3.7 Chapter 3 Summary
Christelle Sabatier
Relevant Course Learning Objectives
- Identify major macromolecules that are essential to life.
- Determine what macromolecules require Carbon, Nitrogen, and/or Phosphorus.
- Identify monomeric components of macromolecules
- Connect between macromolecule catabolism and anabolism and organismal growth
3.1 Synthesis of Biological Macromolecules
- Biological macromolecules are polymers made up of monomers, they are assembled through dehydration synthesis reactions, which link monomers by removing water.
- Polymers can be broken down into monomers through hydrolysis, which adds water.
- Enzymes (a type of protein) catalyze both reactions, aiding in the formation and breakdown of carbohydrates, lipids, proteins, and nucleic acids. These processes are essential for metabolism, nutrient absorption, and cellular function.
3.2 Carbohydrate Structure and Function
- Carbohydrates are macromolecules composed of carbon, hydrogen, and oxygen in a 1:2:1 ratio.
- Monomers of carbohydrate are monosaccharides. These monomers can form larger molecules classified as disaccharides and polysaccharides.
- Glucose, a monosaccharide, is a key energy source, while polysaccharides like starch and glycogen serve as energy storage in plants and animals respectively. Meanwhile, cellulose is a key structural molecule in plants.
3.3 Nucleic Acid Structure and Function
- Nucleic acids, including DNA and RNA, store and transmit genetic information. DNA contains the genetic blueprint, while RNA plays a role in guiding protein synthesis.
- Both are made of nucleotides, which consist of a nitrogenous base, a sugar (deoxyribose in DNA, ribose in RNA), and phosphate groups.
- DNA forms a double helix with complementary base pairing (A pairs with T, C with G), while RNA is typically single-stranded and uses uracil (U) instead of thymine.
3.4 Protein Structure and Function
- Proteins are essential macromolecules with diverse functions, including structural support, catalysis, transport, and defense.
- They consist of amino acids linked by peptide bonds. Amino acids are made up of carbon, oxygen, hydrogen and nitrogen.
- The sequence of amino acids determines the protein’s shape and function. Proteins have four structural levels: primary (amino acid sequence), secondary (alpha-helices and beta-sheets), tertiary (three-dimensional folding), and quaternary (multiple polypeptide chains). Their specific shapes allow them to bind other molecules, making them highly versatile.
3.5 Lipid Structure and Function
- Lipids are hydrophobic molecules composed mainly of hydrocarbons (C–H).
- They serve as long-term energy storage, provide insulation, and form cellular membranes.
- The four main types of lipids are fats, oils, waxes, phospholipids, and steroids.
- Most fats (except for steroids) consist of glycerol and fatty acids, which can be saturated (single bonds) or unsaturated (one or more double bonds). Saturated fats are solid at room temperature, while unsaturated fats are liquid.
- Steroids play a role in hormone production.
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Licenses and Attributions
“3.5 Chapter 3 Summary” was initially generated by ChatGPT4.0 and then modified by Christelle Sabatier. “3.5 Chapter 3 Summary” is licensed under CC-BY-NC 4.0.
a large molecule made up of many repeating units or monomers
smallest unit of larger molecules that are polymers
a subunit that can be bound to other monomers to make a polymer.
the simplest forms of sugar and the most basic units (monomers) from which all carbohydrates are built.
the simplest forms of sugar and the most basic units (monomers) from which all carbohydrates are built.
long chain of monosaccharides linked by glycosidic bonds
complex carbohydrate made up of glucose subunits found in plants. Used to store energy.
complex carbohydrate made up of glucose subunits found in animals. Used to store energy.
complex carbohydrate made up of glucose subunits found in plants. The main component of a plant's cell wall, which provides structural support.
biological macromolecules made up of nucleotides that function in information storage and transfer; DNA or RNA.
double-helical molecule that carries the cell's hereditary information
single-stranded, often internally base paired, molecule that is involved in protein synthesis
monomer of nucleic acids; contains a pentose sugar, one or more phosphate groups, and a nitrogenous base
biological macromolecule made up of amino acids; essential for cellular function.
a protein's monomer; has a central carbon or alpha carbon to which an amino group, a carboxyl group, a hydrogen, and an R group or side chain is attached; the R group is different for all 20 common amino acids
bond formed between two amino acids by a dehydration reaction
macromolecules that is made up of fatty acids. Most lipids such as triglycerides are predominantly nonpolar and hydrophobic.
cell membranes' major constituent; comprised of two fatty acids and a phosphate-containing group attached to a glycerol backbone
type of lipid comprised of four fused hydrocarbon rings forming a planar structure
organic compound (alcohol) with three carbons, five hydrogens, and three hydroxyl (OH) groups
ong chain of hydrocarbons to which a carboxyl group is attached
long-chain hydrocarbon with single covalent bonds in the carbon chain; the number of hydrogen atoms attached to the carbon skeleton is maximized
long-chain hydrocarbon that has one or more double bonds in the hydrocarbon chain
