What Is a Difference Between Parallel and Antiparallel -Sheet

question 16

Multiple Choice

What is a difference between parallel and antiparallel -sheet secondary structures?

• A) Antiparallel -sheets have a larger number of stabilizing H bonds between backbone amides than parallel -sheets.
• B) Parallel -sheets require a larger loop connecting together the individual peptide strands in the sheet.
• C) Parallel -sheets are longer than antiparallel sheets.
• D) Parallel -sheets have amino acid side chains alternating up and down, whereas antiparallel side chains alternate down and up.

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Definitions:

Sponges

Simple aquatic animals belonging to the phylum Porifera, characterized by porous bodies through which water flows.

Echinoderms

A phylum of marine animals including sea stars, sea urchins, and sand dollars, characterized by radial symmetry and a unique water vascular system.

Nematodes

A phylum of worm-like organisms known as roundworms, which can be found in various habitats and play diverse ecological roles.

Cnidarians

A phylum of aquatic invertebrate animals that includes corals, jellyfish, sea anemones, and hydras, characterized by their cnidocytes, stinging cells used for prey capture and defense.