Carbohydrates 7

Question 1

one of five different types of protein glycosylation and it is the most common type of such alteration

Answer 1

N-linked glycosylation

Question 2

N-linked glycosylation occurs in

Answer 2

endoplasmic reticulum

Question 3

N-linked glycosylation involves building a part of the glycosyl chain on a molecule called __________

Answer 3

dolichol pyrophosphate

Question 4

True or False: N-linked glycosylation commonly occurs in eukaryotes, some in archaean cells, and rarely in bacteria

Answer 4

True

Question 5

Bonds between the sugars of the glycan are ____________ and usually occur between carbons ___________

Answer 5

glycosidic; 1&4

Question 6

consensus sequence of the protein attachment site of N-glycosylation is _____________

Answer 6

asparagine

Question 7

What is the sequence of N-glycosylation?

Answer 7

Asn-X-Ser/Thr

Question 8

What is the X in Asn-X-Ser/Thr

Answer 8

any amino acid except proline

Question 9

The process of making N-linked protein begins with synthesis of pre-oligosaccharide on the terminal phosphate of __________

Answer 9

dolichol pyrophosphate

Question 10

The process of making N-linked protein begins with synthesis of pre-oligosaccharide on the ___________ of dolichol pyrophosphate

Answer 10

terminal phosphate

Question 11

lipid molecule comprised of multiple isoprene units

Answer 11

dolichol

Question 12

How is pre-oligosaccharide assembled?

Answer 12

Two molecules of UDP-N-acetylglucosamine donate N-acetylglucosamine to pyrophosphate.

Five molecules of GDP-mannose donate mannose to the N-acetylglucosamines.

Question 13

True or False: dolichol-sugar complex flips with respect to the endoplasmic reticulum membrane, moving the sugar from facing cytoplasm to facing the inside of ER lumen

Answer 13

True

Question 14

dolichol-sugar complex flips with respect to the ___________, moving the sugar from facing cytoplasm to facing the inside of ER lumen

Answer 14

endoplasmic reticulum membrane

Question 15

dolichol-sugar complex flips with respect to the endoplasmic reticulum membrane, moving the sugar from facing _____ to facing the inside of __________

Answer 15

cytoplasm; ER lumen`

Question 16

How many mannoses and glucoses are added to the sugars on the end of the dolichol complex?

Answer 16

4 mannoses
3 glucoses

Question 17

Why is it needed to add 4 mannose and 3 glucose on the end of the dolichol complex?

Answer 17

to finish intermediate (Dolichol-GlcNAc2-Man9-Glc3)`

Question 18

The finished intermediate is transferred to _________ on ________ of the ____________

Answer 18

amide nitrogen; asparagine; target protein

Question 19

In last alterations, the protein folds and __________ are removed

Answer 19

three glucoses

Question 20

True or False: If the protein cannot fold properly, it cannot leave the ER and the glucoses remain intact

Answer 20

True

Question 21

Where is a properly folded protein transferred to give rise to three major glycan types?

Answer 21

cis-Golgi

Question 22

Three major glycan types

Answer 22

high mannose
hybrid glycans
complex glycans