Most Common Elements in Living Things 1.Carbon - C 2.Hydrogen - H 3.Oxygen - O 4.Nitrogen - N Make up 95% of your body weight Organic Compounds – Have carbon in them

Bonding – What holds the molecules together Covalent – strong, hard to break – Carbon can make 4 covalent bonds – Oxygen can make 2 covalent bonds – Hydrogen can make 1 covalent bond Ionic – opposites attract – Gives water special properties Hydrogen – weak, easy to break – Nucleic Acids

Macromolecules Lipids – cell membranes Carbohydrates – energy storage, support Proteins – hormones, enzymes Nucleic Acids – genetic information All are made of smaller subunits

Lipids Made up of carbon and hydrogen Fats, oils, waxes Storage Saturated – Only single bonds between carbons Unsaturated – double bonds between carbons Phospholipid – found in cell membranes.

Fatty Acid Carboxylic Acid 3 Fatty acids glycerol Triglyceride

Carbohydrates Made of atoms of carbon, hydrogen and oxygen Energy storage Ratio of 1 carbon atom, 2 hydrogen atoms, and 1 oxygen atom. Made of subunits called monosaccharides – Glucose: C 6 H 12 O 6

Polysaccharides When two monosaccharides are linked it is called a disaccharide When three or more monosaccharides the molecule is called a polysaccharide – Starch – primary source of calories – Cellulose – plant cell walls – Both are polysaccharides of glucose

Proteins Made of chains of amino acids Amino acids are made of C, H, N and O There are 20 amino acids The sequence of amino acids determines the shape of the protein

Nucleic Acids DNA - Deoxyribonucleic Acid RNA - Ribonucleic Acid Made of two chains nucleotides The nucleotide chains are twisted into a double helix shape DNA – nucleotides A, T, G and C RNA – nucleotides A, U, G and C

Lipids Sudan stain Sudan stain is attracted to lipids If lipids are present they will stain red

Carbohydrate – Monosaccharides and Disaccharides Benedict's Reagent – starts blue If sugars are present changes from blue to green (some sugar) to orange (lots of sugar) HEAT is needed to do this test

Carbohydrate - Polysaccharides Starch Iodine If starch is present, the iodine will turn blackish-blue

Protein Biuret reagent – blue to start If protein is present – turns purple

Enzymes Protein Responsible for most cell functions Functions – to build or break apart – Translate DNA – Breakdown food – Put together macromolecules Very specific – one enzyme for one function – Ends with -ase – Name reflects function lactase breaks apart lactose

Enzyme Action Enzymes have a specific binding site called the active site The molecule or molecules that bind to the active site are called a substrates Some enzymes put two substrates together A + B AB Some enzymes break one substrate apart AB A + B

Active Site Enzyme substrate complex substrate Enzymes do not get used up Reaction stops when there is no more substrate for the enzyme to use

Enzymes are Catalysts Catalyst – a substance that lowers the activation energy of a chemical reaction Reactions involving enzymes will happen with or without the enzyme. Enzymes make the reaction use less energy

Common Enzymes Digestion Muscle contraction Photosynthesis and Respiration Bacterial enzymes Factors that Affect Enzymes Temperature – Too hot – Too cold pH – Acidic conditions