What Are Carbohydrates

CHEMICAL CONNECTIONS 17A Relative Sweetness of Carbohydrate and Artificial Sweeteners 

Carbohydrates are the most abundant organic compounds in the plant world. They act as storehouses of chemical energy (glucose, starch, glycogen) are components of supportive structures in plants (cellulose), crustacean shells (chitin), and connective tissues in animals (acidic polysaccharides) and are essential components of nucleic acids (D-ribose and 2-deoxy-D-ribose). Carbohydrates account for approximately three-fourths of the dry weight of plants. Animals (including humans) get their carbohydrates by eating plants, but 

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Let s begin with the carbohydrates and the polymers they form. What are carbohydrates We know that they are something to be avoided by adherents of certain dietary disciplines, but what are they Originally carbohydrates were thought to be carbon surrounded by water (hence carbo-hydrate), somewhat as our inorganic I I coordination complexes consisted of a... 

What are carbohydrates, and what are the monomers in carbohydrates The monosaccharides in Table 22.8 are all optically active. Explain. What is a disaccharide Which monosaccharide units make up the disaccharide sucrose What do you call the bond that forms between the monosaccharide units What forces are responsible for the solubility of starch in water What is the difference between starch, cellulose, and glycogen ... 

What are carbohydrates What fxmctions do carbohydrates serve in living organisms ... 

What are carbohydrates and in what foods are they found What is fiber ... 

The two isomers of glyceraldehyde (Figure 9.1) are the parent compound of what are known as the D and L series of the aldoses. A similar series of carbohydrates can be derived for the ketoses but because the parent compound... 

Carbohydrates attract water molecules, which is probably why they are to be found on the outside of cell membranes, but compatibility with water is only a minor part of what they do. Some carbohydrates are vital for passing subtle messages between cells. Sometimes the carbohydrates are attached to proteins which are also to be found on the surfaces of cells and these carbohydrates are there to protect the proteins from attack by enzymes. Essential though they are, carbohydrates can be exploited to attack cells and they are the route by which viruses and toxins gain access. 

What are the advantages and disadvantages (if any) to utilizing fat rather than carbohydrate as one s primary dietary fuel ... 

Q2 If Chloe is now suffering from celiac disease, there is likely to be a marked reduction in the surface area of her intestinal mucosa. Assuming that her pancreas is normal, what are the likely effects of this condition on protein and carbohydrate absorption ... 

B. Suppose that /Jcch for the soil is 200 H20/CO2, that 90% of the water vapor passing out of the canopy comes from the leaves, and that the net photosynthetic rate for the forest (using CO2 from above the canopy as well as from the soil) corresponds to 20 kg of carbohydrate hectare-1 hour-1 (use conversion factor in Table 8-2). If Jm from the soil is 0.6 mmol m-2 s-1, what are the. /Co2 s up from the soil and down into the canopy ... 

The following questions may be asked. Which monomeric sugars are present in soil carbohydrates and in what quantities What kinds of carbohydrates occur in soil What proportion of the organic matter of soil is carbohydrate Are carbohydrates linked to other soil constituents What is the source and what is the role of carbohydrates in soils What are the differences between the carbohydrates of different soils ... 

In glycoproteins, what are the three amino acids to which the carbohydrate groups are most frequendy linked ... 

Distinguish between simple and complex sugars. What are some sources of complex carbohydrates ... 

What are glycolipids In glycolipids, a carbohydrate portion is covalently bonded to the lipid. 

What are required nutrients Required nutrients are substances that we must include in the diet and those that we keep track of. Sometimes this varies hy area. For example, in the United States, the only macronutrient we typically monitor is protein, as Americans get plenty of carbohydrates and fats. For micronutrients, we keep track of many vitamins and minerals, all of which are required for optimum health. 

Problem 22.24. What are the specific effects of insulin and glucagon in carbohydrate metabolism Am. 

Problem 22.25. What is the origin of epinephrine, and what are its specific effects in carbohydrate metabolism ... 

EXAMPLE 10.5 What are the initial and final points of fatty acid and carbohydrate catabolism ... 

But what are the elusive ingredients in citrus fruits and rice hulls that prevent these deficiency diseases The late 19th century wimessed trendy attempts to produce synthetic animal feed using pure proteins, carbohydrates, fats, and minerals. The results were vastly inferior compared to animals raised on namral food. In 1906, British biochemist Frederick Gowland Hopkins (1861-1947) (1929 Nobel Prize in physiology or medicine) recognized the existence in natural foods of accessory factors, beyond the major components, that are required for a healthy diet. 

Finally, what areas remain important for future research Prediction is always a dangerous business but to us the key questions of ammonia assimilation all revolve around carbon metabolism—what are the sources for the carbon skeletons of amino acids that are synthesized in the chloroplast How do the anaplerotic sequences that provide a ready supply of 2-oxoglutarate and oxoloacetate operate and how are they controlled What are the critical steps that ensure, in times of plentiful ammonia supply, that sufficient carbohydrates are transported and oxidised And perhaps most interestingly of all, how are the electrons needed to reduce and assimilate N2 in nodules and NO in roots generated from carbohydrate transported from the shoot ... 

What are the four important roles of carbohydrates in Uving organisms ... 

These are given wherever possible, and normally refer to what the Carbohydrates contributor believes to be the best characterised sample of highest chemical and optical purity. Where available an indication of the optical purity (op) or enantiomeric excess (ee) of the sample measured follows the specific rotation value. 

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