Nutrition Ch 4 Study Guide

Define: unrefined carbohydrate

Foods that aren't processed and are all natural. Foods that are eaten as they are in nature or with minimal processing Unrefined = More nutrients

Define: polysaccharides

containing many (hundreds to thousands) of glucose units linked together

Define: oligosaccharides

contains 3 to 10 single sugar units joined together Raffinose and Stachyose Food sources: dried beans, onions, whole wheat, cabbage family These give us gas.

Define: diverticulitis

diverticuli entrap feces becoming inflammed or infected

Name the three disaccharides important in nutrition. What 2 simple sugars are present in each of these disaccharides? In what foods are these sugars found?

>Disaccharides --Sucrose: glucose + fructose >>>Table sugar (cakes, cookies, pies, etc) --Maltose: glucose + glucose >>>Occurs in Malt --Lactose: glucose + galactose >>>Milk, dairy products

Name the three polysaccharides important in nutrition. How are starch, fiber, and glycogen similar, and how do the differ?

>Polysaccharides --Starch >>>storage form of glucose in plants --Glycogen >>>storage form of glucose in animals stored in the liver and muscle. --Fiber >>>indigestible (nonstarch) polysaccharide in plant foods. Cannot by digested by humans. No human enzyme can break beta bonds.

Define: glycemic load

A better indicator of a food's effect on blood glucose levels. (Total carbs (g) in 1 serving x glycemic index)/100 Goal: choose foods w/ low glycemic load less than 20 Foods with high glycemic cause: high insulin drop in blood sugar hunger

Define: non-nutritive sweeteners

Artificial sweeteners: alternatives to sugar Aspartame Sucralose Acesulfame-K

Define: lactase

Breaks down lactose into glucose and galactose

Why is carbohydrate said to spare protein? What is the minimum amount of carbohydrate which must be consumed in one day to ensure complete sparing of body protein and to prevent ketosis?

Carbs are said to spare protein because if enough carbs are present in your diet, your body won't try to break down the protein to get it's energy. The RDA for carbs is 130g/day.

What are the end products of carbohydrate digestion? Name the enzymes that break down starch and the disaccharides lactose, maltose, and sucrose.

Disaccharides and complex carbohydrates must be digested to monosaccharides before they can be absorbed into the body. Once absorbed, carbs travel in the blood to the liver. Carb digestion begins in the mouth, but most starch digestion and the breakdown of disaccharides occur in the small intestine. 1.) In the mouth, the enzyme salivary amylase starts breaking starch into shorter polysaccharides. 2.) In the stomach, salivary amaylase is inactivated by acid, so not carb digestion occurs. 3.) In the small intestine, pancreatic amylase completes the job of breaking down starch into disaccharides and oligosacharides. 4.) At the villi of the small intestine, enzymes attached to the microvilli complete the digestion of disaccharides and oligosaccharides into monosaccharides. 5.) In the large intestine, fiber and other indigestible carbs are partially broken down by bacteria to form short-chain fatty acids and gas. The remaining fiber is excreted in the feces.

Define: diverticulosis

Diverticula: Sac or pouch, protruding form GI wall

Define: glycemic response

Factors influencing: Food's starch structure, fiber content, how processed the food is. A food's glycemic index is based on a serving giving 50g of carbs (unrealistic) and the glycemic index is given if the food is only eaten by itself.

Define: constipation

Feces doesn't come out easily; You have to strain to expel them. Long-term consequences of straining: Hemorrhoids, Diverticulitis and Diverticulosis

What three sugars make up monosaccharides?

Glucose: honey, fruit, "blood sugar" Fructose: ripe fruit, honey, high fructose corn syrup Galactose: a part of milk sugar

Glycogen has a highly branched structure. What is the advantage to this structure?

Greater number of ends for glucose release, resulting in >Rapid breakdown by enzymes >Surge of glucose available as an immediate energy source

Define: complex carbohydrates

Polysaccharides; they are generally not sweet tasting the way that simple carbohydrates are. They include glycogen and starch.

Define: Type II diabetes

Insulin not effective Blood sugars stay high Large blood vessels can cause atherosclerosis Small blood vessels can cause kidney failure; degeneration of the retina, and blindness Can cause nerve damage Increased incidence of infection

Define: Type I diabetes

Insulin-Dependent Diabetes The Pancreas never makes insulin if you're type 1 diabetic. Characteristics: High blood glucose levels Insulin no longer produced pancreas Blood delivery to tissues is reduced drastically Treatment: Maintain blood glucose within normal range to prevent tissue damage

Define: refined carbohydrate

Many of the carbs we ingest are refined carbohydrates. A good majority of our foods today are made from refined grains and added sugars.

Define: simple carbohydrates

Monosaccharides (1 sugar unit) and disaccharides (2 sugar units) are simple carbohydrates Commonly refered to as sugars

What is a monosaccharide?

One sugar unit

Which carbohydrates are described as simple, and which are complex?

Simple: >Monosaccharides --Glucose --Fructose --Galactose >Disaccharides --Sucrose --Maltose --Lactose Complex: >Oligosaccharides --Raffinose --Stachyose >Polysaccharides --Starch --Glycogen --Fiber

What are the two types of fiber?

Soluble: dissolve in water, forming viscous (gel-like) structure found inside and around plant cells Soluble cannot be digested by human enzymes Bacteria in large intestine ferment (break down) soluble fiber Soluble major sources: Oats, barley, orange and apple pulp, and psyllium Insoluble: doesn't dissolve in water; forms structural parts of plants tough, fibrous structures of fruits, veggies, and grains Insoluble cannot be broken down by bacteria in the large intestine Insoluble food sources: Bran layer of all seeds; grains, hulls, skins of fruits and veggies

What three sugars make up disaccharides?

Sucrose: Contains the 2 sugars- glucose + fructose (Example: Table sugar) Maltose: glucose+glucose (Example: Malt) Lactose: glucose + galactose (Example: Milk, dairy products)

What is the function of carbohydrates in the body? After a meal, what are the possible fates of glucose in the body?

The body's main source of fuel. Carbs are easily used by the body for energy. Depending on how glucose enters your body, the sugar can go straight into your blood stream, such as with soda, but if it needs to be broken down then it takes longer and has a better overall effect on your health.

How does the body maintain its blood glucose concentration? What hormones are involved? What happens when the blood glucose concentration rises too high or falls too low?

The pancreas releases insulin to control the transport of glucose from blood into cells In both muscle and liver cells, insulin promotes the conversion of glucose into glycogen for storage In liver and fat-storing cells, insulin promotes conversion of glucose to fat for storage When blood glucose levels are above normal the blood releases insulin. When blood glucose levels are below normal Pancreas releases glucagon Liver Cels break down glycogen Epinephrine "fight or flight" hormone released with stressful situations which causes rapid breakdown of liver glycogen to glucose. Increases supply of glucose for immediate energy needs.

Define: diabetes

characterized by elevated blood glucose

Define: epinephrine (adrenaline)

a "flight or fight" hormone released with stressful situations. Causes rapid breakdown of liver glycogen to glucose. Increases supply of glucose for immediate energy needs

Define: aspartame

a very sweet substance used as an artificial sweetener, chiefly in low-calorie products. It is a derivative of aspartic acid and phenylalanine.

Define: sucralose

a white, crystalline powder, produced synthetically from sucrose, about 600 times as sweet as sucrose but having no calroies

Define: hypoglycemia

abnormally low blood glucose concentrations

Define: glycogen

animal polysaccharide: storage form of glucose in animals; stored in: Liver: source of blood glucose Muscle: supplies energy during high intensity and endurance exercise

Define: amylase

from the pancreas; completes the breakdown of starch into the disaccharide maltose.

Define: protein-sparing action

having adequate carbohydrates in diet prevents the breakdown of protein for energy If your body doesn't have enough carbs, it'll draw its energy from your protein.

Define: ketosis

high levels of ketone bodies in the blood either due to inadequate urinary excretion or high ketone body production.

Define: lactose intolerance

inability to digest milk sugar (lactose) due to insufficient production of lactase

Define: fibers Why can't fiber be digested by humans?

indigestible (nonstarch) polysaccahrides in plant foods Fiber cannot be broken down by humans because no human enzyme can break the beta bonds of the fiber

Define: starch What are some plant-based food sources of starch?

plant polysaccharide: storage form of glucose in plants Food sources of starch: Vegetables- Corn, root veggies (carrots), potatoes Legumes Unripe Fruit Grains

Define: ketone bodies

products of incomplete fat breakdown made by the liver when glucose is not available in the cells. Formed when there isn't enough carbohydrates in body to meet energy needs. Carbs are required for the complete breakdown of fats to yield energy through the citric acid cycle. The units that breakdown fats will form together to make ketone bodies.

Define: insulin

released from pancreas when blood glucose is high. Controls the transport of glucose from blood into cells In both muscle and liver cells, insulin promotes the conversion of glucose into glycogen for storage In liver and fat-storing cells, insulin promotes conversion of glucose to fat for storage

Define: glucagon

released from pancreas when blood glucose is low Causes liver cells to break down glycogen Releasing glucose into the blood Signals liver to synthesize new glucose molecules