Basic Chemistry Chapter 2

Atoms Matter Atoms Elements All matter is made of atoms Atoms consist of electrons, protons, and neutrons Elements Elements are pure substances made of only one kind of atom

Chemical Bonding Covalent Bonds Hydrogen Bonds Ionic Bonds Molecules are groups of atoms linked by covalent bonds Hydrogen Bonds Hydrogen bonding occurs between polar molecules Ionic Bonds An ion is a charged atom or molecule. Ions of opposite charge may form an ionic bond

Water in Living Things Storage of Water Cohesion – sticks to itself Water, which is essential for life, stores heat efficiently and binds to itself and other substances Cohesion – sticks to itself Adhesion – different substances stick together

Aqueous Solutions Polarity Acids and Bases Water dissolves polar molecules and ionic compounds Acids and Bases Acids increase the hydrogen ion concentration of a solution. Bases decrease the hydrogen ion concentration of a solution. The pH scale measures the strength of acids and bases

Carbon Compounds Carbohydrates Carbohydrates, such as glucose, are a source of energy and are used as structural materials in organisms Lipids Lipids are nonpolar molecules that store energy and are an important part of cell membranes Proteins Proteins are chains of amino acids. The sequence of amino acids determines a protein’s shape and specific function Nucleic Acids Nucleic acids store and transmit hereditary information ATP ATP is the main energy currency of cells

Molecular Chains Carbon chains can be 1 or 2 carbon atoms or thousands of carbon atoms Smaller molecules bond together and are known as a polymer Many polymers are formed by condensation = H removed from one, OH removed from another so H2O is pulled out Opposite is called Hydrolysis

Condensation

Hydrolysis

Carbohydrates Made of Carbon, Hydrogen, and Oxygen only in a ratio of 1:2:1 C6H12O6, Provide energy

Monosaccharide = building block Called Simple Sugars (Glucose, Fructose)

Disaccharide = 2 monosaccharides Fructose + Glucose → Sucrose

Polysaccharide = polymer of many monosaccharides Starch, Glycogen, and Cellulose

Lipids Mostly Carbon and Hydrogen, small amount of Oxygen Nonpolar molecules so don’t dissolve in water Energy storage, protection, insulation Major component of membranes

Fatty Acids and Glycerol = building block

If all Carbons have single bonds = saturated Fats from animals; solids at room temp.

If there is a double bond = unsaturated Oils from plants; Liquids are room temp. (Healthier?)

More than 1 double bond = polyunsaturated

Proteins Contain Carbon, Hydrogen, Oxygen, Nitrogen, and sometimes Sulfur Amino Acids = building block 20; Combine using condensation and form a peptide bond Sequence determines protein Tissue and organ structure and cell metabolism

Protein Examples Hemoglobin Carries oxygen in your blood Made in bone marrow Contains iron; too little iron = anemic

Protein Examples Insulin Type I Diabetes – Insulin deficiency; shots Hormone that regulates the amount of sugar in your blood; treats diabetes Secreted by pancreas Tells other cells to absorb glucose (no insulin = no energy absorbed) These cells (liver, muscle, and fat) then store it as glycogen and stop using fat as energy No or low Insulin, no glucose uptake, fat used as energy Type I Diabetes – Insulin deficiency; shots Type II – Insulin resistance; other methods

Special Protein = Enzymes Protein that changes the rate of a chemical reaction (may speed up) Many lower the Activation Energy Activity depends on temperature, enzyme concentration, and pH Specific to certain substrates Works like a lock and key Amino acids make proteins (enzyme) folded in a certain way which determines job

Energy for Life Processes Energy in Chemical Reactions Chemical Reactions absorb or release energy Activation Energy Starting a chemical reaction requires activation energy

Enzyme-Substrate Complex

Nucleic Acids Stores cellular information in the form of a code DNA and RNA Nucleotides = building blocks Carbon, Hydrogen, Nitrogen, and Phosphorous in 3 parts Nitrogenous Base Simple Sugar Phosphate Group

How to Identify Proteins turn a blue Biuret solution to pink-purple Starches (carbohydrates) show up bluish/black when drops of iodine are added Sugars (carbohydrates) turn a blue Benedict’s solution an orange-brown Lipids leave a grease spot on brown paper