -It is not activated, however, until it reaches the acidic environment of the stomach, where it breaks down a small amount, about 10 percent, of fats consumed. -When chyme enters the duodenum, bile released from the gallbladder acts on large fat molecules in a process called *emulsification* and mixes them in the watery environment of the small intestine. -This mixing allows the enzyme *pancreatic lipase* to break down the fat molecules into smaller molecules—fatty acids and glycerol -Once inside the cells of the small intestine, the smaller molecules rejoin to make triglycerides. Some free fatty acids enter the capillaries, but the larger triglycerides must enter the larger vessels of the lymphatic system. -Remember that fat and water don't mix. Therefore, before the larger triglycerides can be transported through the body they are formed into special carriers, called *chylomicrons*, that enable the fat to travel in the watery environment of the blood. -The triglycerides can then pass into the cells of the body to be broken down and used for energy or stored as fat. -After the fat is absorbed, the bile continues through the intestine and most is reabsorbed in the ileum or bound by fiber and excreted.

PROTEINS: -Protein digestion begins in the stomach when *pepsinogen* is released from the wall of the stomach and converted to its active form, *pepsin*, when exposed to stomach acid. -The enzyme pepsin then breaks the peptide bonds in proteins into smaller units. -Stomach acid also assists in the digestive process by denaturing the proteins, or unraveling their three-dimensional shape. -The smaller units then empty into the small intestine, where enzymes secreted by the pancreas break them into still smaller units. -Then, enzymes from the wall of the small intestine act on the peptides to break off one amino acid at a time, and the individual amino acids are absorbed -The amino acids then travel through the blood to the liver. -Once in the liver, their fate depends on several circumstances, such as how many carbohydrates you have consumed. The absorbed amino acids can be used to make proteins, or glucose if you have not consumed enough carbohydrates, and a small amount is kept in the blood for a short time in the amino acid pool. -Any amino acids in excess of the body's needs can be made into fat and stored.

SMALL INTESTINE: -Duodenum and upper part of the jejunum: absorb most minerals, except for electrolytes -Jejunum and upper ileum: absorb carbohydrates, amino acids, and water-soluble vitamins -Ileum: absorbs lipids and fat-soluble vitamins/B12 LARGE INTESTINE: -Absorbs sodium, water, potassium, fatty acids -Bacteria works to create vitamin K

-Height/Weight relationship= (weight x 704.5) x Height in inches squared -Underweight: 18.5 -Overweight: 25 and up -Obese: 30 and up -Not always accurate (bodybuilders)

Overweight= Increased heart disease, high blood pressure, some cancer -Extra body fat -Lack of exercise/poor habits -Poor diet (nutritionally lacking)

THE FUEL CONTINUUM Carbs Fats <----------------------------------> 1. 2. 3. 1. High-Intensity, Short Duration Activites ----Sprinting ----Weight Lifting 2. Moderate-Intensity, Moderate-Duration Activities ----Running/Jogging ----Cycling ----Aerobics class 3. Low-Intensity, Long Duration Activites ----Long Walk ----Yardwork

PROFESSIONAL ATHLETE: Carbs: 6-12 g/kg/day Protein: 1.2-1.7 g/kg/day Fats: remainder of kcals PHYSICALLY ACTIVE: Carbs: 5-7 g/kg/day Protein: 0.8-1 g/kg/day Fats:remainder of kcals

-Your body needs a constant supply of glucose to maintain your blood glucose level and to fuel your brain, central nervous system, and red blood cells. -After about sixty minutes of intense exercise or ninety minutes of moderate exercise, glycogen stores are depleted and exercise performance decreases. -During very long exercise, your body has to get glucose from somewhere. It breaks down other substances to yield glucose. These other substances can be some amino acids, lactate, glycerol, and pyruvate.

BEFORE: -drink 7 ml/lb of body weight -2-3 cups of water/sports drink DURING: 4-6 cups of water AFTER: 3 cups for every pound lost; sports drink + salty snack. IF PREGNANT: add 300ml

VITAMIN A: -Excessive intake can be toxic (3,000 μg per day) -Retinol is most active form, stored in liver -Plays important role in vision, bone growth, disease resistance and gene regulation -Food sources: animal foods and products; fortified milk, cheese, cream, butter, eggs, liver, and margarine with vitamin A added; apricots, cantaloupe, squash, carrots, sweet potatoes, and pumpkins VITAMIN D: -exposure to sunlight is crucial -plays role in bone health -Deficiency leads to rickets(bowlegged children) -Found in Sunlight, oily fishy products, milk, cereal, fortified juices VITAMIN E: -Tocopherols -fights off free radicals (cancer, heart disease, aging) -antioxidant nutrient -enhances immune system and is needed for nerve cell development -deficiency of this vitamin leads to anemia -Found in vegetable oils, nuts, seeds, leafy greens VITAMIN K: -Helps with blood clotting (production of Fibrin) -bone development -Found in Bacteria in Large Intestine, green leafy vegetables, vegetable oils, soybean

VITAMIN C: -also known as ascorbic acid -ANTIOXIDANT -Helps with healing wounds and maintaining structure of blood cells -deficiency results in scurvy and anemia -Produces collagen -Food sources: fruits and vegetables VITAMIN B1 (THIAMIN): -Releases energy from carbs & amino acids -Integrity of nerve and muscle tissue -Found in Pork, Whole Grains, Cereal, Enriched Grains and Pasta, Beans, Milk, Peanuts/Seeds, Orange Juice, Organ Meats VITAMIN B2 (RIBOFLAVIN): -Helps with the release of Energy from foods. -Found in Milk, enriched bread, Cereal, Pasta. VITAMIN B3 (NIACIN): -Can be synthesized from Tryptophan (essential amino acid) -Helps release energy from macronutrients and synthesis of fatty acids. -Found in red meat, dairy products, nuts, seeds, bananas, tuna, shellfish, turkey, soy VITAMIN B5 (PANTOTHENIC ACID): -Involved in Synthesis of ----Lipids. ----Steroid Hormones. ----Neurotransmitters. ----Hemoglobin -Easily destroyed in food processing VITAMIN B6: -has seven forms -converts one amino acid into another -helps convert tryptophan into niacin (B3) -synthesis of glucose and other lipids -important in the production of serotonin from tryptophan, and in hemoglobin synthesis -Food sources: meats, baked potatoes, bananas, broccoli, spinach, watermelons, salmon, and navy beans. VITAMIN B7 (BIOTIN): -Aids in: ----Fatty Acid Synthesis ----Breakdown of Amino Acids ----Glucose production. -Found in Liver, soy, fish, beans, whole grains. VITAMIN B9 (FOLATE): -helps with cell division and developing the central nervous system -Found in orange juice, leafy greens, organ meats, beans, sprouts, veggies, cereal, breads. VITAMIN B12: -found only in animal products. -Converts Folate Coenzymes into active form. -Amino Acid Metabolism -Bone Metabolism -Synthesis of DNA -Found in-Milk, Cheese, poultry, seafood, meat, cereals, soy.

CALCIUM: -Most abundant macromineral in human body -can lower risk for hypertension -Found in spinach, Kale, milk, soybeans, seafood. PHOSPHORUS: -Second most abundant macromineral. -Part of bones and teeth, DNA and RNA, helps balance Ph Levels. -Found in ,eat, fish, poultry, eggs, beans, milk, cereals, grains, coffee, tea, chocolate, soft drinks ZINC: -Micromineral ----Male fertility ----Protein Synthesis and Growth ----Wound Healing ----Affected by Stress ----Alcohol Metabolism ----Protects against free radicals ----Effect on taste and smell ----Hemoglobin synthesis -Found in Meat, turkey, eggs, grain, cereal

Lipids perform various functions in human nutrition, including: -storing energy, -supplying essential fatty acids, -absorbing and transporting fat-soluble vitamins, -protecting and insulating vital organs, -providing flavor in foods and, promoting satiety, -providing cell membrane structure, and -serving as a precursor to steroid hormones -Fats are found in both animal and plant products. Meats, butter, and other dairy products contain significant levels of triglycerides with saturated fatty acids.

Fatty acid saturation refers to whether a fatty acid chain is occupied by all of the hydrogen atoms it can hold. SATURATED: If the chain is fully occupied by hydrogen atoms, then it is a saturated fatty acid UNSATURATED: However, not all fatty acids contain carbons that are fully saturated with hydrogens. Some have areas where hydrogen atoms are missing; we refer to these fatty acids as unsaturated. -These unsaturated fatty acids form a double bond when hydrogen atoms are not present between two carbon atoms. -A fatty acid with one double bond is called a *monounsaturated fatty acid*; -one with two or more double bonds is called a *polyunsaturated fatty acid*

SHORTHAND NOTATION: 18:0 = Saturated fatty acid (straight across) 18:1 = Monounsaturated fatty acid 18:2 = Polyunsaturated fatty acid OMEGA DESGINATION: -Omega 6: first double bond is on sixth carbon from the omega end of the fatty acid -Omega 3: first double bond is on third carbon from the omega end of the fatty acid

Chemical Structure Determines Physical Properties -Length of fatty acids (# of carbons) -Position of fatty acids (methylene interruption) -Degree of unsaturation ---- Unsaturation caused by double bonds in the carbon chain - *Double bonds* make the lipid a more liquid oil - *Partial hydrogenation* makes a more solid fat

Properties depend on structure -Hydrogenation ---- Tends to make solid and more stable to oxidation -Degree of unsaturation ---- Double bonds tend to make liquid and more susceptible to oxidation -Unsaturated fats oxidize faster Antioxidants are used to *prevent lipid oxidation* -Metals ---- Iron, Copper, Other Metals ---- Act as catalysts for autooxidation -Source ---- Impurities accompanying the plant material, packaging of oil, or from processing equipment -Responsible for initiation reactions of free radical reaction with presence of O2

Fatty acids that cannot be made by the body and can be provided only by the diet are called *essential fatty acid*, meaning they must be present in our diets. These essential fatty acids are in two families of fatty acids, omega-6 and omega-3. Linoleic acid (omega-6) and linolenic acid (omega-3) are the two most prominent essential fatty acids

-Linolenic acid -help prevent tissue inflammation, heart disease, and the formation of blood clots. -from plant sources include soybean and canola oils, walnuts, and flaxseed. *eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA):* -important omega-3 fatty acids in addition to linolenic acid -Fish that naturally contain more oil (e.g., salmon, trout, herring) have higher concentrations of EPA and DHA than leaner fish (e.g., cod, haddock, catfish)

-Linoleic acid -plays a role in reproduction and blood flow -found in liquid vegetable oils (soybean, corn, and safflower oils) . -Most Americans get enough omega 6 but not enough omega 3

The building blocks of protein. They contain nitrogen and link together to form proteins.

All amino acids are made of a central carbon connected to four different groups. -One group is called an amine group (this is where the nitrogen is), -one is an acid group (carboxyl), -one is hydrogen, -and the fourth is a side chain, or R group. Every protein in the body has a different chain of amino acids linked together in a specific order by *peptide bonds.* Peptide bonds are formed between the acid group of one amino acid and the amine group of another

Essential amino acids are those that cannot be made in the body in the amounts sufficient to meet its physiological needs, so we must obtain them from the food we eat. If essential amino acids are not consumed in the diet, the body will not be able to make the proteins it needs for growth, maintenance, or any of the other functions mentioned previously without breaking down muscle tissue to acquire the needed essential amino acids.

PROTEIN FUNCTION: body growth, maintenance and repair, and fluid balance The specific order of the amino acids is part of what determines a protein's shape, which in turn dictates its function. -Why does the order dictate the shape? Recall from our previous discussion that the R groups give the protein its unique and specific qualities. The charge of each amino acid influences how it interacts with the other amino acids in the protein and therefore its shape. Because a protein's shape determines its function, we can change a protein's ability to function by altering its shape. -This occurs when we cook food, when we sterilize items such as bandages or a baby's bottle, or when we break down protein during digestion. -A protein's structure and function can be changed by heat, acid, enzymes, agitation, or alcohol in a process called *denaturation.* -Similarly, when we eat proteins we denature them with stomach acid. Stomach acid unravels the three-dimensional structure just as cooking does.

VEGETARIANISM: -can lead to anemia due to inadequate intake of iron or vitamin B12 -Lacto-vegetarians: dairy but avoid eggs, seafood, and meat -Lacto-ovo vegetarians: eggs and dairy products, but no meat or seafood. -Macrobiotic vegetarians: whole grains, vegetables, soy, legumes, fruits, and nuts and seeds/sometimes include fish but avoid meat, poultry, eggs, and dairy. -semivegetarians (or flexitarians): occasionally eats meat and seafood, mostly practice a vegetarian diet VEGANISM: -only plant food/ NO animal products -low in zinc, calcium, protein, vitamin B6, and B12 -can lead to anemia due to inadequate intake of iron or vitamin B12