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69 Cards in this Set
- Front
- Back
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How does photosynthesis relate to carbohydrates?
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In plants, photosynthesis combines six CO2 molecules and six H20 molecules to form one molecule of glycogen, which is a form of carbohydrate that humans find in food.
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What are the three types of monosaccharides?
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1) Glucose
2) Fructose 3) Galactase |
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What are the three types of disaccharides and what are they composed of?
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1) Sucrose: glucose + frutose (table sugar)
2) Lactose: glucose + galatose (milk sugar) 3) Maltose: glucose + glucose (fermented/alcohol sugar) |
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Fructose basics (3)
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1) Metabolized to glucose in liver
2) Found in fruit, honey and high fructose corn syrup 3) Part of sucrose |
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Galactose basics (3)
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1) Usually bonded with glucose to form lactose
2) Converted to glucose in the liver 3) Simplest Sugar (Available fuel source) |
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What is the technical term of simple sugars?
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Disaccharides and monosaccharides are both simple sugars and known only as "sugars" on a nutrition facts label.
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Where is maltose found?
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Maltose is formed during fermentation and alcohol production.
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What are the four types of complex carbohydrates?
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1) Polysaccharides (starch and glycogen)
2) Amylose 3) Amylopectin 4) Dietary fiber |
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What are oligosaccharides?
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They are 3-10 monosaccharides bonded together. Most commonly found in beans and legumes, they are not digested, though they are metabolized by L.I. bacteria, which can result in gas, cramps, bloating, etc.
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How many saccharides bond together to form a polysaccharide.
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1000 or more
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What is the key difference between the two varieties of starch?
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Amylose is a straight-chain polymer. Amylopectin is a highly branched polymer, allowing it to form a very stable starch gel that is broken down more easily by the body.
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Is glycogen more similar to amylose or amylopectin in terms of structure?
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Glycogen has a branched structure, making it more similar to amylopectin. The branched structure gives it more sites for enzyme action, making it easy to break down.
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Where is glycogen found?
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Glycogen is the storage form of glucose and can be found in the muscles and liver. About 1800 kcal can be found in the body at any given time.
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True or False:
The digestive system easily breaks down dietary fiber. |
False: The body cannot break the bonds of fiber.
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What is the difference between soluble and insoluble fiber?
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Soluble fiber is fermented by the bacteria in the colon and can swell or dissolve in water. Insoluble fiber passes through the body undigested and uneffected.
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What are the three types of insoluble fiber?
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1) Cellulose
2) Hemicellulose 3) Lignin |
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What are three types of soluble fiber?
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1) Gum
2) Pectin 3) Mucilage |
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What are four sources of soluble fiber?
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1) Fruit 2) Veggies 3) Rice Bran 4) Psyllium Seed
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What are the six benefits of dietary fiber?
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1) Absorbs and holds water
2) Softens stool 3) Larger stool helps activate peristalsis 4) Promotes regularity 5) Lower risk for cardiovascular disease 6) Decrease of hemorrhoids and diverticula |
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What are diverticula and how are they formed?
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Diverticula are fluid-filled pouches that can form on the our part of the colon. They are thought to be the result of extreme pressure within the colon.
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True or False:
Carbohydrate is found in all varieties of grains, fruits and vegetables. |
True
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What two foods from the dairy group contain carbohydrate?
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1) Milk
2) Yogurt |
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What two foods from the meat group contain carbohydrate?
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1) Beans
2) Nuts |
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What is the average sweetener consumption per person, per year?
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14-48 lbs
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Describe the creation process of high fructose corn syrup and its use.
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High fructose corn syrup is created by treating cornstarch with acid and enzymes, converting the starch's glucose to fructose. It is just as sweet as sucrose but much cheaper, leading to its use in many products.
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How much energy do sugar alcohols provide?
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1.5-3 kcal/g
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How are sugar alcohols different from other sweeteners?
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They have less energy, only 2.6 kcal/gm. Also, they are absorbed and metabolized much more slowly and can cause diarrhea if consumed in excess.
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True or False:
Saccharine is sweeter than sucrose. |
True: It is 180-200x sweeter.
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True or False:
Humans who consume saccharine have a potentially higher risk of bladder cancer. |
False: Though it has been linked to cancer in lab animals, there is no potential risk in humans.
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What are the three components of aspartame?
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1) Phenylalanine
2) Aspartic acid 3) Methanol |
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What is the commercial name for aspartame?
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Nutrasweet
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What is the energy contribution of aspartame?
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4 kcal/gm, but it is 180-200x sweeter, so very little is needed to sufficiently sweeten food.
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True or False:
Some people can exhibit signs of aspartame sensitivity, such as headaches, dizziness, nausea and seizures. |
True: In fact, some people have such severe sensitivity that it is life-threatening. This condition is known as phenylketonuria (PKU).
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Which of the following is not heat stable?
a) Aspartame b) Acesfulame c) Sucralose |
A) Aspertame loses its flavor when cooked.
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How is sucralose made?
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Chemical reactions substitute chlorines for hydroxic groups on the sucrose molecule.
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How does the mouth digest carbohydrate?
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Salivary amalase breaks down starches into shorter saccharides, also the sweetness of carbohydrates encourages prolonged chewing.
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True or False:
The acid in the stomach creates an ideal environment for salivary amylase to work. |
False: The acid deactivates the salivary amylase, ceasing the digestion of starch.
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How are carbohydrates digested in the small intestine?
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The pancreas releases enzymes to break down carbohydrate into monosaccharides, which are then absorbed.
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What are the three enzymes used to break down disaccharides?
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Maltase, Sucrase and Lactase
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What does pancreatic amylase do?
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It breaks starch down into maltose.
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How are carbohydrates digested in the large intestine?
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Bacteria and gases ferment some forms of soluble fiber. The remaining carbohydrate is undigestible and makes up the bulk of stool.
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What type of small intestine absorption is required for glucose and galactose?
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Active absorption, which expends energy.
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What type of small intestine absorption is required for fructose?
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Facilitated diffusion using a carrier
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What do the portal vein and liver have to do with carbohydrate digestion?
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The portal vein transports absorbed monosaccharides to the liver, where they are processed in one of three ways. They are either transformed into glucose for immediate use in the blood stream, converted to glycogen for storage or synthesized into fat.
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What is ketosis and how does carbohydrate ingestion prevent it?
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Carbohydrate aids in the breakdown of fat. Without sufficient carbohydrate, partially broken down fat deposits, known as ketones, form. These attract sodium and potassium out of the body and into the urine and too many can cause dehydration, ion imbalances and death.
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What is the role of the adrenal gland in blood sugar control?
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It releases epinephrine and norepinephrine.
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What is the role of the liver in blood glucose control?
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The liver regulates glucose that enters the bloodstream.
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What is main function of insulin? How does it work?
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Insulin reduces blood glucose by promoting glycogen synthesis, increasing glucose uptake and reducing glyconeogenesis.
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What is the main function of glucogen? How does it work?
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Glucogen raises blood glucose by breaking down glycogen and enhancing gluconeogenesis.
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What two hormones, released during the flight or fight response, are related to blood sugar control?
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Epinephrine and norepinephrine.
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How do epinephrine and norepinephrine raise blood glucose?
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They break down stored glycogen.
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What is Type I Diabetes (Diabetes Mellitis Type I)?
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An immunological disorder that results in a decreased release of insulin. The disease has a strong genetic link and is thought to be related to an early introduction of cow's milk into the diet. It is also known as hyperglycemia.
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What are four ways Type I diabetes is treated?
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1) Carbohydrate counting -- especially sugar
2) Insulin therapy 3) Prescribed high fiber diet 4) Prescribed ratios of CHO:PRO:FAT |
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What is Type II Diabetes (Diabetes Mellitus Type II)?
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A disorder caused by defective insulin receptors in cells, resulting in an over-secretion of insulin. This leads to beta cell failure. Type II has a genetic link but is also strongly associated with obesity. Many sufferers find relief with weight loss and maintenance, though medication is also a treatment option.
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What are four consequences of uncontrolled blood sugar?
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1) Ketosis leading to ion imbalances, dehydration, coma and death
2) Degenerative diseases -- nerve damage, heart disease, kidney disease, blindness 3) Atheroclerosis (thickening of the artery walls) 4) Increased risk for wound infections |
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What are the two types of hypoglycemia and what are they caused by?
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1) Reactive hypoglycemia creates symptoms 2-4 hours after eating and is thought to be due to secretion of insulin.
2) Fasting hypoglycemia is usually caused by pancreatic cancer, which can irritate the organ into overproducing insulin. |
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How much should be consumed to prevent ketosis?
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50 gm/day
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How much of total kcal should be from carbohydrate, according to the National Cholesterol Education Program?
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50-60% (average consumption is roughly 50%).
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What is the recommended dietary fiber intake for adults and children? How does it compare with current consumption?
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Adults should get 20-38 gm fiber a day (10-13 gm/kcal). Children should get around 5gm per day. Average intake in the U.S. is 16gm per day.
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What are four things that can happen if more than 60mg of fiber is consumed per day?
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1) Extra fluids will be required or stool will become hard
2) Fiber bonds to some minerals, which could cause depletion 3) Phytobezoars can develop in large intestine 4) Young children's stomachs can fill too quickly. |
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What is the recommended simple sugar intake and how does it compare with the national average?
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Since simple sugars have a low nutrient density, it is recommended that no more that 10% of total kcal should come from them. The average U.S. intake is 16% of total kcal/day.
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What is the glycemic index?
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The Glycemic Index is a measurement of how food will affect (raise) blood glucose.
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What are five effects of eating a lot of carbohydrate with a high glycemic index?
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Highly glycemic foods cause insulin levels, which can:
1) affect blood triglycerides 2) effect LDC 3) increase fat synthesis 4) cause quicker return to hunger 5) result in the development of insulin resistance |
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What causes lactose intolerance and what are its effects?
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Lactose intolerant people produce less lactase. As a result, lactose is undigested and unabsorbed. Bacteria in the large intestine then ferment it, resulting in gas, bloating, cramping and discomfort.
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Carbohydrate is a major source of fuel for which 3 things?
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1) brain
2) nervous system 3) red blood cells |
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How long does it take to deplete the body's carbohydrate stores?
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18 hours
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True of False:
Animals can produce trace amounts of sucrose. |
False: Sucrose is only produced by plants.
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What is the RDA for carbohydrates?
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130 gm/day
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True or False:
Red blood cells can only use simple carbohydrate for fuel. |
True
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