Biology Unit 2 Test – August 26th Biochemistry Biology Unit 2 Test – August 26th

Atom, Element, Compound Atoms and Their Elements.flv A = smallest unit of matter (1) E = made of one kind of atom (2) C = made of 2 or more atoms joined (3) Valence electron rules 2 1 3 Sodium - NaCl

The Atom Protons (atomic number) Neutrons Electron = P A=Overall neutral charge Energy Levels 2 and 8 Isotope – same element, different # neutrons Atomic Mass Red = protons White = neutrons Outer level electrons = valence electrons

Bonding – to fill outer level Covalent – shares – molecule – water (1) gas or volitile liquid, low melting and boiling, do not dissolve in water Ionic – give and take – ion + or - table salt (2) Solid, Crystal lattice structure, brittle and break, soluble in water, conduct electricity, high melting points 1 2 http://mrsmedenicasciencespot.blogspot.com/2009/04/chemical-bonding-song.html Day 1

Changing an Atom

Mixture Combination of substances – they retain own properties Solution – mixture with one or more substances distributed evenly in another substance

Water http://molo.concord.org/database/activities/202.html Polar covalent bonds Hydrogen bonds – weak bonds, oppositely charged (the + part of one water molecule is attracted to the – part of another molecule). Most imp. compound in an organism

Five Properties of Water Good Solvent Cohesive Adhesive Less dense as a solid than a liquid Unique thermal properties

Acids and Bases A=more hydrogen ions when dissolved in water B= more Hydroxide ions pH – measure of amount of hydrogen ions Increase by 10 pH scale – 0 – 14 (Hydrogen ions) <7=A >7=B

Bonds of Life - Macromolecules Polymer – formed from monomers Covalent Bonds formed around Carbon Large bonds formed from smaller molecules – Condensation

Condensation and Hydrolysis A condensation reaction is responsible for building large molecules.  A hydrolysis reaction is responsible for breaking down large molecules (eg. digestion). 

Carbohydrates Cell’s energy source Monosaccharides – fructose Disaccharides – sucrose Polysaccharides – starch Cellulose – cell wall CHO – 1:2:1

Lipids nonpolar, hydrophobic, waxes, oils, fats, steroids (cholesterol and sex hormones). Molecular structure – 3 fatty acids and a glycerol Contains less oxygen than carbs Phospholipids – cell membrane, saturated –contain no double bonds

Proteins amino acids (20) - joined by peptide bonds building blocks for living things – enzymes Muscle contraction, transporting oxygen

Nucleic Acids DNA and RNA Stores genetic info in cells (nucleus) – forms all proteins and enzymes Nucleotides (sugar, base, and phosphate)

Enzymes Proteins – function as catalyst on a substrate at active site (speed up reaction) - Biological catalysts Reusable -are specific to a reaction, temperature, and pH Involved in all metabolic processes Stop here Sci Skills

Enzyme Movie

Chemical Reactions Metabolism Reactants products Less/more reactant energy Endothermic Exothermic

Structure – 3 phosphates Function – transformed into ADP ATP Energy currency Structure – 3 phosphates Function – transformed into ADP

Photosynthesis and Cellular Respiration Aerobic Must have oxygen to occur Takes place in mitochondria Produces 36 ATP molecules from 1 glucose - Krebs Cycle (2) electron transport chain (34) Anaerobic No oxygen needed Takes place in cytoplasm Produces 2 ATP from 1 glucose Fermentation the process by which plants use the energy from light to generate sugar Chloroplast light reactions Calvin cycle