chapter 5 Flashcards
what are carbohydrates
sugar - macromolecule that has carbonyl group and many hydroxyl groups and carbon hydrogen bonds
(CH2O)
have diverse function in cells
store chemical energy
why are sugars key to life?
they are a reservoir of energy for production of other macromolecules in our cells
monosaccharides/ single sugars are…
monomers that make up carbohydrates (macromolecule)
how do monosaccharides differ from one another?
Due to location of carbonyl groups and or # of carbon atoms in backbone chain
aldose sugars
Monosaccharides with a carbonyl group at either end of the molecule
ketose sugar
monosaccharides with a carbonyl group within the monomer
monosaccs. vary in what?
carbon #
ex- triose sugars have 3 C atoms
hexose sugars has 6 C atoms (glucose)
whats a distinguishing feature of monosaccharides
spatial arrangement of atoms
example:
glucose and galactose have the same molecular formula, yet they differ in the orientation of their 4’ hydroxyl group
spatial arrangement/ structural differences significally affects…
how enzymes recognize carbohydrates as substrates for chemical reactions given that enzymes and substrates interact in “precise” ways
do some monosaccs form cyclic/ ring structures?
Yesss and it forms spontaneously
when do monosaccs. form ring structures?
in aq. solutions and if these monosaccs. consist of 5+ carbons
why do monosaccs. form ring structures?
due to carbonyl group (1’ carbonyl in the case of glucose) reacting with the 5’ (quinary) hydroxyl group, resulting in a newly formed 1’ hydroxyl group
2 possible arrangements for glucose newly hydroxyl group…
- above the plane of the ring (β-glucose)
- below the plane of the ring (α-glucose)
what does the oreintations of this new hydroxyl group dictate?
type of complex sugar molecules form when glucose monomers link together with either themselves or other sugar molecules
why are carbohydrates soluble i water/aq solutions?
Due to the presence of Oxygen atoms and hydroxyl groups in their ring structure, they are polar molecules and hydrophilic [Larger sugars are insoluble in water]
complex sugars/carbohydrates form when
simple sugars/monosaccs polymerize/condesation/dehy. (link) tg
- this happens between 2 hydroxyl group on 2+ monosaccs and can take place between different hydroxyl groups
whats a glycosidic bond?
resulting bond of when 2 monosaccharides polymerize tg
2 most common glycosidic bonds
- α-1,4-glycosidic bonds
- β- 1,4-glycosidic bonds
what does the 1 and 4 correspond to in the glycosidic bonds
carbon atoms involved in the reaction
what does the alpha (α) and beta (β) correspond to in the glycosidic bonds
orientations of the hydroxyl group on the C-1 carbon
what is a disaccharide?
a complex sugar of when 2 monosaccharides polymerized tg
examples of disaccharides
lactose and maltose (differ in constituent monosaccs)