Carbohydrate Structure & Function (Chapter 13)

Question 1

______ is the study of glycan structure and function.

Answer 1

Glycobiology

Question 2

What are the three major groups of carbohydrates?

Answer 2

Simple sugars, polysaccharides, glycoconjugates

Question 3

______ consist of monosaccharides, disaccharides, and oligosaccharides, which often function as metabolic intermediates in energy conversion pathways.

Answer 3

Simple sugars

Question 4

______ consist of either glucose homopolymers, such as cellulose, or disaccharide heteropolymers, such as chitin or heparan sulfate, in which one of the two sugars is a hexosamine – a monosaccharide containing an amino group.

Answer 4

Polysaccharides

Question 5

______ are proteins or lipids with covalently attached glycans, which play a critical role in cellular communication.

Answer 5

Glycoconjuagtes

Question 6

Glucose, galactose and mannose are examples of?

Answer 6

Monosacchrdies

Question 7

Sucrose, lactose and lactose are examples of?

Answer 7

Disaccharides

Question 8

Raffinose is an example of?

Answer 8

Oligosaccahrides

Question 9

Cellulose, starch and glycogen are examples of?

Answer 9

Glucose homopolymers

Question 10

Chitin and keratan sulfate are examples of?

Answer 10

Disaccharide heteropolymers

Question 11

Antibodies and viral coat proteins are examples of?

Answer 11

Glycoproteins

Question 12

Aggrecan, syndecan, glypican are examples of?

Answer 12

Proetoglycans

Question 13

Blood antigens and membrane anchors are known as?

Answer 13

Glycolipids

Question 14

Glycoconjugates are ______ attached to proteins and lipids as branched and unbranched structures.

Answer 14

Covalently

Question 15

What are the four core principles of glycobiology?

Answer 15

Glycan biochemistry
Glycan biosynthesis
Glycan diversity
Glycan recognition

Question 16

Glycan chains arc branched or linear carbohydrate structures consisting of modified and unmodified monosaccharides, which are covalently linked by ______ bonds in either of two conformations (α or β).

Answer 16

Glycosidic

Question 17

True or False: Monosaccharides are scavenged from the environment or synthesized de novo in the cell.

Answer 17

True

Question 18

True or False: Specific binding proteins recognize and bind to glycans to elicit a biological response.

Answer 18

True

Question 19

True or False: Only a few of the more than 100 oligosaccharides detected in breast milk have been biochemically characterized.

Answer 19

True

Question 20

True or False: Lactose-derived oligosaccharides are the third most abundant component in human milk, after free lactose and neutral lipids.

Answer 20

True

Question 21

Studies suggest that ______ provides a probiotic growth advantage to bifidobacteria, which contain the glycosidases required to metabolize this oligosaccharide.

Answer 21

lacto-N-tetraose

Question 22

True or False: Some milk oligosaccharides may function as soluble decoys that inhibit pathogenic bacteria from invading intestinal epithelial cells by providing a large number of competing glycan binding sites.

Answer 22

True

Question 23

______ is found in fungal cell walls and invertebrate exoskeletons.

Answer 23

Chitin

Question 24

Cellulose, hemicellulose and pectin are found in?

Answer 24

Plant cell walls

Question 25

Plants store glucose in the form of ______.

Answer 25

Startch

Question 26

Starch is a mixture of 15-20% ______ and 80-85% ______.

Answer 26

amylose, amylopectin

Question 27

Animals and fungi store glucose in the form of ______.

Answer 27

Glycogen

Question 28

Cellulose provides strength to a plant’s cell wall. This is due to which intermolecular force?

Answer 28

Hydrogen bonding

Question 29

Plant cell walls consist of ______ fibrils hydrogen bonded to the polysaccharides ______ and ______

Answer 29

cellulose, fibrils and pectin

Question 30

Chitin is formed from repeating ______ units,

Answer 30

GlcNAc

Question 31

______ is a linear homopolymer of glucose with six glucose residues per turn

Answer 31

Amylose

Question 32

The amylose polymer forms a ______handed helix stabilized by intrastrand ______ bonds

Answer 32

left, hydrogen

Question 33

______ and ______ are branched forms of glucose homopolymers with α-1,6 linkages connecting linear strands of α-1,4–linked glucose units

Answer 33

Amylopectin, glycogen

Question 34

True or False: Amylopectin has more branching and more glucose units than glycogen.

Answer 34

False, glycogen more than amylopectin

Question 35

______ has a single reducing end (red) and α-1,6 branch points about once every ______ glucose residues

Answer 35

Amylopectin, 15-30

Question 36

______ has branch points about once every ______ glucose residues and a glycogenin homodimeric core protein (red) with two glucose molecules at the center.

Answer 36

Glycogen, 8-12

Question 37

______ glycoconjugate interactions occur within and between cells of the host organism and ______ glycoconjugate interactions occur between host cells and pathogen cells.

Answer 37

Intrinsic, extrinsic

Question 38

True or False: Immune cells communicate with each other by cell–cell interactions between glycoproteins and glycan binding proteins on the cell surface (intrinsic recognition)

Answer 38

True

Question 39

The _______ glycan groups are attached to asparagine residues in the protein using a GlcNAc monosaccharide, whereas _______ glycan groups are attached to serine or threonine residues using a GalNAc monosaccharide.

Answer 39

N-linked, O-linked

Question 40

______ glycan groups have a core structure of GlcNAc2Man3 (outlined), and ______ glycan groups are GalNAc (outlined),

Answer 40

N-linked, O-linked

Question 41

Type ______ blood does not contain functional GTA and GTB enzymes.

Answer 41

O

Question 42

Type ______ blood contain neither anti-A or anti-B antibodies.

Answer 42

Type AB

Question 43

Type ______ blood contains both A and B antigens.

Answer 43

Type AB

Question 44

The universal blood donor type is?

Answer 44

Type O

Question 45

True or False: Proteoglycans primarily function in the extracellular space.

Answer 45

True

Question 46

What two ways can glycoproteins be biochemically synthesized?

Answer 46

analysis using lectin array and identification by mass spectrometry

Question 47

______ glycan groups are removed from purified glycoproteins using enzymatic cleavage with the enzyme PNGaseF. ______ glycans are released using chemical cleavage with NaOH and NaBH4 (a β-elimination reaction).

Answer 47

N-linked, O-linked