actin [ ak-t uhn ] SHOW IPA / ˈæk tən / PHONETIC RESPELLING noun Biochemistry. a globulin that is present in muscle plasma and that in connection with myosin plays an important role in muscle contraction. QUIZZES QUIZ YOURSELF ON “ITS” VS. “IT’S”!
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Origin of actin
-in 2 variant of actino- before a vowel: actinism.
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021
Example sentences from the Web for actin noun a protein that participates in many kinds of cell movement, including muscle contraction, during which it interacts with filaments of a second protein, myosin Word Origin for actin
act + -in
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
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n. One of the protein components found in muscle, existing as F-actin or G-actin, into which actomyosin can be split and which acts with myosin in muscle contraction.
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
A protein found in all eukaryotic cells, forming filaments that make up a main component of the cell's supporting matrix or cytoskeleton. Actin and the protein myosin together make up the contractile units (called sarcomeres) of skeletal muscle fibers.
The American Heritage® Science Dictionary
Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.