Skip to main content
Biology LibreTexts

4.16: Different Types of Biological Macromolecules

  1. Last updated
  2. Save as PDF
  • Page ID
    44319

    • \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\)

    Learning Outcomes

    • Distinguish between the four classes of macromolecules

    Carbohydrates are a group of macromolecules that are a vital energy source for the cell, provide structural support to many organisms, and can be found on the surface of the cell as receptors or for cell recognition. Carbohydrates are classified as monosaccharides, disaccharides, and polysaccharides, depending on the number of monomers in the molecule.

    Lipids are a class of macromolecules that are nonpolar and hydrophobic in nature. Major types include fats and oils, waxes, phospholipids, and steroids. Fats and oils are a stored form of energy and can include triglycerides. Fats and oils are usually made up of fatty acids and glycerol.

    Proteins are a class of macromolecules that can perform a diverse range of functions for the cell. They help in metabolism by providing structural support and by acting as enzymes, carriers or as hormones. The building blocks of proteins are amino acids. Proteins are organized at four levels: primary, secondary, tertiary, and quaternary. Protein shape and function are intricately linked; any change in shape caused by changes in temperature, pH, or chemical exposure may lead to protein denaturation and a loss of function.

    Nucleic acids are molecules made up of repeating units of nucleotides that direct cellular activities such as cell division and protein synthesis. Each nucleotide is made up of a pentose sugar, a nitrogenous base, and a phosphate group. There are two types of nucleic acids: DNA and RNA.

    Practice Questions

    Explain at least three functions that lipids serve in plants and/or animals.

    [practice-area rows=”4″][/practice-area]
    [reveal-answer q=”859705″]Show Answer[/reveal-answer]
    [hidden-answer a=”859705″]Fat serves as a valuable way for animals to store energy. It can also provide insulation. Phospholipids and steroids are important components of cell membranes.

    [/hidden-answer]

    Explain what happens if even one amino acid is substituted for another in a polypeptide chain. Provide a specific example.

    [practice-area rows=”4″][/practice-area]
    [reveal-answer q=”249858″]Show Answer[/reveal-answer]
    [hidden-answer a=”249858″]A change in gene sequence can lead to a different amino acid being added to a polypeptide chain instead of the normal one. This causes a change in protein structure and function. For example, in sickle cell anemia, the hemoglobin β chain has a single amino acid substitution. Because of this change, the disc-shaped red blood cells assume a crescent shape, which can result in serious health problems.[/hidden-answer]

    Contributors and Attributions

    CC licensed content, Original
    • Revision, adaptation, and original content. Authored by: Shelli Carter and Lumen Learning. Provided by: Lumen Learning. License: CC BY: Attribution
    CC licensed content, Shared previously
    All rights reserved content
    • Biological Molecules - You Are What You Eat: Crash Course Biology #3. Authored by: Crash Course. Located at: https://youtu.be/H8WJ2KENlK0. Project: Crash Course Biology. License: All Rights Reserved. License Terms: Standard YouTube License

    4.16: Different Types of Biological Macromolecules is shared under a not declared license and was authored, remixed, and/or curated by LibreTexts.