Milestone 1, Chapter 5: Carbohydrates
Glycemic load =
(GI x grams of carbohydrate)/100 -Divided by 100 because GI is a percentage
List the 5 main sources of the fiber we consume.
(all non-starch polysaccharides) 1. Cellulose 2. Hemicelluloses 3. Pectins 4. Gums 5. Mucilages
List the diet suggestions for a nutritious diet with health and ample sources of carbohydrates.
1. 6 oz of grains 2. 2.5 cups vegetables 3. 2 cups fruit 4. 3 cups of milk
List 5 sources of the oligosaccharides raffinose and stachyose:
1. Cabbage 2. Broccoli 3. Onions 4. Whole wheat 5. Legumes
List the three insoluble fibers.
1. Cellulose 2. Hemicellulose 3. Lignins
What are the health benefits associated with consuming insoluble fiber?
1. Decreased intestinal transit time 2. Decreased rates of constipation 3. Decreased risk of diverticulitis 4. Decreased risk of colon cancer
List 2 sources of pectin (soluble fiber):
1. Fruits 2. Thickener in jam and jellies
List 4 sources of fructose
1. Fruits 2. Vegetables 3. Honey 4. High fructose corn syrup
List two possible effects of straining to eliminate small hard stools as a result of too little fiber.
1. Hemorrhoids 2. Diverticula (when parts of the large intestine wall protrude through the muscle bands forming small pouches)
List 4 results of chronically high insulin output.
1. High blood triglycerides 2. Increased fat production in the liver 3. Increased fat deposition in adipose tissues 4. More rapid return of hunger after a meal
List 5 symptoms of hypoglycemia
1. Hunger 2. Shakiness 3. Irritability 4. Weakness 5. Headache
List 4 symptoms of diabetes:
1. Hunger 2. Thirst 3. Frequent urination 4. Weight loss
Name 6 hormones that control blood glucose levels.
1. Insulin 2. Glucagon 3. Epinephrine 4. Norepinephrine 5. Cortisol 6. Human growth hormone
List the 5 criteria possible in the diagnosis of metabolic syndrome.
1. Insulin resistance or glucose intolerance 2. Abdominal obesity (>35 inches in women and > 40 inches for men) 3. High blood triglycerides (>150 mg/dl) 4.Low HDL (<40 mg/dl for men, and <50 mg/dl for women) and high LDL 5. High blood pressure 6. Increased inflammatory proteins
List 5 nutritive sweeteners:
1. Lactose 2. Maltose 3. Glucose 4. Sucrose 5. Fructose 6. Galactose
List three gums and mucilages (soluble fibers):
1. Legumes 2. Seaweed 3. Psyllium
What are the health benefits associated with consuming soluble fiber?
1. Lower blood cholesterol 2. Delays gastric emptying 3. Lower blood glucose levels
List 3 health benefits of consuming adequate fiber.
1. Lower blood cholesterol (decreased risk of cardiovascular disease) 2. Lower blood glucose levels (decreased risk of diabetes) 3. Lowering intestinal transit time (reduced risk of constipation, diverticulitis, and colon cancer)
List 6 effects of ketoacidosis
1. Lower blood pH 2. Water loss (and possible dehydration) 3. Decreased appetite 4. Muscle loss 5. Electrolyte imbalances 6. Coma or death
List 2 disaccharides that have an alpha bond
1. Maltose 2. Sucrose
What alternative sweeteners can be used in cooking and baking?
1. Neotame 2. Acesulfame-K 3. Sucralose 4. Monk fruit
What are the two types of sweeteners?
1. Nutritive (provide energy/calories) 2. Non-nutritive (or alternative, provide no energy)
List the four soluble fibers
1. Pectins 2. Gums 3. Mucilages 4. Some hemicelluloses
List 6 examples of foods with a high glycemic index.
1. Potatoes 2. Breads 3. White rice 4. Honey 5. Jelly beans 6. Gatorade
List 2 oligosaccharides
1. Raffinose 2. Stachyose
What are the two types of hypoglycemia found in nondiabetics?
1. Reactive hypoglycemia (exaggerated insulin response after eating) 2. Fasting hypoglycemia (low blood glucose after fasting for 8+ hours)
List 5 treatments for hypoglycemia
1. Regular meals with a balance of fat, protein, and low glycemic index carbohydrates 2. Ample soluble fiber 3. Substituting high sugar content snacks for those high in protein .4. Spread out carbohydrate intake over the day 5. Limit caffeine and alcohol intake
Name 2 pentoses
1. Ribose 2. Deoxyribose
List 8 alternative sweeteners:
1. Saccharin 2. Aspartame 3. Neotame 4. Acesulfame-K 5. Sucralose 6. Tagatose 7. Stevia 8. Luo han guo (monk fruit)
List 2 sources of lignins
1. Seeds of fruit 2. Bran layer of whole grains
List 4 sources of cellulose (insoluble fiber):
1. Skins of fruits and vegetables 2. Legumes 3. Celery 4. Whole grains
Name 5 factors that impact a food's glycemic index
1. Starch structure and fiber content (amylose vs. amylopectin) 2. Food processing 3. Physical structure (small vs. large surface area) 4. Temperature 5. Amount of protein and fat in a meal
What are the three types of carbohydrates?
1. Sugar 2. Starch 3. Fiber
List three plants that naturally contain large amounts of sucrose
1. Sugarcane 2. Sugar beets 3. Maple tree sap
List 6 symptoms associated with reactive hypoglycemia.
1. Sweating 2. Irritability 3. Anxiety 4. Headache 5. Weakness 6. Confusion
List 3 components to the treatment of metabolic syndrome.
1. Weight loss 2. Decreased fat intake 3. Increased physical activity
List 2 sources of insoluble hemicellulose:
1. Whole grains and cereal fibers 2. Some vegetables
According to the RDA for glucose, how much digestible carbohydrates to adults need to consume per day to supply adequate glucose to the brain and central nervous system?
130 g/day. But in reality, this should be much higher (45-65% of daily caloric intake)
What is the Adequate Intake for fiber?
14 g/1000 kcal consumed. For adults under 50, t's set at 25 g for women, and 38 g for men. For adults over 50, it's set at 21 g/day and 30 g/day.
In starchy products like potatoes, beans, bread, pasta, and rice, amylose and amylopectin are usually found in a ratio of about ____.
1:4 (there's 4 times as much amylopectin as amylose)
What is the general formula for a disaccharide?
2 monosaccharides = (CH2O)12
What percentage of the recommended intake for fiber to Americans consume across their life span?
25-50%
An oligosaccharides contains _____ sugar units. "Oligo" means ____.
3-10; few
How many calories does consuming caloric sweeteners add to the diet of the average American (ages 2 and older) per day?
300
How much glycogen is stored in the muscles and what is its function?
300 grams (1200 kcal) is broken down for muscle use, particularly during high intensity/endurance exercise
How much sweeter than sucrose is saccharine?
300 times
How much energy per gram does glucose produce?
4 kcal
Aspartame actually has about ____ (the same as sucrose), but because it is about _____ times sweeter than sucrose, only a small amount is needed. As a result it doesn't contribute any ____ to foods or beverages.
4 kcal/kg; 160-220; calories
What is the ADI for saccharin?
5 mg/kg of body weight per day. A 154 lb/70 kg adult could have 3 12 oz. diet soft drinks or 9 packets of sweetener daily.
What is the ADI for aspartame?
50 mg/kg body weight/day. For the average person this is 18 cans of diet soda, or 80 packets of Equal or NutraSweet per day.
North Americans obtain about ____ of their daily calories from carbohydrates. But often these calories are from ___, ____, ____, ____, ____, _____, ______ etc. instead of from ____, ____, and ____.
50%; white bread, soft drinks, cookies, cakes, donuts, sugars, jams, and potatoes; fiber rich fruits, vegetables, and whole grains
What is the fructose content of high fructose corn syrup?
55% (can range from 40-90%)
What percentage of energy intake should come from added sugars? In North America, how much of our energy actually comes from added sugars?
6% (according to Dietary Guidelines for Americans) less than 10% (according to the WHO). 14.5%.
Worldwide, carbohydrates account for ____ of energy consumed.
70-80%
How much glycogen is stored in the liver and what is its function?
90 grams (360 kcal) can be converted into blood glucose to supply the body with energy
What is low glycemic load?
<10
What is considered high glycemic load?
>20
What is considered high glycemic index?
>70
What is lactose?
A disaccharide made up of glucose and galactose
Disaccharides are digested into their monosaccharide units by specialized enzymes in the ____ of the ____.
Absorptive cells; small intestine
The FDA sets an ____ guideline for _____. This is based on the amount of _____ considered safe for daily use over a lifetime. They are based on studies observing lab animals, and are set at ____ times less the amount that caused harm.
Acceptable daily intake (ADI); alternative sweeteners; alternative sweeteners; 100
What are the two types of C-O-C bonds?
Alpha and beta
Glycogen is similar to ____, but is more highly branched.
Amylopectin
What are the differences between amylose and amylopectin?
Amylose is linear (non branched, with only 1,4 alpha bonds) and amylopectin is branched (with both 1,4 and 1,6 alpha bonds at branch points)
What are diverticulosis and diverticulitis?
Both include diverticula. Diverticulosis is asymptomatic (accounts for about 80% of cases, and is one fo the most common conditions in Western countries). Diverticulitis occurs when diverticula become inflamed in response to fibrous material, feces, and bacteria in the diverticula.
List 3 hexoses (all have the same chemical formula, but in different formations)
C6H12O6 1. Glucose 2. Fructose 3. Galactose
What is the general formula for a monosaccharide?
CH2O, or CnH2nOn
What three fibers are more resistant to being broken down by the bacteria in the large intestine?
Cellulose, lignins, and hemicellulose
T/F Amylose causes blood glucose levels to rise more quickly than amylopectin.
F. Because amylopectin has more branch sites, more enzymes can be working from different directions digesting starch at a faster rate than if it were just in a linear conformation like amylose
T/F Eating a set amount of any carbohydrate will correspond to the same change in blood glucose levels.
F. Different carbohydrates have different effects on blood glucose levels
T/F A high fiber diet decreases the risk of colon cancer as a direct result of its fiber content.
F. It is more likely to be a result of the nutrients found in high fiber foods.
T/F The process of absorption for fructose is faster than for glucose and galactose.
F. It's faster for glucose and galactose
T/F. Most nutritive sweeteners are sweeter than non-nutritive/alternative sweeteners
F. Most alternative sweeteners are sweeter
T/F Currently, nutrition fact labels include information about both dietary and functional fiber.
F. They only include information about dietary fiber and not functional or total fiber.
T/F Saccharine can be used in baking.
F. When heated it develops a bitter taste.
T/F Pentoses need to be supplied by our diets
False
T/F Raffinose and Stachyose are digestible
False. These pass undigested into the large intestine because we don't have enzymes capable of breaking the beta bonds found in these sugars. There they are digested by bacteria that produce gas and other byproducts.
What does the highly branched nature of glycogen allow?
For rapid break down in animal muscle cells during activity
What enzyme acts to digest the disaccharide lactose and what are the products?
Lactase, 1 galactose and 1 glucose
Galactose + glucose =
Lactose
What is one disaccharide that forms a beta bond?
Lactose
What is the only non-carbohydrate source of fiber?
Lignins
Once absorbed, galactose, glucose, and fructose are transported to the ____ via the ____. Some of the ___ is converted into ____, but once in the liver, all ____ and ____ are turned into ____.
Liver; portal vein; fructose; glucose; galactose; fructose; glucose
What is the treatment for diverticulitis?
Low fiber diet to keep bacteria from further inflaming diverticula, then once symptoms subside, high fiber, high fluid diet and regular exercise to prevent future flair ups
What enzyme acts to digest the disaccharide maltose and what are the products?
Maltase, 2 glucose molecules
Glucose + glycose =
Maltose
What is the disaccharide product of starch breakdown in the small intestine?
Maltose
Monosaccharides and disaccharides are commonly referred to as _____.
Simple sugars
In general, the more processed the food, the more ____ it contains, and the less ___ it contains.
Simple sugars; fiber
A high fiber diet helps prevent high blood glucose by...
Slowing absorption in the small intestine and slowing the release of insulin
___ is the main source of digestible polysaccharides in our diets. It is the storage form of ____ in plants, and is found in two forms: ____ and ____. These both contain ___ bonds.
Starch; glucose; amylose; amylopectin; alpha
What enzyme acts to digest the disaccharide sucrose and what are the products?
Sucrase, 1 glucose and 1 fructose
Glucose + fructose =
Sucrose
Where is most of the maltose we digest from?
The breakdown of polysaccharides into maltose in the small intestine (we don't actually get much from our diets)
How does cooking aide in carbohydrate digestion?
When heated, starch granules soak up water and swell which makes them much easier to chew, swallow, and break down.
When can hypoglycemia occur in diabetics?
When they inject too much insulin, don't eat enough, or do some physical activity without eating carbohydrates
What largely determines the digestibility of polysaccharides (complex carbohydrates)?
Whether they contain monosaccharides bonded by alpha (digestible) or beta (indigestible) bonds
What is a good source of insoluble fiber?
Whole grains
How is fructose absorbed?
facilitated diffusion, a carrier is used, but no energy is required
A high fiber diet helps reduce cholesterol absorption and risk of gallstones by...
inhibiting the absorption of cholesterol and the reabsorption of bile acids from the small intestine.
What is low glycemic index?
less than 55
What is the general chemical equation for photosynthesis?
nH2O + nCO2 ->(energy from the sun) CnH2nOn + nO
Polysaccharides are broken down by ____ and ____ in the small intestine.
pancreatic amylase; dextrinase
Sugar alcohols do ____, but they are metabolized more ____, so are useful in foods for diabetics.
provide energy; slowly
Amylopectin's branches allow it to retain water to form a stable ____. For this reason it is often used to _____. Amylopectin is also used in many frozen foods because it _____.
starch gel; thicken sauces and gravies; is stable over a wide range of temperatures
What can the brain use for fuel when carbohydrate intake is too low?
Ketone bodies
Sugar alcohols are not easily metabolized by ____, and thus don't promote ____ in the same way as sugars.
Bacteria in the mouth; cavities
What blood glucose levels qualify as hypoglycemia?
Below 50 mg/dl of blood
What are normal blood glucose levels in the fasting state (at least several hours after eating)?
Between 70 and 100 mg/dl of blood
Saccharin was thought to promote ____, but those studies have been dismissed because they were weak and inconclusive.
Bladder cancer
What blood glucose levels qualify as diabetes?
Blood glucose levels above 126 mg/dl of blood
What is the chemical formula of glucose?
C6H12O6
Disaccharides are formed via _____, that link two ____ and produce ____.
Condensation reactions; monosaccharides; water
How is high fructose corn syrup made?
Cornstarch is treated with acid and enzymes to break the starch down into glucose which is then converted into fructose.
The adrenal glands also produce ___, which ___ the use of glucose by ___, to increase blood glucose.
Cortisol; decreases; muscles and other organs
What are sugar alcohols? List three.
Derivatives of monosaccharides used as artificial sweeteners often in sugarless gum or dietetic foods 1. Sorbitol 2. Mannitol 3. Xylitol
Total fiber =
Dietary fiber (fiber found naturally in foods) + functional fiber (may be added to a food for additional health benefits)
The adrenal glands produce ___, ___ in response to an immediate threat. These trigger ____ and ____ so muscles will have enough fuel to act.
Epinephrine; norepinephrine; glycogen breakdown; gluconeogenesis
All monosaccharides, except ____, are absorbed via an _____ process.
Fructose; active absorption
When bacteria in the large intestine break down fiber, they produce ___, and _____, which are used for ____ by the cells of the large intestine.
Gas; short chain fatty acids; energy
Soluble fibers dissolve easily in water, and become ____ in consistency. This makes them useful for ____.
Gel-like; thickening jam, jelly, yoghurt etc.
What is the major storage form of glucose in animals?
Glycogen
The pituitary gland produces ____, which (like ___) decreases the use of glucose by ___. It also increases ____ and ____.
Growth hormone; cortisol; muscles and other organs; fat mobilization; glucose output from the liver
The American Heart Association has set an upper limit of sugar intake at ____ of one's discretionary calorie allowance. This is approximately ___ for women and ____ for men.
Half; 100 calories; 150 calories
If the glucose digested is more than enough to fuel the cells of the body, what happens to excess glucose?
It is stored in muscles and in the liver as glycogen. When glycogen storage is exceeded, the liver converts glucose to fat which is stored in adipose tissue.
Why do so many food manufacturers use high fructose corn syrup instead of sucrose?
It is sweeter and cheaper than sucrose
Where are 1,4 alpha bonds digested?
In the mouth and in the small intestine by amylase, which is present in the mouth as well as being produced by the pancreas
Where does starch digestion begin?
In the mouth, where amylase in the saliva breaks down amylose. Amylase is deactivated by acid in the stomach, so starch digestion stops until it reaches the small intestine.
Where are 1,6 alpha bonds digested?
In the small intestine by an enzyme called alpha-dextrase
What is metabolic syndrome?
Increases the risk of type 2 diabetes and cardiovascular disease. Associated with obesity, physical inactivity, genetic predisposition, and aging. Diagnosed if 3 out of 5 criteria are met.
When does diabetic ketosis occur?
Instead of when carbohydrate intake is too low (as in during starvation), ketosis occurs in diabetics because cells are resistant to insulin and don't open up to accept glucose as they would in response to insulin in a healthy individual. As a result, they think they're starving and signal the breakdown of fatty acids which produce ketones.
What is a major shortcoming of the glycemic index system? What helps account for this?
It is based on a service size of 50 grams, but that isn't always the amount being consumed. The glycemic load measurement system accounts for both the glycemic load of a food as well as the amount being eaten.
List 1 source of soluble hemicellulose:
Oat bran
How do disaccharide bonds form?
One OH is taken off of 1 carbon on one monosaccharides, and 1 H is taken off the other monosaccharide. Together these form water which is released. Then the two carbons (which are not fully bonded) bond to the remaining O in a C-O-C configuration.
What are the three fibers that produce the most energy in the form of short chain fatty acids when digested in the large intestine by bacteria?
Pectin, mucilages, and gums (produce between 1.5-2.5 kcal/g)
Who should avoid aspartame?
People with PKU, which causes problems with the metabolism of phenylalanine (aspartame contains high phenylalanine)
What types of cells rely almost entirely on glucose for energy?
Red blood cells and cells of the central nervous system. Glucose also fuels other body cells, but they might use fatty acids instead during rest or light activity.
What is the oldest alternative sweetener?
Saccharine (Sweet'N Low)
What are the two major storage sites in animals for glycogen?
The liver and muscles
What is the glycemic index?
The ratio of blood glucose response to a food in comparison with a standard (usually glucose or white bread, whose GI = 100).
What happens when people don't consume enough carbohydrates?
The release of insulin decreases, which causes a flood of fatty acids from adipose tissue to provide energy. The break down of these fatty acids for energy forms acidic by-products called ketone bodies, resulting in ketoacidocis or ketosis.
What are some limitations to the glycemic index and load measurement systems?
These measure the effect of a food on blood glucose levels when only that food is eaten. Usually, foods are eaten with other foods that might lower a high glycemic load.
How do beta bonds differ from alpha bonds?
They are more difficult to break down (we often lack the enzymes required, which is why we can't digest dietary fiber, or why some people can't digest lactose)
What is the effect of consuming foods with a high glycemic load?
They trigger a spike in insulin, which results in a drop in blood glucose.
Fasting hypoglycemia is ___, and may be caused by an underlying condition like ____, ____, or ____.
Unusual; cancer; liver disease; renal disease
How are glucose and galactose absorbed?
Via secondary active transport. They are moved into cells along with sodium (down its concentration gradient) which provides energy for them to be transported into the cell. Sodium is then pumped out of the cell using ATP and the sodium potassium pump.
How does fiber make bowel movements easier?
With adequate fiber and water, stools are soft and large because many plant fibers absorb water. The larger size of the feces stimulates the intestinal muscles which aids in elimination.
Some food labels will say "____," or "____," but that doesn't mean a food is actually whole wheat. To ensure that a food is whole wheat, make sure that the first ingredient is ____, or look for the Whole Grains Council Stamp
wheat flour; wheat wheat bread; whole-wheat flour