Biology 101: Chapter 5: Macromolecules

Macromolecules are large molecules, typically polymers, built from smaller molecules called monomers. This process involves linking monomers together to form the larger macromolecule structure.

Polymers are molecules made up of many repeating units called monomers, which can be natural or synthetic and are often used in a wide range of applications from plastics to DNA.

A monomer is a small, repeating organic molecule that serves as a building block for polymers. It is not a single complex molecule but rather a simple unit that can link together to form larger polymer structures.

The Dehydration Reaction involves the removal of water molecules to form bonds between monomers, leading to the synthesis of polymers. Hydrolysis is the opposite process, involving the addition of water molecules to break bonds. Oxidation refers to the loss of electrons, not water molecules. Decomposition involves breaking down polymers, but not through the removal of water molecules specifically.

Enzymes are specialized proteins that function as biological catalysts by speeding up chemical reactions within cells. They play a crucial role in various cellular processes such as synthesis and degradation reactions.

Carbohydrates are not limited to fruits and vegetables, play a crucial role in energy storage and cell structure, and are not irrelevant in human biology.

Monosaccharides are the simplest form of carbohydrates, consisting of just a single sugar molecule. They are the primary source of energy for cells and serve as building blocks for more complex molecules.

Glucose is the main fuel used for cellular work as it is a simple sugar that provides energy to cells for various functions such as growth, metabolism, and repair.

Fructose, commonly known as fruit sugar, is the natural sugar found in fruits. Glucose is found in many carbohydrates, sucrose is table sugar made from glucose and fructose, and lactose is the sugar found in milk.

Lactose is a sugar compound made up of galactose and glucose, commonly found in milk and dairy products.

A disaccharide is a type of carbohydrate formed when two monosaccharides are joined together through a dehydration reaction. An example of a disaccharide is lactose, which is composed of glucose and galactose. It is not related to proteins, vitamins, or fats.

Polysaccharides are complex carbohydrates made up of long chains of monosaccharide units. They are essential for energy storage and structural support in living organisms.

Glycogen is a storage form of glucose in animals, primarily stored in the liver and muscle tissue. It is not found in plants or classified as a protein or lipid.

Starch is a storage polysaccharide specifically found in plants, serving as a major source of energy. It is composed of glucose units and is stored in granules within plant cells.

Cellulose is a complex carbohydrate that gives strength and rigidity to plant cell walls, it is not a building block of proteins, an energy storage molecule, or a type of sugar found in human blood.

Chitin is a structural polysaccharide found in the exoskeleton of arthropods and cell walls of fungi. It is similar to cellulose, except for the nitrogen-containing appendage on each glucose monomer.

Lipids are non-polar molecules that consist mainly of hydrocarbon chains, making them hydrophobic and insoluble in water.

Hydrophobic substances repel water and are unable to mix with it, such as lipids like fats and oils.

Hydrophilic substances have an affinity for water and tend to adhere water to their surface, while the incorrect options do not accurately describe the term.

Triglycerides are actually formed by fats and oils, not proteins, carbohydrates, or minerals.

Saturated fats have no double bonds in the fatty acid chain, making them solid at room temperature and commonly found in animal fats. This structure differs from unsaturated fats, which have one or more double bonds.

Unsaturated fats are characterized by the presence of double bonds in their fatty acid chains, which distinguishes them from saturated fats. This double bond creates kinks in the chain, preventing the molecules from packing tightly together and resulting in a liquid state at room temperature. Unsaturated fats are commonly found in plant and fish oils.

Hydrogenation involves adding hydrogen to fatty acid chains, converting unsaturated fats to saturated fats, making liquid fats solids at room temperature, and creating trans-fat. The other options listed involve different processes and outcomes.

Phospholipids are a class of lipids that are a major component of all cell membranes, composed of two fatty acids and a phosphate group attached to a glycerol molecule. They play a crucial role in cell structure and function.

Steroids are a specific type of lipids, not proteins, simple sugars, or nucleic acids.

Cholesterol in an animal cell's plasma membrane acts as a 'precursor' that provides physical stability by acting as scaffolding. It also serves as a precursor for other steroids, such as testosterone and estrogen, playing a crucial role in various cellular functions.

Proteins are made up of long chains of amino acids, not lipids, carbohydrates, or nucleotides.

Amino acids have a specific structure consisting of a central carbon atom with attached hydrogen, amino group, carboxyl group, and an unique --R group among the 20 different types.