Introduction to Carbohydrate Unit

1. What is the predominant monosaccharide in carbohydrates? Glucose, also referred to as dextrose

“Di” = 2; two monosaccharide units Oligo: 3-10 monosaccharide units Poly: >10 monosaccharide units

Saccharide: derived from the Greek sakchar, meaning sugar or sweetness #5 What is a common suffix for [specific] carbohydrates? List common carbohydrates -Ose Saccharide: derived from the Greek sakchar, meaning sugar or sweetness

#5 Specific examples of carbohydrates Monosaccharides Examples: glucose (C6H12O6), fructose, and galactose, ribose Disaccharides Examples: sucrose, lactose, and maltose 

#5 Specific examples of Carbohydrates Oligosaccharides: 3-10 sugars Raffinose and stachyose Polysaccharides Examples: starch, pectin, cellulose, and glycogen Sugar alcohols Sorbitol, xylitol

Dehydration synthesis/condensation #6 & #9: What is the name of the reaction by which di-, oligo-, and polysaccharides are formed? What is the name of the bonds between carbohydrates monomers? Dehydration synthesis/condensation (#9 )This type of rxn forms a glycosidic bond (C-O-C) also called glycosidic linkage Two forms: alpha and beta

10. How do alpha and beta glycosidic bonds differ and how can this affect digestion? Alpha differs from the beta glycosidic bond only in the angle of formation between the two sugars Alpha-glycosidic linkage is below the plane of the rings and the beta glycosidic linkages are above Humans lack enzymes needed to cleave beta-glycosidic linkages – lactose intolerance

16. Why are oligosaccharides "gassy"? Can’t be broken down in small intestine and become “food” for bacteria of large intestine Bacterial metabolism of oligosaccharides results in gas byproducts

The addition of a water molecule across a bond 7. What is the name of the reaction by which di-, oligo-, and polysaccharides are broken down? Hydrolysis The addition of a water molecule across a bond The breaking down of a chemical compound into two or more simpler compounds by reacting with water. http://nhscience.lonestar.edu/biol/dehydrat/dehydrat.html

#8 – Summarize the relationship between dehydration synthesis and hydrolysis They are reverse rxns, where one is a synthesis rxn and one is a break down rxn Hydrolysis  Dehydration Synthesis Disaccharide + H20  MonoSach + MonoSach

http://youtu.be/b7TdWLNhMtM

11. In your own words, describe how/why cyclic carbohydrates form.

12. How are carbohydrates found in humans classified? 6 By number of carbons Trisoses Pentoses Hexoses Septoses…. 5

Aldoses – contain aldehyde functional group 13. Carbs are also classified by their functional groups - what are the names of these classifications? Aldoses – contain aldehyde functional group Terminal carbonyl C=O Ketoses – contain ketone functional group Internal carbonyl Carbonyl carbon polyhydroxyaldehydes

Carbonyl Carbon In the closed-ring (cyclic) structure, the carbonyl carbon is the one which is attached to the O of the ring and an OH group

14. Where can your body storage glucose? Liver as glycogen Smaller amounts in muscles and brain as glycogen Circulates in blood stream in very specific range he glycogen is able to be broken back down into glucose when the muscle contracts and requires energy. The body is able to store 500 g of glycogen, roughly equivalent to 2,000 calories, in the muscles. Therefore, if you did not eat for a day, you will have drastically depleted these stores. After an intense workout, when these glycogen stores have been tapped into, consuming carbohydrates will replenish these reserves.

15. What are indigestible forms of polysaccharides known as? Dietary fiber

17. Explain the basic relationship between sugar and diabetes. Insulin: pancreatic hormone which signals cells to uptake glucose from blood (into cells) People with Diabetes either do not produce insulin or do not respond to insulin that is present

18. How does the glycemic index classify carbohydrates? By how quickly and how high a specific carbohydrate boosts blood glucose levels compared to pure glucose

19. List food sources of carbohydrates Grains (breads, rice, pasta, cereal) Fruit Dairy Beans, legumes Soda, candy, etc.

20. List some functions of carbohydrates: Energy source for cells; primary for brain Protein sparing Breakdown of fats and preventing ketosis Biological recognition *Dietary fiber & digestive health *Flavor and sweeteners