Unit 1 Introducing Biology Ch 1 Biology in the 21st Century Ch 2 Chemistry of Life
CH 1 Biology in the 21st Century 1.1 The Study of life Biosphere: all living things and all places Biodiversity Variety of life (species) Increases from poles to equator Characteristics of Life Made up of 1 or more cells (basic unit of life) Need energy (carry out cell functions) Respond to environment (response to stimulus) Reproduce (pass genetic material on to offspring)
1.2 Unifying Themes of Biology Life following system Organized pattern Parts within a system have specific structures and functions Structures/functions like analogies Homeostasis is the driving force Organism must maintain homeostasis to survive Ecosystem must maintain homeostasis too! Evolution creates unity and diversity of Life Natural selection of adaptations Unity of life is diversity and similarities from evolution
1.3 Scientific Thinking and Processes Scientific Method Make observations Develop a hypothesis Experimentation of hypothesis Independent (manipulated) vs dependent (responding) variables Controlled variables Experimental vs control groups Statistically significant vs nonsignificant Analyze Data Make conclusions Repeat experiment- is it reproducible? Compare/analyze results Obshypothesis (over time) theory (over time) law
1.4 Biologists’ Tools and Technology Microscopes Light Microscopes: magnify living or preserved specimens Electron Microscopes: use e- instead of light to magnify SEM: Scanning Electron Microscope: e- deflect off image, 3-D TEM: Transition Electron Microscope: e- pass through image, 2-D, higher magnifications Imaging Includes microscopes, x-rays, MRI (magnetic resonance imaging), fMRI (functional MRI) Computer Models Complex systems of research/LOTS of data Geonomics: studying of person’s DNA using computer databases (data mining)
1.5 Biology and Your Future! Your Health Diet/nutrition Medical/health issues Your World Increase knowledge of your environment or things you’re using from the environment Benefits and Risks Transgenic organisms what is their impact? Do benefits outweigh negative risks? Benefits and Ethical Considerations Genetic Screening should/shouldn’t we? Who can access information? Future unanswered questions…
Ch 2 Chemistry of Life 2.1 Atoms, Ions, and Molcules Atom proton (+), neutron (no charge), and electron (-) Isotopes have different # of neutrons- changes mass #, has same chem properties still 2 or more combined elements; molecule is smallest unit of Ionic bonds- 1+ (-) transfered Covalent bonds- (-) shared Subatomic Particles Isotopes vs elements What is a chem. compound? Two types of chem bonds
2.2 Properties of Water Why is water polar? Uneven distribution of (-) Solutions vs suspensions Uneven distribution of (-) -H end is slight + -O end is slight – Solution: solute “dissapears” but takes up space; Suspension: non-dissolved material Solvent dissolves solute
Acid: pH 0-6; high concentration H+ bile pH between 8 and 9 more basic more acidic stomach acid pH between 1 and 3 Acid: pH 0-6; high concentration H+ Base: pH 8-14; high concentration OH- Neutral: pH 7; H+=OH- Acids and Bases
2.3 Carbon-Based Molecules Monomer + polymer undergo polymerization Carbohydrates: main E source; also structural Lipids: “fats”; store E; also membranes/ waterproof covering Nucleic Acids: store/ transmit DNA or RNA Proteins: contain N, C, H, and O; control rate of rxn/ form bone or muscle/ transport in or out of cell/ fight disease Macromolecules: Organic compounds
2.4 Chemical Reactions Chem rxn affects chem bond How E changes affect chem rxn Chem rxn changes the chem bond joining compounds Release E- spontanous rxn (exothermic rxn) Absorb E- need E source to start rxn (endothermic rxn)
2.5 Enzymes Catalysts in an exp Enzymes Importance of enzymes Substrates Lowers activation E (start rxn) and increases rate of chem rxn Living catalyst, most proteins (amino acids) Speed up chem rxn (catalyst); base inhibits enzyme = less effective/ acid deactivate enzyme = no rxn Temporary bind to specific enzymes called activation sites