L1.6 CARBS

Question 1

List features shared by all carbohydrates.

Answer 1

1. polymerize when a condensation reaction occurs between two hydroxyl groups, resulting in a GLYCOSIDIC LINKAGE
2. can be covalently linked into chains to form complex carbohydrates

Question 2

identify an example of structural isomers

Answer 2

Butane and isobutane (C4H10) are structural isomers

Question 3

Describe the type of monomer, type of linkage, branching (if any), and major functions of starch, glycogen, and cellulose

Answer 3

Starch and glycogen are storage polysaccharides in plant and animal cells, respectively, that are composed of α-glucose monomers joined by α-glycosidic linkages. Cellulose is a structural polysaccharide in plants, which is composed entirely of β-glucose monomers joined together by β-1,4-glycosidic linkages.

Question 4

• Explain the major functions that carbohydrates perform in cells

Answer 4

1. provide structural support
2. function in cellular identity
3. store and provide energy for cells
4. provide a substrate for synthesizing more complex molecules

Question 5

α-glycosidic linkage

Answer 5

1,4 alpha glycosidic bonds are formed when the OH on the carbon-1 is below the glucose ring

Question 6

β-glycosidic linkage

Answer 6

1,4 beta glycosidic bonds are formed when the OH is above the plane

Question 7

aldose

Answer 7

monosaccharide that contains an aldehyde group (-CHO)

Question 8

amino sugar

Answer 8

a sugar molecule in which a hydroxyl group has been replaced with an amine group.

Question 9

carbohydrate

Answer 9

are sugars, which provide chemical energy & function as molecular building blocks

Question 10

Disaccharide

Answer 10

2 monosaccharides held together by glycosidic linkages

ex: Maltose, Sucrose, Lactose

Question 11

glucose

Answer 11

1. a simple sugar that naturally occurs and is found in fruits and other parts of plants in its free state
2. C6H12O6; aka dextrose; is a monosaccharide
3. exists in an open-chain (acyclic) and a ring (cyclic) form

Question 12

glycogen

Answer 12

a multibranched polysaccharide of glucose that serves as a form of energy storage in animals, fungi, and bacteria. The polysaccharide structure represents the main storage form of glucose in the body
(C6H10O5)n

Question 13

glycoprotein

Answer 13

A molecule that consists of carbohydrate plus a protein; proteins that contain oligosaccharide chains (carbs) covalently attached to amino acid side-chains (protein) .

Question 14

Glycosidic linkage

Answer 14

Monosaccharides polymerize when a condensation reaction occurs between two hydroxyl groups, Glycosidic linkages can form between any two hydroxyl groups

Question 15

hexose

Answer 15

a 6-carbon sugar

ex: fructose, a-glucose, a-mannose

Question 16

ketose

Answer 16

a monosaccharide that contains a ketone (C=O)

Question 17

monosaccharide

Answer 17

the monomeric unit of carbohydrates

ex: sucrose, maltose, Glucose, Fructose, Galactose

Question 18

N-acetyl group

Answer 18

an acetyl group that contains a methyl group (CH3) single-bonded to a carbonyl (C=O)

Question 19

Oligosaccharide

Answer 19

are small polymers of 3-20 monosaccharides

ex: raffinose, maltotriose, Stachyose

Question 20

pentose

Answer 20

a 5-carbon sugar

ex: ribose and deoxyribose

Question 21

Polysaccharide

Answer 21

are large polymers of carbohydrates (100-1000)

ex: Starch (Amylose), Glycogen, Cellulose, Chitin

Question 22

starch

Answer 22

a polysaccharide comprising glucose monomers joined in α 1,4 linkages; occurring in the form of minute granules in the seeds, tubers, and other parts of plants,

Question 23

structural isomer

Answer 23

are molecules made up of the same kinds and numbers of atoms, but that differ in how their atoms are joined together
The spatial arrangement of hydroxyl groups distinguishes one molecule from another

Question 24

sugar

Answer 24

the generic term for any disaccharides and monosaccharides. Sugars are an essential structural component of living cells and a source of energy in many organisms. Sugars are classified based on the number of monomeric units present.

1. Glucose –> exists as a simple sugar
2. Fructose (a.k.a. fruit sugar) –> exists as a simple sugar
3. Sucrose (a.k.a. table sugar) = fructose + glucose
4. Lactose (a.k.a. dairy sugar) = galatose + glucose

Question 25

sugar-phosphate

Answer 25

defined as carbohydrates to which a phosphate group is bound by an ester or an ether linkage,

Question 26

triose

Answer 26

a 3-carbon sugar

Question 27

Compare and contrast the synthesis of polypeptides, nucleic acids and polysaccharides from
monomeric units.

Answer 27

• A condensation reaction occurs between the three hydroxyl groups of glycerol and the carboxyl groups of three fatty acids
• This reaction forms a triglyceride (and three molecules of water)
• The bond between the glycerol and the fatty acids is an ester linkage
• When one of the fatty acids is replaced by a phosphate group and phospholipid is formed
• Hydrolysis reactions will, in the presence of water, break these molecules down into their constituent subunits

Question 28

cellulose

Answer 28

a polymer of β-glucose monomers that serves as a structural polysaccharide in plants