Which Polysaccharide Gives Arthropods Their Tough Exterior?

This free textbook is an OpenStax resource designed to increase student access to high-quality, peer-reviewed learning materials. Arthropods, the largest phylum in the animal world, have an exoskeleton made principally of chitin, a waterproof, tough polysaccharide composed of N-acetylglucosamine. Chitin is a large, structural polysaccharide made from chains of modified glucose and is found in the exoskeletons of insects, the cell walls of fungi, and certain hard structures in invertebrates and fish.

The cuticle is the covering of an arthropod, consisting of two layers: the epicuticle, a thin, waxy, water-resistant outer layer containing no chitin, and the β-linked N-acetylglucosamine (GlcNAc) polymer. It is a primary component in the exoskeletons of arthropods and crustaceans, as well as the cell walls of fungi. Chitin is excreted by the epidermal cells in arthropods and is a primary component of cell walls in fungi, particularly filamentous and mushroom-forming fungi, and the exoskeletons of arthropods such as crustaceans.

Chitin is an aminated polysaccharide biosynthesized in several invertebrate animal species and is a main compound of the exoskeleton of arthropods. The material form of chitin is usually a white and hard nitrogenous polysaccharide that is inelastic. It has been considered to be the most abundant polysaccharide in the exoskeleton of arthropods.

Chitin forms protective structures in arthropods and fungi, with alternating N-acetyl groups attached to a carbon-sugar backbone. It is primarily found in fungal cell walls and the exoskeletons of arthropods, and is notably absent from plants and vertebrates. The tensile strength of chitin is a major factor in the exoskeleton of many arthropods, including insects, spiders, and crustaceans.

What is the outer covering of some insects?

Insects are invertebrate animals with an exoskeleton, a segmented body, and jointed appendages, making up about 90% of all life forms on Earth. They belong to the taxonomic phylum Arthropoda, which includes insects, arachnids, and crustaceans. There are over one million insect species worldwide, with some entomologists estimating there may be up to 10 million. These species are divided into 32 orders, with beetles being the largest group.

In Everglades National Park, over 5, 000 insect specimens are housed by the South Florida Collections Management Center. Insects have six legs, two antennae, and a body consisting of three main regions: head, thorax, and abdomen. They have an exoskeleton with sense organs for light, sound, temperature, wind pressure, and smell. Insects have four life stages: egg, larvae or nymph, pupa, and adult. They are cold-blooded, do not have lungs, but many can fly and have compound eyes.

Arachnids, such as spiders, scorpions, mites, ticks, whip scorpions, and pseudoscorpions, are also found in Everglades National Park. They have eight legs and no antennae, and their body is divided into a cephalothorax and abdomen. Some arachnids, like the black widow spider and bark scorpion, are poisonous, but most pose no risk to humans. Many arachnids are considered beneficial, feeding on insects considered pests.

What is the hard outer covering of insects made of?

An exoskeleton is a hard covering that supports and protects the bodies of certain animals, including invertebrates like insects. These exoskeletons are made of chitin and have joints for easy movement. Land animals also have small breathing holes called spiracles. As animals age, their soft inside parts grow, but their exoskeletons do not. When an animal’s soft body becomes too big for the exoskeleton, it splits open and falls away, called molting. The animal then forms a new exoskeleton, without protection while the new exoskeleton is forming.

What is the hard thick outer covering of the arthropods?

Arthropods have a hard exoskeleton made of chiton, providing protection and support for their muscles. They must periodically shed their exoskeletons to grow, and they have jointed appendages that can regenerate lost limbs. The most common crab along the New England shore is the green crab, which lives in crevices, hiding in kelp, or under submerged rocks. The spider crab, with a brownish shell, grows up to four inches across and can span a full foot.

Its round shell is covered with short hairs and spines called tubercles, camouflaged by snagging algae and debris. Spider crabs are harmless, lethargic creatures that eat sea worms, dead fish, detritis, and algae.

What are insects outer covering made of?

Insects have a segmented body supported by an exoskeleton, a hard outer covering made mostly of chitin. The body is organized into three interconnected units: the head, thorax, and abdomen. The head supports sensory antennae, compound eyes, ocelli, and mouthparts. The thorax carries three pairs of legs and up to two pairs of wings, while the abdomen contains most digestive, respiratory, excretory, and reproductive structures.

The head is enclosed in a hard, heavily sclerotized, unsegmented head capsule, containing most sensing organs. The thorax is composed of three sections: prothorax, mesothorax, and metathorax. The abdomen is the largest part of the insect, typically with 11-12 segments, less strongly sclerotized than the head or thorax. Each segment carries a pair of spiracles.

The outer skeleton, the cuticle, is made up of two layers: the epicuticle, a thin, waxy water-resistant outer layer without chitin, and the thick chitinous procuticle. The procuticle has two layers: an outer exocuticle and an inner endocuticle. The endocuticle is built from fibrous chitin and proteins, while the exocuticle is rigid and sclerotized.

Insects have an enzyme that uses atmospheric oxygen to harden their cuticle, making it a lightweight material compared to crustaceans.

What polysaccharide is found in hard shelled insects?

Chitin is an aminated polysaccharide found in various invertebrate animal species, including insects and crustaceans. It is a key component of the exoskeleton of arthropods. ScienceDirect uses cookies and acknowledges the use of them. Copyright © 2024 Elsevier B. V. All rights reserved, including those for text and data mining, AI training, and similar technologies. Open access content follows Creative Commons licensing terms.

What is the structural polysaccharide in insects?

Chitin, an abundant aminopolysaccharide polymer, is used as a building material for the exoskeletons of crustaceans, insects, and fungi. It is also used in wound healing as a material for wound dressing applications. Studies have shown that biomaterials based on chitin and chitosan have shown potential in wound dressing applications. Chitin and chitosan have been studied for their properties and applications in various fields, including wound dressing, biotechnology advances, and biotechnology advances.

What do arthropods have a hard external covering made of?

Arthropods are a group of animals with joints and appendages that serve various functions such as eating, sensing, mating, respiring, walking, and defense. They have a hard, protective exoskeleton made of chitin, which is secreted by some groups like crabs and barnacles. To grow, arthropods must molt their exoskeletons periodically, forming a larger one for expansion. The combination of an exoskeleton and jointed appendages is analogous to a suit of armor.

An arthropod’s body is divided into segments, with millipedes and centipedes having similar segments, while insects have clustered segments in major body regions. Insects have an abdomen with several segments and a separate head and thorax. Most segments have a pair of attached jointed appendages, with posterior pairs serving as swimming legs, middle pairs as walking legs, and anterior pairs as food-getting apparatuses or sensory organs.

Insects have an abdomen of several segments and a separate head and thorax, while vertebrates like fish and humans have an internal skeleton called an endoskeleton with muscles attached to its outer surface.

What polysaccharide is found in the exoskeleton of arthropods?

The exoskeleton of arthropods is composed of a complex polysaccharide called chitin.

Which of the following polysaccharides is found in the exoskeleton of insects?

Chitin is a polysaccharide that is found in the cell walls of fungi and the exoskeletons of insects. It is derived from the sugars that are present in these organisms.

What polysaccharide forms the outer covering of many insects?

The polysaccharide chitin is responsible for the formation of the protective outer layer of insects and crabs.

What substance is found in the exoskeleton of arthropods?

The exoskeleton of an arthropod is a rigid outer covering, primarily composed of chitin, a robust material analogous to cellulose.