Principles Of Biochemistry (Lechniger) Ch. 7

Front 1

What is a homosaccharide?

Back 1

It is a polysaccharide composed of only one type of monomer

Front 2

What is a heterosaccharide?

Back 2

It is a polysaccharide composed of several different types of monomers

Front 3

What is glycogen: a homopoloysaccharide or heterosaccharide? What glucose polysaccharide is it like: amylose or amylopectin? What is glycogen's major function?

Back 3

Homosaccharide; like amylopectin, it contains (1-->4 alpha-D- glucose molecules) and branched points of 1-->6 links every 8-12 residues (more compact); It is a major main storage unit for animals

Front 4

Starch is a mixture of two homopolysaccharides. What are they and are they branched or unbranched? What is starch's main function?

Back 4

It contains two homopolysaccharides: amylose and amylopectin;

Amylose is a string of unbranched 1-->4 alpha-D-glucose monomers;

Amylopectin is a string of 1-->4 alpha-D-glucose monomers with branched chains of 1-->6 links every 24-30 residues (not compact);

Starch's major function is the main storage polysaccharide in plants

Front 5

What is cellulose? What is its major function? What else is interesting about this polysaccharide?

Back 5

Cellulose is a branched homopolysaccharide of glucose (Beta 1-->4 linked chains). It serves as a structural polysaccharide due to H bonds between adjacent chains. It is the most abundant in nature and makes up the cotton we wear.

SO WE WEAR B 1-->4 LINKED GLUCOSE MONOMERS (CELLULOSE) AND EAT A 1-->4 LINKED GLUCOSE MONOMERS (STARCH)

Front 6

How is cellulose metabolized? Why can't humans use it as a fuel source? What does cellulose's future have in store for it?

Back 6

It is metabolized by enzymes that can break the B 1-->4 linked bonds (cellulase); Humans lack these enzymes but termites and other bacteria have it.

Cellulose can be used and turned into biofuels in the future by turning cellulose-->glucose-->fuel

Front 7

What is chitin? Where is it found? Can it be digested by vertebraes?

Back 7

Chitin is a linear homopolysaccharide of N-acetylglucosamine (Beta 1-->4 linked chains); It is found in mushrooms, insects, crabs, spiders etc.; It is tough and cannot be digested by vertebraes

Front 8

What is agar and agarose and what are they made of? What are they the main component of? Which one do we use in the lab?

Back 8

Agar is a mix of heteropolysaccharides containing modified galactose units; Agar is a main component of cell wall in seaweed; Agarose is one component of agar; WE USE AGAROSE FOR GELS IN LAB

Front 9

What is glycosaminoglycans major function? What 2 repeating disaccharides are usually involved?

Back 9

Its major function is to form a meshlike structure with other proteins to form the extracellular matrix (in connective tissue and help lubricate joints); Heparin and Heparan Sulfate are good glycosaminoglycans

Front 10

What are the roles of Heparin and Heparan Sulfate? What are they? Anything interesting about them?

Back 10

Heparin is a LINEAR polymer; Heparan sulfate is like heparin except it is usually attached to proteins;

Their major roles are to prevent blood clotting by activating antithrombin

They also help in developing blood vessels

They can also bind to viruses and bacteria to decrease virulence

Tumors happen because these two polymers vascularize and form blood vessels for the tumor to feed off of and continue to grow

Front 11

Glycoconjugates serve as information carriers. What is a glycoprotein? What is a glycoprotein's major function? How does this relate to viral proteins?

Back 11

Glycoproteins are proteins with oligosaccharides attatched.

Half of a mammal's proteins are glycoproteins.

They play a role in protein-protein recognition;

Viral proteins are heavily glycosylated making it easy for them to invade the immune system (our body thinks they are part of us because they have the same proteins)

Front 12

What is a glycolipid? What are some major functions of glycolipids?

Back 12

It is a lipid with covalently bound oligosaccharide;

They are found in cell membranes; they cover the peptidoglycan layer in gram-negative bacteria; and they help determine blood groups in vertebraes.

Front 13

What is a proteoglycan? What is its major function?

Back 13

It is a sulfated glucoseaminoglycan that is attached to a rod-shaped protein in the cell membrane;

It helps regulate cell growth through communication with neighboring cells

Front 14

What form of glycoconjugates help in regulation of cell growth, cell mobility, apoptosis, and wound healing through extracellular matrix and cytoskeleton?

Back 14

Proteoglycans