Types of Carbohydrates
Functions of Carbohydrates
Metabolism of Carbohydrates and Exercise
How to Cite This SparkNote
Table of Contents
, which you don't seem to have. Please try a different browser.
Full Book Quiz
1. Cellulose contains beta 1,4 glycosidic linkages as well as intramolecular hydrogen bonds. This allows cellulose to:
Form a long, straight polymer of glucose that is very rigid and strong
Create extensive twisting in the polymer to increase its surface area
Form a network of branching patterns through intramolecular hydrogen bonding
Be very soluble in water
2. While glycogen and starch consist of long chains of alpha 1,4 glycosidic linkages, the branching points on these molecules are formed through:
Alpha 1,6 glycosidic linkages
Alpha 1,2 glycosidic bonds
Beta 1,6 glycosidic linkages
Intramolecular hydrogen bonds
3. What is an epimer?
It is an isomer that differs in the configuration about a single asymmetric center
It is simply a structural isomer of another compound having the same chemical formula but a different three-dimensional structure
It is an isomer of glucose having a different chemical formula and a different three-dimensional structure
It is a type of monosaccharide
4. Why is the chair conformation the most stable structure that glucose and other six-membered rings can adopt?
The chair conformation minimizes steric hindrance by forcing bulky side groups to point away from the ring
The chair conformation adopts a chair-like structure that points functional groups towards the ring
The chair conformation is not glucose's most stable structure; the most stable form of glucose is the boat conformation
The chair conformation allows the glucose molecule to become more compact and therefore more stable
5. Why is sucrose an excellent preservative?
Sucrose contains the ketone fructose that can readily react with potential contaminants in solution
Sucrose contains a 1,2 alpha glycosidic bond that eliminates the reducing end from the dissacharide, preventing side reactions with other molecules
Sucrose is a dissacharide and all dissacharides have some preservative-like qualities
Sucrose contains glucose, which generally is a non-reactive compound that can act like a preservative in solution
6. What is lactose intolerance?
Lactose intolerance is the inability to digest lactose and results in intestinal cramping and bloating when it is consumed
Lactose intolerance is the inability to absorb lactose from the small intestine
Lactose intolerance is a disease in which alpha glycosidic bonds cannot be degraded by the small intestine
Lactose intolerance is a condition in which only a small amount of lactose can be digested by the small intestine, releasing excess lactose into the blood
7. Maltose is a dissacharide consisting of what two simple sugars?
Two glucose molecules
One glucose molecule and one fructose molecule
One glucose molecule and one molecule of galactose
One molecule of galactose joined to one molecule of fructose
8. After a meal, why do levels of insulin rise?
Pancreatic cells sense the rise in glucose and release insulin into the blood to allow cells to uptake glucose
Pancreatic alpha cells sense the rise in amino acids and release insulin into the blood to allow cells to uptake amino acids for use in the citric acid cycle
Pancreatic beta cells sense the rise in blood glucose and release insulin into circulation so that the brain and muscle cells can uptake glucose
Galactose binds to alpha cells in the pancreas, stimulating the release of insulin into the bloodstream
9. How does the liver respond to increases of insulin in the bloodstream?
The liver begins to uptake glucose for the synthesis of glycogen, a long polymer of glucose residues
The liver begins to degrade glycogen to glucose so that glucose can be distributed to working muscle tissue as an energy source
The liver begins to uptake glucose for the synthesis of amylose, a long, highly branched polymer of glucose
The liver responds only weakly to insulin; it responds strongly to glucagon
10. What is the function of the hormone glucagon?
Glucagon acts on the liver to increase the breakdown of glycogen to glucose from the liver and promotes gluconeogenesis
It inhibits the uptake of glucose by muscle cells and promotes the synthesis of fatty acids in adipose tissue
It inhibits the uptake of glucose by the muscle and promotes the synthesis of amino acids and proteins
11. What is gluconeogenesis?
It is the process by which glucose is synthesized from pyruvate under conditions of low blood glucose
It is the process by which glucose is synthesized from pyruvate in the cytosol under conditions of high blood glucose
It is process by which glucose is degraded to pyruvate in order to generate ATP
Gluconeogenesis is process of producing glycogen from glucose
12. What are sources of gluconeogenesis?
Proteins and amino acids
13. What happens when fasting is prolonged for more than a day?
The levels of glucagon in the blood rise in response to low blood glucose and fatty acids are converted to ketones that can be used by the brain and muscle
The levels of insulin rise in response to low blood glucose and the body enters a state called ketosis
Fasting for more than a day causes levels of glucagon rise in response to low blood glucose and fatty acids are utilized by the muscle and brain as an energy source
Glucagon is released into the bloodstream and glycogen begins to be synthesized in the liver
14. A friend of yours goes on a low carbohydrate, high protein diet in order to lose weight. Why is he experiencing headaches and fatigue?
Your friend's blood glucose is low and his ketone bodies are high with respect to normal values. Since you know the brain preferentially uses glucose as an energy source, he is getting headaches due to a lack of carbohydrates in his diet.
He is losing weight at a rapid weight and his organs are having a difficult time adjusting to a new rate of metabolism.
She is eating too many foods containing a lot of protein in them. Excess proteins are absorbed into the blood and certain types of protein can attack the brain.
Your friend's blood glucose is low and his levels of glucagon are dangerously high. In excessive amounts, glucagon can pass the blood-brain barrier and cause brain damage.
15. Which of the following is a type of nutritive sweetner?
High fructose corn syrup
16. What is the primary priority of metabolism?
To provide enough glucose for the brain and other organs that depend upon it for energy
To shift the use of fuel from glucose to fatty acids and ketone bodies
To promote the degradation of protein from various tissues in the body
To increase the amount of insulin in the blood relative to glucagon in order to keep the level of glucose at a maximum level
17. Dietary fiber serves all of the following functions except:
Increasing the overall digestibility of foods in the large intestine
Decreasing the transit time of food in the intestines
Increasing the bulk of stools to stimulate intestinal muscles
18. How do the diverticula in the large intestine become inflamed?
Bacteria begin to metabolize food particles that become trapped in the folds of the diverticula
The folds in the diverticular begin to push outward into the kidney and spleen, causing abdominal pain
The excessive pressure during defecation causes the smooth muscle surrounding the diverticula to become inflamed
The folds in the diverticula begin to collect water that becomes contaminated with carcinogens that begin to attack the wall of the large intestine
19. How is the level of insulin controlled by the intake of dietary fiber?
While passing through the small intestine undigested, dietary fiber slows the absorption of glucose into the bloodstream and therefore controls the release of insulin from pancreatic beta cells
Dietary fiber speeds the absorption of insulin, preventing it from reaching excess levels in the blood
Dietary fiber speeds the absorption of glucose by absorbing more water into the intestines and preventing the release of glucagon from pancreatic alpha cells
20. Glucose is metabolized for energy in what order?
Glycolysis, Citric Acid Cycle, Oxidative Phosphorylation
Citric Acid Cycle, Glycolysis, Oxidative Phosphorylation
Oxidative Phosphorylation, Glycolysis, Citric Acid Cycle
Glycolysis, fermentation, Citric Acid Cycle, Electron Transport Chain
21. An athlete takes a new supplement before a basketball game that inhibits the enzyme lactate dehydrogenase in the liver. How do you expect him to perform?
Poorly, because he can no longer convert lactic acid to pyruvate in the liver and increasing levels of lactic acid will cause fatigue and cramping
Well, because the increasing levels of lactic acid increase the pH of muscle and favor oxygen unloading in skeletal muscle
Well, because inhibition of the enzyme lactate dehyrogenase will increase the production of glucose that is needed by working muscle
Poorly, because the athlete will no longer be able to breakdown glucose at a fast enough rate for working muscle
22. Your father decides to grab a quick bite to eat before he plays a pick-up game of basketball with his friends. You try to tell your dad to eat after the game but he doesn't listen. What do you expect to happen to your father during the game?
He starts out feeling fine, but quickly begins to experience stomach cramps and an early onset of fatigue he normally doesn't feel. It's because his sympathetic nervous system is inhibiting the gastrointestinal tract while food is present in the stomach and because his ratio of glucagon to insulin is not as high as it should be.
He starts out feeling great and continues to feel even better as the game wears on. It's because his levels of insulin are high and his cells are able to uptake a lot of glucose for energy.
He starts out feeling miserable and begins to feel a little better as the game continues. It's because his levels of insulin rose quickly at the start of the game and then reached a plateau so he was able to adjust to the sudden change in hormone levels.
He does not notice any difference in his endurance or stamina. Eating a meal right before an endurance-type activity does not interfere with the metabolic activity of the body.
23. Your friend has lost a lot of weight in the last month by going on a very low calorie diet. She prefers dieting instead of exercise. Why is it likely she will gain the weight back after she goes off the diet and begins eating normally?
Due to protein degradation, she has lost a lot of muscle mass in addition to fat. Therefore, her resting metabolism is much lower because lean tissue requires more energy than fat cells and because it has adapted to lower sources of energy. Less glucose, dietary protein and dietary fat will be utilized as energy by the body and the excess of these energy sources will be deposited as fat.
Levels of glucagon have remained high for so long that her skeletal muscle has become resistant to the hormone and she can no longer use fatty acids as an energy source.
Levels of insulin have remained low for such a long period of time that her liver has become insensitive to the hormone and her liver can no longer uptake any glucose. The excess glucose can only be converted to fat.
The rate of production of ketones in her body have remained so fast throughout her diet that she will continue to produce large amounts even though she begins to eat normally again. These ketones will be converted to acetyl CoA and then be converted to fat.
24. Low carbohydrate diets will slow down metabolism.
25. The ratio of glucagon to insulin must be high in order to burn fat effectively.
26. Oxaloacetate is a four-carbon molecule that is formed through the breakdown of fatty acids and is required for the Citric Acid Cycle.
27. The Cori cycle allows the liver to assume part of the metabolic burden for working muscle.
28. Meals high in fats inhibit gastric emptying.
29. Most of the energy consumed by working muscles comes from glucose in the blood that is absorbed after a meal.
30. Phosphofructokinase is an enzyme that regulates the metabolism of glucose during glycolysis.
From the SparkNotes Blog
Every Shakespeare Play Summed Up in a Quote from
Can You Say Awkward?
Great American Novels, Ranked from "Pretty Great, Actually" to "Meh"
Pick 5 Fictional Couples and We'll Tell You if Your Relationship is Doomed
18 of the Most Brilliant Lines of Foreshadowing in Literature