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Biology 181 Lab. TA: Heidi Ma heidima@email.arizona.edu Section 55 Office Hours: Tuesday 9:30-10:30 AM Koffler 422. Office Hours. I’m only in my office hours if you ask me to be I am more than willing to meet personally with you on another day if you need. A Little About Me….
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Biology 181 Lab TA: Heidi Ma heidima@email.arizona.edu Section 55 Office Hours: Tuesday 9:30-10:30 AM Koffler 422
Office Hours I’m only in my office hours if you ask me to be I am more than willing to meet personally with you on another day if you need
A Little About Me… I’m an undergraduate just like you. I’m a Biology Major with a minor in Ecology and Evolutionary Biology. I’m from Tempe, AZ.
A Little About You… Name Year in School Major How much music on your iPod is illegally downloaded
Course Homepage http://blc.arizona.edu/courses/181lab or http://www.mcb.arizona.edu/courses/181lab
Important Tabs • Course homepage • Instructor Tab • Section 55 under my picture • Access to class calendar and links to assignments
Course Software • ADOBE SHOCKWAVE PLAYER • Course Homepage • Software Tab • Left Column under “General” • Find “Get Shockwave” link and download program
Course Software • Bio181L_GO • Is a folder that contains all the programs you will need for homework • Course Homepage Software Links for “MAC” and “WIN” at top of page • DOWNLOAD AND KEEP!!!! • This is how you will access your homework
Course Software • Bio181L_Go package • Has various homework assignments • The most important one is ASSESSOR • This contains the majority of your online tutorials
Syllabus • Course homepage- link is in right column • READ for next week • Questions from syllabus included on next week’s quiz and this week’s homework
Asya Roberts Asya handles absences- not me If you know in advance you will miss a lab, see her IMMEDIATELY BSE Room 109, Mon-Fri: 800AM- 200PM is her general schedule
Plagiarism Contract • Page xiii of Lab Manual • Sign and return to me by beginning of lab next week • Having a signed syllabus will be 10 points of your first quiz
HOMEWORK Online assignments due by 10:00 PM the night before lab CARE NOW!!!! Not at the end of the semester……
Weekly Quizzes Quiz in the first ten minutes of class every week Used as late penalty Material covers current day’s lab and concepts you need to complete the lab READ lab manual….it will save time
Create 181L Account Homepage Left Column- MCB 181L Homework Account Enroll in your section 55 Create a password and WRITE IT DOWN- this is what you will use the rest of the course
The World is made of Atoms Made up of protons, neutrons, and electrons
Review of Terminology Nucleus (the center)= protons (+ charge) and neutrons (neutral charge) Electrons (- charge) - rotate AROUND the nucleus
Periodic Table of Elements (0-1 Lab Manual) • The number below the elemental symbol refers to the amount of PROTONS in the nucleus • This EQUALS THE NUMBER OF ELECTRONS rotating about the nucleus • This is meant to BALANCE THE CHARGE
BUT Atoms “prefer” to have EIGHT electrons in their outermost shell- based off a mathematical model This fact is what characterizes how atoms will BOND with other atoms….creating a MOLECULE (many atoms)
Review The rings around the atoms are a way to depict “orbitals” or the “electron shell” – which is the space where electrons reside Atoms like to have EIGHT electrons in their OUTERMOST orbital or electron shell (EXCEPT HYDROGEN AND HELIUM)
Electronegativity A characteristic that describes how BADLY an atom wants an electron This property determines how the atom will bond and HOW MANY bonds it will make
How badly do atoms want electrons? The CLOSER an atom is to having the full eight electrons in the outer shell, the MORE they want electrons= the more electronegative they are Elements are organized into columns on the PTE to denote how many electrons are still needed
Everyone wants to be a noble gas Every atom seeks to be like the gases in the right hand column of the periodic table These elements already have eight electrons in the outer shell The column number indicates how many more electrons the element needs to have eight total
How many bonds? However many electrons are missing from the outer shell is how many bonds the atom will make EX: Nitrogen- in column 5, meaning it needs 3 more electrons, meaning it will bond 3 times NH3 Ammonia
Bonding Covalent Ionic Hydrogen interactions These are discussed in GREAT DETAIL in your homework- this review will be BRIEF
Covalent Bonding The SHARING of electrons If an atom needs more electrons to reach the desired eight, it BONDS to another atom
Polar vs. Nonpolar Covalent This is a VERY essential concept to being successful in this course and understanding today’s exercise
Polar The electrons shared in the covalent bond spend MORE TIME ROTATING ABOUT THE MORE ELECTRONEGATIVE ATOM UNEQUAL SHARING OF ELECTRONS BETWEEN ATOMS Results in partial charges on each atom
What creates the charge? How many protons does oxygen have? How many electrons does oxygen have? How many does it have if the two electrons from water is rotating around it? Is this a charge balance?
Polar Interactions Molecules with polar covalent bonding tend to be attracted to OTHER molecules with polar covalent bonding Why? Because charges attract each other
Nonpolar EQUAL SHARING OF ELECTRONS This occurs most regularly in molecules with a lot of C – H bonds Carbon and hydrogen have the same electronegativity- no partial sharing
Nonpolar interactions There are none. There is no partial charge to be attracted to anything Nonpolar substances don’t care about anyone Oils are common examples
Ionic Bonding Arises due to the attraction of opposite charges One atom steals the electron= has total ownership over electron
Hydrogen “Interactions” • Happens BETWEEN molecules • Does NOT MEAN A BOND WITH HYDROGEN • Is the INTERACTION of hydrogen with an electronegative atom, such as oxygen, nitrogen, or fluorine • Example: Network of water molecules
Today’s Lab Activity Computer desktops- Lab 1 Tao Stack Exercise Work in groups of 3-4
Discussion Points Why did water “bead up” on wax paper? Why did adding salt to the alcohol mixtures create a layer for the propanol mixture? Why did the pepper flakes “flee” the toothpick dipped in detergent?
CLEAN UP This is your responsibility, not the prep staff’s Please return everything at your station back to normal Bio 181L homepage- bottom right link says “weekly cleanup”- follow that
Homework for next week • Signed plagiarism contract • Assessor: “181 Lab Intro” • Assessor: “Molecular World Tutorial” • “Atoms and Molecules” • Crosswords OR OR OR VocabuWary • VIA BIO181_ GO package
For Homework You must download the BIO181_GO package and access the homework there OR access it via the Software tab on the website, but downloading the package works better The website is less secure, it functions slower than the BIO181L_GO package
Next Week’s Quiz Next week’s quiz will include Concepts from today Atom colors Deducing partial charges (from tutorial)