Mini Lecture on Carbohydrates Flashcards
What are carbohydrates used for?
energy
structure
cell identifcation
Two major forms of monosaccharides
aldehydes and ketones
What conformation are sugars generally in?
D-conformation
Epimers
carbohydrates have the same chemical formula but are different from each other because of the arrangment of functional groups
Examples of epimers
D-glucose versus D-galactose versus D-Mannose
How is ring structure formed?
an oxygen from an -OH group interacts with a carbonyl group
Alpha rings
the hydroxyl group in down from the carbonyl group
Beta rings
the hydroxyl group is up from the carbonyl group
Anomeric relationship
relationship between alpha and beta monosaccharides
Hemiacetal group
formed when the ring structure is created
have the ability to linearize and be a reducing agent
Acetal
formed when another sugar is added to make a glycosidic bond
does not have the ability to linearize and be a reducing agent
Hemiacetal chemical structure
Carbon connected to an -OR, -OH, H, and -R group
What type of chemicals are linear monosaccharides?
reducing agents
Oxidation of monosaccharides
have to be linear
a metal like copper is reduced and monosaccharide is oxidized (loses electrons)
we add oxygen to the sugar to oxidize it
How do you form a glycosidic bond?
condensation
remove water
How do you break a glycosidic bond?
hydrolysis
add water
Energy levels of two monosaccharides versus disaccharide
Disaccharide is higher in free energy because there was a decrease in entropy
Disaccharide is unfavored
How does the creation of a glycosidic bond occur?
need to use energy coupling with ATP to make occur
Is ring forming spontaneous?
yes
for sugars with more than 5 carbons
What type of reaction is the creation of a glycosidic bond?
endergonic
Homopolysaccharide
has the same type of sugar repeated
Heteropolysaccharide
uses different types of sugars
Why is it advantageous for animals to have highly branched polysaccharides?
this branched structures can condense which is good for animals that move
Example of branched polysaccharides found in animals
glycogen
Where are the links in glycogen?
1-6 links allow for branching
1-4 links allow for linear polymerize
What is cellulose held together by?
beta 1-4 glycosidic bonds
Why is the beta form significant in cellulose?
animals cannot break down these bonds and use cellulose as an energy source
How do animals use cellulose?
bacteria and fungi in the gut breakdown cellulose