UNIT 3: MATTER ENERGY LIFE

1. UNIT 3: MATTER ENERGY LIFE

2. objectives Students can: • Describe matter, atoms and molecules and give simple examples of the four major kinds of organic compounds in living cells • Describe the difference between ionic and covalentbonds in chemical reactions • Explain the difference between kinetic and potential energy • Know the principles of the conservation of matter and energy • Describe the BGC Cycles (BioGeoChemical): how water, carbon, nitrogen, and phosphorus cycle between Earth Systems • Understand the reciprocal nature of photosynthesis and respiration in capturing and using energy • Discuss food chains, webs, and trophic levels; explain why there are pyramids of energy, biomass, and individuals

3. vocab • Covalent, Ionic • Archaea, Extremophile • Nucleic Acid, Nucleotide • Diffuse • Logarithm • Oxidize • reduce

4. Elements of life • Matter is anything that takes up space and has mass • Law of Conservation of Matter: it cannot be created or destroyed, but it can be transformed” • Elements cannot be broken down into simpler substances by chemical reactions, • Atoms are the smallest whole particle of an element, consisting of a nucleus (containing protons and neutrons) and orbiting electrons

5. facts about atoms • Atomic number = # of protons the atom contains (usually equals the # of electrons) • Atomic mass = # of protons + # of neutrons • Atoms with a different number of neutrons are known as isotopes • Ions are charged atoms that have lost or gained electrons (during chemical reactions)

6. Ions and inorganic chemical reactions • Oxidation – many elements can react with oxygen. They lose electrons to oxygen (LOX = loss of electrons)because oxygen is an effective electron grabber • Metals reacting with non-metals create ionic bonds (involving loss and gain of electrons) • Acids, bases and salts are inorganic ionic compounds • Water H2O is the medium in which acids, bases and salts dissolve. • Acids and bases are measured on the pH scale

7. Organic Chemistry • Four elements make up 96% of the mass of most living organisms: • carbon • hydrogen • oxygen • Nitrogen In contrast to inorganic compounds, organic compounds form covalentbonds. These compounds tend to be more stable, less reactive, and require more energy for reactions to occur.

8. Organic Chemistry These (and 3 other) elements cycle continuously between living and non-living systems. • Four major categories of organic compounds • Carbohydrates – glucose, cellulose, fructose • Proteins – enzymes, structures • Lipids – cell membranes, fats, oils, waxes • Nucleic acids – DNA, RNA

9. Cells • All living organisms are composed of cells • Cells are composed of lipids (cell membranes), proteins (structures and enzymes), nucleic acids (DNA and RNA), and carbohydrates furnish the energy for functioning

10. Cells • Photosynthesis transforms energy from the sun into stored sugars (carbohydrates) 6CO2 + 6H2O  C6H12O6 + 6O2 • Metabolism is the energy-releasing reactions performed during respiration C6H12O6 + 6O2 6CO2 + 6H2O

11. Non-photosynthesizers • Extremophiles (also known as Archaea) transform chemicals or heat energy into their energy supply through chemosynthesis • They live in places like hot springs, heat vents at divergent boundaries on the sea floor, and high concentration salt, acid, or base solutions.

12. Energy • Defined: the ability to do work or cause heat transfer • Potential energy: stored (by position, in chemical bonds) • Kinetic energy: exhibited by movement of objects (atoms, molecules, gross matter) • Food is a form of potential energy that is released when we digest it

13. Laws of Conservation of Energy • Energy cannot be created or destroyed; it can only be transformed • Every time energy is transformed from one type to another, some energy is lost as heat. • It can no longer perform useful work • It is referred to as “low-quality” • Entropy is the term describing disorder,

14. Energy Cycle • Species – a group of individual organisms that can reproduce only with each other • Population – group of a single species • Community – groups of populations interacting • Ecosystem – communities interacting in their physical environment • Feeding relationships describe how energy moves through an ecosystem

15. Food Chains / Webs • Feeding relationships

16. Illustration of 2nd law of thermodynamics NOTE: Only 10% of consumed energy is passed from one trophic level to the next.

17. Cycling of Matter • Carbon cycle • Water (Hydrologic) cycle • Oxygen cycle • Nitrogen cycle • Phosphorus cycle • Sulfur cycle

18. Carbon cycle

19. Water cycle

20. Nitrogen cycle • Driven largely by bacteria in the soil, that: • Capture N2 from the atmosphere and make it usable for plants • Break down waste and dead organic matter, to release nitrogen either back to the soil or back to the atmosphere • Can live in plant roots • Will be assimilated into new living things once it’s been taken up by plants

21. Phosphorus cycle Phosphorus never reaches the atmosphere It is carried by water (weathering, erosion, fertilizer) Can cause “eutrophication in water bodies Ultimate effect is a “dead zone”