Carbohydrates Flashcards Preview

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Flashcards in Carbohydrates Deck (26)
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1
Q

Most abundant class of biological molecules

A

Carbohydrates

2
Q

Monosaccharide

A
Smallest unit of carbohydrate structure
Empirical formula (CH2O)n, where n= 3-9 (5-6 common)
3
Q

Oligosaccharide

A

Polymers containing 2-20 monosaccharide residues

4
Q

Polysaccharide

A

Polymers that typically contain more than 20 residues

5
Q

2 types of monosaccharides

A

Aldoses (aldehydes)

Ketoses (ketones)

6
Q

Epimers

A

Stereoisomers that differ in configuration at only 1 chiral center

7
Q

Hemiacetal/hemiketal

A

Structure with hydroxyl group and ether at same carbon

8
Q

2 forms of cyclized rings

A

Furanose (5-membered)

Pyranose (6-membered)

9
Q

Alpha and beta anomeric positions in D-sugars

A

Alpha: trans to C6
Beta: cis to C6
L-sugars: switched

10
Q

Sugar phosphates

A

One of the carbohydrate’s hydroxyl groups is converted to a phosphate ester

11
Q

Deoxy sugars

A

Hydrogen replaces the hydroxyl in the parent sugar

12
Q

Amino sugars

A

Amino group replaces a hydroxyl in the parent monosaccharide

Position of amino group is not always obvious, since it isn’t numbered (but often carbon #2)

13
Q

Sugar alcohols

A

Carbonyl of parent sugar is reduced to an alcohol

Replace -ose with -itol

14
Q

Sugar acids

A

Either C-1 aldehyde is oxidized to carboxylic acid or primary alcohol (highest carbon number) is oxidized to an acid

15
Q

Disaccharides

A

Covalent linkage of 2 monosaccharides through a glycosidic bond at the anomeric carbon
Named in order with “free anomeric” sugar last
Glycosidic bonding is indicated using numbers separated by an arrow

16
Q

Reducing sugars

A

Sugars with an aldehyde or a hemiacetal can be oxidized to an acid and can reduce other ions

17
Q

2 types of polysaccharides

A

Homoglycans: 1 type of monomer
Heteroglycans: several types of monomers

18
Q

Amylose

A

Type of starch (storage polysaccharide)
Smaller than amylopectin and glycogen
Alpha- (1 -> 4) glycosidic linkages

19
Q

Amylopectin

A

Type of starch (storage polysaccharide and polymer of glucose)
Bigger than amylose, but smaller than glycogen
Amylose with alpha- (1 -> 6) branches every ~25 residues

20
Q

Glycogen

A

Form of storage used in most animals
Main chain is alpha- (1 -> 4)
Alpha- (1 -> 6) linkages every 8-12 residues
Bigger than amylose or amylopectin

21
Q

Cellulose

A

Linear polymer of glucose
Structural polysaccharide in plants
Unbranched, beta- (1 -> 4) glycosidic bonds
Highly rigid

22
Q

Chitin

A

Structural polysaccharide in bugs and crustaceans
Linear polymer of N-acetylglucosamine
Beta- (1 -> 4) glycosidic bonds

23
Q

Glycoconjugates

A

Polysaccharides covalently bound to proteins or peptides

24
Q

Proteoglycans

A

Complexes of proteins and glycosaminoglycans

High surface area: attract water for connective tissue

25
Q

Glycoproteins

A

Carbohydrates attached to proteins

Classified as N-linked (asparagine) or O-linked (serine)

26
Q

Peptidoglycans

A

Polysaccharides linked to small peptides

Found in the cell walls of many types of bacteria: keeps cell in rigid shape by maintaining osmotic balance