Biology 2581B Chapter Notes - Chapter 14: Glycosidic Bond, Dehydration Reaction, Amylopectin

8 views4 pages

spectral

3 May 2020

School

Department

Course

Professor

For unlimited access to Textbook Notes, a Class+ subscription is required.

Document Summary

Glucose monomers linked via a -1,4 glycosidic bonds in a helical fashion. The helical chain is branched every 10 or so units via a - This makes glycogen a highly branched polysaccharide, which makes it easily hydrolyzed and good for energy storage. Glucose monomers linked together by -1,4 glycosidic bonds, which give it a long linear structure. These long unbranched chains can connect via h-bonds and stack on top of each other. This makes it optimal for providing structure and protection. A carbohydrate used by arthropods (insects, spiders, crustaceans, Chitin and which use it to build their cell walls. related animals) to build exoskeletons. Lipids hydrophobic molecules assembled from smaller molecules by dehydration: not big enough to be considered macromolecules (no covalent bonds, mix poorly or not with water, because they consist mostly of hydrocarbon reactions. region, fats, phospholipids, steroids.

Related Questions

please i need help with this qustions answer the multiple choice that is all and be clear not writes un clear stuff just asnswer the qustions please

Question 1

Starch is: (select all the correct answers)

an energy storage carbohydrate in plants

an energy storage carbohydrate in animals

a structural carbohydrate in plants

a polymer of glucose

Question 2

The monomers in starch are joined together by which type of linkage?

beta 1-4 glycosidic linkage

alpha 1-4 glycosidic linkage

alpha 1-6 glycosidic linkage

Question 3

Glycogen is: (select all that are correct)

a polymer of glucose

a long chain molecule with very few if any branches

an energy storage carbohydrate in plants

a highly branched molecule with alpha 1-4 & alpha 1-6 glycosidic linkages

has many beta 1-4 glycosidic linkages

an energy storage carbohydrate in animals

Question 4

What type of reaction will break down glycogen and produce glucose molecules?

Question 5

Cellulose is: (select all that apply).

an energy storage carbohydrate in plants

has both alpha 1-4 and beta 1-4 glycosidic linkages

a structural carbohydrate in plant cell walls

a polymer of glucose

a structural carbohydrate in animals

Question 6

In cellulose, covalent bonds link glucose monomers and hydrogen bonds hold the long glucose chains together.

True

False

Question 7

Chitin is: (select all that apply)

a polymer of glucose

can be used as sutures

a structural carbohydrate in plants

a structural polysaccaride found in the exoskeleton of animals like arthropods

an energy storage carbohydrate in animals

Question 8

Lipids are not true polymers?

True

False

Question 9

Steroids are lipids

True

False

Question 10

A fat is composed of

4 fused carbon rings

a glycerol and 3 fatty acids

a phosphate a glycerol and 2 fatty acid chains

Can somebody check if my answer is rght? Thank you

Complex carbohydrates

Indicate whether each of the following statements about polysaccharides is True or False.

1. Polysaccharides are long polymers made of many nucleotides that have been joined through dehydration synthesis. False
2. Cellulose is the main storage polysaccharide in plants while glycogen is an important storage polysaccharide in many animals. False
3. Both starch and glycogen are composed of Î±-glucose subunits. True
4. Starch is composed of amylose and amylopectin, which are unbranched and branched chains of Î±-glucose subunits, respectively. False
5. Like amylopectin, glycogen is insoluble in water, but it has a longer average chain length and fewer branches. True
6. Although some polysaccharides are used to store energy, others serve as structural material for cells. True
7. The principal structural polysaccharide in plants is starch. True
8. Cellulose is composed of a long, branched chain of Î²-glucose subunits. True
9. The starch-hydrolyzing enzymes produced by most organisms cannot break the bond between two Î± -glucose subunits because they only recognize Î² linkages. False
10. Chitin is a structural polysaccharide found in the exoskeleton of arthropods and the cell wall of many fungi. True

1) Why might it be advantageous for a storage polysaccharide to have a branched-chain structure instead of a linear structure?

A) Compared to a linear molecule, a branched-chain polymer has less termini for addition or hydrolysis of glucose units per unit volume of polymer, thereby facilitating both the deposition and mobilization of glucose by providing more sites for enzymatic activity.

B) Compared to a linear molecule, a branched-chain polymer has more termini for addition or hydrolysis of glucose units per unit volume of polymer, thereby complicating both the deposition and mobilization of glucose by providing less sites for enzymatic activity.

C) Compared to a linear molecule, a branched-chain polymer has more termini for addition or hydrolysis of glucose units per unit volume of polymer, thereby facilitating both the deposition and mobilization of glucose by providing more sites for enzymatic activity.

D) Compared to a linear molecule, a branched-chain polymer has less termini for addition or hydrolysis of glucose units per unit volume of polymer, thereby complicating both the deposition and mobilization of glucose by providing less sites for enzymatic activity.

2) Can you foresee any metabolic complications in the process of glycogen degradation? How do you think the cell handles this?

A) Every branch point will have an Î± (1â6) glycosidic bond that will have to be hydrolyzed. This is handled by the presence of an additional enzyme specific for the Î±(1â6) bond.

B) Every branch point will have an Î² (1â6) glycosidic bond that will have to be hydrolyzed. This is handled by the presence of an additional enzyme specific for the Î²(1â6) bond.

C) Every branch point will have an Î± (1â4) glycosidic bond that will have to be hydrolyzed. This is handled by the presence of an additional enzyme specific for the Î± (1â4) bond.

D) Every branch point will have an Î² (1â4) glycosidic bond that will have to be hydrolyzed. This is handled by the presence of an additional enzyme specific for the Î² (1â4) bond.

3) Can you see why cells that degrade amylose instead of amylopectin have enzymes capable of endolytic (internal) as well as exolytic cleavage of glycosidic bonds?

A) Exolytic cleavage breaks the molecule internally, creating additional ends for exolytic attack and thereby banning the mobilization of more glucose per unit time.

B) Endolytic cleavage breaks the molecule internally, creating additional ends for endolytic attack and thereby allowing the mobilization of more glucose per unit time.

C) Exolytic cleavage breaks the molecule internally, creating additional ends for endolytic attack and thereby allowing the mobilization of more glucose per unit time.

D) Endolytic cleavage breaks the molecule internally, creating additional ends for exolytic attack and thereby allowing the mobilization of more glucose per unit time.

4) Why do you suppose the structural polysaccharide cellulose does not contain branches?

A) Branches in the molecule would generate side chains that would almost certainly make it difficult to pack the cellulose molecules into microfibrils, thereby increasing the rigidity and strength of the microfibrils.

B) Branches in the molecule would generate side chains that would almost certainly make it difficult to pack the cellulose molecules into microfibrils, thereby decreasing the rigidity and strength of the microfibrils.

C) Branches in the molecule would generate side chains that would almost certainly make it difficult to pack the cellulose molecules into globules, thereby decreasing the flexibility and strength of the globules.

D) Branches in the molecule would generate side chains that would almost certainly make it difficult to pack the cellulose molecules into globules, thereby increasing the flexibility and strength of the globules.