Chapter 4 -- Carbohydrates

energy, store, minerals, protein, vitamins

Plants use the glucose they produce directly for ___________, _________ it, or combine it with _______________ from the soil to make other compounds, including __________ and ______________.

18

After about ____ hours of fasting, liver glycogen is depleted and the body will begin to look for other sources, mostly stored fat, to meet the body's energy needs.

200

Because aspartame is _______ times sweeter than sucrose, only a small amount is needed to sweeten a food.

glycosidic bond

Bond that forms when two sugar molecules are joined together during condensation.

amylopectin

Branched chain of polysaccharides found in starch.

ketone bodies

By-products of the incomplete breakdown of fat.

chlorophyll

Green pigment in plants that absorbs energy from sunlight to begin the process of photosynthesis.

norepinephrine

Hormone produced by the adrenal glands that stimulates glycogenolysis and gluconeogenesis.

glucagon

Hormone secreted from the alpha cells of the pancreas that stimulates glycogenolysis and gluconeogenesis to increase blood levels of glucose.

insulin

Hormone secreted from the beta cells of the pancreas that stimulates the uptake of glucose from the blood into the cells.

growth hormone

Hormone that regulates glucose metabolism by increasing glycogenolysis and lipolysis.

glycogenolysis

Hydrolysis of glycogen to release glucose.

1981

In ________, the FDA approved aspartame for use in tabletop sweeteners and to sweeten breakfast cereals, chewing gums, and carbonated beverages.

1996

In ________, the FDA gave the food industry carte blanche to use aspartame in all types of food and beverages.

lactose intolerance

When maldigestion of lactose results in symptoms such as nausea, cramps, bloating, flatulence, and diarrhea.

300, 200

Adult males consume, on average, over ________ grams of carbohydrates daily, whereas adult females eat over _______ grams daily.

12, 18

Adults in the United States fall short of fiber recommendations and currently consume only about ____-____ grams per day.

sugar substitutes

Alternatives to table sugar that sweeten foods for fewer kilocalories.

glycemic load (GL)

Amount of carbohydrate in a food multiplied by the amount of the glycemic index of that food.

complex carbohydrates

Category of carbohydrates that contain many sugar units combined; oligosaccharides and polysaccharides are examples.

condensation

Chemical reaction in which two molecules combine to form a larger molecule, and water is released.

sucrose

Disaccharide composed of glucose and fructose; also known as table sugar.

maltose

Disaccharide composed of two glucose units joined together.

smaller, well-balanced

Eating ____________, _______-___________________ meals throughout the day can help avoid reactive hypoglycemia.

pectins, beta-glucans, gums, guar gum, mucilages

Examples of soluble fiber include ___________; _______-____________; some _______, such as ________ _______; and ________________ (e.g., psyllium).

waking, meals, exercise, medication, illnesses, tumors, hormone imbalances, alcohol

Fasting hypoglycemia can occur upon __________, during long stretches between ________, or after _____________; some ____________________, ________________, certain __________, ____________ ________________________, or drinking too much _____________ may cause this type of hypoglycemia.

dietary fiber

Food components that humans cannot digest; most are carbohydrates.

six, fourth, hydroxyl, hydrogen

Glucose and galactose are both ______-sided ring structures that, at first glance, look identical; however, on the __________ carbon, the _______________ group and the _______________ switch places.

brain, nervous system, red blood

Glucose is the most abundant monosaccharide in foods and in the body; ________ cells and other __________ ___________ cells in particular rely on it as their main source of ATP, and ______ _________ cells can only use glucose.

undigested, digest, ferment

Humans lack the enzyme necessary to break oligosaccharide bonds; therefore, like dietary fiber, they pass ____________________ into the large intestine, where the GI flora _________ and ___________ them.

glycogen

In addition to helping glucose enter cells, insulin helps convert glucose to __________________ if the amount of glucose in the blood exceeds the body's immediate energy needs.

lactose maldigestion

Inability to digest lactose due to low levels of the enzyme lactase.

bran

Indigestible outer shell of the grain kernel.

phenylketonuria (PKU)

Individuals with a rare inherited disorder known as ____________________________________________ are unable to metabolize phenylalanine.

diverticulitis

Infection of the diverticula.

blood glucose regulation

Its role in stimulating the uptake of glucose by body cells makes insulin critical to _______ ____________ ______________________.

enriched grains

Refined grain foods that have folic acid, thiamin, niacin, riboflavin, and iron added.

colorectal cancer

Research also suggests that as dietary fiber consumption increases, the incidence of ____________________ ____________ decreases.

oligosaccharides

Three to 10 units of monosaccharides combined.

dental caries

Tooth decay.

sugar units

We classify carbohydrates according to how many _________ ________ are in the molecule.

2

When selecting packaged foods, choose products that contain at least ___ grams of dietary fiber per serving.

digestibility

Whether it is an alpha or beta glycosidic bond affects the _________________________ of the disaccharide.

liver, kidney, brain

________, ____________, and _________ cells can use glucose without the aid of insulin.

stevia

__________, one of the most popular sugar substitutes, is a natural sweetener extracted from a plant related to an aster or chrysanthemum.

simple carbohydrates

Carbohydrates that consist of one sugar unit (monosaccharides) or two sugar units (disaccharides).

soft drinks, energy drinks, sports drinks

The number-one source of added sugars in the United States is sweetened ______ ________, _________ _________, and _________ _________.

stomach

There are no carbohydrate-digesting enzymes in the _____________; thus, little to no carbohydrate digestion takes place there.

raffinose, stachyose

Two common examples of oligosaccharides are ________________ and __________________.

70, 110

Two hormones secreted from the pancreas, insulin and glucagon, maintain blood glucose levels between ______ and ________ milligrams per deciliter.

soluble fiber

Type of fiber that dissolves in water and is fermented by intestinal bacteria; many are viscous and have thickening properties.

insoluble fiber

Type of fiber that isn't dissolved in water or fermented by intestinal bacteria.

resistant starch

Type of starch that is not digested in the GI tract but has important health benefits in the large intestine.

sugar alcohols

Type of sweetener often used in sugar-free foods; includes xylitol, mannitol, and sorbitol; also known as polyols.

10, 18

Under the control of glucagon, liver glycogen stores will be depleted after _____-______ hours without sufficient dietary carbohydrate intake.

germ

Vitamin-rich embryo, or seed, of a grain.

heart disease, cancer, stroke, intestinal health, body weight

As little as one serving of whole grains daily may help lower the risk of dying from ________ ____________ or __________, reduce the risk of __________, improve ___________________ _________, and improve ________ ___________.

stimulates

Glucagon has the opposite effect of insulin on blood glucose levels: It ________________ release of glucose into the blood.

cortisol

Hormone produced by the adrenal cortex that stimulates gluconeogenesis and lipolysis.

epinephrine

Hormone produced by the adrenal glands that signals the liver cells to release glucose; also referred to as the "fight-or-flight" hormone.

ketoacidosis

If left unchecked, ketosis can progress to _____________________________, an increase in blood acidity to levels that lead to nervous system, liver, and kidney problems.

lipolysis

Insulin also inhibits ___________________ (fat breakdown) by reducing the activity of the enzyme that hydrolyzes stored fat.

pregnant women, children, 65

Over 4 million Americans report being constipated, with ______________ __________, ________________, and adults ______ years and older affected more often than others.

15, 30, 2

Pectin makes up about _____-______ percent of the fiber in fruit; fruit overall contains about ___ grams of dietary fiber per serving.

glucose

Primary monosaccharide and primary energy source for the body.

photosynthesis

Process by which plants create carbohydrates using the energy from sunlight.

glycogenesis

Process of assembling excess glucose into glycogen in the liver and muscle cells.

lipogenesis

Process that converts excess glucose into fat for storage.

glycemic index (GI)

Rating scale of the likelihood of foods to increase the levels of blood glucose and insulin.

sweetener, shelf-life, processed

Manufacturers add maltose as a ___________________ and to improve _________-_______ of their products; this makes ____________________ food the main source of maltose in our diets.

polysaccharides

Many sugar units combined; starch, glycogen, and fiber are all examples.

1, 17

Milk and milk products, including cheese and yogurt, contain ___-_____ grams of lactose per serving.

long, branched, muscle, liver

Molecules of glycogen are _______, _____________ chains, similar to amylopectin, and are stored in __________ and in the ________.

galactose

Monosaccharide that links with glucose to create the disaccharide found in dairy foods.

enzyme

Muscle glycogen cannot be used to raise blood glucose levels because muscles lack the _____________ necessary to release glucose into the blood.

three

MyPlate recommends __________ servings per day of whole grains.

lignin

Noncarbohydrate form of dietary fiber that binds to cellulose fibers to harden and strengthen the cell walls of plants.

insulin

In people with hypoglycemia, the pancreas releases too much ____________.

amino acids

In times of carbohydrate deprivation, the body turns to noncarbohydrates, particularly ________ _______, to generate glucose.

ketosis

Condition of increased ketone bodies in the blood.

salivary amylase

Digestive enzyme that begins breaking down carbohydrate (starch) in the mouth.

cell membranes, glucose transporters

Insulin travels through the bloodstream, attaching to specific receptor sites on ______ _____________________, where it stimulates mechanisms that result in an increase in the number of __________ _________________________ found on the membrane surface; these transporters then shuttle the glucose into the cell.

least, starch

Maltose is the ________ common of the disaccharides and is formed during the digestion of __________.

cellulose

Nondigestible polysaccharide found in plant cell walls.

functional fiber

Nondigestible polysaccharides that are added to foods because of a specific desired effect on human health.

1

Nuts provide about ___ gram of fiber in a half-ounce or small handful.

beans, legumes, cabbage, brussel sprouts, broccoli, human breast milk

Oligosaccharides are found in ________ and other ______________, ___________, ___________ ___________, and ______________; also present in _________ _________ ________.

plant cell walls

Oligosaccharides make up part of ________ _______ _________.

60, 80, 80

Approximately 50 percent of Americans ages _____-_____ and the majority of individuals over _____ years of age have diverticulosis.

water, gas, short-chain fatty acids

The bacteria in the colon can metabolize some of the fiber, producing _________, _______, and some ________-_________ _________ ________.

blood cholesterol, heart disease, stroke

A diet rich in viscous, soluble fiber has been shown to help lower elevated ________ ______________________ levels, which in turn is associated with a decreased risk for ________ _____________ and _________.

polyols, stevia, saccharin, aspartame, acesulfame-K, sucralose, rebaudioside A, neotame

Several sugar substitutes are presently available to consumers, including __________ (also referred to as sugar alcohols), _________, ______________, _____________________, __________________________-____, __________________, ________________________________ ____, and _____________.

disaccharide

Simple sugar that consists of two sugar units combined; the three most common examples are sucrose, lactose, and maltose.

fat, carbohydrates

Slow-moving, viscous, soluble fibers may also reduce the rate at which ______ and __________________________________ are absorbed from meals.

bulk, blood glucose regulation, GI flora

Some researchers have reported that resistant starch may improve the health of the GI tract by increasing _______, improve ________ __________ _____________________, and stimulate the growth of the _____ ________.

endosperm

Starchy inner portion of a cereal grain.

250

Stevia registers about _______ times sweeter than table sugar, so you use much less to achieve the same sweetness.

glycogen

Storage form of glucose in animals, including humans.

starch

Storage form of glucose in plants.

amylose

Straight chain of polysaccharides found in starch.

alpha, beta

Sucrose and maltose are formed with an _________ bond and are easily digested; lactose is formed with a ________ bond.

glucose, fructose, glucose, galactose, glucose

Sucrose consists of ____________ and ____________; lactose is ____________ and ____________________; maltose is two ____________ units linked together.

hexose

Sugar that contains six carbons; glucose, galactose, and fructose are all examples.

stress hormone

Cortisol is often referred to as the "________ _____________."

60, 40

Plants contain both amylose and amylopectin, typically about _____ percent amylopectin and _____ percent amylose.

enterocytes

After carbohydrate digestion, the monosaccharides are absorbed into the ______________________.

glucose

All disaccharides have a common characteristic: At least one of their monosaccharides is ____________.

six, 12, six, hexose

All three monosaccharides share the same molecular formula of _____ carbon atoms, _____ hydrogen atoms, and ______ oxygen atoms, referred to as a ____________.

aspartic acid, phenylalanine

Aspartame is composed of two amino acids: a modified ________________ _______ and __________________________.

hypoglycemia

Blood glucose level that drops to lower than 70 mg/dl.

half, fats

Carbohydrates -- primarily glucose -- provide about ________ of the energy used by the muscles and other tissues; the rest of the energy you use each day comes mostly from ________.

energy, plants, glucose, ATP

Carbohydrates are __________-yielding macronutrients, most of which are produced in _________; their main role in the body is to supply fuel, primarily in the form of ___________, which cells convert to the energy molecule ________.

fluid imbalance, mineral deficiencies

Consuming too much fiber may cause ________ __________________________ or lead to _____________ _________________________ by reducing the absorption and increasing the excretion of minerals.

gluconeogenesis

Creation of glucose from noncarbohydrate sources, predominantly protein.

16, 60

Currently, Americans are consuming an average of _____ grams of whole grains per day, or about _____ percent of the recommended intake.

lactose

Disaccharide compose of glucose and galactose; also known as milk sugar.

diverticulosis

Existence of diverticula in the lining of or colon.

five, six

Fructose contains the same number of carbon, hydrogen, and oxygen atoms as glucose and galactose but its molecular structure is arranged as a ______-sided, rather than a _____-sided, ring.

facilitated diffusion

Fructose is absorbed by ___________________ ________________, which requires no energy and is slower; thus, fructose stays in the enterocytes longer than glucose or galactose and does not raise blood glucose levels.

liver, kidneys

Gluconeogenesis primarily takes place in the ________, but can also take place in the ___________ because these are the only organs that contain the enzymes needed for this process.

refined grains

Grain foods that are made with only the endosperm of the kernel; the bran and germ have been removed during milling.

whole grains

Grain foods that are made with the entire edible grain kernel: the bran, the endosperm, and the gram.

stimulating, reducing, increasing

Growth hormone has the opposite effect of insulin: It conserves glucose by _________________ fat breakdown for energy, ______________ the uptake of glucose by the muscle cells, and ________________ glucose production in the liver.

1965, James Schlatter

In _______, a scientist named ________ _______________ discovered aspartame.

glycerol, fatty acids, triglyceride, adipocytes

Once the glycogen stores are fully replenished, and presuming the diet contains sufficient kilocalories to meet energy needs, excess glucose is converted into _______________ and _________ ________; these two are combined into a ______________________________ and stored in the _____________________ (fat cells).

epinephrine, norepinephrine, cortisol, growth hormone

Other hormones, including ________________________, _______________________________, ______________, and __________ _____________, assist in the process of maintaining blood glucose levels.

pancreatic amylase, maltase, sucrase, lactase

Other important enzymes during carbohydrate digestion include _________________ ___________, ___________, ____________, and ____________.

2, 4, hemicellulose

Overall, a serving of vegetables contains approximately ___ grams of soluble and insoluble fiber; legumes provide an average of ___ grams of fiber per 1/2 cup serving, about half of which is the form of __________________________________.

estrogen

Research suggests that fiber binds to the _________________ in bile and then eliminates it in the feces.

monosaccharide

Simple sugar that consists of a single sugar unit; the three most common examples are glucose, fructose, and galactose.

diverticula

Small bulges at weak spots in the colon wall.

fructose

Sweetest of all the monosaccharides; also known as fruit sugar or levulose.

45, 65, 25, 38, 14

The AMDR for carbohydrate is ______-______ percent of total daily kilocalories; the AI for fiber is ______-______ grams per day for adult females and males, respectively, through age 50, or ____ grams of fiber for every 1,000 kilocalories consumed.

130

The RDA for carbohydrate intake for adults and children is _______ grams daily.

glycemic index, glycemic load

The ______________ ________ and ______________ ________ are measures of the effects of carbohydrate-containing foods on blood glucose.

age, health problems, genetics

The ability to taste sweetness may be influenced by _______, _________ ______________, or _________________.

carbon dioxide, glucose

The absorbed energy in plants splits water molecules in the plant into their component atoms of hydrogen and oxygen; the hydrogen joins with the __________ _____________ that the plant has taken in from the air to form _______________.

linear

The amylose in starch is more resistant to digestion than is the amylopectin --> __________ chains of amylose are harder to break down during digestion because the molecules stack together into tight granules, which hinder the ability of enzymes to reach and break down the bonds.

pancreatic amylase

The arrival of polysaccharides in the small intestine signals the pancreas to release an enzyme called __________________ _____________, which breaks down the remaining starch units from the bread into maltose.

type, timing, epinephrine, glucagon

The cause of reactive hypoglycemia is not known, but contributing factors may include the _______ of food eaten and the ___________ of the food as it moves through the GI tract; some people may be overly sensitive to __________________________; the hormone ___________________ may also play a role.

brush border enzymes

The disaccharides maltose, lactose, and sucrose will need further dismantling by the ________ __________ _______________ housed in the microvilli of the small intestine.

galactose, fructose, glucose, glycogen

The liver uses ___________________ and _____________ for energy or converts them to ____________ before releasing them into the bloodstream; any surplus glucose that is not used immediately for energy is stored as ___________________.

liver

The main target organ of glucagon is the _________, where it promotes glycogenolysis to release a burst of glucose into the blood.

glucose receptors

The method insulin uses to promote lipogenesis is similar to the way it promotes glycogenesis: by increasing the number of ___________ ___________________ on the surface of the fat cell.

blood, muscle cells

When blood glucose levels decrease, the liver breaks down the stored glycogen and releases the glucose into the ________; muscle glycogen can similarly be broken down to glucose to provide energy for the __________ _______.

cellulose, lignin, hemicelluloses

_______________, __________, and some ______________________________ are examples of insoluble fiber.