Ch 7: Carbohydrates Flashcards
1
Q
Primary Source of Energy
A
Carbohydrates
2
Q
Non-plant sources of Carbohydrates
A
Lactose and Glycogen
3
Q
Starches
A
Grains, Corn, Barley, Vegetables, Beans and Wheat
4
Q
Single sugar units of Glucose, Fructose and Galactose. Represents the ONLY absorbable forms of carbohydrates for the body
A
Monosaccharides (Simple Sugars)
5
Q
Pairs of sugar units: Sucrose, Maltose and Lactose
A
Disaccharides (Simple Sugars)
6
Q
Glucose chains longer than 10 units in length. Can be as large as several thousand glucose units in length
A
Polysaccharides
7
Q
They define sugar units ranging from 3 to 10 units in length and are largely indigestible to humans.
A
Oligosaccharides
8
Q
Carbohydrates content
A
CHO (Carbon, Hydrogen and Oxygen)
9
Q
Largest storage depots for carbohydrates (Glycogen)
A
Liver and Muscle cells
10
Q
Other names for Glucose
A
Dextrin or Dextrose
11
Q
Hydrocarbons (Monosaccharides)
A
C6H12O6
12
Q
Sucrose
A
One glucose molecule joined with one fructose molecule. Examples include cane sugar, brown sugar, and date sugar. Sucrose contributes as a primary sugar in most fruits
13
Q
Lactose
A
One glucose molecule joined with one galactose molecule. It is only found in dairy products
14
Q
Maltose
A
Two glucose molecules. Examples include corn syrup, brown rice syrup, and molasses
15
Q
Sources of Oligosaccharides
A
- Legumes (e.g., peas, lentils, or beans) and plant sources; contain glucose, fructose, and/or galactose; and are touted for health-promoting benefits
- Oligosaccharides are largely resistant to digestion because the human digestive tract lacks the necessary enzymes that can chemically break down many of these structures. This allows them to pass to the large intestine where intestinal bacteria act on them.
16
Q
Fructo-oligosaccharides
A
Jerusalem artichoke, leeks, onions, and asparagus
17
Q
Galacto-oligosaccharides
A
Soybeans and human breast milk
18
Q
Inulin
A
Chicory root, sugar beets, leeks, asparagus, and banana
19
Q
A straight chain and digestible form of starch containing glucose molecules.
A
Amylose
20
Q
Amylopectin
A
A branched-chain and digestible form of starch containing glucose molecules.
21
Q
Polysaccharides in Block form
A
Fiber
22
Q
Amylopectin and blood sugar
A
Greater levels of amylopectin result in a faster and a greater spike in blood sugar than a similar compound with more amylose
23
Q
Type of Soluble Fiber that dissolves in water to form a gel, associated with heart benefits and glucose control
Can be digested by bacteria in the large intestine (Fermentable)
A
Soluble Fiber
24
Q
Examples of Soluble Fibers
A
pectins, gums, and mucilages that originate from the inside of the plant cell.
25
Sources of Soluble Fiber
Qat bran, oatmeal, beans, fruits (e.g., apples or pears) and vegetables (e.g., artichoke, leeks, or sweet potatoes), as well as in many commercial products like salad dressings, jams, and jellies.
26
Benefits of Soluble FIber
- Weight Loss (delay gastric emptying, feeling full)
- Reduces risk of cardiovascular disease (binds cholesterol)
- Bowel movement and Intestinal health (bulk to stool)
- Diabetes protection (reduces sugar spike)
- Improved Absorption of Foods (slows food through the small intestine)
27
Form the structural parts of plants and include compounds like cellulose, hemicellulose, and lignin, and are often found in the outermost portion of grains, vegetables, fruits, and seeds (e.g., whole-grain wheat, celery, brown rice, quinoa, apple peels, or broccoli).
Insoluble FIber (Water Insoluble)
not easily digested by intestinal bacteria
28
Benefits of Insoluble Fiber
1. Digestive Health--adds bulk and draws water into the GI tract (avoids Constipation)
2. Reduces Cancer Risk--reduces risk of colon cancer
3. Reduces Diverticulosis
4. Weight Loss--Delays gastric emptying (feeling of fullness)
29
Whole Grains
Contain the Kernel (entire seed)
Kernel contains: Bran (outermost layer), Germ and Endosperm
30
Bran contains?
B Vitamins, antioxidants and fiber
31
Germ of whole grains
The germ is the embryo of the kernel and contains B vitamins, minerals, some protein, and healthy fats
32
Endosperm of whole grains
Largest portion of the kernel. It contains starchy carbohydrates, some protein, and small amounts of vitamins and minerals
33
A compound derived from isolated indigestible fiber to potentially provide some of the health-promoting benefits of natural fiber.
Functional Fiber (polydextrose and inulin)
34
Recommended Fiber Intake
25 g for women, 38 g for men
35
Good Sources of Fiber
High fiber bran ready-to-eat cereal
Navy Beans
Split peas
Lentils
Pinto Beans
Wheat bran flakes, ready-to-eat cereal
Avocado
Pear
Apple with skin
Prunes
Almonds
Banana
36
Storage molecule of glucose in animals, similar to how starch is the storage form of carbohydrate in plants
Glycogen
-large molecule with a pinwheel orientation centered around a protein core (glycogenin), and it can range from 100 to over 30,000 glucose units
-Only Glucose Molecules
37
Enzymes that create a free glucose molecule from glucose 6-phosphate, a compound that is formed when stored glycogen is broken down for energy
Glucose 6-phosphatase
38
Normal carbohydrate storage in muscle cells
Approximately 15 grams per kilogram (6.8 g/lb.) of muscle tissue
250 and 600 grams
39
Normal carbohydrate storage in Liver cells
Liver cells store approximately 50 grams per kilogram (22.7g/lb.) of tissue, and, considering how the liver weighs approximately 1.5 to 2.5 kg, this totals about 75 to 125 grams (300 to 500 kcal)
40
The primary storage and transportable form of fats in the body, composed of three free fatty acids bound to a glycerol backbone.
Triglycerides
41
A group of incompletely metabolized fat fragments that are normally produced during fat metabolism in the absence of adequate carbohydrates.
Ketones
42
A metabolic pathway that results in the generation of glucose from non-carbohydrate carbon substrates such as lactate, glycerol, and glucogenic amino acids.
Gluconeogenesis
43
Salivary amylase MOA
Starts the digestive process by cleaving large-chain polysaccharides into smaller segments.
44
Pancreas product that neutralizes the Chyme
Sodium Bicarbonate
45
Location Pancreatic Amylase continues digestion of carbohydrates
Jejunum (digestible carbohydrates are further broken down to disaccharide and monosaccharide forms)
46
Location where most carbohydrates are Absorbed
Ileum
47
Disaccharides undergo further digestion to single sugar units
Brush Border (villi and microvilli)
48
The vein that transports blood from the spleen, stomach, pancreas, and the intestinal tract to the liver.
Hepatic Portal Vein
49
The development of a fatty liver resulting from excessive quantities of fats being deposited from causes that exclude alcohol.
Non-Alcoholic Fatty Liver Disease
- Sedentary people who consume large amounts of Fructose
- excess energy intake, not fructose per se, are the leading cause of NAFLD
50
Primary cause of lactose intolerance
Genetic Inheritance
51
Lactase non-persistence
The small intestine begins to make less lactase after infancy and continues to decrease with age
52
Rate of Monosaccharide Absorption
Glucose and galactose, however, are absorbed via a different process than fructose. This process results in glucose and galactose being absorbed into the body at a faster rate than fructose.
53
Two primary hormones for preserving blood glucose
Insulin and Glucagon
54
Insulin
Escorts glucose in the blood to the liver, muscle, and fat cells. In the liver cell, it inhibits the release of glucose into circulation. In cells, it promotes glycogenesis and inhibits gluconeogenesis. It is also involved in amino acids and fatty acid uptake into cells.
55
Glucagon
Raises blood sugar levels during periods of hypoglycemia by facilitating glucose release from the liver into circulation. In other words, glucagon is the hormone responsible for telling the liver to release glucose into the bloodstream. It promotes glycogenolysis and gluconeogenesis, and it also inhibits lipogenesis.
56
Absorbs insulin out of circulation
Liver and Kidneys
57
Exercising Hormones
Norepinephrine and Epineprine
58
Breakdown of nutrients to release energy
Catabolic
59
Non-insulin mediated glucose uptake (NIMGU) pathway
Insulin production and release is suppressed during exercise
60
During exercise
Epinephrine, norepinephrine, and glucagon levels all increase to stimulate glycogenolysis and glucose release from the liver into the blood
- Under scenarios of prolonged exercise, glycogen depletion, or carbohydrate or caloric restriction, cortisol levels elevate to preserve liver glycogen, which, in turn, preserves blood sugar.
61
A relative ranking of a food’s effect on blood glucose (blood sugar) 2 hours after the consumption of that food.
Glycemic Index
62
Glycemic Index of Glucose
100
63
Glycemic Index of 50
Elevates Blood Glucose Half the amount of Glucose
64
Low Glycemic Index foods
Under 55
65
Medium Glycemic Index foods
56 - 69
66
High Glycemic Index Foods
70 and above
67
Key observations to Glycemic Index
Not all simple sugars have high GI scores (e.g., fructose or sucrose). Fructose is absorbed more slowly and needs conversion to glucose in the liver. This subsequently lowers its GI score.
Not all complex carbohydrates have low GI scores (e.g., instant rice, instant mashed potatoes, or cornflakes). Removing fiber can increase a food’s GI score.
68
Considerations of Glycemic Index
Monosaccharide form—glucose versus fructose
Polysaccharide form—amylopectin versus amylose
Liquid vs Solid
Degree of Processing
Presence of other nutrients (Fiber, protein, fats)
69
A method for determining how the quantity of carbohydrates consumed impact blood sugar levels.
Glycemic load (GL)
70
The recommended dietary allowance (RDA) for carbohydrates for adults aged 19 years and older
130 mg/day
71
Acceptable Macronutrient Distribution Range (AMDR) for carbohydrates
45 - 65% of the total caloric intake daily, which might be at least double the RDA.
72
Largest source of Sugars
Beverages
73
Represent all sugars derived from food sources that exclude those sugars found naturally in fruits and dairy
Added Sugars
74
Overall goal for healthy eating is to reduce the total percentage of added sugars
From 13% down to under 10% of caloric intake (no more than 12 added teaspoons)
AHA – limit of 6 added teaspoons (women) and 9 added teaspoons (men) (AHA, 2016)
CSPI – limit 100 kcal or 6 ½ teaspoons (women) and 150 kcal or 9 ½ teaspoons (men) (CSPI, 2015)
75
Recommended Fiber per day
28 grams per day for women and 35 grams per day for men
