macromolecules one page study guide

Daniel Parker

2 min read

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19-03-2025

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Introduction:

Macromolecules are large molecules essential for life. They're built from smaller subunits called monomers, linked together to form polymers. Understanding their structure and function is crucial in biology. This guide covers the four main types: carbohydrates, lipids, proteins, and nucleic acids.

Carbohydrates

Function: Primary energy source; structural components (e.g., cellulose in plant cell walls).

Monomers: Monosaccharides (simple sugars like glucose, fructose).

Polymers: Disaccharides (two monosaccharides, like sucrose), polysaccharides (many monosaccharides, like starch, glycogen, cellulose).

Examples:

• Starch: Energy storage in plants.
• Glycogen: Energy storage in animals.
• Cellulose: Structural component in plant cell walls.
• Chitin: Structural component in fungi and insect exoskeletons.

Lipids

Function: Energy storage, insulation, cell membrane components, hormones.

Monomers: Fatty acids and glycerol (for triglycerides).

Polymers: Triglycerides (fats and oils), phospholipids (cell membranes), steroids (hormones).

Types:

• Saturated Fats: Solid at room temperature; single bonds between carbons in fatty acid tails.
• Unsaturated Fats: Liquid at room temperature; one or more double bonds in fatty acid tails.
• Phospholipids: Form the lipid bilayer of cell membranes. They have a hydrophilic head and hydrophobic tails.
• Steroids: Four fused carbon rings; examples include cholesterol and hormones.

Proteins

Function: Enzymes (catalyze reactions), structural support, transport, defense (antibodies), movement (muscle proteins).

Monomers: Amino acids (20 different types).

Polymers: Polypeptides (chains of amino acids); proteins are one or more polypeptide chains folded into a specific 3D shape.

Levels of Structure:

• Primary: Amino acid sequence.
• Secondary: Local folding patterns (alpha-helices and beta-pleated sheets).
• Tertiary: Overall 3D shape of a polypeptide.
• Quaternary: Arrangement of multiple polypeptide chains.

Protein Denaturation: Loss of protein's 3D structure due to heat, pH changes, or other factors. This disrupts function.

Nucleic Acids

Function: Store and transmit genetic information.

Monomers: Nucleotides (sugar, phosphate group, nitrogenous base).

Polymers: DNA (deoxyribonucleic acid) and RNA (ribonucleic acid).

Differences between DNA and RNA:

• Sugar: DNA has deoxyribose; RNA has ribose.
• Structure: DNA is double-stranded helix; RNA is usually single-stranded.
• Bases: DNA has A, T, C, G; RNA has A, U, C, G (uracil replaces thymine).

Summary Table

This study guide provides a concise overview. Consult your textbook or other resources for more detailed information. Remember to practice drawing the structures and understanding the relationships between monomers and polymers. Good luck!