Quizlet - Summary Basic Nutrition PDF

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Study guide for nutrition's first exam ...

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Nutrition study guide first exam Study online at quizlet.com/_82ufj9 1.

1) If your blood sugar (glucose) is low where can glucose come from to increase the levels back into the normal range?

Glucagon causes body proteins to amino acids so that the liver can stimulate glucogenesis and make glucose from amino acids (epinephrine and cortisol stimulate gluconeogenesis as well) Gluconeogenesis involves breaking down proteins in blood and tissues into amino acids and converting them into glucose Happens when there are not enough carbohydrates This means that the body cannot use protein to make new cells, repair tissue damage, support the immune system, or perform other functions

2.

1) Name of metabolic pathway that converts glucose to pyruvate?

glycolysis

3.

cis vs trans triglycerides:

Unsaturated fatty acids can be either trans or cis. Only cis is kinked Cis means that both hydrogen atoms are on the same side à kind at the double carbon bond o Usually find cis in nature and thus in foods such as plant oils, fresh vegetables, and whole grains Trans fatty acids à hydrogen atoms are on opposite sides of the double carbon bond. So they are more straight and rigid Small amounts of trans are found in meats and full-fat dairy products. Majority of trans fats are commercially produced during food processing. Ex: hydrogenation of oils such as corn or safflower oil adds hydrogen to the fatty acids. The monounsaturated and polyunsaturated fatty acids in the oil are broken and additional hydrogen is inserted at diagonally opposing sides. This straightens out the molecules and makes the oil more solid. Hydrogenation of fats helps foods that have these such as cakes, cookies, and crackers to resist rancidity because the additional hydrogen reduces the susceptibility of the carbon atoms to undergo oxidation Hydrogenation can be controlled to make the oil less or more saturated. Ex: corn oil that is partially hydrogenated becomes margarine Saturated and trans fatty acids raise blood cholesterol levels and appear to change cell membrane function and the way cholesterol is removed from the blood à increase CVD risk

4.

glycemic index vs glycemic load

Glycemic index is the potential of foods to raise blood glucose levels. Foods with a high index cause a sudden surge in blood glucose which triggers a large increase in insulin and then a dramatic drop in blood glucose. Low glycemic index causes a low to moderate fluctuation in blood glucose The way the food is prepared and its fat and fiber content can also affect how quickly the body absorbs it Some believe that the glycemic load is better because it is the number of carbohydrates it contains * glycemic index of that carbohydrate. Foods with a lower glycemic load are a better choice for people with diabetes because it will not trigger a dramatic fluctuation in their blood glucose. Can also reduce risk of heart disease because they usually have more fiber Lower glycemic index diet decreases total blood cholesterol and LDL

5.

how are carbohydrates absorbed?

Monosaccharides are then absorbed in the mucosal cell lining the small intestine where they pass through and enter the blood o Glucose and galactose are absorbed through active transport using a carrier protein saturated with sodium o Fructose is via facilitated diffusion, so no energy needed. It is a slower process and too much fructose can lead to diarrhea

6.

How are carbohydrates stored in the body and where?

lipid stores glycogen and releases it when we need glucose once carbohydrate storage of muscle and liver are reached, any excess glucose can be stored as fat in adipose tissue

7.

how are fats used for physical activity?

o Lipids are the major energy source during physical activity, especially those 30 mins or more. Best way to lose body fat is to exercise and moderately reduce energy intake o Adrenaline strongly stimulates breakdown of stored fat which activates hormone-sensitive lipase, an enzyme in adipose cells that remove single fatty acids from stored triglycerides. Then free fatty acids and glycerol are released in the blood o Epinephrine also signals the pancreas to decrease insulin production because insulin inhibits fat breakdown. o When fatty acids are released from adipose cells, they travel in the blood attached to albumin to the muscle cells. Then they enter the mitochondria and use oxygen to produce ATP o Some of the free glycerol from triglycerides go to the liver and make glucose

8.

how are triglycerides catogorized based on saturation?

Adjacent carbons can have double bonds which makes the fatty acid less saturated If a fatty acid does not have any double bonds, it is a saturated fatty acid. Ex: coconut oil, palm kernel oil, butter, cheese, whole milk, cream, lard, and beef fat If there is one double bond: monosaturated fatty acid which are usually liquid at room temperature. Ex: olive oil, canola oil, peanut oil, and cashew nuts If there is more than one double bond: polyunsaturated fatty acid. They can also be classified by where the double bonds are. If they are next to the third carbon from the omega carbon, they are called omega-3 fatty acids and if next to the 6th, they are omega -6. They are also liquid at room temperature. ex: soy, canola, corn, and safflower oils Animal fats give 40-60% of their energy from saturated fats whereas plants give 80-90% of their energy from monosaturated and polyunsaturated fats o Most oils are a good source of MUFAs and PUFAs Diets in plant foods are lower in saturated fats than diets in high animal products

9.

how are triglycerides classified based on chain length?

The most common fatty acids in our diet are 18 carbons in length. Usually fatty acids have even number of carbons from 4-24 Short chain: less than 6 carbons Medium chain: 6-12 Long chain: 14 or more The beginning carbon is alpha and the end carbon is omega w Chain length affects method of digestion, absorption, and how triglycerides are metabolized and used in the body Short and medium are digested, transported, and metabolized more quickly than long ones. Long ones are more abundant in nature and so there are more of them in our diet

10.

how do carbohydrates spare proteins?

Gluconeogenesis involves breaking down proteins in blood and tissues into amino acids and converting them into glucose Happens when there are not enough carbohydrates This means that the body cannot use protein to make new cells, repair tissue damage, support the immune system, or perform other functions

11.

how does glucagon increase blood glucose levels?

When you have not eaten for a while, glucose drops. So alpha cells of the pancreas secrete glucagon that causes the liver to convert stored glycogen to glucose and secrete it in the blood also stimulates gluconeogenesis

12.

how does the body break down carbohydrates?

Saliva amylase breaks down starch into smaller particles and then disaccharide maltose. Disaccharides are not digested in the mouth As the bolus leaves the mouth and enters the stomach, carbohydrate digestion stops because the acid inactivates salivary amylase Majority of carbohydrate digestion is in the small intestine by pancreatic amylase that is secreted from the pancreas. Pancreatic amylase digests remaining starch to maltose. Other enzymes in the microvilli (maltase, sucrase, lactase) break down other disaccharides to monosaccharides

13.

how does the body store sugar?

as glycogen and fat

14.

how does the type and amount of food affect hunger?

Foods that have protein have the highest level of satiety because they increase satiety hormones and reduce ghrelin secretion. Next is high-fat and then carbohydrates Meal bulk also affects hunger: fiber and water in the food. Bulky meals stretch the stomach and small intestine, which sends signals to the hypothalamus telling us that we are full Beverages < semisolid foods < solid foods in terms of satiety

15.

how do fats help maintain cell function and provide protection to the body?

o Lipids, especially PUFAs, phospholipids, and cholesterol, are a critical part of every cell membrane, where they help maintain membrane integrity, determine what substances are transported into and out of the cell, and regulate what substances can bind to the cell o Help maintain cell fluidity. Ex: wild salmon that live in cold water have high levels of omega-3 fatty acids that help membranes stay fluid at low temperatures o Lipids are primary components of tissues of the nervous system. The body uses lipids for development, growth, and maintenance of these tissues and transmission of impulses from one nerve to the next o Adipose tissue pads the body and protects organs such as the kidney and liver o Fat under the skin helps with insulation to retain body heat

16.

how do fats help transport fatsoluble vitamins?

o Help absorption and transport of fat-soluble vitamins (A, D, E, and K) o Fat soluble vitamins are transported in the gut to the intestinal cells for absorption as part of micelles and are transported to the body cells as part of chylomicrons o Vitamin A: normal and night vision o Vitamin D: regulate blood calcium and phosphorus concentrations à bone health o Vitamin E: cell membranes healthy o Vitamin K: proteins in blood clotting and bone health

17.

how do fibers help us stay healthy?

Fiber consumption has many benefits Helps prevent hemorrhoids, constipation, and other intestinal problems by keeping the stool moist and soft Reduces risk of diverticulosis, a condition caused by trying to eliminate small, hard stools. When there is too much pressure used, the intestinal cause bulge out and form pockets. Feces and fibrous material can get trapped in these pockets, which become infected and inflamed Can reduce risk of colon cancer May reduce risk of heart disease by delaying or blocking the absorption of dietary cholesterol in the blood. Also, when soluble fibers are digested, bacteria in the colon make short-chain fatty acids that reduce production of LDL May lower risk of type 2 diabetes. Fiber slows release of glucose in the blood, so helps body better regulate insulin production and glucose levels Enhance weight loss because causes one to be more full

18.

how do micelles help in digestion of fat in the small intestine?

Most of the digestion happens in the mucosal lining of the small intestine with the help of micellesà spherical compound made of bile salts and biliary phospholipids that capture the lipid digestion products such as fatty acids, free cholesterol, and monoglycerides and transport them to the enterocytes for absorption

19.

how is glucose regulated?

Insulin comes from the beta cells of the pancreas and transported in the blood to cells of tissues throughout the body. Insulin stimulates glucose transporters that are carrier proteins to transport glucose across the cell membrane Insulin also stimulates the liver and muscles to take up glucose and store it as glycogen When you have not eaten for a while, glucose drops. So alpha cells of the pancreas secrete glucagon that causes the liver to convert stored glycogen to glucose and secrete it in the blood Glucagon also causes body proteins to amino acids so that the liver can stimulate glucogenesis and make glucose from amino acids Epinephrine, norepinephrine, cortisol and growth hormones are also hormones that work to increase blood glucose Epinephrine and norepinephrine are secreted by the adrenal glands and nerve endings when blood glucose is low and increase glycogen breakdown in the liver. They also increase gluconeogenesis Cortisol and growth hormones are secreted by the adrenal glands to act on the liver, muscle, and adipose tissue o Cortisol increases gluconeogenesis and decrease the use of glucose by muscles and body organs Growth hormone decreases glucose uptake by the muscle and increases mobilization and use of fatty acids stored in the adipose tissue, and increases the liver’s output of glucose

20.

Key enzyme for digestion of starch and what is produces?

Plants store glucose as starch Two types of starch are amylose and amylopectin o Amylose is a straight chain o Amylopectin is highly branched Being branched increases exposure to digestive enzymes. So, it is digested quicker than amylose. Amylopectin raises blood glucose more quickly than amylose Saliva amylase breaks down starch into smaller particles and then disaccharide maltose. Disaccharides are not digested in the mouth Pancreatic amylase digests remaining starch to maltose. Other enzymes in the microvilli (maltase, sucrase, lactase) break down other disaccharides to monosaccharides

21.

linoleic acid vs alpha linolenic acid:

Eicosanoids are produced in nearly every cell in the body. They help regulate Gi tract motility, secretory activity, blood clotting, vasodilation and vasoconstriction, vascular permeability, and inflammation o Ex: prostaglandins, thromboxane, and leukotrienes Linoleic acid is an omega-6 fatty acid. Found in vegetable and nut oils such as sunflower, safflower, corn, soy, and peanut oils. Metabolized in the body to arachidonic acid which is a precursor to some eicosanoids Alpha-linolenic acid is an omega-3 fatty acid. Found in dark green, leafy vegetables, flaxseeds and flaxseed oil, soybeans, and soybean oil, walnuts, and canola oil. o Precursor to two omega-3 fatty acids: eicosapentaenoic acid EPA and docosahexaenoic acid DHA that protect against CVD. The body only makes limited amounts of these in the body. They are in fish (salmon and tuna have more than cod and flounder), shellfish, and fish oils Diets high in EPA and DHA make prostaglandins and thromboxanes that reduce inflammatory

22.

List three health Helps prevent hemorrhoids, constipation, and other intestinal problems by keeping the stool moist and soft benefits of Reduces risk of diverticulosis, a condition caused by trying to eliminate small, hard stools. When there is too much dietary fibers. pressure used, the intestinal cause bulge out and form pockets. Feces and fibrous material can get trapped in these pockets, which become infected and inflamed Can reduce risk of colon cancer May reduce risk of heart disease by delaying or blocking the absorption of dietary cholesterol in the blood. Also, when soluble fibers are digested, bacteria in the colon make short-chain fatty acids that reduce production of LDL May lower risk of type 2 diabetes. Fiber slows release of glucose in the blood, so helps body better regulate insulin production and glucose levels Enhance weight loss because causes one to be more full

23.

What are added sugars?

added sugars in general—that is, any form of sugars and syrups added to foods during processing or preparation—that have become a concern in the American diet. Added sugars are not chemically different from naturally occurring sugars. however, foods and beverages with added sugars have lower levels of vitamins, minerals, and fiber than fruits and other foods that naturally contain simple sugars.

24.

what are carbohydrates?

one of three macronutrients, preferred energy source of nerve cells such as the brain

25.

what are cofactors? + their two types

o Many cofactors are minerals such as iron or zinc that help bind different parts of an enzyme together, thereby speeding up the reaction o If the cofactor is organic (has carbon) it is termed coenzyme o A lot of coenzymes come from vitamins, especially vitamin Bs. Ex: FAD and FADH2 are derivates of B-vitamin riboflavin and are coenzymes

26.

what are complex carbohydrates?

they are oligo and polysacharides

27.

what are dietary, functional, and total fiber?

o Dietary fiber is the nondigestible parts of plants that form the support structure of leaves, stems, and seeds. Plant’s skeleton o Functional fiber is nondigestible forms of carbohydrates that are extracted from plants or other manufactured in a lab that have known health benefits. It is added to foods and is the form found in fiber supplements such as cellulose, guar, gum, pectin, inulin, and psyllium o Total fiber is the sum of dietary fiber and functional fiber

28.

what are dietary reference intakes?

Dietary Reference Intakes DRIs are the standards for recommended intake values for various nutrients goal: prevent and reduce risk of chronic disease and promote optimal health for healthy people, not those with disease and deficiencies

29.

what are enriched vs fortified foods?

Enriched foods are foods in which nutrients that were lost during the processing have been added back, so the food meets a specified standard. But they only put a handful of nutrients and leave the product low in fiber Fortified foods have nutrients added that did not originally exist in the food like cereals with vitamins

30.

what are essential fatty acids?

Length and placement of double bond of fatty acids determine their function in the body When making fatty acids, the body cannot insert double bonds before the ninth carbon from the w-carbon. Therefore, fatty acids with double bonds closer to the methyl end at w-3 and w-6 are essential fatty acids because we can’t make them and have to eat them There are two essential fatty acids: linoleic acid and alpha-linolenic acid ALA. The body synthesizes these into longer chain fatty acids that are precursors to biological compounds called eicosanoids that we need for growth and health

31.

what are lactose, maltose, and sucrose?

disaccharides Lactose is made of glucose and galactose and is in sugar. Maltose has two glucose molecules. Does not occur in the body by itself but is bound together with other molecules. When body breaks down other things, the by-product is maltose. o Also results from fermentation during beer and alcohol production o Fermentation is an anaerobic process where an agent like yeast breaks down organic substances and makes ATP Sucrose is made of one glucose and one fructose. It is sweeter than lactose and maltose. This is in honey, maple syrup, fruits, and vegetables. o Table sugar, brown sugar, and powdered sugar are made by refining the sucrose in sugarcane and sugar beets Disaccharides are held together by a bond between the oxygen and carbon. There are either alpha bonds or beta bonds. Alpha bonds are easily digestible by humans (sucrose and maltose) and beta bonds are very difficult to digest and may not even by digestible at all (lactose)

32.

what are macronutrients?

Carbs, proteins, and lipids are the only nutrients that the body breaks down to give energy. Water and energy nutrients are called macronutrients which are needed in a large quantity to support life functions are to provide energy and support activity

33.

what are miconutrients?

they do not directly provide energy types: vitamins and minerals called micro because we need less of them

34.

what are nutrients?

chemicals found in food that are critical to growth and function there are 6 groups of nutrients in foods: organic: carbs, lipids, proteins, and vitamins inorganic: minerals and water

35.

what are oligosaccharides?

have 3-10 monosaccharides. two of the most common ones are raffinose and stachyose

36.

what are percent daily values?

–How much a ser...