Download Biochemistry Review / Crash Course

Biochemistry
Review / Crash Course
Classification of
monosaccharides
• classified by type of carbonyl group
• aldoses - polyhydroxylaldehydes
• ketoses - polyhydroxylketones
L-glyceraldehyde
O
H
C1
HO
C2 H
CH2OH
3
O
H
C1
H
dihydroxyacetone
1CH OH
2
C2 OH
CH2OH
3
D-glyceraldehyde
2C
O
3 CH2OH
Classification of
monosaccharides
• classified by number of carbons
• trioses - 3 carbon sugars
– aldehydic triose or aldotriose
– ketonic triose or ketotriose
•
•
•
•
•
tetroses
pentoses
hexoses
heptoses
etc.
Cyclic hemiacetals
•formed by intramolecular reaction
•represented by Haworth projection formulas
O
H
C1
6
6
H C OH
CH2OH
CH2OH
2
5
5
O
H
OH
H
HO C H
H
H
3
H
1
4
H
OH
C
4
H
OH
H C OH
O
OH
4
OH
2
3
2
3
H C OH
H
OH
H
OH
5
CH2OH
-D-glucopyranose
O
6
(Haworth projection)
D-glucose
(linear form)
pyran
H
1
OH
Anomers
•cyclization forms a new asymmetric carbon
•two possible stereoisomers could result
•inconvert in a process called mutarotation
CH2OH
CH2OH
O
H
H
OH
H
H
OH
H
OH
OH
H
OH
-D-Glucopyranose
8
O
H
OH
H
H
OH
H
OH
-D-Glucopyranose
2
Cyclic hemiketals
CH2OH
C
O
HO
C
H
H
C
OH
H
C
OH
CH2OH
D-fructose
(linear form)
CH2OH
H
CH2OH
OH
HO C
O
6
CH2OH
5
H
H
OH
H
1
CH2OH
O
HO
H
4
OH
2
OH
3
H
-D-Fructofuranose
O
furan
Disaccharides
CH2OH
O H
H

1
H
OH
H
OH
H
OH
Glucose
CH2OH
O OH
H
H
4 OH
H 1 
H
O
H
OH
Glucose
 anomer of Maltose
-D-Glucopyranosyl-(14)--D-glucopyranose
Disaccharides
H
CH2OH
O H
H
H 1
OH
OH

Glucose
OH O
H
HOH2C
O
H

HO
Fructose
H
CH2OH
HO
H
Sucrose
-D-Glucopyranosyl-(12)--D-fructofuranoside
Polysaccharides (glycans)
Storage Polysaccharides: Amylose
H
CH2OH
O
H
H
OH
H
H
CH2OH
O
H
H
OH
O
O
H
OH
H
H
OH
n
Storage Polysaccharides: Amylopectin
Branch
CH2OH
O H
H
H
OH H
H
OH
Main chain
O
H
OH
CH2OH
O H
H
H
OH H
H
CH2OH
O H
H
H
OH H
CH2OH
O H
H
H
OH H
O
H
OH
OH O
H2C
O H
H
H
OH H
O
H
CH2OH
O H
H
H
OH H
O
OH
H
O
OH
starch (amylopectin)
branches every 24 to 30 glucoses
glycogen
branches every 8 to 12 glucoses
Storage Polysaccharides: Amylopectin
Amylopectin
amylase
Free Glucose
molecules
hydrolysis
Preparatory Phase of Glycolysis (figure 14-2a)
Payoff Phases of Glycolysis (figure 14-2b)
Overall Glycolysis:
produces two ATP, two NADH, and
2 pyruvates from 1 glucose
Two Types of Energy-Yielding
Metabolism
• aerobic (or respiration)
– utilization or consumption of O2 to
make pathways go forward
• anaerobic (or fermentation)
– final electron acceptor is not O2
Fate of
Pyruvate
Formation of Ethanol
Thiamine Pyrophosphate (TPP)
Reactions Catalyzed
by Thiamine
1) -keto acids
decarboxylation
O
H3C
C
C
O
O
CO2
O
H3C
C
H
Reactions Catalyzed by Thiamine
2)  -condensation reactions
2
H3C
C
C
O
pyruvate
O
CO2
O
O
H3C
C
O
CH3
C
C
OH
O
α-acetolactate
Formation of Ethanol
Nicotinamide
COOH
N
N
pyridine
nicotinic acid
O
C
N
nicotinamide
N
NH2
CH3
N
nicotine
Nicotinamide Adenine Dinucleotide