9.1 Glycolysis Flashcards
What is the general end result of glycolysis?
Splits one glucose into two pyruvates
Glucose Molecular Formula
C6 H12 O6
Flux
How things work; controlled by enzyme activity and substrate levels
What is the influx and efflux of glycolysis?
Glucose influx and pyruvate efflux
How can multiple reactions be coupled?
Through a common intermediate
Negative delta G
Exergonic, favorable, spontaneous
Positive delta G
Endergonic, unfavorable, not spontaneous
What are the three types of sugar projections?
Fischer, Haworth, and Chair
Why is there a sweet taste to sugars?
GCPRs binding on the tongue (G coupled protein receptors), neuronal signals. Affinity for receptors determines sweetness
Aldose
have aldehyde at C1
Ketose
have ketone at C1
How are monosaccharides named?
According to the number of C’s: triose, tetrose, pentose, hexose
What is special about the middle carbons of monosaccharides?
They are chiral
Enantiomers
Mirror images that are not superimposable. Lack a plane of symmetry; Two types - L and D
What determines enantiomeric configuration?
OH on last chiral carbon
D-Glucose
last OH on right of Fischer
L-Glucose
last OH on left of Fischer
Epimers
Differ by one chiral carbon
When are 5-7 carbon monosaccharides more stable as rings?
in aqueous solutions; form spontaneously through bonding carbonyl with hydroxyl
Aldoses form?
hemiacetals
Ketoses form?
hemiketals
6 membered rings are called
pyranose
5 membered rings are called
furanose
Anomers
Differ by anomeric carbon or carbonyl carbon of sugars
alpha anomer
OH down on ring
Beta anomer
OH up on ring
What is the anomeric carbon always attached to?
2 oxygens
Right side of the fischer projection will be?
Down on the ring
Left side of the fischer projection will be?
Up on the ring
What are the two types of simple sugars?
monosaccharides and disaccharides
Reducing sugars
have at least one reducing end, aldehyde as reductant, open chair form, free anomeric carbon
Non-reducing sugars
cannot reduce oxidizing agents, no free anomeric carbon, anomeric carbon can not be isomerized into an aldehyde
Disaccharides can be reducing sugars if..
have at least one reducing end
Reducing ends have..
a free anomeric carbon
Nonreducing ends have..
anomeric carbon in a glycosidic bond
Naming disaccharides
- start from the nonreducing end with first monosacchride
- abbreviation of M1
- anomeric configuration of M1
- carbon number of linkage in M1
- Single arrow for single reducing and double arrow for nonreducing
- Add anomeric configuration for M2 if needed
- carbon number of glycosidic linkage in M2
- abbreviation for M2
Glucose abbreviation
Glc
Fructose abbreviation
Fru
Galactose abbreviation
Gal