Essential Questions How does the structure of water make it a good solvent? What are the similarities and differences between solutions and suspensions? What are the differences between acids and bases? Water and Solutions Copyright © McGraw-Hill Education The properties of water make it well suited to help maintain homeostasis in an organism. Section 3: Water and Solutions

Water and Solutions Copyright © McGraw-Hill Education Water’s Polarity 1.Water molecules are formed by covalent bonds that link two hydrogen (H) atoms to one oxygen (O) atom. 2.Water molecules that have an uneven distribution of charge are called polar molecules, meaning they have oppositely charged regions.

Water and Solutions Copyright © McGraw-Hill Education Water’s Polarity When a charged region of a polar molecule comes close to the oppositely charged region of another polar molecule, a weak attraction forms. A hydrogen bond is a weak interaction involving a hydrogen atom and a fluorine, oxygen, or nitrogen atom.

Water is Important to Life Because

Water and Solutions Copyright © McGraw-Hill Education Water is Considered the Universal Solvent In a solution, there are two components: A solvent is a substance in which another substance is dissolved. A solute is the substance that is dissolved in the solvent. i.e. LIKE SALT (solute) and WATER (solvent.)

Water and Solutions Copyright © McGraw-Hill Education Mixtures with Water Acids and bases Many solutes readily dissolve in water because of water’s polarity. Substances that release H + when they are dissolved in water are called acids. Substances that release hydroxide ions (OH − ) when they are dissolved in water are called bases.

Water and Solutions Copyright © McGraw-Hill Education Mixtures with Water pH and buffers The measure of concentration of H + in a solution is called pH. Acids have pH values < 7; Bases have pH values > 7 Buffers are mixtures that can react with acids or bases to keep the pH within a particular range.

Water and Solutions Copyright © McGraw-Hill Education Review of SECTION III Essential Questions How does the structure of water make it a good solvent? What are the properties of WATER that make it essential to support life? What are the differences between acids and bases? Vocabulary base pH buffer polar molecule hydrogen bond mixture solution solvent solute acid

Essential Questions What is the role of carbon in living organisms? What are the four major families of biological macromolecules? What are the functions of each group of biological macromolecules? The Building Blocks of Life Copyright © McGraw-Hill Education SECTION IV – The Building Blocks of LIFE ****All organisms are made up of CARBON.

The Building Blocks of Life Copyright © McGraw-Hill Education Organic Chemistry 1.Organic chemistry is the study of organic compounds – compounds that contain carbon. 2.Carbon is a component of almost all biological molecules. 3.Carbon atoms bond together to form a variety of important organic compounds.

The Building Blocks of Life Copyright © McGraw-Hill Education Macromolecules Macromolecules are polymers which are molecules made from identical repeating units called monomers. Macromolecules have four major categories: Carbohydrates Lipids Proteins Nucleic acids

The Building Blocks of Life Copyright © McGraw-Hill Education Macromolecules Carbohydrates Compounds composed of a ratio of 1 carbon :2 hydrogen :1 oxygen are called carbohydrates. Carbohydrates have a general formula of (CH 2 O) n where n indicates the number of CH 2 O units in the chain. Carbohydrates are a central energy source in organisms, as well as functioning as cellular support in plants, fungi, and animals.

The Building Blocks of Life Copyright © McGraw-Hill Education Macromolecules Lipids Lipids are molecules made mostly of carbon and hydrogen that make up the fats, oils, and waxes. A lipid’s primary function is to store energy, but they are also used to prevent water loss in plants and form the honeycomb in beehives.

The Building Blocks of Life Copyright © McGraw-Hill Education Macromolecules Proteins Proteins are compounds made of smaller carbon compounds called amino acids. All amino acids are made of carbon, nitrogen, oxygen, hydrogen, and sometimes sulfur and share the same general structure.

The Building Blocks of Life Copyright © McGraw-Hill Education Macromolecules Proteins There are 20 different amino acids, and proteins are composed of various combinations Proteins are responsible for structural support in cells, transporting substances within and between cells, signaling within and between cells, speeding up chemical reactions, and controlling cell growth.

The Building Blocks of Life Copyright © McGraw-Hill Education Macromolecules Nucleic acids Nucleic acids are complex macromolecules that transmit and store genetic information. Nucleic acids are composed of smaller repeating subunits composed of carbon, nitrogen, oxygen, phosphorus, and hydrogen called nucleotides.

The Building Blocks of Life Copyright © McGraw-Hill Education Macromolecules Nucleic acids There are two types of nucleic acids in living organisms: Deoxyribonucleic acid (DNA) Ribonucleic acid (RNA)

The Building Blocks of Life Copyright © McGraw-Hill Education Review Essential Questions What is the role of carbon in living organisms? What are the four major families of biological macromolecules? What are the functions of each group of biological macromolecules? Vocabulary nucleic acid nucleotide macromolecule polymer carbohydrate lipid protein amino acid

Crash Course LINK to Macromolecules Watch for FUN