Chapter 4: Carbohydrates, Starch & Fiber

What substance does the pancreas secrete when blood glucose falls? - ketone bodies - glycogen - insulin - glucagon

- glucagon (The pancreas secretes the hormone glucagon when blood glucose falls.)

If you haven't eaten for a few (about four) hours, the body initiates __________, using __________ glycogen stores to increase blood glucose levels. - glycogenesis; liver and muscle - gluconeogenesis; liver - glycogenolysis; muscle - glycogenolysis; liver

- glycogenolysis; liver (Liver glycogen stores are mobilized to increase blood glucose levels if you haven't eaten for longer than four hours.)

Which food would provide the lowest glycemic index? - ice cream with chocolate syrup - popcorn - white bread with jam - baked potato with low-fat cheese

- popcorn (Popcorn has the lowest glycemic index of all the answers provided.)

Which food contains the most carbohydrates? - 1 cup of cooked corn - 1 tablespoon of peanut butter - 1/2 cup of raisins - 1 cup of low-fat milk

- 1/2 cup of raisins (A half-cup of raisins contains about 60 grams of carbohydrate.)

Which blood glucose lab value is considered a "positive" test indicative of diabetes mellitus? - 100 milligrams per deciliter (after eating 50 grams of carbohydrate) - 101 milligrams per deciliter (fasting) - 125 milligrams per deciliter (after eating 50 grams of carbohydrate) - 130 milligrams per deciliter (fasting)

- 130 milligrams per deciliter (fasting) (Fasting readings above 126 milligrams per deciliter are considered a "positive" test; there must be two separate positive tests for an official diagnosis of diabetes.)

The day-to-day choices people make can help prevent type 2 diabetes. For those who have diabetes, there are lifestyle guidelines to follow that will help control the disease. Read the statements below and select the correct preventative measures or behaviors that can help control the disease. Select all that apply. - A preventative measure for type 1 diabetes is to maintain a healthy weight. - A preventative measure for type 2 diabetes is to eat a healthful diet. - Many people with type 2 diabetes would likely benefit from moderate weight loss. - Those with diabetes should limit alcoholic beverage intake. - A preventative measure for type 2 diabetes is to get regular physical activity.

- A preventative measure for type 2 diabetes is to eat a healthful diet. - Many people with type 2 diabetes would likely benefit from moderate weight loss. - Those with diabetes should limit alcoholic beverage intake. - A preventative measure for type 2 diabetes is to get regular physical activity.

Which of the following statements correctly describes the triggers that result in the release of hormones which regulate blood glucose? - Cortisol, often referred to as the stress hormone, is released from the adrenal cortex when blood glucose levels are high. - Insulin is secreted from the alpha cells of the pancreas when blood glucose levels rise after a carbohydrate-rich meal. - The levels of epinephrine, an adrenal gland hormone, are reduced when blood glucose levels are low. - Glucagon is secreted from the alpha cells of the pancreas when blood glucose levels are low.

- Glucagon is secreted from the alpha cells of the pancreas when blood glucose levels are low.

Which of the following statements correctly describes the process of carbohydrate absorption? - Glucose and galactose are absorbed into the enterocyte by active transport before they enter the capillaries for transport through the bloodstream. - Fructose and galactose must be converted to glucose in the enterocyte before they can be absorbed by active transport. - Galactose and fructose are absorbed into the enterocyte by active transport. - Disaccharides are broken down by the brush border enzymes into glucose, which is then absorbed into the enterocyte by facilitated diffusion and transported through the lacteal into the bloodstream.

- Glucose and galactose are absorbed into the enterocyte by active transport before they enter the capillaries for transport through the bloodstream.

The carbohydrate-rich foods you consume start out with a variety of complex and simple carbohydrates, but ultimately, they must be digested into monosaccharides in order to be absorbed into the bloodstream. Blood glucose levels are regulated closely by insulin and glucagon (and four other hormones) in order to ensure a steady supply of glucose to the brain and other tissues. Select all of the sentences below that correctly describe a step in the processes of digestion, absorption, and/or blood glucose regulation. - Some fiber is broken down by bacteria in the small intestine, and the smaller chains are absorbed through the brush border into the bloodstream. - Glucose, fructose, and galactose are absorbed by the enterocytes and then enter the bloodstream. - After a meal, blood glucose levels rise, and the pancreas secretes insulin, which aids in glucose uptake into cells and stimulates glycogenesis and lipogenesis. - After a meal, blood glucose levels rise, and the pancreas secretes glucagon, which stimulates glycogenolysis and gluconeogenesis. - The brush border of the small intestine produces enzymes that digest disaccharides into glucose, fructose, and galactose.

- Glucose, fructose, and galactose are absorbed by the enterocytes and then enter the bloodstream. - After a meal, blood glucose levels rise, and the pancreas secretes insulin, which aids in glucose uptake into cells and stimulates glycogenesis and lipogenesis. - The brush border of the small intestine produces enzymes that digest disaccharides into glucose, fructose, and galactose.

How does dietary fiber reduce blood cholesterol? - It digests the cholesterol. - It hydrolyzes the cholesterol. - It deactivates the cholesterol. - It binds bile acids in the intestinal tract, which increases removal of cholesterol from the blood.

- It binds bile acids in the intestinal tract, which increases removal of cholesterol from the blood. (Cholesterol-rich bile acids are sequestered by fiber and excreted. The liver then removes cholesterol from the blood to replace the bile acids.)

What happens to excess glucose? - It is converted to protein. - It is eliminated. - It causes glycogen stores to expand past capacity. - It is ultimately stored as fat.

- It is ultimately stored as fat. (Excess glucose is stored as glycogen in the muscles and liver. When glycogen stores are full, excess glucose is stored as fat.)

Diabetes is an increasingly common health condition with a host of potential complications. Fortunately, good diet choices can help a person control his or her blood glucose levels, leading to better management of the disease. Which of these statements are consistent with the dietary recommendations for someone with diabetes? Select all that apply. - The type of carbohydrate food chosen is more important than the total amount of carbohydrate consumed. - Saturated fat should be limited to less than 10%% of daily kilocalorie intake, or less than 7% if a person has heart disease. - About 60 to 70%% of calories should come from carbohydrates and monounsaturated fats combined. - High-fiber foods like whole grains, vegetables, and fruits can help control blood glucose and blood lipids. - Those with diabetes who wish to improve blood glucose control should eliminate all sugar (added and natural) from their diets.

- Saturated fat should be limited to less than 10%% of daily kilocalorie intake, or less than 7% if a person has heart disease. - About 60 to 70%% of calories should come from carbohydrates and monounsaturated fats combined. - High-fiber foods like whole grains, vegetables, and fruits can help control blood glucose and blood lipids.

Which of the following statements best describes the role of dietary fiber in reducing the risk of developing diseases? - Diverticulosis is caused when increased pressure in the colon causes weak spots to bulge forming pouches called diverticula. Consuming a diet high in fiber slows the passage of stool causing greater risk for diverticulitis. - Soluble fibers slow the digestion and release of glucose preventing a spike in blood glucose following a meal. This increase in transit time may improve long-term control of diabetes. - Dietary fiber reduces the growth of intestinal bacteria in the colon, which may reduce the risk of colon cancer. - As insoluble dietary fiber passes through the large intestine, it binds to bile acids preventing them from being reabsorbed. Binding or sequestering bile acids helps lower elevated blood cholesterol and the risk of cardiovascular disease.

- Soluble fibers slow the digestion and release of glucose preventing a spike in blood glucose following a meal. This increase in transit time may improve long-term control of diabetes.

How is digestion altered in individuals who have been diagnosed with lactose intolerance? - Lactose intolerance is due to a deficiency of lipase, a brush border enzyme that breaks down the disaccharide lactose. - The continuous exposure to undigested lactose in the intestinal tract promotes an alkaline environment created by the intestinal bacteria fermenting the carbohydrate, which increases further fermentation. - Undigested lactose draws water into the gastrointestinal tract, causing diarrhea and cramping. - The monosaccharides glucose and galactose that make up the disaccharide lactose are linked with an alpha bond.

- Undigested lactose draws water into the gastrointestinal tract, causing diarrhea and cramping.

The alpha bonds of carbohydrates are broken down during digestion by specific enzymes. Lactose contains a beta bond, which is digestible by lactase. Most carbohydrates that contain beta-glycosidic bonds are not digestible because humans lack the enzyme needed to break down the bond. Which of the following carbohydrates contain alpha bonds that are digestible by humans? - amylose and amylopectin - cellulose and hemicellulose - pectin and stachyose - raffinose and beta-glucan

- amylose and amylopectin

Whole grains contain __________. - bran, endosperm, and glucose - soluble and insoluble fibers - bran, endosperm, and germ - bran, starch, and germ

- bran, endosperm, and germ (Whole grain foods contain all three parts of the grain: the bran, endosperm, and germ.)

Insoluble fiber promotes gastrointestinal health by increasing stool __________, which _________ stool transit time through the GI tract. - bulk; decreases - cholesterol; increases - bulk; increases - cholesterol; decreases

- bulk; decreases (Increased bulk stimulates peristalsis, which speeds up the movement of feces through the intestines.)

The chemical reaction in which two molecules combine to form a larger molecule, and water is released is called __________. - photosynthesis - glycosidic bond - condensation - hydrolysis

- condensation

Refined-grain foods to which vitamins and minerals are added back after processing are called __________. - processed - health foods - fortified - enriched

- enriched (Refined-grain foods to which vitamins and minerals are added back after processing are called enriched. Folic acid, thiamin, niacin, and iron are examples of nutrients added to enriched grains.)

The nondigestible polysaccharides that are added to foods because of a specific desired effect on human heath are called __________. - insoluble fiber - soluble fiber - functional fiber - simple carbohydrates

- functional fiber (Functional fiber is the term for the nondigestible polysaccharides that are extracted from plants or manufactured and then added to foods because of a specific desired effect on human health.)

In times of carbohydrate deprivation, the body can create glucose from amino acids in a process called __________. - cellular uptake - gluconeogenesis - glycogenesis - glycogenolysis

- gluconeogenesis (In times of carbohydrate deprivation, the body can create glucose from amino acids in a process called gluconeogenesis.)

The storage form of glucose in animals, including humans, is __________. - cellulose - polysaccharides - starch - glycogen

- glycogen

Foods with natural sugars generally provide __________ compared with foods with added sugars. - less fiber and fewer kilocalories - more nutrients and more kilocalories - fewer nutrients and fewer kilocalories - more nutrients and fewer kilocalories

- more nutrients and fewer kilocalories (Foods with naturally occurring sugars, such as whole fruit, tend to be more nutrient dense and provide fewer kilocalories than sweets with added sugars.)

The dietary enzyme that begins breaking down carbohydrates in the mouth is __________. - salivary amylase - maltase - sucrase - lactase

- salivary amylase (Salivary amylase is the digestive enzyme that begins breaking down carbohydrates in the mouth.)

The disaccharides are __________. - sucrose, lactose, and maltose - fiber and glucose - glucose, fructose, and galactose - glucose and glycogen

- sucrose, lactose, and maltose

Carbohydrates' main role in the body is to __________. - supply fuel - make hormones - build muscle - increase immune function

- supply fuel

The best place to identify whether sugars have been added to a food product is __________. - the ingredients list - the front of the food label - nutrient content claim - the nutrition facts panel

- the ingredients list (The ingredient list contains all sugars; having many varieties of sugars or being listed as one of the first ingredients is an indication that a food is likely to contain a large amount of added sugars.)

Which type of diabetes mellitus is characterized by the inability of pancreatic cells to produce insulin? - type 1 diabetes - gestational diabetes - diabetic ketoacidosis - type 2 diabetes

- type 1 diabetes

1. Insulin stimulates _______, which is the process of storing excess glucose in the liver and muscle cells. 2. When blood glucose levels are low, glucagon stimulates _______ in the liver to break down stored glycogen and increase the levels of blood glucose. 3. Epinephrine acts on the liver to stimulate _______ from noncarbohydrate sources. 4. Growth hormone stimulates _______ to provide fuel for energy from fatty acids stored in adipose tissue. 5. After glycogen stores are full, insulin favors _______, which results in glucose being converted to fatty acids.

1. glycogenesis 2. glycogenolysis 3. gluconeogenesis 4. lipolysis 5. lipogenesis

1. _______ can result as a complication of diabetes due to damage to the arterial walls and an excess amount of fat in the blood. 2. Diabetes can cause _______ because of the leaking of tiny blood vessels in the retinas. 3. Due to reduced circulation to the limbs, people with diabetes are at an increased risk of infection, which can result in _______. 4. _______ is classified as an autoimmune disease, and involves the destruction of insulin-producing cells in the pancreas. This type most often begins in childhood. 5. People with type 2 diabetes exhibit _______ when their cells fail to respond to insulin. 6. _______ is a common risk factor that can lead to insulin resistance, prediabetes, and type 2 diabetes. 7. Increased age is a risk factor for _______, which develops progressively over time and accounts for 90 to 95% of diabetes cases. 8. _______, also called impaired glucose tolerance, may be diagnosed if a person has blood glucose levels that are higher than normal, but not high enough to indicate type 2 diabetes. 9. A potentially fatal consequence of poorly managed diabetes is _______, which occurs when ketone bodies accumulate in the blood.

1. heart disease 2. blindness 3. amputation 4. Type 1 diabetes 5. insulin resistance 6. Obesity 7. type 2 diabetes 8. Prediabetes 9. ketoacidosis

Carbohydrates and Their Functions in the Body 1. Carbohydrates are a _______ whose primary function it to provide energy to the body. All digestible forms of carbohydrates provide 4 kcal/g of energy. 2. Fiber, starch, and _______ are complex carbohydrates, while glucose, fructose, and sucrose (made up of glucose and fructose combined) are simple carbohydrates. 3. Simple carbohydrates can be monosaccharides, like glucose and _______ or disaccharides, like lactose and maltose. Complex carbohydrates can be oligosaccharides or polysaccharides. Starch consists of chains of glucose molecules. 4. Some _______ is resistant and harder to digest because it consists of linear chains with no branching. 5. Other starch is much easier to digest and has _______ chains. 6. Dietary fiber is nondigestible because of beta-glycosidic bonds between _______ molecules that you lack the enzymes to break. 7. Dietary _______ consists of soluble and insoluble types, which both possess important benefits like reducing the risk of constipation, heart disease, and obesity. 8. Soluble fiber also helps reduce the risk of diabetes. Glycogen is a highly branched polysaccharide created by a process called _______ and is stored in the liver and muscles for later use. 9. Carbohydrates in the diet are said to spare _______ from being used to provide for fuel for cells.

1. macronutrient 2. glycogen 3. galactose 4. starch 5. branching 6. glucose 7. fiber 8. glycogenesis 9. protein

Low to Midrange GI (less than 50), Midrange to High GI (50 to 100), Very High GI (greater than 100) - corn - plain bagel - kidney beans - apple - cake with icing - oatmeal - Cheerios

Low to Midrange GI (less than 50): - kidney beans Midrange to High GI (50 to 100): - apple - corn - oatmeal Very High GI (greater than 100): - plain bagel - cake with icing - Cheerios

Lowers Blood Glucose Levels, Raises Blood Glucose Levels, Has No Effect On Levels - growth hormone - cholecystokinin - secretin - glucagon - cortisol - norepinephrine - insulin - epinephrine

Lowers Blood Glucose Levels: - insulin Raises Blood Glucose Levels: - growth hormone - glucagon - cortisol - norepinephrine - epinephrine Has No Effect On Levels: - cholecystokinin - secretin

Prediabetes or impaired glucose tolerance can lead to type 2 diabetes if left uncontrolled. In a healthy individual, insulin is secreted in levels sufficient to maintain a normal blood glucose level following a meal. Focus your attention on the high blood glucose reactions in the focus figure. Order the labels to indicate the effects of insulin to bring blood glucose levels to normal following a meal. - Insulin stimulates glycogenesis in the muscle cells. - Insulin is secreted from the beta cells of the pancreas into the bloodstream. - Insulin stimulates the liver to store excess glucose as glycogen. - Insulin increases the number of glucose transporters on the cell membranes to allow the transport of glucose into the cells. - Insulin stimulates lipogenesis in the adipose tissue. - Blood glucose levels rise following the digestion of a carbohydrate-rich meal.

Step 1: - Blood glucose levels rise following the digestion of a carbohydrate-rich meal. Step 2: - Insulin is secreted from the beta cells of the pancreas into the bloodstream. Step 3: - Insulin increases the number of glucose transporters on the cell membranes to allow the transport of glucose into the cells. Step 4: - Insulin stimulates glycogenesis in the muscle cells. - Insulin stimulates the liver to store excess glucose as glycogen. Step 5: - Insulin stimulates lipogenesis in the adipose tissue.

Carbohydrate digestion begins in the mouth and ends with the elimination of dietary fiber through the large intestine. Review the steps of carbohydrate digestion in this focus figure. Trace the digestion of carbohydrates through the gastrointestinal tract by arranging the steps of chemical digestion of a piece of bread beginning when you take your first bite. - Dissacharides are digested by the brush border enzymes sucrase, maltase, and lactase to yield monosaccharides. - Salivary amylase breaks down amylose and amylopectin in the bread into smaller chains. - Carbohydrate-digesting enzymes are inactivated by hydrochloric acid. -Dietary fiber from the bread passes into the large intestine to be eliminated. - Pancreatic amylase breaks down amylose and amylopectin into the disaccharide maltose.

Step 1: - Salivary amylase breaks down amylose and amylopectin in the bread into smaller chains. Step 2: - Carbohydrate-digesting enzymes are inactivated by hydrochloric acid. Step 3: - Pancreatic amylase breaks down amylose and amylopectin into the disaccharide maltose. Step 4: - Dissacharides are digested by the brush border enzymes sucrase, maltase, and lactase to yield monosaccharides. Step 5: -Dietary fiber from the bread passes into the large intestine to be eliminated.

Low blood glucose levels often result after an overnight fast. Maintaining a normal level of blood glucose is important to prevent hypoglycemia. In a healthy individual, glucagon helps to maintain a normal blood glucose level. Focus your attention on the low blood glucose reactions in the focus figure. Sort the events in the sequence they follow from a lower blood glucose level to a normal blood glucose level. Rank the events from lower blood glucose levels to normal blood glucose levels. - When blood glucose levels are low, glucagon is secreted from the alpha cells of the pancreas into the bloodstream. - Glucagon targets the liver and stimulates glycogenolysis to release a burst of glucose into the bloodstream. - Gluconeogenesis in the liver is activated and converts glucogenic amino acids and lactic acid to glucose, which is released into the bloodstream.

Step 1: - When blood glucose levels are low, glucagon is secreted from the alpha cells of the pancreas into the bloodstream. Step 2: - Glucagon targets the liver and stimulates glycogenolysis to release a burst of glucose into the bloodstream. Step 3: - Gluconeogenesis in the liver is activated and converts glucogenic amino acids and lactic acid to glucose, which is released into the bloodstream.

Type 1 Diabetes, Type 2 Diabetes, Prediabetes, Normal Function - This condition accounts for approximately 5 to 10% of all diabetes cases. - Cells begin to exhibit insulin resistance. - People with this disease are often overweight or obese. - Cells of the pancreas are damaged or destroyed. - Little or no insulin is released into the bloodstream. - Insulin produced by the pancreas efficiently stimulates glucose transporters within body cells. - Changes in the body develop progressively over a long period of time and result in this disease. - Glucose transporters efficiently prompt the uptake of glucose into body cells.

Type 1 Diabetes: - Cells of the pancreas are damaged or destroyed. - This condition accounts for approximately 5 to 10% of all diabetes cases. - Little or no insulin is released into the bloodstream. Type 2 Diabetes: - People with this disease are often overweight or obese. - Changes in the body develop progressively over a long period of time and result in this disease. Prediabetes: - Cells begin to exhibit insulin resistance. Normal Function: - Insulin produced by the pancreas efficiently stimulates glucose transporters within body cells. - Glucose transporters efficiently prompt the uptake of glucose into body cells.