Carbs

Question 1

Two major types of complex carbohydrates

Answer 1

glycoproteins & proteoglycans

Question 2

What proteins contain short glycan (sugar) chains

Answer 2

glycoproteins

Question 3

Glycan chains in glycoproteins are how long?

Answer 3

3 to 15 sugars long

Question 4

Are the glycan chains branched?

Answer 4

Yes, highly branched

Question 5

Do the glycan chains have a repeating unit

Answer 5

NO

Question 6

By weight, how much carbohydrate is in glycan chains?

Answer 6

10-15%

Question 7

Where would you find glycoproteins

Answer 7

cell surface proteins, ER & Golgi apparatus or they are secreted

Question 8

What are the 6 functions of carbs on glycoproteins

Answer 8

1. assist in protein folding to the correct conformation
2. stabilize the protein against denaturation
3. protect the protein from proteolytic degraduation
4. enhance protein solubility
5. target the protein to specific subcellular locations
6. serve as recognition signals for carbohydrate binding proteins (lectins)

Question 9

What are the main amino sugars?

Answer 9

N- acetylglucoasmine

N-acetylgalactosamine

Question 10

What are the neutral sugars

Answer 10

galactose
mannose
fructose

Question 11

What are the acidic sugars

Answer 11

sialic acid

N-acetylneuraminic acid

Question 12

Proteoglycans contain what % of sugars

Answer 12

50-60 %

Question 13

How are sugar chains normally oriented?

Answer 13

Long, unbranched polymers that can contain 100s of monosacchararides usually having a repeating disaccharide unit

Question 14

what are the 2 types of linkages of carbohydrates to proteins

Answer 14

N-linked: sugar is attached to an asparagine

O linked: where the sugar is attached to a serine, threonine or hydroxylysine

Question 15

How many complex carbs structures have been identified?

Answer 15

100

Question 16

What makes up the core structure of complex carbs

Answer 16

2 N-acetylglucosamines and 3 mannose residues

Question 17

What are the 2 linkages that proteins have?

Answer 17

N linked and O linked

Question 18

Are there essential sugars

Answer 18

No. Cells can use glucose to make all other sugars needed.

Question 19

What do Lectins do? & Where are they located?

Answer 19

Lectins are on the surface of the endothelial cells which recognize signals on leukocytes

Question 20

Where are complex carbs found?

Answer 20

surface of bacteria

Question 21

Gram-positive vs. Gram-negative

Answer 21

Gram-positive: THICK layer of peptidoglycan on their surface

Gram-negative: THIN layer of peptidoglycan between two lipid bilayers

Question 22

What makes up the carb portion of peptidoglycan

Answer 22

alternating copolymers of N-acetylglucosamine (NAG)
and
N-acetylmuramic acid (NAM)

Question 23

What is the target of several antibiotics including penicillin

Answer 23

Synthesis and deposition of peptidoglycan

Question 24

What is surrounded by a thick polysaccharide capsule?

Answer 24

Bacteria

Question 25

what helps bacteria stick to each other to form plaque on the surface of teeth?

Answer 25

glucans of S. Mutans