A tissue.
Then a group of tissues that work together is an organ.
The a group of organs is an organ system.
A group of organ systems is and organism.
The R group is what allows amino acids to form macromolecules with different properties. every amino acid has the same basic structure, the only difference is what the R group is made up of. The similarities allow the amino acids to form a chain while the differences allows them to have different functions. Hope this helped!
1.Proteins are linear polymers built of monomer units called amino acids. The construction of a vast array of macromolecules from a limited number of monomer building blocks is a recurring theme in biochemistry. Does protein function depend on the linear sequence of amino acids? The function of a protein is directly dependent on its threedimensional structure.<span>Remarkably, proteins spontaneously fold up into three-dimensional structures that are determined by the sequence of amino acids in the protein polymer. Thus, </span>proteins are the embodiment of the transition from the one-dimensional world of sequences to the three-dimensional world of molecules capable of diverse activities<span>.
</span>2.Proteins contain a wide range of functional groups<span>. These functional groups include alcohols, thiols, thioethers, carboxylic acids, carboxamides, and a variety of basic groups. When combined in various sequences, this array of functional groups accounts for the broad spectrum of protein function. For instance, the chemical reactivity associated with these groups is essential to the function of </span>enzymes,<span> the proteins that catalyze specific chemical reactions in biological systems</span><span>
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The answer is D, The structure was probably functional in some ancestor of the modern organism. Vestigial structures are structures that have remained from ancestors but have no function in modern times.
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