NUT Chapter 4

4 emergent properties of water

cohesive and adhesive behavior (which also result in surface tension), ability to moderate temperature, expansion upon freezing, versatility as a solven

It takes more than 8 hours for ingested carbohydrate to be digested, absorbed, and circulated in the cells.

false

Carbon

the backbone of life; living organisms consist mostly of carbon-based compounds Carbon has 4 valence electrons and can form 4 covalent bonds

Organic chemistry

the study of compounds that contain carbon and hydrogen

Fiber is not digested by the human digestive tract.

true

Acidic Solutions (High H+ Concentration)

Acidic solutions have a high hydrogen ion (H+) concentration. An example of a strong acid is hydrochloric acid (HCl) which dissociates in water: HClH+ + Cl-

Which of the following statements is CORRECT in regard to the role of insulin in blood glucose regulation?

All of these statements are correct.

Basic Solutions (Low H+ Concentration)

Basic solutions have a low hydrogen ion (H+) concentration. An example of a strong base is sodium hydroxide which dissociates in wate

valence electrons

first shell holds 2 electrons, second shell holds 8, third shell holds 8 etc; outermost shell is valence shell; if full, element is chemically inert; if not full, element participates in chemical reactions; share or transfer electrons/form chemical bonds

Polymer

long molecule consisting of many similar building blocks, called monomers

Which of the following foods provides carbohydrate but NOT dietary fiber?

low-fat dairy products

mass number

sum of protons plus neutrons; be familiar with periodic table

Atom

the smallest unit of matter that still retains the properties of an element; composed of neutrons, protons, electrons; neutrons and protons form the atomic nucleus; electrons form cloud around nucleus

Why does the body need carbohydrate?

to provide energy

Which of the following statements is not true about carbohydrate digestion?

Disaccharides like sucrose do not need to be further broken down before being absorbed.

What is the role of the hormone glucagon in regulating blood glucose?

Glucagon stimulates glycogenolysis, the breakdown of glycogen, to increase blood glucose concentrations.

Which of the following statements regarding glucose absorption is TRUE?

Glucose is absorbed mostly through the lining of the small intestine.

If the Nutrition Facts Panel on a food label indicates that a food has 24 grams of total carbohydrates, 2 grams of fiber and 12 grams of sugar, what is the true amount of carbohydrates in this food?

If the Nutrition Facts Panel on a food label indicates that a food has 24 grams of total carbohydrates, 2 grams of fiber and 12 grams of sugar, what is the true amount of carbohydrates in this food?

Which of the following is a characteristic of type 1 diabetes?

Inadequate amounts of insulin are produced.

Which of the following statements is false regarding type 2 diabetes?

It is an autoimmune disease.

Which of the following statements regarding absorption of monosaccharides is TRUE?

Some, but not all, monosaccharides are absorbed by passive transport.

The Nutrition Facts Panel indicates that there are 12 grams of sugar in one serving of the food. The ingredients listed are wheat flour, high fructose corn syrup, milk powder, and apple juice. Are all 12 grams of sugar in this product the added sugars?

The 12 grams of sugar in this product include both naturally occurring and added sugars.

What occurs when blood glucose levels rise following the ingestion of a glucose-rich meal?

The beta cells of the pancreas release insulin.

pH

The pH scale was created to indicate the hydrogen ion concentration of a solution. The lower the pH, the more acidic the solution, and the higher the pH, the more alkaline/basic the solution. The pH scale is on a scale of 0-14. A pH of 7 is considered neutral. Buffers help maintain a certain range of pH

The Nutrition Facts Panel provides information about the amount of sugar in a product, but it does not distinguish between naturally occurring and added sugars.

True

If a food product has an ingredient list of wheat flour, high fructose corn syrup, milk powder, and apple juice, which of the following is TRUE?

Wheat flour is a main ingredient in this product.

Which of the following would have the highest glycemic index?

a meal high in carbohydrate

Compound

a substance consisting of two or more elements in a fixed ratio

Element

a substance that cannot be broken down to other substances by chemical reactions

Whole grains

are defined as grain foods that are made with the entire edible grain kernel: bran, the endosperm, and the germ. In contrast, refined grains are found in wheat or white breads and white rice; a milling process strips out the bran and germ, leaving only the endosperm. Much of the B vitamins, iron, phytochemicals, and dietary fiber are removed. Restoring some of the nutrition lost from refined grains through manmade techniques produces enriched grains.

Simple carbohydrates

are either a single sugar unit (monosaccharide) or two units bonded together (disaccharide).

Insoluble fiber promotes gastrointestinal health by increasing stool __________, which _________ stool transit time through the GI tract.

bulk; decreases

What substance does the pancreas secrete when blood glucose falls?

glucagon

In times of carbohydrate deprivation, the body can create glucose from amino acids in a process called __________.

gluconeogenesis

Once absorbed, the monosaccharides are all converted to ________ by the liver.

glucose

The storage form of glucose in animals is

glycogen.

If you haven't eaten for a few (about four) hours, the body initiates __________, using __________ glycogen stores to increase blood glucose levels.

glycogenolysis; liver

Fiber

helps prevent constipation and diverticulosis. Over 4 million Americans complain about being constipated, with pregnant women, children, and older adults more often experiencing it. Sluggish muscle contractions in the colon can lead to constipation, but the problem can often be relieved by a diet plentiful in insoluble fibers. Chronic constipation can lead to diverticulosis, in which pressure on the colon creates weak spots to bulge out and form pockets (diverticula). Diverticulitis (infection of the diverticula) can cause stomach pain, fever, nausea, vomiting, cramps, and chills.

Which of the following is a common ingredient in processed foods that would be considered an added sugar?

high fructose corn syrup

Diabetes mellitus

is a condition related to inadequate regulation of blood glucose. An estimated 25.8 million Americans (more than 8 percent of the population) have diabetes. The incidence of adults being diagnosed with diabetes in the U.S. has more than doubled since the early 1990s. There are different types of diabetes, but all result from the inability of the body to make or properly use the hormone insulin. Diabetes develops when individuals produce an inadequate amount of insulin and/or develop insulin resistance.

Gestational diabetes

is a form of the disease that may develop during pregnancy in women who have not been diagnosed prior to the pregnancy. The cause is an ineffectiveness of insulin, most likely due to elevated pregnancy-related hormones. Gestational diabetes is temporary, but the new mother is at risk for type 2 diabetes.

Type 1 diabetes

is an autoimmune disease and is the rarer of the two main forms, affecting 5 percent of all diagnosed cases in the U.S. Symptoms include obsessive thirst, excessive urination, a strong desire to eat, blurred vision, weight loss, and fatigue. Individuals with type1 diabetes must monitor their glucose levels and inject insulin every day in order to avoid these symptoms.

Galactose

is found as part of lactose in milk and milk products.

Fructose

is found in fruit ("fruit sugar") and as part of high-fructose corn syrup. Consumption of high-fructose corn syrup in soft drinks and fruit beverages is likely contributing to the obesity epidemic.

Type 2 diabetes

is more common than type1, accounting for 90 to 95 percent of diagnoses of the disease. People with type 2 diabetes initially produce insulin but have become insulin resistant. o Prediabetes, denotes blood glucose levels higher than they should be but not yet high enough to be classified as diabetes.

Sucrose

is the most commonly used natural sweetener. It is found in sugar beets and sugar cane.

Photosynthesis

is the process by which glucose (carbohydrates) is produced in plants.

Glycogen

is the storage form of carbohydrates in humans (whereas starch is the storage from of glucose/carbohydrate in plants). It is defined as long, branched chains of glucose. The liver breaks down glycogen when glucose levels in the blood decrease, releasing glucose into the blood; muscle glycogen can also be broken down for muscle energy. When ______________ stores are full, excess glucose can be converted to fatty acids through lipogenesis, which insulin stimulates by increasing the number of glucose receptors on the surface of the fat cell. Fat breakdown is inhibited by insulin.

Which of the following enzymes is lacking or insufficient in an individual with lactose intolerance?

lactase

The body absorbs which form of digested carbohydrates?

monosaccharides

Atomic number

number of protons in nucleus

Dehydration reaction

occurs when 2 monomers bond together through the loss of a water molecule

Hypoglycemia

results when blood glucose drops below normal.

Double bond

sharing of 2 pairs of valence electrons

Covalent bond

sharing of a pair of valence electrons by 2 atoms

Single bond

sharing of one pair of valence electrons

The majority of carbohydrate digestion occurs in the

small intestine.

The storage form of glucose in plants is

starch

Soluble fiber

(dissolves in water) is more easily fermented by intestinal bacteria and has numerous health benefits. In general, soluble fiber helps reduce serum cholesterol, improve appetite control, normalize blood glucose levels, and protect against colon cancer.

Insoluble fiber

(does not dissolve in water) increases the bulk of stool to further stimulate peristalsis, helping to relieve constipation.

Lactose

(milk sugar) is found in milk and dairy products.

What happens to excess glucose?

It is ultimately stored as fat.

Glucose, fructose, and galactose all have how many atoms of carbon?

6

Maltose

(malt sugar) is formed during the digestion of starch. It is found in beer.

Carbohydrates

are made up of bound strings of sugar units. are absorbed into the intestinal cell mucosa as monosaccharides via active transport or facilitated diffusion. They are then transported to the liver through the portal vein. The fate of the monosaccharides in the liver depends on the metabolic needs of the individual. Glucose and galactose are used as energy by the liver but can also be converted to glucose in a process called glycogenesis and released into the blood. Excess glucose is converted to glycerol and fatty acids; these are then combined into a triglyceride and stored in the adipocytes (fat cells). —primarily in the form of glucose—provide about half of the energy used by the muscles and other tissues; the rest of the energy comes mostly from fats. spare protein. If sufficient carbohydrates are not available, the body begins to draw on amino acids (from muscle) to generate glucose in a process called gluconeogenesis.

The chemical reaction in which two molecules combine to form a larger molecule, and water is released is called __________.

condensation

Disaccharides

consist of two sugar units. lactose, sucrose, and maltose—incorporate glucose into their structures. Monosaccharides are linked with a glycosidic bond to form disaccharides through a process called dehydration. The type of bond can affect the digestibility of the sugar.

Molecule

consists of 2 or more atoms held together by covalent bonds

Oligosaccharides

contain three to ten sugar units These are short chains of three to ten monosaccharides that are similar in length to simple carbohydrates. A common oligosaccharide is raffinose. Oligosaccharides are present in breast milk.

Complex carbohydrates (polysaccharides)

have more than ten sugar units and include starch and fiber. Monosaccharides are single sugar units. Long chains and branches of sugars come together to form polysaccharides, e.g. starch, glycogen, and fiber. Plants store glucose in straight chains (amylose) and branched chains (amylopectin) of starch. Amylose is more resistant to digestion than amylopectin, as the chains are more difficult for the body to break down. Resistant starch found in food is considered dietary fiber. Most forms of dietary fiber occur naturally as cellulose in the cell walls of plants and are nondigestible. Humans lack a digestive enzyme to properly digest fiber, so most of it passes through the digestive tract intact. Most plant foods contain both soluble and insoluble fiber, both of which are helpful to the body.

glucose

is used as energy for blood, the brain, and the nervous system. is the most abundant monosaccharide in the body (also being found in every disaccharide, in starch, and in most plant foods). It is known as blood glucose or blood sugar.

Which of the following sugars is a disaccharide?

lactose

All of the following are considered simple carbohydrates except

polysaccharides.

Blood glucose

levels are not constant; they rise and fall depending upon bodily energy needs and following consumption of a high-carbohydrate meal. Blood glucose levels are maintained between 70 and 110 mg/dl mainly by two hormones: insulin and glucagon. Other hormones help regulate blood glucose levels such as epinephrine, norepinephrine, cortisol, and growth hormone.

Hydrolysis

occurs when polymers are disassembled to monomers with addition of water

Ionic bonds

one atom strips electrons from its bonding partner(s) eg NaCl

Hydrocarbons

organic molecules consisting of just carbon and hydrogen

Insulin

regulates glucose in the blood. helps glucose enter cells by attaching to receptor sites on the cell membrane, stimulating an increase in glucose transporters on the surface of the membrane, and allowing transportation of glucose inside the cell

Electronegativity

tom's attraction for the electrons in a covalent bond; polar and non-polar covalent bonds. In non-polar bond, atoms share electron equally; oxygen is electronegative