Carbohydrates (CH 3.2)

Question 1

What are Carbohydrates?

Answer 1

• Hydrated carbons bc water & carbon are repeated multiple times
• A group of molecules that contain C,H, & O in a molar ratio of 1:2:1
• Empirical Formula is (CH2O)n where n= number of carbon atoms
• Many contain C-H bonds= release energy when oxidation occurs

Question 2

What is the Simplest form of Carbos?

Answer 2

-Monosaccharides (simple sugars)

Question 3

What are Monosaccharides?

Answer 3

• Simple sugars
• Can contain as few as 3 Carbon atoms to 6 or more= arranged in a ring form
• Those that have 6 carbon atoms= play a central role in energy storage
• Often used as building blocks to form larger molecules

Question 4

What is the Monosaccharide that contains 3 Carbon atoms?

Answer 4

-Glyceraldehyde

Question 5

What are the Monosaccharides that contain 5 Carbon atoms?

Answer 5

• Ribose

- Deoxyribose

Question 6

What are the Monosaccharides that contain 6 carbon atoms?

Answer 6

• Glucose (most important for energy storage)
• Fructose (structural isomer that differs in the position of C-O double bonds)
• Galactose (Stereoisomer that differs in position of -OH & -H groups)

Question 7

What are the characteristics of 6 Carbon Monosaccharides?

Answer 7

• EXIST in STRAIGHT CHAIN form but when they DISSOLVE in water they form RINGS
• Glucose is the most important for energy storage bc it has 7 C-H bonds
• Glucose can exist in Alpha or Beta

Question 8

What is a Disaccharide?

Answer 8

• They’re made by linking 2 monosaccharides together
• Serve as transport molecules in plants & provide nutrition in animals
• Some are used to transport Glucose from one part to another

Question 9

What do the Transport forms of Disaccharides depend on?

Answer 9

• Which monosaccharide are linked to form the Disaccharide

- Glucose can form transport disaccharides w/ itself or with other monosaccharides like fructose & galactose

Question 10

How is Sucrose made & what is it’s purpose?

Answer 10

• When glucose links w/ fructose

- Sucrose is the form most plants use to transport glucose

Question 11

How is Lactose made & what is it’s purpose?

Answer 11

• Glucose is linked w/ galactose

- Mammals use lactose to supply energy to their babie

Question 12

What are Polysaccharides?

Answer 12

-Longer polymers that of course are made up of monomers, but those monomers have gone through dehydration reaction

Question 13

What is Starch?

Answer 13

• Mixture of linear & branched polymers of Alpha-glucose subunits
• Found in plants that is composed of Amylose & Amylopectin
• Starch stores energy

Question 14

How do organisms store metabolic energy contained in Monosaccharides?

Answer 14

-Convert them into Disaccharides like maltose and these are linked together into insoluable polysaccharides=Starches

Question 15

What is the Starch with the simplest structure?

Answer 15

• Amylose! (linear)
• Each linkage of the Alpha Glucose occurs between C-1 of one glucose molecule to the C-4 of another= Alpha (1—->4) linkages
• The long chains coil up in water which makes amylose insoluable

Question 16

What is Amylopectin?

Answer 16

• More complicated variation of Amylose
• They are BRANCHED polysaccharides with branches occuring between C-1 of one molecule & C-6 of another = Alpha (1—->6) linkages
• The amylose branches consist of 20-30 glucose subunits
• Also insoluable

Question 17

What is Glycogen?

Answer 17

• Super BRANCHED of Alpha-glucose subunits
• Kinda like starch but it’s found in animals
• Has much longer average chain length & more branches than plant starch
• Stores energy & provides limited short term stored energy

Question 18

What is Cellulose?

Answer 18

• Polymer of LINEAR Beta Glucose w/ the Beta (1—->4) linkages
• These long chains of Beta Glucose form tough fibers which makes Cellulose a key component in plant cell walls
• Beta Glucose bonds can’t be broken down by starch-hydrolizing enzymes bc those enzymes only recognize Alpha linkages

Question 19

What is Chitin?

Answer 19

-Structural material found in anthropods & many fungi
-It’s a polymer of N-acetylglucosamine
(subsituted version of glucose)
- When its cross-linked by proteins, it forms a tough/ resistant surface= hard exoskeleton for insects & crustaceans

Question 20

What is the function for Carbohydrates?

Answer 20

• Energy metabolism
• Components of cell to cell recognition molecules
• Components of complex carb polymers

Question 21

What are Complex Carbohydrates?

Answer 21

• Large polymers of glucose
• Have same monomers but polymers are differentiated by the bonds between glucose & whether if its a branching or unbranching polymer

Question 22

What are the 3 most important Complex Carbohydrates?

Answer 22

• Cellulose
• Starch
• Glycogen

Question 23

How are Complex Carbohydrates formed?

Answer 23

-By dehydration synthesis

Question 24

-What is the function for Carbohydrate Polymers?

Answer 24

-Structural & energy storage

Question 25

So what are Macromolecules?

Answer 25

• Proteins
• Starches
• Lipids
• Carbs

Question 26

What do the properties of Macromolecules determine?

Answer 26

-The taste, smell, nutrition, cooking properties, digestibility of our food & what mechs we use to digest it

Question 27

What are people ACTUALLY allergic too when they say that they’re allergic to certain foods?

Answer 27

-They’re actually reacting to specific proteins in the food that makes them sick