Chapter 02 _ Chemistry of Life
Chapter Overview
Focus on the fundamental chemistry that underpins biological processes.
Learning Objectives (1 of 2)
Describe the structure of an atom.
Define and discuss the terms:
Element
Molecule
Compound
Compare and contrast major types of chemical bonding.
Distinguish between organic and inorganic compounds.
Discuss the chemical characteristics of water.
Discuss acids, bases, and salts.
Learning Objectives (2 of 2)
Explain the concept of pH.
Discuss the structure and function of organic molecules:
Carbohydrates
Lipids
Proteins
Nucleic acids
Levels of Chemical Organization
Atom: Smallest unit of matter.
Nucleus: Central core of the atom.
Proton: Positively charged particle.
Neutron: Uncharged particle.
Atomic Number: Number of protons.
Atomic Mass: Combined number of protons and neutrons.
Atoms
Energy Levels: Regions surrounding the nucleus containing electrons.
Electron: Negatively charged particle.
Each level can hold up to eight electrons.
Energy levels increase with distance from the nucleus.
Model of the Atom
Visual representation of atomic structure.
Elements, Molecules, and Compounds
Element: Pure substance made of one kind of atom.
Molecule: Group of atoms bonded together.
Compound: Molecules containing more than one kind of atom.
Chemical Bonding
Bonds form to stabilize atoms.
Atoms react to fill their outermost energy levels.
Atoms may share, donate, or borrow electrons.
Ionic Bonds
Ions: Formed when atoms gain or lose electrons.
Positive Ion: Loses electrons (e.g., Na+).
Negative Ion: Gains electrons (e.g., Cl−).
Ionic bonds form between oppositely charged ions.
Electrolyte: Ionic compound that dissociates in water.
Covalent Bonds
Formed by sharing outer energy electrons.
Generally do not dissociate in water.
Essential for forming major organic compounds.
Hydrogen Bonds
Weak bonds between neighboring molecules.
Present in water, DNA, and proteins.
Inorganic Chemistry
Organic molecules contain carbon-carbon or carbon-hydrogen bonds; inorganic do not.
Organic molecules are typically larger and more complex.
Water
Essential inorganic compound.
Acts as a solvent, forming aqueous solutions.
Involved in chemical reactions (e.g., dehydration synthesis, hydrolysis).
Energy transfers occur during chemical reactions.
Acids, Bases, and Salts
Water dissociates into H+ and OH− ions.
Acid: Increases H+ concentration.
Base: Decreases H+ concentration.
pH: Measures H+ concentration; 7 is neutral.
Neutralization forms salts; buffers maintain stable pH.
Organic Chemistry: Carbohydrates
Composed of C, H, and O.
Monosaccharides: Basic unit (e.g., glucose).
Disaccharides: Two monosaccharides (e.g., sucrose).
Polysaccharides: Many monosaccharides (e.g., glycogen).
Lipids
Triglycerides: Glycerol + three fatty acids; energy storage.
Phospholipids: Form cell membranes; have hydrophilic heads and hydrophobic tails.
Cholesterol: Stabilizes membranes; precursor for steroid hormones.
Proteins
Large molecules made of amino acids.
Structural Proteins: Form body structures (e.g., collagen, keratin).
Functional Proteins: Involved in chemical processes (e.g., enzymes).
Enzymes: Catalysts for chemical reactions; operate on a lock-and-key model.
Nucleic Acids
Composed of nucleotides (phosphate, sugar, nitrogen base).
DNA: Master code for protein assembly; double helix structure.
RNA: Temporary working copy of DNA; single-stranded.
Adenosine Triphosphate (ATP)
Energy currency of the cell.
**Questions?
Chapter Overview
Focus on the fundamental chemistry that underpins biological processes.
Learning Objectives (1 of 2)
Describe the structure of an atom.
Define and discuss the terms:
Element
Molecule
Compound
Compare and contrast major types of chemical bonding.
Distinguish between organic and inorganic compounds.
Discuss the chemical characteristics of water.
Discuss acids, bases, and salts.
Learning Objectives (2 of 2)
Explain the concept of pH.
Discuss the structure and function of organic molecules:
Carbohydrates
Lipids
Proteins
Nucleic acids
Levels of Chemical Organization
Atom: Smallest unit of matter.
Nucleus: Central core of the atom.
Proton: Positively charged particle.
Neutron: Uncharged particle.
Atomic Number: Number of protons.
Atomic Mass: Combined number of protons and neutrons.
Atoms
Energy Levels: Regions surrounding the nucleus containing electrons.
Electron: Negatively charged particle.
Each level can hold up to eight electrons.
Energy levels increase with distance from the nucleus.
Model of the Atom
Visual representation of atomic structure.
Elements, Molecules, and Compounds
Element: Pure substance made of one kind of atom.
Molecule: Group of atoms bonded together.
Compound: Molecules containing more than one kind of atom.
Chemical Bonding
Bonds form to stabilize atoms.
Atoms react to fill their outermost energy levels.
Atoms may share, donate, or borrow electrons.
Ionic Bonds
Ions: Formed when atoms gain or lose electrons.
Positive Ion: Loses electrons (e.g., Na+).
Negative Ion: Gains electrons (e.g., Cl−).
Ionic bonds form between oppositely charged ions.
Electrolyte: Ionic compound that dissociates in water.
Covalent Bonds
Formed by sharing outer energy electrons.
Generally do not dissociate in water.
Essential for forming major organic compounds.
Hydrogen Bonds
Weak bonds between neighboring molecules.
Present in water, DNA, and proteins.
Inorganic Chemistry
Organic molecules contain carbon-carbon or carbon-hydrogen bonds; inorganic do not.
Organic molecules are typically larger and more complex.
Water
Essential inorganic compound.
Acts as a solvent, forming aqueous solutions.
Involved in chemical reactions (e.g., dehydration synthesis, hydrolysis).
Energy transfers occur during chemical reactions.
Acids, Bases, and Salts
Water dissociates into H+ and OH− ions.
Acid: Increases H+ concentration.
Base: Decreases H+ concentration.
pH: Measures H+ concentration; 7 is neutral.
Neutralization forms salts; buffers maintain stable pH.
Organic Chemistry: Carbohydrates
Composed of C, H, and O.
Monosaccharides: Basic unit (e.g., glucose).
Disaccharides: Two monosaccharides (e.g., sucrose).
Polysaccharides: Many monosaccharides (e.g., glycogen).
Lipids
Triglycerides: Glycerol + three fatty acids; energy storage.
Phospholipids: Form cell membranes; have hydrophilic heads and hydrophobic tails.
Cholesterol: Stabilizes membranes; precursor for steroid hormones.
Proteins
Large molecules made of amino acids.
Structural Proteins: Form body structures (e.g., collagen, keratin).
Functional Proteins: Involved in chemical processes (e.g., enzymes).
Enzymes: Catalysts for chemical reactions; operate on a lock-and-key model.
Nucleic Acids
Composed of nucleotides (phosphate, sugar, nitrogen base).
DNA: Master code for protein assembly; double helix structure.
RNA: Temporary working copy of DNA; single-stranded.
Adenosine Triphosphate (ATP)
Energy currency of the cell.
**Questions?
