Carbohydrate Metabolism and Structures

This set of flashcards covers key concepts from the lecture on carbohydrate structure, metabolism, and function, focusing on monosaccharides, glycosidic bonds, enzyme roles, and carbohydrate classifications.

Monosaccharides are the simplest form of carbohydrates, consisting of ____ or ____ that contain two or more alcohol groups.

aldehydes, ketones

The D form of monosaccharides has the hydroxyl group on the furthest asymmetric carbon to the ____, while the L form has it to the ____.

right, left

The general formula for carbohydrates can be written as ____, where n represents the number of carbon atoms.

CH2On

____ are specific types of stereoisomers that differ in configuration only at the anomeric carbon after the formation of a cyclic structure.

Anomers

Cyclic forms of monosaccharides create a new asymmetric carbon at the ____ carbon, changing the spatial arrangement of the hydroxyl groups.

anomeric

A ____ bond is formed when the anomeric carbon of a monosaccharide bonds with the hydroxyl of another molecule.

glycosidic

Enzymes called ____ catalyze the formation of glycosidic bonds between monosaccharides in oligosaccharides.

glycosyltransferases

In alpha glycosidic bonds, the hydroxyl group on the anomeric carbon points ____, while in beta bonds, it points ____.

down, up

____ sugars are sugars that can react with oxidizing agents, usually because they can exist in their open chain form with a free aldehyde group.

Reducing

What is the significance of hemoglobin A1c?

Hemoglobin A1c provides information on long-term blood glucose levels, indicating average glucose concentration over the past 90 to 120 days.

Humans lack the enzyme ____, which is needed to break down the beta 1-4 glycosidic bonds found in cellulose.

cellulase

____ consist of repeating units of the same monosaccharide, while ____ consist of different types of monosaccharides.

Homopolymers, heteropolymers

What are the common three disaccharides that need to be recognized?

The common disaccharides are sucrose, lactose, and maltose.

Glucose is an ____, while fructose is a ____, leading to different structural properties.

aldehyde (aldose), ketone (ketose)

____ are proteins that have carbohydrate components and play a critical role in cell recognition and signaling.

Glycoproteins

____ acts as a carrier for monosaccharides during their conversion into oligosaccharides, helping regulate their availability for metabolism.

UDP

What are the monosaccharide components of sucrose, lactose, and maltose?

Sucrose is made of glucose and fructose; lactose is made of glucose and galactose; maltose is made of two glucose units.

A non-reducing sugar, like sucrose, has its ____ carbons involved in a glycosidic bond, preventing it from opening into an aldehyde or ketone form.

anomeric

____ is the primary storage polysaccharide in plants, ____ in animals, and ____ is a major structural polysaccharide in plants.

Starch, glycogen, cellulose

The two main types of starch are ____ (unbranched, alpha-1,4 glycosidic bonds) and ____ (branched, alpha-1,4 and alpha-1,6 glycosidic bonds).

amylose, amylopectin

Cellulose provides ____ in plant cell walls, contributing to the rigidity and strength of plants.

structural support

A ____ is a five-membered ring structure of a monosaccharide, formed by the intramolecular reaction of a hydroxyl group with an aldehyde or ketone group.

furanose

A ____ is a six-membered ring structure of a monosaccharide, formed by the intramolecular reaction of a hydroxyl group with an aldehyde or ketone group.

pyranose

Epimers are specific types of stereoisomers that differ in the configuration at only ____ asymmetric carbon atom.

one