Atoms & Life Substances Section 6.1 & 6.3

Atomic Structure 6.1 Nucleus = center of an atom, contains protons (p+ positively charged) and neutrons (nº neutral) Electrons (eˉ) are negatively charged particles that surround the nucleus Atoms are neutral because they contain equal numbers of protons and electrons

Biomolecules (6.3) These are the molecules required by living things 1. Carbohydrates 2. Proteins 3. Lipids 4. Nucleic Acids (There are other types of molecules too!!!)

Organic Compounds = contain carbon, all biomolecules are organic Monomer = a building block, smaller subunits Polymer = made up of lots of monomer subunits

CARBOHYDRATES pg. 158 Source of energy Structural materials Monosaccharides & Polysaccharides

Monosaccharide Carbs They’re Monomers =1 Carbohydrate Glucose = main source of energy for cells, diabetics need to monitor glucose levels

Polysaccharide Carbs Polysaccharide = 3 or more monosaccharides Glycogen = how animals store glucose Starch = how plants store glucose Cellulose = polysaccharide, provides plants with structure

2. PROTEINS pg. 161 Hair, horns, nails, skin, muscle Act as biological catalysts (enyzmes) which help to kick start reactions in the body

Amino Acids Protein monomer 20 different amino acids Peptide Bond = connects amino acids http://www.biotopics.co.uk/as/aminocon.html Polypeptide = long chain of amino acids

Enzymes Enzymes change the rate of reactions in the body Help cells reproduce, digest food, get rid of waste, make new biomolecules Active Site = a section of the enzyme shaped to fit a specific substrate Substrate = something that’s being broken apart or made (catalyzed) http://www.lpscience.fatcow.com/jwanamaker/animations/Enzyme%20activity.html http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_enzymes_work.html

3. LIPIDS pg. 160 Insoluble = Don’t dissolve in water Best for storing energy Insulation, protective coverings Major part of cell membranes

Saturated & Unsaturated Fats Saturated Fat = found in butter, red meat (solid at room temperature), saturated with hydrogen Unsaturated Fat = vegetable fats (liquid at room temperature)

Phospholipids Cell membranes made up of two layers of phospholipids, forms a barrier Keeps things that are supposed to be out, out of the cell Keeps things that are supposed to be in, in the cell 2 fatty acids attached to glycerol, and a phosphate group Phosphate Lipids

Practice What percent of your body is made of water? Explain why a cell needs a structure that helps it maintain water levels inside? What could happen to the cell if this structure wasn’t working properly?

Other types of LIPIDS besides fats… Wax Structural Makes a coat on plants for water proofing Steroids Hormones that cause physical changes in the body

4. NUCLEIC ACIDS pg. 163 Store and transfer info in the cell Nucleotide = monomer of nucleic acids 2 kinds of nucleic acid polymers: DNA = deoxyribonucleic acid RNA = ribonucleic acid