The key difference between arabinose and xylose is that arabinose is an aldopentose type monosaccharide isolated from gum arabic, while xylose is an aldopentose type monosaccharide isolated from wood.
In biochemistry, pentose is a monosaccharide that has five carbon atoms. The chemical formula of pentoses is C5H10O5. Its molecular weight is 150.13 g/mol. Aldopentoses are a subclass of pentoses. The linear form aldopentoses have a carbonyl at carbon 1 atom, forming an aldehyde derivative with structure H-C(=O)-(CHOH)4-H. Some aldopentoses, such as ribose, are constituents of RNA. Phosphorylated aldopentoses such as ribose 5 phosphate are important products of the pentose phosphate pathway. Other important members of this subclass are arabinose, xylose, and lyxose.
CONTENTS
1. Overview and Key Difference
2. What is Arabinose
3. What is Xylose
4. Similarities – Arabinose and Xylose
5. Arabinose vs Xylose in Tabular Form
6. Summary – Arabinose vs Xylose
What is Arabinose?
Arabinose is an aldopentose monosaccharide isolated from gum arabic. The functional group of arabinose is the aldehyde (CHO) group. Generally, in nature, the D isoform of saccharides is more common than the L isoform. However, in the case of arabinose L isoform, it is more common than D isoform in nature, and it is found abundantly as a component of biopolymers such as hemicelluloses and pectin. The L-arabinose operon (araBAD) is involved in the catabolism of arabinose in E. coli. This operon is activated in the presence of arabinose and the absence of glucose in E. coli. This operon has been a focus for research since 1970 in molecular biology. Moreover, the L-arabinose operon can be used for producing targeted expression under tight regulation.
Figure 01: Arabinose
The classical method of biochemical synthesis of arabinose is from glucose through Wohl degradation. The presence of arabinose is sometimes an indication of the overgrowth of microorganisms. Some organic acid tests check for the presence of arabinose, which may indicate the overgrowth of microorganisms like Candida albicans. Furthermore, arabinose can be used as a sweetener and favor agent in the food industry. It is also an important pharmaceutical intermediate that can be used to synthesize nucleoside antiviral drugs. Some organisms are also capable of producing energy substances such as ethanol and butanol from L arabinose through genetic recombination.
What is Xylose?
Xylose is an aldopentose monosaccharide isolated from wood. It contains five carbon atoms and an aldehyde functional group. Xylose is derived from hemicelluloses, one of the main constituents of biomass. It can adopt many structures depending on the condition, like many other sugars. Moreover, as it has a free aldehyde group, and it is a reducing sugar. Xylose is the main building block of hemicellulose xylan. Plants like birch have 30% xylan in their structure, while plants like spruce and pine have about 9% xylan in their structures. Furthermore, xylose can also be found in defensive glands of beetles such Chrysolina coerulans.
Figure 02: Xylose
Xylose has different applications. Xylose can be dehydrated to furfural, which is a biofuel precursor. It is also metabolized by humans. It produces 2.4 calories for 1 gram. In animal medicine, xylose is used to test for malabsorption. This is done by administrating xylose in water to the patient after fasting. If xylose is detected in blood or urine within the next few hours, it has been absorbed by the intestines. Xylose is also used to produce hydrogen. Furthermore, the reduction of xylose produces sugar substitute xylitol.
What are the Similarities Between Arabinose and Xylose?
- Arabinose and xylose are two aldopentoses that are monosaccharides.
- They are derivatives of hemicellulose.
- They have five carbon atoms.
- Both share the same chemical formula of C5H10O5.
- They have the same molecular mass of 150.13 g/mol.
- These appear as colorless needles or prisms.
- Their functional group is an aldehyde.
- They have wide commercial applications.
What is the Difference Between Arabinose and Xylose?
Arabinose is an aldopentose monosaccharide isolated from gum arabic, while xylose is an aldopentose monosaccharide isolated from wood. Thus, this is the key difference between arabinose and xylose. Furthermore, the density of arabinose is 1.585 g/cm3. On the other hand, the density of xylose is 1.525 g/cm3.
The below infographic presents the differences between arabinose and xylose in tabular form for side by side comparison.
Summary – Arabinose vs Xylose
Arabinose and xylose are two aldopentose type monosaccharides. They have the same chemical formula C5H10O5. Arabinose is usually isolated from gum arabic, while xylose is usually isolated from wood. So, this is the key difference between arabinose and xylose.
Reference:
“Arabinose.” An Overview | ScienceDirect Topics.
“Xylose.” An Overview | ScienceDirect Topics.
Image Courtesy:
1. “WohlDegradation overview” By V8rik at the English Wikipedia (CC BY-SA 3.0) via Commons Wikimedia
2. “DL-Xylose” By akane700 – Own work (CC BY-SA 3.0) via Commons Wikimedia