Building blocks and biological functions of the four classes of macromolecules that make up the human body: Carbohydrates, Lipids, Nucleic Acids & Proteins

What are macromolecules

• Large polymers made of repeating units called monomers

What is a monomer

• A small, repeating building block of a polymer

What is a polymer

• A chain-like molecule made of many monomers

What are the four classes of macromolecules

• Carbohydrates

• Lipids

• Nucleic acids

• Proteins

What elements do carbohydrates contain

• Carbon

• Hydrogen

• Oxygen

Example of a carbohydrate

• Glucose (C₆H₁₂O₆)

What are the building blocks of carbohydrates

• Monosaccharides (simple sugars)

What is a monosaccharide

• A single sugar monomer

• (e.g., glucose)

What is a disaccharide

• Two sugar monomers joined together

• (e.g., sucrose, lactose)

What is a polysaccharide

• Many sugar monomers linked together

• (e.g., glycogen)

Main function of carbohydrates

• Provide energy for cellular function

How does glucose provide energy

• It is used to make ATP

What is glycogen

• A storage form of glucose in the body

What are the three types of lipids?

• Triglycerides

• Phospholipids

• Steroids

Building blocks of triglycerides

• Fatty acids and glycerol

Functions of triglycerides

• Long‑term energy storage

• Thermal insulation

• Protection from mechanical traum

Structure of a phospholipid

• Hydrophilic “water‑loving” head

• Hydrophobic “water‑fearing” tails

Function of phospholipids

• Form the phospholipid bilayer of all cell membranes

What is the basic structure of steroids

• Flat molecules made of four interlocking hydrocarbon rings

Why is cholesterol essential for cell membranes

• It helps maintain membrane stability and fluidity

How is cholesterol related to hormones

• It is the precursor for hormones, which act as chemical messengers regulating physiological processes

How is cholesterol related to vitamin D

• It is required to produce vitamin D, essential for bone growth

What are bile salts and how are they related to cholesterol

• Bile salts are made from cholesterol and aid in fat digestion

What are nucleic acids

• The largest molecules in the body; they store and transmit genetic information

What are the two types of nucleic acids

• DNA (deoxyribonucleic acid)

• RNA (ribonucleic acid)

What are the building blocks of nucleic acids

• Nucleotides

What are the three components of a nucleotide

• A phosphate group

• A ribose sugar

• A nucleotide base

Key difference between DNA and RNA

• DNA stores genetic information

• RNA helps build proteins

What is the main function of nucleic acids

• They store and transmit hereditary information

How do nucleic acids relate to proteins

• They provide the instructions for building every protein in the body

What is a gene

• A segment of DNA that contains instructions for making one protein

What is the structure of DNA

• A double helix formed from two strands of nucleotides

What holds the two DNA strands together

• Complementary base pairing between nucleotide bases

What is the structure of RNA

• A single strand of nucleotides

What is the main function of RNA

• It carries out protein synthesis as instructed by DNA

How does RNA relate to DNA

• DNA provides the instructions

• RNA performs the steps needed to build proteins

What is transcription

• The process where a DNA sequence is copied into a complementary strand of mRNA, allowing genetic instructions to leave the nucleus and move to the ribosome

What is translation

• The process where the ribosome reads mRNA and uses tRNA to assemble amino acids in the correct order, building a protein according to the original DNA instructions

What is ATP

• An adenosine nucleotide with two extra phosphate groups (three total)

Why does ATP store energy

• he bonds between phosphate groups hold potential energy

How does ATP release energy

• Breaking a phosphate bond releases energy for cellular functions

What is the main role of ATP

• It provides an easily accessible energy source for the cell

What are the building blocks of proteins

• Amino acids

What determines a protein’s function

• Its structure — the specific 3‑D shape it folds into

What are the two structural types of proteins

• Fibrous proteins

• Globular proteins

What determines the structure of a protein

• The identity and sequence of amino acids.

• How the amino‑acid chain folds into its 3‑D shape.

How do amino acids form peptides and proteins

• Amino acids link together by peptide bonds to form peptides (short chains).

• As more amino acids join, peptides grow into polypeptides, which fold into specific 3‑D shapes to become functional proteins

What are fibrous proteins

• Elongated

• Strand‑like

• Stable proteins that provide mechanical support and tensile strength

Examples of fibrous (structural) proteins

• Keratin and collagen

What are globular proteins

• Compact

• Spherical

• Chemically active proteins crucial for biological processes

Examples of globular (functional) proteins

• Hormones and enzymes

What type of protein is an enzyme

• A globular, functional protein that speeds up chemical reactions

Why does protein structure matter

• A protein’s function depends entirely on its 3‑D shape; any change in structure can alter or destroy its function

What is protein denaturation

• When a protein’s shape is altered so much that its function is lost; the nature of the protein has been changed

Why must the body maintain stable internal conditions

• Because the function of every cell, tissue, organ, and system depends on properly shaped proteins

What internal changes can cause protein denaturation

• Changes in pH and temperature