Biology Macromolecules Overview

Macromolecules

• Four major macromolecules: proteins, carbohydrates, lipids, and nucleic acids

Organic Molecules

• Usually composed of carbon atoms with other atoms attached, such as hydrogen, oxygen, and nitrogen.

Monomers

• Atoms or small molecules that bond together to form more complex structures such as polymers.

• Four main types: sugars, amino acids, fatty acids, and nucleotides

Polymers

• Large molecules made by bonding (chemically linking) a series of building blocks.

Dehydration Synthesis

• When two molecules or compounds are joined to form a larger molecule following the removal of water.

Hydrolysis

• A chemical reaction in which a molecule of water breaks one or more chemical bonds.

Carbohydrates

• A carbohydrate is an organic compound such as sugar or starch.

• Elements: carbon, hydrogen, and oxygen (CHO)

• Function: energy storage.

• Monomers: monosaccharides (e.g., glucose, fructose)

• Polymers: starch, glycogen, cellulose, and chitin

Lipids

• Fatty, waxy, or oily compounds that are soluble in organic solvents and insoluble in polar solvents such as water.

• Elements: carbon, hydrogen, and oxygen (CHO)

• Monomers: glycerol and fatty acids

Triglycerides

• Structure: a glycerol molecule bound to three fatty acid molecules.

• Function: store unused calories and provide your body with energy.

Phospholipids

• Structure: glycerol backbone, fatty acid chain, and a phosphate group.

• Function: a barrier to protect the cell against exterior stimuli.

Cholesterol

• Structure: a molecule with four connected carbon rings, a short tail, and a hydroxyl group.

• Function: helps build cell membranes and is used to produce important molecules like hormones, bile acids, and vitamin D.

Carbohydrate Polymer Functions

• Starch: energy storage in plants.
• Glycogen: primary storage form of glucose in animals.
• Cellulose: structural support in plant cell walls.
• Chitin: structural support in the exoskeletons of arthropods and cell walls of fungi.

Proteins

• Monomers: amino acids.

• Amino Acids: organic molecules that serve as the building blocks of proteins.

• Polypeptides: long chains of amino acids linked together by peptide bonds, forming the basic structure of proteins.

• Function: Providing structural support, regulating gene expression, transporting molecules like oxygen, and defending against disease as antibodies.

• Protein structure: long chains of amino acids that fold into specific three-dimensional shapes.

• Enzymes: proteins that act as catalysts in living organisms, speeding up chemical reactions without being changed themselves.

• Denatured Enzyme: enzyme whose structure is altered, losing its function.

• Enzyme-Substrate Complex: the structure formed when the substrate binds to the enzyme's active site. This facilitates the chemical reaction.

• Lock and Key Hypothesis: enzymes and substrates fit together precisely like a lock and key

• Induced-Fit Model: the enzyme changes shape to better accommodate the substrate, enhancing reaction rates.

Nucleic Acids

• Monomers: nitrogen-containing base, a sugar (either ribose or deoxyribose), and a phosphate group.

DNA

• Function: carries genetic information, providing instructions for protein synthesis and enabling the transmission of hereditary traits from parents to offspring.

• Structure: structured as a double helix, resembling a twisted ladder, with sugar-phosphate backbones forming the sides and paired nitrogenous bases (adenine with thymine, and guanine with cytosine) as the rungs.

RNA

• Function: carries genetic information from DNA to the ribosomes, directing protein synthesis; acting as a messenger, a translator, and a catalyst in various cellular processes.

• Structure: typically a single-stranded molecule composed of ribose sugars, phosphate groups, and four nitrogenous bases (adenine, cytosine, guanine, and uracil).

Cell Theory

• Three principles:
  • All living organisms are composed of one or more cells.
  • The cell is the basic unit of structure and function in living organisms.
  • All cells arise from pre-existing cells.

Cell Organelles

• Ribosomes: protein synthesis.
• Lysosomes: break down waste materials and cellular debris using enzymes in an acidic environment.
• Endoplasmic Reticulum: processing and transport of molecules
• Golgi Apparatus: modifies and packages proteins
• Nucleus: controls cellular activities

Explore the four major macromolecules: proteins, carbohydrates, lipids, and nucleic acids. Understand their structures, functions, and the processes of dehydration synthesis and hydrolysis. This quiz will test your knowledge on organic molecules, monomers, and polymers.