Intro to Energy Substrates Flashcards
Blue = dietary
Green = glycogen
Red = gluconeogenesis
What is an epimer?
A structure that differs from another structure at only 1 chiral center
Is this alpha or beta glucose?
Alpha
Is this alpha or beta glucose?
Aldoses cyclize to yield a _____ ring.
Ketoses cyclize to yield a _____ ring.
Pyranose
Furanose
How are glycosidic bonds formed?
The hemiacetal group of one monosaccharide attacks the alcohol group of another monosaccharide, resulting in loss of H2O
Which end is the reducing end? Which is the non-reducing end?
What are the main functions of carbohydrates?
energy storage
structural components
Information (signaling)
Describe the branching in starch?
Alpha 1–>4, linear
Describe the branching in amylopectin?
Alpha 1–>4
Some branching, linked 1–>6
Describe the branching in glycogen?
Same as amylopectin (linked 1–>4 linearly, branched at 1–>6) but more branching happening
Why do polysaccharides pack in a helical fashion?
Because the alpha 1–>4 bond angle facilitate helical packing
Why are plant polysaccharides important in our diet?
- We do not have the enzymes to digest them, but the gut bacteria do so they act as a major source of energy for gut flora. Products of bacterial fermentation in gut can be absorbed by body for energy.
- Holds water in with stool, helps us poop
What is an O-linked polysaccharide?
Polysaccharide attached to lipids/proteins. Not for signaling.
What is an N-linked polysaccharide?
Linked to protein via Asn (N) amino acid, function as binding site for cell signaling/protein trafficking
Which amino acids is alpha keto-glutarate similar to?
Glutamate
Glutamine
Which amino acid is pyruvate similar to?
Alanine
Which AA is Oxaloacetate similar to?
Aspartate
