Presentation on theme: "Welcome to Biol 201 Majors Biology I! Lectures: MWF 1:00-1:50pm in ST-148 Labs: #4022: M&W 2:10-4:00pm; #4023 T&TH 2:10-4:00pm; labs are in ST-243 Instructor:"— Presentation transcript:
Welcome to Biol 201 Majors Biology I! Lectures: MWF 1:00-1:50pm in ST-148 Labs: #4022: M&W 2:10-4:00pm; #4023 T&TH 2:10-4:00pm; labs are in ST-243 Instructor: Dr. Vic Landrum (Ph.D. 1997, University of Texas at Austin) Office Hrs.: T&TH 1:30-2:00pm, or before/after classes. Need to leave something for me? This can be done in the main office in ST-103.
The Course: An introduction to the biological sciences, emphasizing genetic and cellular processes common to plants and animals. For majors and non-majors; prepares students for advanced biology courses and pre-professional programs. PLEASE NOTE: This course is Canvas-enhanced, meaning we’ll use the Canvas system to keep grades and occasionally submit assignments (usually lecture assignments). If you’re note familiar with Canvas, please attend one of the many introduction sessions available on campus or online. I can help you a bit, but a Canvas intro session is much more comprehensive. Prerequisite: None, however, to satisfy the prerequisite for upper division biology courses at some institutions, a year of general chemistry must be completed.
Topics covered: The structure and function of major molecules that constitute living organisms. The organization of cells and functions of their organelles. The principles of classical genetics for predicting inheritance. The molecular basis of genetics, including the structure and replication of DNA, regulation of gene expression, and protein synthesis. Various aspects of DNA biotechnology. The mechanisms of evolution and the origin of biological diversity. The structure and evolution of the following basic groups of living organisms: prokaryotes, protests, invertebrates, and vertebrates. The flow of energy within cells, including cellular respiration. The mechanism and functions of cell division.
Evaluation Criteria & Grading Standards Your grade total is based on a total of 1000 points, and is composed of the following parts: 3 lecture exams—each worth 150 points, for a total of 450 points; 8 lecture assignments—usually 20 points each, for a total of 160 points; 16 lab activity sheets—10 points each, for a total of 160 points 2 laboratory exams—each worth 100 points, for a total of 200 points. Lab attendance (2 pts per lab starting with Lab 2) = 30 points.
Powerpoint lectures: All notes online after class Write as little as possible during class Listening as important as writing!
How Science started Until 1200AD--only 3 ways to explain why/how things happened in nature: religious metaphysical speculative
1. Religious method universe is assumed to either to be created by gods or to contain them their actions cannot be studied or predicted
2. Speculative method Greek philosophers- -analyze by logic Ex.: Democritus, and atomic theory; Aristarchus & the heliocentric model of the solar system
3. Metaphysical method Universe governed by both natural forces & supernatural, hidden forces Natural forces predictable, can study Supernatural forces see religious method Ex.: bad omens, accurate horoscopes, good/bad luck
4. Scientific Method Began in the early 1200s in Italy, Germany has a rigid set of rules that govern it
The Scientific Method 1. information is derived only from carefully documented and controlled observations or experiments
The Scientific Method 2. All claims must be subjected to verification and proof. Revolutionary!
The Scientific Method 3. Only phenomena and objects that can be observed and studied are dealt with, no supernatural forces accepted
The Scientific Method 4. All proposed explanations of natural phenomena must be retested and verified, otherwise they are rejected.
The Scientific Method 5. Present means to examine hypotheses may not be adequate; may have to wait until technology catches up ex. Wegner—in early 1900s, based on aerial photography, he proposed that South America and Africa were once joined. He was roundly criticized, and it wasn’t until 1960s that he was vindicated.
The Scientific Method: Steps Observation Hypothesis Experimentation (& repeated experimentation!) Theory
Four basic theories of Biology 1. Cell—all life composed of cells. 2. Gene—genes carry information to reproduce the organism. 3. Biogenesis—only life can create life. 4. Evolution—organisms, by natural selection and mutations, change over time to fit their environments.
Science and Society "bad" science versus "good" science
Life is chemistry! Elements (atoms) simple molecules Carbon + 2 oxygens = Carbon dioxide (CO 2 ) Simple molecules complex molecules Six CO2 + six waters (H2O) = sugar Complex molecules life All organic molecules have carbon Oxygen, hydrogen, nitrogen also very important
Atoms/Molecules important to Biology are based on how many electrons are involved and what happens to them: 2 electrons can ‘fit’ closest to the nucleus A little further out, 8 electrons can fit. HydrogenCarbon Neon
Periodic Table of Elements Numbers=number of protons Rows=# possible electron orbits Columns=# electrons in outer orbit
The number of electrons per orbit determines how reactive an atom is: For example, Hydrogen has 1 electron (e-), but needs 2 e- to be stable—it often gives up its electron to stronger atoms, making it only positive (H+) Carbon has 4 e- in its outer orbit, so it can give up its 4 or take in 4 other e- from somwhere else, making Carbon a reactive atom Neon has 8 in its outer orbit, so it is stable and hardly ever reacts with other atoms—in chemistry, Neon and atoms like Neon with their outer orbits full are called “Noble gases”
Atoms Ions - Atoms in which number of electrons does not equal number of protons.
Chemical bonds are created between atoms when electrons get involved; 3 main types: 1.Ionic—one atom gives up electron to another atom, making the donor more positive and the receiver more negative 2.Covalent—usually involves Hydrogen; hydrogen is weak; when attached to a stronger atom, the stronger atom steals the hydrogen’s electron most of the time as it orbits. 3.Hydrogen—form when the H has lost its electron to a stronger atom like Oxygen, and becomes more +; this attracts other negative atoms (-). These bonds are the weakest of the major bonds, but can be powerful in huge numbers, as in DNA— your DNA is held together by the hydrogen bonds of the individual parts, so billions of hydrogens make a strong force.
Making molecules: ex. salt Sodium (3 electrons) will lose 1 e- to chlorine; this makes sodium more positive, and chlorine becomes more negative. This +/- attractions forms an ionic bond. As a result, table salt or Sodium chloride (NaCl) is formed.
Making molecules Ex. Water (hydrogen bonding e- lost most of time but also covalent bond e- of H are shared with oxygen
Water Water (H2O) has several unusual properties: – Absorbs heat when it evaporates – Releases heat when it freezes – Loves to bond to itself (=cohesive) – Loves to bond to other things (=adhesive) cohesion
Water Water also easily breaks down into H+ and OH- Pure water has an equal balance of H+ and OH- Thus water is considered neutral, neither acidic or basic
Acids & Bases Acids: release H+ if dropped in water; ex. pepsi Bases: release OH- if dropped in water; ex.oven cleaner Amount of each released determines pH!
Why pH is important: pH determines: – If an enzyme (a chemical accelerator molecule) works or not; ex. Amylase in saliva (spit) – If your blood chemistry is balanced – Whether you digest properly – Whether proteins are stable or break down
Remember: Electrons = energy in Biology – In living organisms, chemical energy is stored by using it to move electrons to more distant orbits.