Download Aldehyde(Aldopentose)

Overview Praktikum Biokimia
Karbohidrat
www.carakerja.net
Carbohydrate
Carbohydrates (glycans) have the following
basic composition:
(CH2O)n
I
or H - C - OH
I
 Monosaccharides - simple sugars with multiple OH
groups. Based on number of carbons (3, 4, 5, 6), a
monosaccharide is a triose, tetrose, pentose or hexose.
 Disaccharides - 2 monosaccharides covalently linked.
 Oligosaccharides - a few monosaccharides covalently
linked.
 Polysaccharides - polymers consisting of chains of
monosaccharide or disaccharide units.
!!!
Carbon atoms
Examples
Functional groups
Trioses (3 carbon)
Glyceraldehyde
Dihydroxy acetone
Aldehyde (aldotriose)
Ketone (Ketotriose)
Tetroses (4 carbon)
Erythrose
Aldehyde (aldotetrose)
Pentoses (5 carbon)
Ribose
Xylose
Xylulose
Aldehyde(Aldopentose)
Aldehyde(Aldopentose)
Ketone (Ketopentose)
Hexoses (6 carbon)
Glucose
Galactose
Fructose
Aldehyde (Aldohexose)
Aldehyde (Aldohexose)
Ketone (Ketohexose)
Monosaccharides
Aldoses (e.g., glucose) have
Ketoses (e.g., fructose) have
an aldehyde group at one end. a keto group, usually at C2.
H
O
CH2OH
C
C
O
HO
C
H
OH
H
C
OH
OH
H
C
OH
H
C
OH
HO
C
H
H
C
H
C
CH2OH
CH2OH
D-glucose
D-fructose
Sugar derivatives
CHO
COOH
CH2OH
H
C
OH
H
C
OH
H
C
OH
CH2OH
D-ribitol
H
C
OH
HO
C
H
OH
H
C
OH
OH
H
C
OH
H
C
OH
HO
C
H
H
C
H
C
CH2OH
D-gluconic acid
COOH
D-glucuronic acid
 sugar alcohol - lacks an aldehyde or ketone; e.g., ribitol.
 sugar acid - the aldehyde at C1, or OH at C6, is oxidized
to a carboxylic acid; e.g., gluconic acid, glucuronic acid.
Sugar derivatives
CH2OH
CH2OH
O
H
H
OH
H
H
OH
H
OH
OH
H
NH2
-D-glucosamine
O
H
H
H
O OH
OH
H
N
C
CH3
H
-D-N-acetylglucosamine
amino sugar - an amino group substitutes for a hydroxyl.
An example is glucosamine.
The amino group may be acetylated, as in
N-acetylglucosamine.
Disaccharides:
Maltose, a cleavage
product of starch
(e.g., amylose), is a
disaccharide with an
(1 4) glycosidic
link between C1 - C4
OH of 2 glucoses.
It is the  anomer
(C1 O points down).
6 CH2OH
6 CH2OH
H
5
O
H
OH
4
OH
3
H
H
H
1
H
4
4
maltose
OH
H
H
H
H
H
1
OH
2
OH
1
O
4
5
O
H
OH
H
H
3
H
6 CH2OH
O
H
OH
H
OH
3
OH
5
O
O
2
6 CH2OH
H
5
2
OH
3
cellobiose
H
2
OH
1
H
OH
Cellobiose, a product of cellulose breakdown, is the
otherwise equivalent b anomer (O on C1 points up).
The b(1 4) glycosidic linkage is represented as a zig-zag,
but one glucose is actually flipped over relative to the other.
Other disaccharides include:
 Sucrose, common table sugar, has a glycosidic bond
linking the anomeric hydroxyls of glucose & fructose.
Because the configuration at the anomeric C of glucose
is  (O points down from ring), the linkage is (12).
The full name of sucrose is -D-glucopyranosyl-(12)b-D-fructopyranose.)
 Lactose, milk sugar, is composed of galactose &
glucose, with b(14) linkage from the anomeric OH of
galactose. Its full name is b-D-galactopyranosyl-(1 4)-D-glucopyranose
CH2OH
H
O
H
OH
H
H
H
1
O
OH
6CH OH
2
5
O
H
4 OH
3
H
OH
H
H
H
H 1
O
H
OH
CH2OH
CH2OH
CH2OH
H
H
H
O
H
OH
H
O
O
H
H
O
H
OH
H
O
OH
2
OH
H
OH
H
OH
H
H
OH
amylose
Polysaccharides:
Plants store glucose as amylose or amylopectin, glucose
polymers collectively called starch.
Glucose storage in polymeric form minimizes osmotic
effects.
Amylose is a glucose polymer with (14) linkages.
The end of the polysaccharide with an anomeric C1 not
involved in a glycosidic bond is called the reducing end.
CH2OH
CH2OH
O
H
H
OH
H
H
OH
H
O
OH
CH2OH
H
H
OH
H
H
OH
H
H
OH
CH2OH
O
H
OH
O
H
OH
H
H
O
O
H
OH
H
H
OH
H
H
O
4
amylopectin
H
1
O
6 CH2
5
H
OH
3
H
CH2OH
O
H
2
OH
H
H
1
O
CH2OH
O
H
4 OH
H
H
H
H
O
OH
O
H
OH
H
H
OH
H
OH
Amylopectin is a glucose polymer with mainly (14)
linkages, but it also has branches formed by (16)
linkages. Branches are generally longer than shown above.
The branches produce a compact structure & provide
multiple chain ends at which enzymatic cleavage can occur.
CH2OH
CH2OH
O
H
H
OH
H
H
OH
H
O
OH
CH2OH
H
H
OH
H
H
OH
H
H
OH
CH2OH
O
H
OH
O
H
OH
H
H
O
O
H
OH
H
H
H
OH
H
O
4
glycogen
H
1
O
6 CH2
5
H
OH
3
H
CH2OH
O
H
2
OH
H
H
1
O
CH2OH
O
H
4 OH
H
H
H
H
O
OH
O
H
OH
during exercise.
H
OH
H
Glycogen, the glucose storage polymer in animals, is
similar in structure to amylopectin. But glycogen has
more (16) branches.
The highly branched structure permits rapid glucose
release from glycogen
stores, e.g., in muscle
H
OH
CH 2OH
D-glucuronate
6COO
H
4
6

5
H
OH
3
H
H
2
OH
1
H
H
OH
O
O
H
4
O
H
5
3
H
2
1 O
H
NHCOCH 3
N-acetyl-D-glucosamine
hyaluronate
Glycosaminoglycans (mucopolysaccharides) are linear
polymers of repeating disaccharides.
The constituent monosaccharides tend to be modified,
with acidic groups, amino groups, sulfated hydroxyl and
amino groups, etc.
Glycosaminoglycans tend to be negatively charged,
because of the prevalence of acidic groups.
CH 2OH
D-glucuronate
6

6COO
H
4
5
H
OH
3
H
H
2
OH
1
H
H
OH
O
O
H
4
O
H
5
3
H
2
1 O
H
NHCOCH 3
N-acetyl-D-glucosamine
hyaluronate
Hyaluronate (hyaluronan) is a glycosaminoglycan with a
repeating disaccharide consisting of 2 glucose derivatives,
glucuronate (glucuronic acid) & N-acetyl-glucosamine.
The glycosidic linkages are b(13) & b(14).
Terima Kasih
1 Desember 2014
Pretes (tidak lupa kok…)
Tutup buku, kerjakan sendiri
Tuliskan Nama, NIM, tanggal
Tuliskan urut ke bawah, nomor 1 hingga 10
Jawablah dengan tulisan yang jelas, dengan
ejaan yang benar
Teliti dalam memahami soal dan peraturan
Nilai 0-60: Dapat tugas tambahan!
Pretes
Jika eritrosa memiliki rumus
kimia C4H8O4, maka tuliskanlah
rumus kimia untuk:
1. Glukosa
2. Fruktosa
3. Ribosa
4. Galaktosa
5. Gliseraldehid
Jawaban:
1, 2, 4 : C6H12O6
3 : C5H10O5
5 : C3H6O3