Biology 181 Lab - Biology Learning Center at the University of Arizona
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Transcript Biology 181 Lab - Biology Learning Center at the University of Arizona
Biology 181 Lab
TA: Heidi Ma
[email protected]
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/181
lab
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: 800AM200PM 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
55
Enroll in your section
Create a password and WRITE IT
DOWN- this is what you will use the
rest of the course
LAB 1: MOLECULAR TAO
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
Coloring Your World
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 shellbased 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
The GENERAL trend
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
Example: 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
Example
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
THE Example: Water
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
Example:
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)