Intro to Bio: Exam 1 Study Guide

1. Be able to list organization amongst living things - from the smallest unit (atom) up through biosphere (largest). -Atom: smallest unit of an element: protons, electrons and neutrons -Molecule: two or more atoms combined -Cell: structural and functional unit of all living organisms -Tissue: a group of cells with a common structure and function -Organ: composed of tissues functioning together for a specific task – i.e. a heart -Organ System: Composed of several organs working together – i.e. cardiovascular system -Organism: an individual: complex individual containing organ system – i.e. a human -Population: organisms of the same species in a particular area – i.e. a herd of elephants -Community: interacting populations in a particular area - i.e. animals and plants in a forest -Ecosystem: a community plus the physical environment – i.e. a forest -Biosphere: regions of the Earth’s crust, waters and atmosphere inhabited by living organisms 2. What is descriptive of all living organisms? -Create energy -Maintain homeostasis -Respond to their environment -Reproduce -Develop -Adapt to their environment 3. List the levels of classification from largest (domain) to smallest (species). -Species: i.e. H.sapiens -Genus: i.e Homo -Family: i.e. Homindae -Order: i.e. Primates -Class: i.e. Mammalia -Phylum: i.e. Chordata (have a backbone) -Kingdom: i.e. Animalia -Domain: i.e. Eukarya (cells with a nucleus) 4. Be able to discuss various aspects that influence desertification on our Earth and some mechanisms that have proved to be beneficial to improve the soil. Review the videos if necessary. • Fossil Fuels and Climate Change • Desertification occurs when there are humid months followed by dry months • Water and carbon leave the ground into the atmosphere • Runoff is the cancer of desertification • Livestock leaves ground bare and hard • Macroclimate vs. Microclimate • Tall grass must decay biologically before the next season; otherwise it will shift to oxidation which kills other grasses, reducing the garden -- traditionally we use fire because it removes the dead material [to help break down the grass] but pollutes more than 6,000 cars -- cannot burn without causing desertification and climate change • Use livestock for rotational grazing in order to get rid of grass--creates a mulch with manure from livestock allowing soil to regrow grass the following season (“holistic planned grazing”) • 400% increase to mimic nature by using livestock • What we are doing globally is causing climate change, war, pollution, world suffering, etc. -- as this continues, climate change will still be here even if we eliminated fossil fuels 5. What is an atom and the parts that make it up (protons, neutrons and electrons) An atom is the smallest unit of an element: protons, electrons and neutrons • Protons: positively charged subatomic particles • Neutrons: uncharged subatomic particles • Electrons: negatively charged subatomic particles 6. What is the difference between a cation and an anion? • Cation [ex. Na+] (Plussy Cat) -- lost an electron to look like a noble gas • Anion: [ex. Cl-] (Ant Anion) -- gained an electron to look like a noble gas 7. Be able to note the element symbol, the molecular weight, proton number and number of neutrons on any element on the periodic table. -Number of neutrons found by subtraction the number of protons by the molecular weight 8. What is a free radical and why is it damaging to cells and tissues? Typically oxygen (8 electrons); has one electron that is not bound to anything and is unstable; could bind to cell membrane, fatty acids (unsaturated), DNA; free radicals binding to those things causes them to be unstable; to stop free radicals: peroxisomes, antioxidants, oxidation 9. What is a covalent bond? Covalent Bonds: When Molecules come together and share electrons (in the outer shell) • Nonpolar [ The charge is equally dispersed throughout the bond] • Polar [Although the electrons are still being shared, one side is going to be more negative , and one side is going to be more positive; Unequal -- this can be compared to water tension and the way that it is attracted ] 10. What is the difference between a nonpolar and polar bond and what is their relationship like with water? Which one is hydrophobic and which one is hydrophilic? • Hydrophilic: molecules that can attract water (likes water) • Hydrophobic: nonionized and nonpolar molecules that cannot attract water (fears water) 11. What is hydrogen bonding? How does this make water unique? Hydrogen Bonding: Polar Covalent ; i.e. water • Negative side of oxygen (in water molecule) will attract to positive side of a water molecule; very weak bond • Salt dissolves really easily because of this Hydrogen bonding and water: • High cohesion for water - results in high surface tension • Highest cohesion of any non-metallic substance • Capillary Action: cohesion causes the water molecules to climb up the straw • Amazing solvent--more substances that can be dissolved in water than any other substance on earth • Table Salt is ionic • Hydrophobic substance (Non Polar -- fearful of water) • Gases are less dense than liquids • Ice Density -- Water molecules begin to solidify which spaces the electrons out • Heat Capacity -- water is really good at holding onto heat 12. What are some of the primary properties of water that make it unique? • All living organisms: 70-90 % water • Life as we know it • Set boiling point (100* Celcius) • Set freezing point (0* Celcius) • Life cannot exist without water 13. What is heat capacity (in relation to water)? -Calorie: Amount of heat energy needed to raise the temperature of one gram of water by one degree celsius • Hydrogen bonds: help water absorb heat without a great change in temperature • Heat Retention • Gains heat and acquires heat more slowly • Why is this important? -Heat of Evaporation: 540 calories of energy required to convert one gram of hot water to a gas • High heat of evaporation • Hydrogen bonds must be broken • Why is this aspect important? • In relation to water in the environment as it keeps water at a more stable/ constant temperature; better for wildlife 14. What is heat evaporation (in relation to water)? In relation to water in the environment as it keeps water at a more stable/ constant temperature; better for wildlife 15. Why is water a good solvent? Water is a good solvent because it easily dissolves solutes (polar) 16. Be able to define cohesion, adhesion, and surface tension. Water molecule to a water molecule; Ability of water molecules to cling to each other due to hydrogen bonding; 17. Why is ice less dense than water? Why is this important? Hydrogen bonding; water as a liquid has a loose structure of molecules, molecules in ice are “stuck” into a rigid geometrical structure making ice less dense than water; ice insulates (i.e. snow cave for survival, ocean--ice freezes on the top) 18. What makes a molecule organic? In chemistry, organic means that a molecule has a carbon backbone with some hydrogen thrown in for good measure. Living creatures are made of various kinds of organic compounds. Inorganic molecules are composed of other elements. They can contain hydrogen or carbon, but if they have both, they are organic. 19. What are the primary organic biomolecules? Lipids, Proteins, Carbohydrates, Nucleic Acids 20. What are the subunits for all of the primary biomolecules? Glycerol, fatty acids, amino acids, monosaccharides, nucleotides 21. What is a dehydration reaction? A hydrolysis reaction? Dehydration: helps with building up by taking away water Hydrolysis: helps with breaking down by adding water 22. What is the purpose of carbohydrates? Are they polar or nonpolar? • Immediate energy source for living organisms • Primarily made up of carbon, hydrogen and oxygen (CH2O) • Single sugar molecules and chains of sugar. 23. Be able to provide an example of monosaccharide, disaccharide and polysaccharide. Monosaccharide: Form together to make more complex carbohydrate chains • Single sugar molecule • Contain hydroxyl groups (polar) • Glucose • Fructose • Galactose • Ribose / Deoxyribose: RNA & DNA Disaccharide: • Two monosaccharides formed together via dehydration Polysaccharide: • Long polymers of monosaccharides • Plants: starch • Amylose: unbranched • Amylopectin: branched – no main carbon chain • Animals: glycogen • Examples: cellulose (plants), chitin (fungus), peptidoglycan (bacteria) -I.e. complex carbohydrates – can be temporarily stored as energy -Glycogen – stored in liver and muscle for later energy. Stored there via the hormone insulin. -Not as soluble in water -Larger than simple sugars -Cannot easily pass through the plasma membrane – have to be broken down. -Cellulose: glucose chains - most abundant carbohydrate on earth – cannot be digested by animals due to the bond between the cellulose molecules. In humans it functions as dietary fiber and is broken up by gut bacteria – maintains feces regularity. 24. What are the different categories of lipids? Be able to depict their unique structures and why some are more stable than others. What are the purposes of these various lipids in the body? • Hydrocarbon chains: non-polar • Fats: Triglycerides -- insulation and long-term storage • Animals: Adipose Tissue • Plants: Oils • Phospholipids • Steroids • Waxes • Triglyceride: glycerol and three fatty acid chains. • Fatty acids – made up of a hydrocarbon chain with a carboxyl group at the end.