Carbohydrates (w/examples)
Class of nutrients that is a major source of energy for the body
Certain carbohydrates serve as the "______" that holds cells together in tissues.
Glue
What bodily fluids contain Mucins, a class of carbohydrates that are chemically associated with proteins?
Saliva, mucus, and the fluid that lubricates skeletal joints
What are the 2 groups of Carbohydrates?
1) Simple carbohydrates
2) Complex carbohydrates (includes most forms of dietary fiber)
Why are plants rich sources of Carbohydrates?
Some of the energy from the sun is transferred to the bonds that hold the carbon and hydrogen atoms together
Monosaccharide (C6H12O6)
Simple sugar that is the basic molecule of carbohydrates
What are the 3 most important dietary monosaccharides?
Glucose, Fructose, Galactose
Glucose, Fructose, and Galactose all contain carbon, hydrogen, and oxygen in the ratio of __ carbon:__ hydrogen: __ oxygen.
1;2;1
Glucose (C6H12O6)
Most important monosaccharide because it is the primary fuel for muscles and other cells; "dextrose" or "blood sugar"; Example: Fruits and vegetables
Under normal conditions, red blood cells as well as brain and other nervous system cells burn mostly ______ for energy.
Glucose
Fructose
Monosaccharide in fruits, honey, and certain vegetables; Not used much by the body; "levulose" or "fruit sugar";
Galactose
Monosaccharide that is a component of lactose (Carbohydrate in milk); Not commonly found in foods
Disaccharide (C12H24O12)
Simple sugar comprised of two monosaccharides
What are the major dietary Disaccharides?
Maltose, Sucrose, Lactose
Maltose
Disaccharide composed of two glucose molecules; Few foods contain Maltose; "malt sugar
Sucrose
Disaccharide composed of a glucose and a fructose molecule; "table sugar
Lactose
Disaccharide composed of a glucose and a galactose molecule; "milk sugar
Disaccharides form as a result of ______ reactions.
Condensation
Although ______ occurs naturally in honey, maple syrup, carrots, and pineapples, much of the sucrose in the American diet is refined from sugar ______ and sugar ______.
Sucrose; Cane; Beets
Why should honey not be fed to children younger than 12 months of age?
Botulism poisoning; Honey can contain spores of Clostridium botulinum which resist destruction by the child's weak stomach acid
High-Fructose Corn Syrup (HFCS)
Syrup (food additive) obtained from the processing of corn; Can contribute to greater risk of diabetes and heart disease
Which tastes sweeter, Glucose or Fructose?
Fructose
Nutritive Sweeteners
Substances that sweeten and contribute energy to foods
How many kcals of energy does 1g of mono and disaccharides supply?
4 kcal
Added sugars (Refined)
Sugars added to foods during processing or preparation; Contribute to browning, tenderness in baked cereal products; Serves as preservative (Inhibits molds/bacteria growth)
Alternative Sweeteners
Substances that sweeten foods while providing few or no kilocalories; "Sugar substitutes" or "Artificial" sweeteners
Sugar Alcohols
Alternative sweeteners used to replace sucrose in some sugar-free foods; Sorbitol, xylitol, and mannitol; Provide 2 kcal of energy due to imcomplete digestion (Can cause diarrhea); Does not promote dental decay
Nonnutritive Sweeteners
Group of synthetic compounds that are intensely sweet tasting compared to sugar; No energy; Can help control energy intake
Phenylketonuria (PKU)
Rare inherited disorder that results in abnormal phenylalanine metabolism;
Aspartame contains ______, a nonnutritive sweetener.
Phenylalanine
Which nonnutritive sweetener is better for baking because it does not break down in the heat, Aspartame or Sucralose?
Sucralose
A group of international health and safety organizations, including the FDA, have established Acceptable Daily Intakes (ADIs) for certain ______ sweeteners.
Nonnutritive
Complex Carbohyrdates
Carbohydrates comprised of three or more monosaccha-rides bonded together
Polysaccharide
Carbohydrates comprised of 10 or more monosaccharides bonded together
Oligosaccharide
Carbohydrates comprised of three to 10 monosaccharides bonded together
What are the 2 most common Oligosaccharides found in food?
Raffinose, Stachyose
What are some food sources of Raffinose and Stachyose (Oligosaccharides)?
Onions, brussel sprouts, cabbage, broccoli, legumes, whole grains
Raffinose
Nondigestible oligosaccharide made of three monosaccharides
Stachyose
Nondigestible oligosaccharide made of four monosaccharides
Human digestive enzymes do not readily break down ________.
Oligosaccharides
What happens with the Oligosaccharides that cannot be broken down in the digestive system?
Most pass through the stomach and small intestine intact. Large intestine bacteria use them as a source of energy, producing waste products (various gases) as a result
______ and ______ are polysaccharides that contain hundreds of glucose molecules bound together into large, chainlike structures.
Starch; Glycogen
Starch
Storage polysaccharide in plants; composed of amylose (linear glucose chain) and amylopectin (branched glucose chain)
What are some rich food sources of Starch?
Bread
Cereal products: Wheat, rice, barley, and oats
Vegetables: Corn, squash, beans, and peas
Tubers: Potatoes, yams, taro, cassava, and jicama
Sports drinks and sports or energy bars often include modified starches such as maltodextrin and dextrin. (TRUE/FALSE)
TRUE
Glycogen
Highly branched storage polysaccharide in animals
The human body stores limited amounts of glucose as ______.
Glycogen
What are the main sites of glycogen formation and storage in the body?
Muscles, liver
Dietary Fiber ("Fiber")
Nondigestible plant material; most types are polysaccharides
What are the carbohydrate forms of Fiber?
Cellulose, hemicellulose, pectin, gums, mucilages
What is the only form of Fiber that is not a carbohydrate?
Lignin
What are the 2 types of Dietary Fiber?
1) Soluble Fiber
2) Insoluble Fiber
Soluble (Viscous) Fiber
Forms of dietary fiber that dissolve or swell in water; Delay Gastric Emptying, Slow Glucose Absorption, Lower Blood Cholesterol; Include Fruits (apples), Oats, Barley, Legumes (beans & peas) (pectins, gums, mucilages, and some hemicellulose)
Insoluble (Fermentation-resistant) Fiber
Forms of dietary fiber that generally do not dissolve in water; Does not break down completely and contributes to softer, easier to eliminate feces, Anti-Cancer Effects; Include Whole Wheat Bran, Whole Grain Breads & Cereals, Some Veggies, Nuts, Seeds (cellulose, hemicelluloses, and lignin)
What must be present in a food labeled "Whole grain?
Starchy endosperm, oily germ, and fiber-rich bran seed components in the same relative proportions as they exist in the intact grain
Refined grain products are generally low in ______, because such foods lack the fiber-rich bran seed component.
Fiber
What are the recommended Adequate Intakes (AIs) for Fiber?
38 and 25 g/day for young men and women (respectively)
How much fiber does the typical American diet supply?
About 16 g/day
How percentage of the body's total energy (calories) should come from carbohydrates?
45 to 65%
What is the main site of Carbohydrate (as monosaccharides) digestion and absorption?
Small Intestine
Where does Starch digestion begins in the mouth. How? Where does it end?
Salivary Amylase (converts oat starch molecules into maltose); Stomach (due to acidic environment)
Pancreatic Amylase
Enzyme secreted by pancreas that breaks down starch into maltose molecules
Maltase
Enzyme in Small Intestine; Splits maltose molecule into 2 glucose
Sucrase
Enzyme in Small Intestine; Splits sucrose molecule into glucose and fructose
Lactase
Enzyme in Small Intestine; Splits lactose molecule into glucose and galactose
At what point in digestion have the disaccharides and complex carbohydrates (except fiber) been broken down into monosaccharides?
Small Intestine
Intestinal cells absorb glucose and galactose by ______ ______.
Active transport
Intestinal cells absorb fructose by ______ ______.
Facilitated diffusion
How do monosaccharides enter the capillary system when being absorbed?
Villi of Small Intestine
Resistant Starches
Starches found in seeds, legumes, whole grains, and some fruits and vegetables that resist digestion; Not broken down in the human GI tract
Insulin
Hormone secreted from the beta cells of the pancreas that helps regulate blood glucose levels (TOO HIGH) by enabling glucose to enter most cells; Enhances energy storage by promoting cellular fat, glycogen, and protein production
Glucagon
Hormone secreted from the alpha cells of the pancreas that helps regulate blood glucose levels (TOO LOW) by promoting the release and breakdown of glycogen releasing glucose into the bloodstream; Stimulates Lipolysis
Glycogenolysis
Breakdown of glycogen by glucagon to increase blood glucose levels
Lipolysis
Process by which triglycerides (fats) are broken down and glycerol and fatty acids are released into the bloodstream; Stimulated by Glucagon
The liver uses glycerol to produce ______.
Glucose
Most cells, including muscle cells, can metabolize fatty acids for ______.
Energy (The body cannot use fatty acids to make glucose)
What does the body store extra glucose as in a resting ("fed state")?
Glycogen
When ______ storage reaches maximum capacity, the liver can convert excess glucose into ______.
Glycogen; Fat
Cells metabolize glucose to release the energy stored in the molecule. (TRUE/FALSE)
TRUE
Ketone Bodies (Ketones)
Chemicals formed from the incomplete breakdown of fat; Formed from poorly managed diabetes, fasting/starving, low-carb/high-protein diet
What cells can use Ketone Bodies for energy?
Muscle and brain cells
Ketosis
Condition in which ketone bodies accumulate in the blood; Can result in loss of consciousness and death in severe cases
What is the Recommended Dietary Allowance (RDA) for Cabohydrates, and is enough to prevent Ketosis?
130 g/day
Diabetes Mellitus (Diabetes)
Group of serious chronic conditions characterized by abnormal glucose, fat, and protein metabolism
What is the primary sign of Diabetes?
Hyperglycemia (elevated blood glucose levels)
What is a normal blood glucose level?
70-110 mg/dL
What are the major signs and symptoms of hyperglycemia?
Excessive thirst, frequent urination, blurred vision, and poor wound healing
What diseases is poorly controlled diabetes a major cause of?
Heart disease, kidney failure, blindness, poor blood circulation
Type 1 Diabetes
Autoimmune disease that results in destruction of the beta cells (Insulin production) of the pancreas; as a result, insulin must be supplied to the affected person regularly through exogenous sources
Type 2 Diabetes
Most common type of diabetes; "Insulin Resistant;" Beta cells of the pancreas produce insulin, but the hormone's target cells are insulin-resistant, leading to elevated blood glucose levels
What individuals have a greater risk of developing Type 2 Diabetes?
Physically inactive (sedentary), overweight, genetically related to a close family member with type 2 diabetes, Hispanic, Native American, Asian, African, or Pacific Islander ancestry
Gestational Diabetes
Type of diabetes that develops in some pregnant women (usually after the 24th week of pregnancy)
What individuals have a greater risk of developing Gestational Diabetes?
Women who have a family history of type 2 diabetes, overweight, or have high blood pressure
As many as __% of pregnant American women develop a form of diabetes called Gestational Diabetes.
10%
What is a common result to the fetus of a mother who has Gestational Diabetes?
Heavier at birth (too much glucose during development)
Hemoglobin A1c (HbA1c)
Glycosylated hemoglobin; blood test used to measure a person's average blood glucose over several months' period of time
According to the ADA, people with diabetes should strive to maintain their HbA1c level below __%
7%
What does treatment for Diabetes include?
Diet, exercise, insulin injections, oral medications
What are some factors that affect the treatment option a person receives for Diabetes?
Type of diabetes, age, current health status.
Carbohydrate Counting
Diabetes management tool in which an individual tracks his or her daily carbohydrate intake; 45 to 60 grams/meal of carbohydrate recommended
Glycemic Index (GI)
Tool to measure the body's insulin response to a carbohydrate-containing food
Glycemic Load (GL)
Tool to measure the body's insulin response to a carbohydrate-containing food; similar to the glycemic index, but also factors in a typical serving size of the food
Hyperinsulinemia
Condition in which the pancreas releases an excessive amount of insulin; over time, condition may contribute to the development of type 2 diabetes
People with type __ diabetes rely on daily insulin injections, either by the use of multiple daily insulin shots or an insulin pump.
1
Some people with type __ diabetes can take oral medication to stimulate their bodies' insulin production.
2
At this time, there is no way to prevent Type 1 Diabetes. (TRUE/FALSE)
TRUE
How can people reduce their risk of Type 2 Diabetes?
Avoid excess body fat, exercise daily, improve their diets (Therapeutic Lifestyle Changes)
Therapeutic Lifestyle Changes
Actions, such as avoiding excess body fat, exercising daily, and improving the diet, that promote health and reduce risk for chronic disease
Hypoglycemia
Condition that occurs when blood glucose level is too low (Below 70 mg/dL
Epinephrine
Hormone produced by the adrenal glands; Secreted in response to declining blood glucose levels; Can cause person to be irritable, restless, shaky, and sweaty
Reactive Hypoglycemia (Postprandial Hypoglycemia)
Low blood glucose that occurs within 4 hours of eating; Results from eating too much highly refined carbohydrates, and the pancreas responds by releasing too much insulin
Syndrome
Group of signs and symptoms that occur together and indicate a specific health problem
Metabolic Syndrome
Condition that increases risk of type 2 diabetes and CVD;
What are the signs of Metabolic Syndrome?
1) Large waist circumference
2) Chronically elevated blood pressure (hypertension)
3) Chronically elevated fasting blood fats (triglycerides)
4) Low fasting high-density lipoprotein cholesterol (HDL cholesterol)
5) High fasting blood glucose
How can individuals who already have Meabolic Syndrome reduce their risk of Cardiovascular Diseases (CVD)?
Lose excess weight, exercise regularly, reduce intakes of saturated fat and simple sugars (Sucrose and Fructose)
How does Tooth Decay occur?
Bacteria metabolize carbohydrates left on the teeth for their energy needs and produce acid that damages tooth enamel
Lactose Intolerance (Maldigestion)
Inability to digest lactose properly because of a deficiency in the enzyme lactase; Bloating, Diarrhea, Gas (More likely to occur in adulthood)
What are milk and milk products excellent sources of?
Protein, vitamins, minerals (Calcium, Phosphorus)
What can people with lactose-intolerance do to achieve a nutritionally adequate diet without drinking milk?
Eat hard cheeses and yogurt
Does sugar cause Hyperactivity?
No
Eating high-fiber foods may reduce a person's risk of what diseases?
Obesity, type 2 diabetes, certain intestinal tract disorders, cardiovascular disease (Heart disease, stroke)
Fiber is considered, by the Dietary Guidelines, as a "nutrient of public health concern. (TRUE/FALSE)
TRUE
A diet of what foods can reduce the likelihood of developing the colon cancer?
Rich in whole grains, fruits, vegetables
What food can lower cholesterol levels by binding to bile and causing it to be eliminated?
Oat cereal
Carbohydrates are an important source of energy for the body. Plants use carbon dioxide, water, and the sun's energy to make carbohydrates. Human cells break down the bonds in carbohydrates, releasing energy for cellular work. (TRUE/FALSE)
TRUE
The three most important dietary monosaccharides are glucose, fructose, and galactose. (TRUE/FALSE)
TRUE
Glucose is a primary fuel for muscles and other cells; nervous system and red blood cells rely on glucose for energy under normal conditions. (TRUE/FALSE)
TRUE
Alternative sweeteners provide few or no kcal while sweetening foods and beverages. (TRUE/FALSE)
TRUE
Starch, glycogen, and most forms of dietary fiber are polysaccharides. (TRUE/FALSE)
TRUE
Fibers are categorized as soluble or insoluble based on their solubility in water. Whole-grain products are rich sources of fiber, particularly insoluble fiber. (TRUE/FALSE)
TRUE
Healthy Americans should consume diets that furnish 45 to 65% of energy from carbohydrates, primarily complex carbohydrates. Intake of added sugars should be limited to less than 10% of total calories. (TRUE/FALSE)
TRUE
Glucose, fructose, and galactose are absorbed by the small intestine and travel through the hepatic portal vein to the liver. (TRUE/FALSE)
TRUE
Humans cannot digest dietary fiber. (TRUE/FALSE)
TRUE
Regular blood glucose monitoring is important for diabetes management. Physicians treating diabetes evaluate both daily blood glucose measurements as well as hemoglobin A1c in determining treatment options. (TRUE/FALSE)
TRUE
Tooth decay is the only health problem that is clearly associated with eating carbohydrates. (TRUE/FALSE)
TRUE
Starches (in plants) and Glycogen (in body) are simple carbohydrates. (TRUE/FALSE)
False; Complex carbohydrates
Condensation Reaction
Forms bonds; H2O by-product
Hydrolysis Reaction
Breaks bonds; H2O needed
What is the biggest contributor to added sugar in the typical American's diet?
Soda
Natural Sugar
Monosacchrarides or disaccharides in whole foods like fruits, vegetables, grain products, milk, etc. (i.e. Apples)
Table Sugar
Sucrose. The common name for "regular" white granulated sugar. Usually extracted from sugar cane or sugar beets
Carbohydrate is the exclusive energy source for what 3 cell types?
Brain cells, Nerve cells, and red blood
cells (RBC).
The carbohydrate "family" includes sugars, starch, and fiber. (TRUE/FALSE)
TRUE
Carbohydrates are sometimes found in meat. (TRUE/FALSE)
FALSE