Nutrition ch 4-6 Flashcards
What is a whole grain?
contain all of the essential parts (starchy endosperm, germ, and bran) of the entire grain seed in its original proportions. Dietary Guidelines for Americans advise half of the grains consumed should be whole grains.
Beneficial nutrients and phytochemicals are found in the bran and germ
what is an enriched grain?
cereal grains that lost nutrients during processing but have vitamins and minerals added back in; refined grains are often enriched.
What are the four functions of carbs in the body
The energy source for red blood cells, Important for intestinal health, reduces the use of protein for energy, energy for physical exertion and for the brain.
Define Disaccharide
a carbohydrate that consists of two sugar molecules; for example, maltose, sucrose, and lactose. simple carb
define Monosaccharide
a carbohydrate that consists of only one sugar molecule; for example, glucose, fructose, and galactose. simple carb.
Only monosaccharides can be absorbed by cells of the small intestine.
Where can these monosaccharides be found; fructose, glucose and galactose?
fructose and glucose(most abundant) can be found in fruit,veg and honey. They are converted to glucose by the liver.
Galactose is one of the monosaccharides that makes up milk sugar(lactose) the other is glucose.
What is the most abundant monosaccharide in our diet?
Glucose-it is part of all disaccharides, starches, and many fibers.
What are oligosaccharides
a short-chain carbohydrate that consists of 3–10 monosaccharide units joined together.
What are polysaccharides
Chains (or polymers) of more than 10 monosaccharides.
a long-chain carbohydrate that consists of more than 10 monosaccharides joined together; tend not to have a sweet taste (unlike monosaccharides and disaccharides) and can be found in foods such as whole grain breads, dried beans, and starchy vegetables.
What is fiber
carbohydrates that include cellulose and hemicellulose, which make up plant cell walls and impart structure to the plant; humans lack the digestive enzymes to break down plant fiber, so it passes undigested through the digestive tract.
What are starches
complex carbohydrates that are abundant in grains, legumes, and starchy vegetables; they consist of long chains of glucose joined together by digestible bonds; examples include amylose and mylopectin.
What is glycogen
a polysaccharide consisting of many glucose molecules; acts as the storage form of glucose (carbohydrate) in animal tissues (liver and muscles).Liver breaks down glycogen into glucose. Glycogen is broken down into glucose muscles for exercise.
Anatomy of grains-endosperm
Endosperm the element of a grain that contains the highest amount of starch and protein; this is all that remains when grain is refined.The endosperm is surrounded by nondigestible fibrous bran. It needs to be crushed,cracked, milled etc to expose the endosperm.
Where is amylase found and what does it break down?
Amylase breaks down starch molecules into shorter polysaccharides from salivary glands in the mouth.
Salivary amylase is inactivated by gastic acid and starch digestion stops.
In the small intestine, pancreatic amylase digests starch into oligosaccharides and maltose.
What is lactose intolerance
Low production of lactase in the intestines.
a disaccharide sometimes called “milk sugar,” as it is found only in milk, yogurt, and other dairy products; it is made up of glucose and galactose.
What hormone does the pancreas secrete to signal for tissue to take up glucose from the blood?
Insulin-skeletal muscle, cardiac muscle, and adipose tissue take up glucose from the blood. Signals muscles and liver to store as the polysaccharide glycogen or glucose into fat.
What is glucagon
A hormone released by the pancreas signals liver cells to release glucose into the blood to maintain blood glucose levels-release hours after eating.
Describe the four enzymes that break down carbs. Where are they and what do they break down
Amylase: digests starch into oligosaccharides and maltose. Saliva and sm. intestine.
Maltase: breaks down maltose into two glucose unites
Sucrase:digests sucrose into fructose and glucose
Lactase: Breaks down lactose into glucose and galactose. Absorbed by cells in sm. intestine
What is resistant starch?
Starch that is partially “trapped” in the physical structure in the internal portion of larger food particles. These structures can make it difficult for digestive enzymes to gain access to the starch, slowing digestion and the subsequent appearance of glucose in blood. It may improve our responsiveness to insulin and help feel full longer. Beans, underripe bananas, whole grain kernels, and pasta. Sucrose,lactose and fructose foods such as candies,dairy foods and fruit ofen produce a less dramatic rise in blood glucose then do starchy foods. This is because fructose and galactose have no immediate impact on blood glucose levels until they are covered to glucose in the liver.
Name the variety of names for added sugars
brown sugar, corn sweetener, dextrose, fructose, fruit juice concentrate, glucose, honey, invert sugar, lactose, maltose, molasses, raw sugar, sucrose, table sugar and high fructose corn syrup.
How does high fructose corn syrup differ from other sugars?
Its ratio of sucrose to glucose is 55% instead of 50%
What health issues do added sugar cause?
It contributes to about 13% of total calories for most Americans. Sugar creates additional calories without fiber or nutrition which contributes to obesity and cavities.
What are the two types of sugar alternatives?
Nutritive: Include polyols-alcohol forms of sugars sorbitol(from glucose), mannitol(mannose) made from sugars in plants, poorly absorbed by the body less then 4kcal per gram. Excessive consumption of sugar alcohol cause gastrointestinal symptoms including diarrhea.
Non nutritive: Aspartame made by linking two amino acids together (nutrasweet and equal). It is 200x sweeter then sucrose.
Stevia, Splenda(sucralose) and Sweet’n Low (saccharin)
The health and medicine division recommends how much fiber
38 grams for men and 25 grams for women under 50.
What is the difference between soluble and insoluble fiber?
Insoluble does not disolve in water and typically poorly fermented passes through gi mostly intact.
Benefit-soften stools and maintains reg BMs, reduce risk of hemorrhoids and diverticular disease.
Soluble fiber dissolves in water and easily fermented(broken down) by bacteria in the colon. whole grain oats,barley, rye citrus fruits legumes Mangos avocados pears apples psyllium Benefits-decrease risk of diabetes and coronary heart disease. Slow the emptying of food from the stomach into the small intestine which extends fullness following a meal.Slow digest and absorption and reduce rise of blood glucose following carb meal-beneficial for diabetics.
Both fibers:reduce cancer risk, more likely to be nutrient dense and lower in sat.fat, sodium and added sugar.
What is the difference between dietary fiber and functional fiber?
Dietary fiber-undigestible carbs that are present naturally in intact plant foods
Subtract fiber from total carbs to determine the amount of carbs that can be digested and absorbed.
Functional fiber is nondigestible carbs that have been added to a food product and have health benefits that are similar to those of dietary fiber.
Psyllium husks and Pectin from fruit.
When you add dietary fiber and functional fiber you get its total fiber
What does the FDA require added fiber to do?
Demonstrated to have at least one beneficial effect such as lowering blood cholesterol or improving bowel function.
A food label cannot display the 100% whole grain stamp if_____wheat germ has been added to the food.
Wheat germ
What role does the pancreas play?
Delivers digestive enzymes and regulating the body’s levels of blood glucose
What are the two types of diabetes and what happens in the body?
Type 1- autoimmune disease characterized by the destruction of insulin-producing cells in the pancreas pancreas does not produce enough insulin for blood glucose control
Type 2- specific tissues become resistant to the effects of insulin
Diabetes is an overload of glucose in the blood causing vascular(blood vessel) damage that can lead to serious and often fatal complications.
Hyperglycemia begins when fasting blood glucose concentrations are
100 mg/dl or greater
The number one killer for diabetes is
heart disease
What is the glycemic Index
Ranking of foods by how quickly and to what degree they raise blood glucose levels.
Low GI foods cause a smaller and more gradual increase
High GI foods create fast spikes
____is an increase in the acidity of the blood, which can lead to coma and death.
Ketoacidosis
____% of adults in the US are insulin-resistant
35
All of the following symptoms would be experienced by someone with untreated type 1 diabetes
extreme thirst, unintended weight loss, frequent urination
The following are true of infants born to mothers with gestational diabetes
They ahve an increased risk of
developing diabetes as an adult
becoming an obese child
shoulder injury during birth
Insulin stimulates the production of
proteins, glycogen and fat
What complications occur from gestational diabetes
high blood glucose levels cause the baby to grow too large-extra exercise and high fiber low GI diet.
Higher blood pressure and likely cesarean section
Gestational diabetes goes away after birth but remain at high risk for type two later in life.
Caused by obese prior to preg, older then 25, prediabetic, fam history of type 2, non white
A triglyceride is made up of ________ bound to one glycerol
three fatty acid chains
Define Lipoprotein
Lipoproteins are protein-containing spherical particles that act as the primary carriers of lipids in blood.
What are Chylomicons and what do they do?
They are a large lipoprotein. Chylomicron transports dietary fats from the small intestine during absorption.
Currently one-_____ of the calories in the average American diet come from fat. What is the acceptable macronutrient distribution range?
one third. The AMDR for total fat is 20-35%
What are sterols?
Complex lipids of four interconnected carbon rings with hydrocarbon side chain. Cholesterol is a sterol
What does cholesterol do in the body?
Its needed as a precursor(synthesizes other compounds) for the synthesis of bile acids, vitamin D and steroid hormones-does not provide energy
Explain the four Lipoproteins and what they transport.
Chylomicron: transports dietary fats and cholesterol from intestines to muscles and adipose tissue. Too large to travel in the blood stream. They travel in the lymph system. The will increase the most dramatically of all lipoproteins after a fatty meal.
Very Low-density lipoproteins(VLDL):Carries mainly triglycerides from liver to muscle and adipose tissue.
Low-density Lipoprotein(LDL): Primary cholesterol carrier, carries to all cells in the body. Converted from VLDL “bad” as elevated levels associate with heart disease
HDL: Picks up cholesterol from the body cells and returns them to the liver.(clean up crew)
What is the function of enzymes in the body
Enzymes are proteins that accelerate (catalyze) the thousands of critical chemical reactions that occur in our body (metabolism) and break down nutrients during digestion. They facilitate chemical reactions and are a function of protein. Many hormones are proteins.
Which two fatty acids are essential(cannot be self-generated, must be from diet)
Alpha-linoleNic acid(omega-3) and linoleic (omega-6). Both long chain polyunsaturated fatty acids with 18 carbon molecules
Hormone-like _____ compounds, which are produced from essential fats, modulate blood pressure and inflammation in the body.
Eicosanoid
Which enzyme breaks down triglycerides in the capillaries of adipose tissue?
lipoprotein lipase
What is the MIND diet?
MIND (Mediterranean-DASH Intervention for Neurodegenerative Delay) Diet for cognitive benefits.
green leafy vegetables, berries, beans, nuts, whole grains, poultry, and fish and subs sat fats for olive oil.
A fatty acid that is 18 carbons long and contains its first double bond at the third carbon molecule from the methyl end is called an:
Omega-3 fatty acid
Compare omega3 to omega 6 and the food sources of each.
Omega-3 fatty acids decrease heart disease risk, whereas omega-6 fatty acids promote blood clotting and inflammation.
Omega 3-walnuts, flax, chia, salmon,soy
Omega 6-vegetable oil,nuts and seeds
What are micelles?
Structures that transport dietary lipids to the surface of mucosal cells. They are the products of triglyceride digestion, along with bile acids and other fat-soluble dietary substances
What change in the structure of dietary lipids results in those lipids being harmful to health?
The conversion of cis fatty acids to trans fatty acids.
Which factor helps to distinguish between fatty acids
The length of the carbon chain
What characteristic of a fat determines wheather it is unsaturated?
Whether the fat has double bonds
Describe the sources and differences of Saturated and unsaturated fatty acids.
Sat: Carbon atoms have every bond filled with hydrogen atoms and solid at room temp.
Unsat: Have less hydrogen and one or more double bonds between carbon atoms. Liquid at room temp.
Plant foods-seeds, nuts, grains,veg oil
Eicosanoid
Hormonelike signaling molecules synthesized by arachidonic acid and eicosapentaenoic acid. Essential fatty acids provide parent compounds to produce eicosanoids. They are released during injury, stress, regulate blood pressure, inflammation, body temperature, and even pain. eicosapentaenoic acid(EPA) and arachidonic acid are both polyunsaturated fatty acids used for eicosanoid synthesis.
Pro-inflammatory eicosanoids are synthesized by arachidonic acid.
A fatty acid that is 18 carbons long and contains its first double bond at the sixth carbon molecule from the methyl end is called a(n):
Omega 6 fatty acid
Plaque
a waxy accumulation of cholesterol and triglycerides that infiltrate the arterial lining causing inflammation and injury to the vessel wall.
High _____ levels are common in people with heart disease or diabetes.
triglyceride
The American Heart Association recommends limiting trans fat to less than _____ percent of total calorie intake.
one
atherosclerosis
a type of inflammatory cardiovascular disease characterized by the narrowing and loss of elasticity of blood vessel walls, caused by accumulation of plaque and inflammation of tissue.
atherosclerosis
a type of inflammatory cardiovascular disease characterized by the narrowing and loss of elasticity of blood vessel walls, caused by the accumulation of plaque and inflammation of the tissue. Usually caused by elevated levels of cholesterol-rich low density lipoproteins in the blood. As LDL blood levels rise, they inflitrate the artery wall where the LDLs are likely to become oxidized(by reacting with unstable oxygen-containing molecules). Oxidized LDLs cause injury to cells that line the vessel wall, and this intiates an inflammatory process that attracts white blood cells called macrophages inside the arterial lining.
metabolic syndrome
a cluster of risk factors associated with the development of cardiovascular disease and type 2 diabetes.
_____ store(s) the body’s genetic information.
Deoxyribonucleic acid
Describe both steps of protein synthesis
Transcription -segments of DNA called genes provide the instructions for the assembly of amino acids into particular proteins.
The instructions are transcribed into mRNA.
Translation-ribosomes (read)translate the instructions(mRNA sequence) translated into the amino acid sequence to assemble the proteins
Protein is synthesized by linking different amino acids together by _____ bonds into a chain.
enzyme
How does protein get digested? list all steps
- In the stomach, pepsin breaks down denatured proteins into large polypeptide fragments
- Polypeptides are broken down by pancreatic proteases into smaller peptide fragments
- Protein digestion continues at the brush border by proteases anchored to the microvilli on the surface of mucosal cells.
- Individual amino acids, dipeptides, and tripeptides are absorbed by the mucosal cells of the small intestine, assisted by a variety of transport proteins.
- Dipeptides and tripeptides are broken down to single amino acids and leave the cell via transport proteins to enter the bloodstream.
What happens to excess amino acids
stored as fat or used as energy
_____ is the continuous breakdown and resynthesis of proteins in the body
protein turnover
The overall shape of a protein molecule determines its:
function
Define denaturation
the unfolding or breakdown of a protein into smaller peptide units or amino acids
The denaturation of protein by hydrochloric acid allows enzymes to access peptide bonds.
allows enzyme access to the peptide bonds
List a few caratenoids
beta-carotene, lycopene, lutein, and zeaxanthin
A possible mechanism of action of polyphenols in cancer prevention is their ability to:
trigger cell death in cancer cells.
Polyphenols interrupt cellular communication systems.
Complete proteins provide all of the
essential amino acids in the ideal proportions.
moderate amounds of dark chocolate may have beneficial effects on
Insulin resistance. Dark chocolate contains flavanols.
Iron sources from a vegetarian diet are more absorbable with what? Which mineral should not be taken with iron-rich meals?
Vitamin C helps with iron absorption-dried apricots, raisins, green leafy vegs like broccoli and bok choy have both.
Legumes and nuts are high in iron add peppers or citrus to improve iron absorption.
Calcium decreases iron absorption.
describe the four stages in the development of cancer
Initiation-cells DNA becomes permanently mutated from exposure to uv light, pollution, cigarette smoke. All cells that result from the division of this cell are also mutated. The immune system may recognize the mutated cell and destroy it.If not it progresses to the next stage
Promotion-inflammation or chemicals promote mutated Cells divide into a colony called a tumor.
Tumor progression-additional mutations occur even faster.
Malignancy-Mutated cells begin spreading to other tissue by way of the bloodstream. They disrupt the function of tissues.
Glycemic load calculates the effect of the actual serving size of food on ______?
blood glucose levels.
Glycemic Load is the extent of increase in blood glucose levels, calculated by multiplying the glycemic index by the carbohydrate content of a food. More useful then the Glycemic Index.
Insulin resistance
Cells respond poorly to insulin.the pancreas can no longer keep up with the increased demand for insulin; consequently, the concentration of glucose in the blood increases. Insulin resistance also interferes with insulin’s ability to signal the liver to stop glucose production, and the liver’s continued production of glucose also contributes to the increase in blood glucose levels.
How are foam cells(fat-laden macrophages) formed?
Inside the vessel wall, macrophages take up the oxidized LDLs.
