Carbohydrates Exam 2 PDF

Carbohydrates Examples of mono-, di-, oligo- & polysaccharides & dietary sources ○ monosaccharides carbohydrate consisting of a single sugar molecule (1 sugar) simple carbohydrate glucose fructose galactose ○ disaccharide...

Carbohydrates Examples of mono-, di-, oligo- & polysaccharides & dietary sources ○ monosaccharides carbohydrate consisting of a single sugar molecule (1 sugar) simple carbohydrate glucose fructose galactose ○ disaccharides simple carbohydrate carbohydrate made of two sugar molecules (2 sugars) lactose sucrose maltose ○ oligosaccharides complex carbohydrate carbohydrate made of 3-10 sugar molecules raffinose stachyose ○ polysaccharides complex carbohydrate carbohydrate made of more than 10 sugar molecules glycogen starch dietary fiber Know general sources of the individual mono- & disaccharides ○ glucose monosaccharide most abundant in plants ○ fructose monosaccharide highly processed foods that contain added sugars ○ galactose monosaccharide most comes from lactose that comes from diary products ○ lactose disaccharide glucose + galactose ○ sucrose disaccharide most abundant in honey, fruits, and vegetables  glucose + fructose table sugar ○ maltose disaccharide glucose + glucose Know the significance of glucose in the human body – why is it important? ○ provides energy to the cells (nervous system, nerve cells, and brain) ○ sole energy source for red blood cells Know the general molecular structure of sugar molecules, how they are named ○ carbon, hydrogen and oxygen ( in a 1:2:1 ratio) ○ each contain 6 carbon atoms, can be referred to as hexose (6) sugars Dietary fiber – functions of soluble, insoluble in digestion, good sources (no need to memorize slide #28, but do look this over for general information on physiological effects of fibers as a category) ○ promotes the selective growth of beneficial bacteria in various regions of the GI tract, which in turn help inhibit the growth of other disease-causing (pathogenic) bacteria ○ unable to digest ○ occurs naturally in plants grains legumes vegetables fruit ○ soluble fiber tends to dissolve or swell in water ○ insoluble fiber does not readily trap water and therefore remains relatively unchanged ○ functional fiber fibers added to food as an ingredient typically extracted from natural fibrous plant sources can be synthetically manufactured ○ total fiber combination of dietary fiber plus functional fibers What is significant of alpha and beta bonded carbs and digestion/absorption? ○ alpha and beta bonds offer a convenient way to describe the important structural features of carbohydrates and can determine whether a carbohydrate is digestible or indigestible ○ alpha bonds produce glucagon (a hormone) stimulated when blood glucose is low stimulates breakdown of glycogen (glycogenolysis)  ○ beta bonds can not be digested in the small intestine, is resistant to digestive enzymes (like fiber) lowers blood glucose (when high) stimulates storage of glycogen (glycogenolysis) Bonding of sugars –condensation/hydrolysis reactions– what happens? ○ glycosidic bond a type of chemical bond that forms between two monosaccharides the name of sugar bonds formed when the hydroxyl group (-OH) from one monosaccharide interacts with a hydrogen group (-H) from another monosaccharide forms one water (H2O) molecule Compare/contrast amylose, amylopectin, & glycogen ○ amylose consist of entirely glucose molecules type of starch consisting of a linear (nonbranching) chain of glucose molecules is a starch from converted glucose by photosynthesizes ○ amylopectin consist of entirely glucose molecules is a starch from converted glucose by photosynthesizes a type of starch consisting of a highly branched arrangement of glucose molecules ○ glycogen (find this one) polysaccharide consisting of a highly branched arrangement of glucose molecules; found primarily in liver and skeletal muscles ○ comparing/contrast both amylose and amylopectin consist of entirely glucose molecules that was converted to starch through the process of photosynthesizes all are polysaccharides glycogen and amylopectin both consist of highly branched arrangement of glucose molecules contrast what makes them different is the arrangement of glucose molecules amylose is a linear (unbranched chain) of glucose molecules held together entirely by a-1,4 glycosidic bonds amylopectin and glycogen are a highly branched arrangement of glucose molecules. the linear portions contain a-1,4 glycosidic bonds, with a-1,6 glycosidic bonds occurring at branch points glycogen is found in the liver and skeletal muscles glycogen is highly more branched than amylopectin glycogen can be broken down quickly  amylose and amylopectin are found in starchy foods (i.e. grains; corn, rice, and wheat - food made from grains; pasta and bread - legumes; lentils and spilt peas) General carbohydrate digestion beginning in mouth – know secretions/accessory organs involved ○ firstly digestion begins in the mouth when salivary glands release the enzyme salivary a-amylase salivary a-amylase hydrolyzes the a-1,4 glycosidic bonds in both amylose and amylopectin ○ secondly begins in the stomach HCL (hydrochloric acid) stops amylase activity ○ lastly ends in the small intestine pancreatic a-amylase finishes the breakdown of small sugars to singular molecules for absorption ○ circulation of monosaccharides goes through the bloodstream directly to the liver absorbed through the small intestines ○ glycemic response change in blood glucose following ingestion of food containing carbs different responses from different foods Function of glycogen, glucagon, and insulin ○ glycogen storage form of glucose for potential fuel in the body in the liver "backup" source when glucose in the bloodstream gets low in muscles directly fuels muscle activity resembles amylopectin starch in plants broken down quickly for energy typically only lasts 1-2 days depending on stores and activity if energy gets low (fasting is an example) ○ insulin hormone secreted by the pancreatic B-cells in response to increased blood glucose blood regulation and energy storage when blood glucose levels are increased, the pancreas releases more insulin which in turns lowers the blood glucose when food provide more glucose than we need, insulin stimulates its storage as glycogen  beta cells ○ glucagon hormone secreted by the pancreatic a-cells in response to decreased blood glucose blood regulation and energy storage to increase glucose levels, glucagon stimulates the breakdown of glycogen that is stored in the liver alpha cells Difference between lactose intolerance & milk allergy ○ lactose intolerance lack of lactase enzyme produced, lactose travels through to large intestine, fermented by bacteria digestive issue not an allergy symptoms: gas, diarrhea bloating cramps types primary (natural aging) secondary (GI damage) genetics premature infants risk factors: ethnicity native american african american asian american surgery medications disease (celica, crohn's) coping (stress) ○ milk allergy most common in children immune system response to milk to milk proteins digestive issues vomiting diarrhea abdominal pain nausea cramping skin issues  hives itching tingling feeling around the mouth or lips respiratory issues throat issues neurological issues eye issues nose issues blood pressure What are diverticulosis & diverticulitis? Why do these occur? When to increase or avoid dietary fiber ○ diverticulitis occurs when the diverticula becomes infected or inflamed symptoms: cramping diarrhea fever on occasion bleeding from the rectum dietary fibers may help the prevent the formation by increasing fecal mass, making bowel movements easier ○ diverticulosis occurs when small, bulging sacs or pouches form on the inner wall of the intestine (diverticula) symptoms abdominal pain cramping, especially in the lower left abdomen constipation diarrhea bloating gas loss of appetite small amounts of blood in stool or on toilet paper What does the glycemic index measure? What is the difference between a food that is high or low on this rating system? ○ rating system from a scale of 0-100 ○ tests for diabetes, hypoglycemia checks rate of how well we use glucose from the bloodstream ○ 100 = 100 response to pure glucose solution white bread ○ higher than or equal to 70 = 70 high glycemic index food increases glucose more quickly in bloodstream  potatoes some bread cereals sweet potatoes baked potatoes taco shells ○ lower than or equal to 55 = 55 low glycemic index food lower is better for glucose control peanuts plain yogurt soy milk orange Signs/symptoms of diabetes, differences between Type 1 & Type 2 (causes, treatment) *Information from the video link at the end of this chapter – Diabetes Mellitus ○ type 1 occurs when the pancreas is no longer able to produce insulin people with type one needs to inject or infuse insulin with an insulin pump autoimmune disorder, which is caused by antibodies that destroy the insulin-producing cells of the pancreas can develop at any age but mostly occurs during childhood and early adolescence lack of insulin production by the pancreatic B-cells weight lost is a sign symptoms: frequent urination excessive thirst fatigue unusual weight loss extreme hunger ketosis treatment taking insulin ○ type 2 most common caused by insulin resistance insulin receptors do not respond normally to insulin insulin is released from the pancreas but does not readily bind with insulin receptors insulin resistance  symptoms: frequent urination excessive thirst fatigue frequent infections blurred vision vaginal itching cuts or bruises that are slow to heal tingling or numbness in hands or feet frequent urinary tract infections treatment: taking insulin counting carbohydrates, fats, and proteins monitoring blood sugar often eating healthy foods exercising regularly and keeping a healthy weight medications prediabetes ○ 100 to 125 mL/dL normal (no diabetes) ○ 70 to 99mL/dL diabetes ○ 126 or higher mL/dL what is a glycosidic bond ○ a bond that holds sugar bonds together Which of the following is a disaccharide that occurs naturally in fruits and vegetables and is known as table sugar? ○ sucrose For an adult to meet the amount of glucose needed for utilization by the brain, what is the minimum amount of glucose (in grams per day) recommended by the National Academy of Medicine? ○ 130 Glucagon and which other hormone produced by the pancreas aid in regulating blood glucose levels and producing energy? ○ insulin Which specific type of dietary fiber is recognized to help lower heart disease risk? ○ soluble dietary fiber  If David consumes 2300 calories a day, approximately how many grams of carbohydrates would he need per day according to the AMDR for carbohydrates established at 45%–65%? ○ 259-374, respectively 0.45 x 2300 = 1035 calories 1035/4 (carbohydrates is 4 grams) = 258.75 0.65 x 2300 = 1495 1495/4 = 373.75 According to the 2020 Dietary Guidelines, it is recommended that less than what percent of your daily calories should come from added sugars. ○ 10 The synthesis of glucose from noncarbohydrate sources is known as which of the following terms? ○ gluconeogenesis What is likely the most important role of monosaccharides? ○ producing ATP Dietary fiber has not been shown to be beneficial in helping to prevent which disease? ○ influenza In America, what percentage of people with diabetes have type 2 diabetes? ○ 90%-95% Which of the following is not a polysaccharide? ○ raffinose Which type of diabetes relates to the body's inability to produce insulin? ○ type 1 diabetes Which common sugar has seen an increase in consumption in America over the past century, from approximately 15 grams per day to approximately 55 grams per day? ○ fructose A food listed on a food label as being "an excellent source of fiber" must contain at least how many grams of fiber per serving, according to the USDA food-labeling guidelines? ○ 5 Which of the following is the starting point in the human body of starch digestion? ○ mouth When blood glucose levels rise above the normal range, the pancreas secretes ________, but when blood glucose levels fall below the normal range, the pancreas secretes ________. ○ insulin; glucagon Glucagon increases blood glucose levels by stimulating ________________. ○ liver cells to break down liver glycogen All statements regarding diabetes are true EXCEPT which one?  ○ Type 2 diabetes only occurs in adults, never in children. Protein Know the generic structure of an amino acid –What happens to nitrogen when protein is deaminated? ○ amino acids are joined together by peptide bonds ○ peptides are chains of fewer than 50 amino acids ○ oligopeptides are 2 to 10 amino acids ○ more then 10 amino acids are called polypeptides ○ a peptide bond is formed when a hydroxyl group (-OH) from one amino acid is joined with a hydrogen atom (-H) from another amino acid that release a water molecule in the process ○ R-group unique side chain that differentiates each AA How are amino acids bonded? ○ contains one or more nitrogen atoms ○ most proteins have 250-300 amino acids ○ amino acids have three common parts which are referred to as the common structure a central carbon atom bonded to a hydrogen atom a nitrogen-containing amino group (-NH2) a carboxylic acid group (-COOH) ○ R-groups are the portion of an animo acid's structure that distinguishes it from other amino acids ○ the chemical and physical properties of amino acids depend on subtle differences in the R-groups ○ the body needs 20 different amino acids to make all the proteins it requires these amino acids can be categorized by essential, nonessential, or conditionally essential ○ there are nine essential amino acids the body can't make these ○ there are 11 nonessential amino acids the body can make these ○ there are 6 amino acids that are considered conditionally essential when a nonessential becomes a essential  Digestion of proteins – where it starts, what happens to digest proteins in the stomach, etc. Digestive secretions (hormones, enzymes, HCL) involved with protein digestion ○ chemical digestion begins in the stomach gastrin (hormone) triggers release of hydrochloric acid (HCL) disrupts secondary, tertiary, and quaternary structures, but primary structure stays the same pepsinogen (inactive proenzyme) activated by HCL in acidic environment when protein foods present convers to active pepsin enzyme, breaks proteins PEPSINOGEN + HCL = PEPSIN (active form) ○ protein digestion continues in the small intestine hormones are also involved with signaling secretions pancreas releases bicarbonate and pepsin deactivated pancreas more protein enzymes (trypsin) mucosal cells also secrete protein enzymes to complete digestion/absorption ○ protein absorption through brush border active transport (carriers + ATP) and passive transport (simple absorption) ○ circulation into the bloodstream and then circulated to the liver What are deamination & transamination? When/why do these occur? ○ deamination breaking apart of amino acids to make lipids or glucose if needed ammonia (NH3) - toxic cells liver converts to urea - to kidneys - urine Define what “essential” and “nonessential” amino acids are (no need to memorize amino acids) ○ essential amino acids must be obtain through food ○ nonessential amino acids body makes it doesn't really need to be obtained through food Number of essential vs. nonessential amino acids needed by the human body ○ body needs 20 different amino acids ○ 9 essential aminos (EAA) must eat  ○ 11 nonessential amino acids (NEAA) body can make from other compounds transamination transfer of an amine group from one amino acid to molecules called keto acids ○ 6 conditionally amino acids may not be able to synthesize normally under some circumstances for some people Protein complementation – when necessary? Why necessary? Examples of complemented dishes/meals ○ protein complementation combining incomplete proteins to provide adequate amounts of all EAA combining different plant sources to "fill in" gaps rice and beans, PB sandwich, hummus and crackers (combining grain with legumes ○ protein quality based on how complete the protein is, bioavailability (AAs actually absorbed and used) high-quality vs low-quality protein sources animal (high) vs. plant sources (low) Define: complete & incomplete proteins (define) & general food sources, high-quality proteins- know examples of high-quality protein foods ○ complete proteins foods that contain adequate amounts of all EAA meat poultry eggs dairy (animal) ○ incomplete protein foods that supply low amounts of one or more EAAs limiting amino acids the EAA in short supply plant foods The different protein structures – describe – primary, secondary, etc. How is our DNA involved with protein structures? What can happen if DNA coding misplaces amino acids in the primary chain? ○ primary structure (most simple) determined by DNA code basic identity of protein determines chemical and physical characters  hair skin muscle number and sequence determines type simple chain joined by peptide bonds critical to function of larger proteins ○ secondary structure amine and carboxyl group have opposing charges, cause folding of chains in 3D structure, more complex, with weak hydrogen bonds, causes bending a-helix (spiral) B-folded sheets (pleated) ○ tertiary structure additional folding of big sections; stronger than secondary folding due to R-group interactions-strong disulfide bonds more complexity straight vs. wavy ○ quaternary structure two or more peptide chains come together largest proteins prosthetic group non-protein additional compound connected allows protein to function heme in hemoglobin Different ways proteins are denatured in foods/human body ○ unfolding of a protein by a denaturing agent changes protein form and function does not affect primary structure, but the more complex protein structures break down happens with food and body protein denaturing agents physical agitation heat (foods) acids/alcohols enzymes/bacteria heavy metals (lead, mercury) FDA and EPA roles What is gluconeogenesis? ○ glucose synthesis and ATP production  gluconeogenesis new glucose from protein proteins break down, reassemble to form glucose if needed; excess can be stored as fat deamination breaking apart of amino acids to make lipids or glucose if needed Recommendation for dietary protein in adults; how to figure ○ RDA measured as g/day (depends on your individual needs) AMDR: 10-35% of daily kcal needs measured as g/kg/day adult: 0.8 g/kg/day to figure divide lbs by 2.2 = 2.2 kg body weight X 0.8 Major functions of proteins in the body (transport, structure, etc.) – particularly fluid balance ○ provide structure important during periods of growth and development collagen keratin for skin and hair ○ enzymes are proteins catalysts speed up chemical reactions ○ facilitate movement contraction and relaxation of muscles actin myosin in skeletal muscles ligaments tendons cardiac muscle smooth muscle ○ transport proteins helps transport substances cross cell membranes through the circulatory system (e.g. lipoproteins) ○ hormones insulin glucagon gastrin estrogen ○ immune system  antibodies and other related immune factors are proteins ○ fluid balance protein deficiency edema due to low albumin ○ regulate pH changes acid/base balance when needed ○ glucose synthesis and ATP production gluconeogenesis new glucose from protein proteins break down, reassemble to form glucose if needed; excess can be stored as fat Types/characteristics of protein malnutrition ○ protein-energy malnutrition (PEM) micronutrient deficiencies there are many types marasmus severe chronic overall malnutrient adults children kwashiorkor edema (extremities) ascites (swelling in the belly) What are risks for those on strict vegan diets? ○ deficiency risks calcium B12 iron zinc heme (animal) vs. non-heme (plants) iron heme iron better absorbed - non-heme + vitamin C for better absorption Some conditions can disrupt the shape of a protein, such as when a protein unfolds due to the addition of heat or acid. What is the term for this unfolding of proteins? ­ ○ Den atur  atio n ○ Which of the following terms describes the process by which information is encoded in our genes to instruct cells how much and which type of proteins need to be made? ○ Gene expre ssion ○ If Omar's protein intake from food equals his protein losses from body secretions, he would be known to be in which of the following states? ○ Nitrogen balanc e ○ Amino acids are joined together by peptide bonds to form complex molecules containing nitrogen. These complex molecules are referred to as which of the following? ○ Proteins Which type of amino acids must be supplied by the diet? ○ Essential What term refers to the time elapsed between when an infected food is eaten and when a person becomes ill? ○ Incubation period ○ Which term is used to describe plant products that supply low levels of one or more of the essential amino acids? ○ Incomplete proteins  ○ Which hormone is released when food is present in your stomach? ○ Gastrin The Institute of Medicine recommends that healthy adults consume 0.8 g/kg/day of protein. If Natasha weighs 132 pounds, how many grams of protein does she need per day? (Note: Divide weight in pounds by 2.2 to determine weight in kilograms.) ○ 48 g When a body's immune system reacts against a protein such as those found in eggs or milk, the person is said to have developed which of the following? ○ Food allergy According to your textbook, while many vegetarians today may consume dairy products and eggs, vegans follow which of the following practices? ○ they omit all animal foods from their diet Food proteins that contain adequate amounts of all the essential amino acids—such as meat, poultry, and eggs—are known as what? ○ complete proteins How many amino acids are needed by the body to make all the necessary proteins? ○ 20 Which food group contains nutrient-dense, high-protein foods? ○ seeds Which of the following terms describes the modification of a person's genetics not affecting their DNA but that produces different amounts and combinations of proteins? ○ epigenetics Lipids Characteristics of lipids ○ consume 20-35% of adult energy ○ fatty acids ○ triglycerides energy source (9 kcals/gm) storage of excess energy insulation subcutaneous (temperature regulation) protection visceral (pregnancy organs ○ phospholipids ○ sterols  ○ fat-soluble vitamins ○ fats and oils ○ organic molecules consisting mostly of carbon, hydrogen, and oxygen atoms (relatively water-insoluble and hydrophobic) ○ oils are liquid at room temperature ○ fats are solids at room temperature ○ exception is coconut oil that is considered a fat because it is solid at room temperature What kind of bonds hold together lipid molecules? Why is the number of double bonds in fatty acid chains significant in identifying different lipid? ○ carbon, hydrogen, and oxygen atoms ○ a chain of carbon atoms forms a backbone of each fatty acid one end is called the alpha (a) end (contains a carboxylic acid group -COOH) the other end is called omega (w) end (contains a methyl group CH3) ○ the carbon atoms determines its chain length ○ short-chain fatty acid fewer than 8 carbon atoms ○ medium-chain fatty acid 8-12 carbon acids ○ long-chain fatty acid more than 12 carbon acids ○ chain length affects its chemical properties and physiological functions chain length influences the temperature that a fatty acid can melt short-chain fatty acids has low melting points, they take less heat to melt (mostly oils and gases) longer-chain fatty acids has high melting points, they take more heat to melt (mostly fats) ○ chain-length affects which fatty acids are soluble in water ○ the body has different mechanisms that fatty acids with different chain lengths are absorbed and transported ○ saturated fatty acid (SFA) single carbon-carbon bond ○ unsaturated fatty acids one or more double bonds ○ monounsaturated fatty acids (MUFAs) fatty acids with one double bond ○ polyunsaturated fatty acid (PUFAs) two or more double bonds ○ cis double bond hydrogen atoms positioned on the same side of a double bond  ○ trans double bond hydrogen atoms are on opposite sides of the double bond ○ trans fatty acids fatty acids containing at least one trans double bond, have fewer bends in their backbones most likely to be fats at room temperature found naturally in some food can be produced commercially by partial hydrogenation partial hydrogenation converts the majority of carbon-carbon double bonds into carbon-carbon single bonds, causing oils (like corn oil) to become fats (such as margarine or shortening) Configuration on FA chains – how to describe FA chains (18:2, omega, double bonds, etc.) ○ alpha (a) 18 carbon atoms in length 2 cis double bonds first cis double bond between the 9th and 10th carbon atoms from the carboxylic acid second cis double bond between the 12th and 13th carbon atoms from the carboxylic end cis9,cis12-18:2 ○ omega (w) fatty acids are described based on where the first double bond is located relative to the methyl (w) end of the molecule omega-3 (w-3) fatty acid first double bond is between the third and fourth carbon atoms from the w end omega-6 (w-6) fatty acid first double bond is between the sixth and seventh carbon atoms w-7 and w-9 usually does not identify whether the double bonds are in the cis or trans configuration or the location of the other double bonds in the molecule Structure of saturated, monounsaturated, polyunsaturated – describe/identify/sources ○ saturated fatty acids abbreviated to SFA contain all single carbon-carbon bonds organized molecules solids (fats) at room temperature  ○ unsaturated fatty acids contains one or more double bonds ○ monounsaturated fatty acids abbreviated to MUFA containing one double bond characteristics that lies in-between being a soft solid or a thick liquid at room temperature ○ polyunsaturated fatty acid abbreviated to PUFA containing two or more double bonds unorganized molecules liquids at room temperature What are HDL, LDL, and functions? How do they differ structurally? What are health implications? ○ very low density lipoprotein abbreviated to VLDL similar to chylomicrons mostly contain triglycerides and cholesteryl esters in cores surrounded by phospholipids, free cholesterol, and apoproteins have lower lipid-to-protein ratio denser primary function is to deliver fatty acids to cells with enzymatic action of lipoprotein lipase deliver fatty acids derived from liver and adipose produce lipoprotein lipase, the enzyme cleaves fatty acids in the blood circulation which are taken up by the surrounding cells ○ intermediate-density lipoproteins abbreviated to IDL when VLDL lose fatty acids because of lipoprotein lipase and becomes denser and smaller some are taken up by the liver some remain in the circulation and they continue to lose additional fatty acids ○ low-density lipoproteins abbreviated to LDL when IDL becomes cholesterol-rich LDL receptors are specialized proteins that are on the cell membranes liver adipose tissue muscle  bind to LDL apoproteins to allow them to be taken up and broken down by the cell can be taken up and degraded by white blood cells uptake of too much LDL can result in plaque which are buildup of fatty substance within the vessal wall, slowing or even blocking blood flow high levels are related to increase in risk for cardiovascular disease ○ high-density lipoproteins abbreviated to HDL liver and small intestine to an extent makes lowest lipid-to-protein ratio high densities and are small in size salvage excess cholesterol from cells an din some cases from other lipoproteins, transporting it back to the liver reverse cholesterol transport transfer of cholesterol from nonhepatic (nonliver) cells back to the liver high levels are related to a lower risk of cardiovascular disease referred to as "good cholesterol" several types Trans vs. cis fats-know differences, physical characteristics, health effects, sources, identify structures ○ trans fats hydrogen atoms are positioned on the opposite side of the double bond are called trans double bond do not cause bending containing at lease one trans double bond have fewer bends in their backbone more likely to be solid at room temperature ○ cis fats are double bonds hydrogen atoms are positioned on the same side of the double bond are cis double bond most naturally occurring The essential FAs, identify from chain structure (the essential omegas) ○ linoleic acid 17 grams per day for adult males 12 grams per day for adult females 18 carbon atoms two cis double bonds w-6 fatty acid precursor of hormone-like compounds called eicosanoids  ○ linolenic acid 1.6 grams per day for adult males 1.1 grams per day for adult females 18 carbon bonds three cis double bonds w-3 fatty acid precursor of hormone-like compounds called eicosanoids What are triglycerides? Structure? Roles in the body? – general role in foods and body (energy, storage in body, most common large lipid in our foods and body) ○ triglyceride three fatty acids can be either saturated, monounsaturated, polyunsaturated, or a combination of both 10 fatty acids that are common over 1000 unique ones consists of a glycerol molecule bonded to three fatty acids via "ester" linkages sources of essential fatty acids needed to bodily functions body's richest source of energy yields around 9kcal energy must be disassembled first to be used as energy process is called lipolysis is then catalyzed by enzymes called lipases lipoprotein lipase removes the fatty acids from the backbone adipose is the storage of excess energy adipose protects internal organs from injury and provides insulation What is bile? Where is it produced, stored, major function? ○ is a mixture of bile acids, cholesterol and phospholipids ○ stored in the gallbladder ○ major function is is to help generate emulsification when bile is released the hydrophobic portions are drawn toward the lipid globules while the hydrophilic portions are drawn to the water. these then disperse the large lipid globules into smaller droplets Know the structure of phospholipids/characteristics/function ○ consist of a glycerol molecule, a polar head group, and two fatty acids ○ most common ones are choline, ethanolamine, inositol, and serine ○ contain both polar and nonpolar regions making it an amphipathic ○ polar parts are drawn to water ○ nonpolar parts are drawn to lipids ○ major components of cell membranes and plays a roles in digestion, absorption, and transports lipids in the body  What types of fats should we avoid? Which ones to choose for lowering risk for heart diseases? ○ what are some health concerns of over intaking lipids obesity is linked to several types of cancer cardiovascular disease type 2 diabetes some forms of cancer ○ limited saturated fat ○ to lower risk for heart disease we need to consume additional omega 3- fatty acids eating fatty fish at lease two times a week ○ limiting trans fatty acids ○ general guidelines for a healthy heart total fat limit to 20-35% of total calories saturated fat limited to lower or equal to 10% of total calories trans fat intake should be minimal omega 3 (w-3) fatty acids recommended to consume fish at least twice a week complex carbohydrates consume greater or equal to 3 servings of whole grain products daily soluble fiber consume 5 to 10 grams soluble fiber daily Hydrogenation of oils (trans fats in food processing) & the consequences of this process ○ partial hydrogenation converts the majority of carbon-carbon double bonds into carbon-carbon single bonds causing oils to become fats decreases double bonds and increases single bonds converts from cis double bonds into trans double bonds results in high saturated and trans fatty acids What term is given to the manufacturing process of hydrogens atoms being chemically added to oils to impart texture and reduce spoilage? ○ partial hydrogenation There are two fatty acids that adults cannot synthesize and have to get from food: linoleic and linolenic fatty acids. What is the term that is given to these fatty acids?  ○ essential fatty acids What process occurs when large lipid globules are broken down into smaller lipid droplets? ○ emulsification Ketogenesis is triggered when which of the following occurs in the body? ○ glucose is low Chemists use the term "lipids" to describe fats and oils. What term is used to describe how these organic molecules are "water-fearing"? ○ hydrophobic The chain length of a fatty acid affects its chemical properties and physiological functions. Which of the following is not a physiological function of a fatty acid that is affected by its chain length? ○ saturation point The body has an infinite ability to store excess energy in adipose tissue. However, its capacity to store glycogen is limited. The body can store how much more energy in one pound of adipose tissue than it can in one pound of liver glycogen? ○ 6 times more energy Manuel has a family history of heart disease and wants to maintain his current health to prevent future disease. What percentage of Manuel's daily energy intake should come from lipids? ○ 20%-35% Animal-derived foods are the main dietary source of which sterol? ○ cholesterol The mechanisms by which dietary lipids are circulated throughout the body are referred to as which of the following? ○ exogenous lipid transport Which lipoprotein delivers cholesterol to cells to use for structural and metabolic purposes? ○ LDL Where does the final stage of lipid digestion occur? ○ small intestine Which lipid is found in cell membranes and cell walls, and thus is found naturally in most foods? ○ phospholipids The American Heart Association recommends that fatty fish should be consumed at least how many times a week to help prevent cardiovascular disease? ○ 2 times a week Which of the following diseases is not associated with a high dietary intake of some lipids? ○ type 1 diabetes Which lipoprotein transports dietary fat to the cells in your body?  ○ Chylomicrons Which lipoprotein carries cholesterol to the cells in your body, but can get stuck in arteries while traveling in the blood, depositing cholesterol that eventually leads to plaque formation? ○ LDL Which lipoprotein picks up cholesterol from your arteries and other places in the body and returns it to the liver for further metabolism? ○ HDL