Embed Size (px)
Citation preview
Rules of the Road
• Turn off your cell phones
• Use laptops for constructive purposes
• Ask lots of questions!
Learning Goals for 2-semester series(1) Identify how a given biological structure or process is
directly involved in your life
(2)
(3)
Learning Goals for 2-semester series(1) Be able to identify how a given biological structure or process
is directly involved in your life
(2) “Think Like a Biologist”: Understand What Life Is. How all life is the same and yet so different
(3)
-“Unity” of life: What are the common features of all life? Covered by EBIO 1210 (Cellular Metabolism / Genetics)
-“Diversity” of Life: How and why does life come in many variations of the theme? Covered by EBIO 1220 (Evolution / Ecology)
Learning Goals for 2-semester series(1) Be able to identify how a given biological structure or process
is directly involved in your life
(2) “Think Like a Biologist”: Understand What Life Is. In how all life is the same (life’s unity) and yet so different (life’s diversity)
(3) “Think like a Scientist”:Support arguments with evidence; don’t just know
what the “right” answer is, but understand why
(on a broader scale, understand the process of setting up testable predictions as a unifying framework among all of science)
Textbook
Biology, 8th Edition by Campbell, Reece et al.
Available at CU Bookstore in UMC
and online
Choices:Hardcopy or eBook
Covers entire 2-semester series
Fig. 1-4a
The Biosphere
Communities
Populations
Organisms
Ecosystems
Biology:An Adventurein Scale
Fig. 1-4b
Organs and organ systems
Cells
Cell
Organelles
Atoms
MoleculesTissues
10 µm
1 µm
50 µm
Key Themes for this Course
(2) “Think Like a Biologist”: Understand What Life Is. “Unity” of life: What are the common features of all life?
• UNIT 1: • Structure, function of life’s molecules and cells • Balance of cell internal & external environments
• UNIT 2: • Life’s energy supplies
• UNIT 3: • Cellular, chromosomal, & molecular basis of biological inheritance
• UNIT 4: • How genes come to life
What to Expect
• Interactive Lectures
(Participation and Exit Tickets)– 10% of grade
• Daily Quizzes– 25% of grade
• Four Exams– 65% of grade
What to Expect
– Exit Tickets• 1 point each – guaranteed if you
give concerted effort
• GOAL: Did you understand the
key concept of the day?• Make sure to get a notebook!
Questions/Concerns About:
Special needsDisabilitiesReligious observances The CU Honor CodeDiscrimination and sexual harassment
See syllabus first, butWHEN IN DOUBT, PLEASE CONTACT ME!
• Lab (EBIO 1230) is an independent course
You are here.
Why do biologists study life?...because our future depends on it.
medical breakthroughs
habitat preservation
global sustainability
Real-World Connections
Real World Connection: Energy
Energy capture, and flow, and use of plants for renewable energy & materials
Fig. 1-5
Sunlight
Ecosystem
Heat
Heat
Cyclingof
chemicalnutrients
Producers(plants and other
photosyntheticorganisms)
Chemical energy
Consumers(such as animals)
Real World Connection:Human Health
The role of nutrition in(physical & mental) health
“Your genetic background loads the gun, but the environment pulls the trigger”
STOP Healthful dietRegular exercise
etc
GOToday’s U.S. dietLack of exercise
etc
Master
Control
Genes
Pima Indians & Diabetes
http://paleobioticslab.com/general-interest-articles/so-go-the-pimas-so-go-the-rest-of-us/
A Complex Issue
npr.org
PREVENT
Healthful diet
PROMOTE
Modern western diet
“Bad” Carbohydrates
“Bad” fats
Few fruits/veggies
“Good” Carbohydrates
“Good” fats
Lots of fruit/veggies
& little exercise & regular moderate exercise
High blood pressure
Heart attacks & strokes
Autoimmune diseases
All cancers
Alzheimer’s
Obesity
Diabetes
Arthritis
EpilepsyInfertility
Mental disorders
Learning disorders
PREVENT
Healthful diet
PROMOTE
Modern western diet
“Bad” Carbohydrates
“Bad” fats
Few fruits/veggies
“Good” Carbohydrates
“Good” fats
Lots of fruit/veggies
& little exercise & regular moderate exercise
5 minute break…
Key Themes(1) “Think Like a Biologist”: Understand What Life Is.“Unity” of life: What are the common features of all life?
• Molecules of life
Water and its unique role for life
http://www.lovelyish.com/690691674/confessions-of-a-sweat-er/
Life as we know it depends on water. Why?
Water: The Molecule That Supports All of Life
• Most cells are surrounded by water, and cells themselves are about 70–95% water
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
http://www.c2cinternet.org/index.php?id=589
Water supports life by
dissolving sugars, salts & other essentials
moderating temperature
Fig. 3.3
forming water strands
COHESION: water molecules stick to each other
ADHESION: water molecules stick to other molecules
Water molecules stick to things because they are polar and form hydrogen bonds
Fig. 2.13
δ –
δ+ δ+
H H
O
H2O
δ –
Oxygen is electronegative
(“pulls” electrons [-] toward it).
WHY?
The water molecule has negativeand positive areas= polar molecule
Oxygen:• Is “missing” 2 electrons• Can complete it’s outer shell by stealing or sharing electrons
Periodic Table of Elements
Outer (second shell) is complete when it holds 8 electrons
The larger the “desire” for electrons, the more electronegative the atom.(Senioritis)
δ –
δ+ δ+H2O
δ –
Unequal sharing of electrons
AND
extra, unbonded electrons of oxygen on one side
Polarity:
Reminder
Electronegativity = ATOMS
Polarity = MOLECULES
Nwyouth.org; amyreneepowell.blogspot.com
Hmm…I only need 2 more electrons…
Sure, hydrogen, I’d love to “share” with you. (Mwahahaha)
http://faculty.njcu.edu/tpamer/chemprep/Goldberg13.htmhttp://plus.maths.org/content/os/latestnews/may-aug10/ice/index
Hydrogen bond formed by electrical attraction of partially-positive H atom to a partially-negative atom in another molecule.
http://www.mie.utoronto.ca/labs/lcdlab/biopic/fig/2.9.jpg
δ+
δ-
δ+δ+
δ+δ-
δ-
δ-
δ+
δ+
δ+
δ+δ+
Fig. 2.16
δ-
δ-
δ-
The polarity of water molecules, and the resulting hydrogen bonds among molecules,give water properties that support life on Earth• Cohesion• Temperature moderation• Solvent of life
Water molecules stick together via hydrogen bonds.
Fig. 3.6 Liquid water
Cohesion among water molecules
provides a stretchable liquid.
Water-conductingcells
Adhesion
Cohesion
150 µm
Directionof watermovement
CohesionExample 1: Pulling water up trees
Fig. 3.3
Let’s see how cohesion of water contributesto its transport from soil up through plant.
http://www.colorado.edu/ebio/genbio/03_03WaterTransport_A.html
Cohesion of water moleculesExample 2: Water strider walks on water
Fig. 3.4Fig. 3.4
Moderation of temperatureExample: Coastal areas have moderated climate because water resists temperature changes
San Diego 72°
40 miles
Pacific Ocean
70s (°F)
80s
90s
100s
Santa Barbara 73°
Los Angeles (Airport) 75°
Burbank90°
San Bernardino100°
Riverside 96°Santa Ana 84° Palm Springs
106°
Fig. 3-5
• Temperature of liquid depends on how fast its molecules move. • Before H2O molecules can move faster, hydrogen bonds must be broken, which requires energy. • It takes a lot of energy to increase the temperature of water.
Moderation of temperature
Fig. 3.6
• Water resists temperature changes• Earth absorbs a lot of solar energy without much change in temperature• Prevents extreme temperature swings• Improves the stability of Earth’s environment
A habitable planet!
Moderation of body temperature
• For H2O to become vapor, hydrogen bonds must be broken (uses energy)
• The free, vaporized H2O molecule must move fast enough to leave the liquid as gas (carrying energy with it).
• For every water molecule that leaves, the remaining liquid gets cooler.
• Water loss (sweating / evaporation) cools many living organisms & keeps them from overheating.
http://www.lovelyish.com/690691674/confessions-of-a-sweat-er/
Water is the solvent of life!
Water dissolves sugar
http://www.c2cinternet.org/index.php?id=589
Water also dissolves large molecules like proteins.
Many protein surfaces are polar or charged.Being suspended in water is essential to proper functioning of many proteins, and thus to life.
Fig. 3.8
Two more terms:
Hydrophilic = “Water-loving” • Charged or polar compounds• Attract water molecules• Mix readily with water
Hydrophobic = “Water-fearing”• Non-polar compounds • No attraction for polar water molecules• Do not mix with water
Equal sharing of two electrons
Polar or non-polar molecule???
Or: Oxygen can share electrons with TWO hydrogen atoms
Unequal sharing of electrons - polar molecule
Fig. 2-12
Name andMolecularFormula
Electron-distributionDiagram
Lewis DotStructure andStructural Formula
Space-fillingModel
(a) Hydrogen (H2)
(b) Oxygen (O2)
(c) Water (H2O)
(d) Methane (CH4)
Hydrophobes:Who’s afraid of
the big bad water?
Ionic, Polar, and Non-Polar Molecules
IONIC COVALENT
Ions Polar Non-Polar
Complete transfer of electrons
Unequal sharing of electrons
Equal sharing of electrons
Full Ionic Charges
(Na+Cl-)
Partial Ionic Charges(Hδ+Clδ-)
No Charges
(H-H)
OR ? OR ?
scienceunleashed.ie
What about CO2?
a) CO2 is polarb) CO2 is non-polarc) I have no idea
Other hydrophobic and hydrophilic substances
Example: Vitamins
Severe Vitamin D deficiency(bone softening,
immune system malfunction)
Severe Vitamin C deficiency(gum bleeding, compromised
immune system)
Rickets Scurvy
Water-soluble vitamins are taken up easily from multivitamin supplements, whereas fat-soluble vitamins cannot, unless they are consumed with foods containing fats or oils!
Vitamin C Vitamin D2 Vitamin E
Vitamin C, D, E: hydrophilic or hydrophobic???
Vitamin C Vitamin D2
Vitamin A
Vitamin C
Vitamin D2
Vitamin E
Vitamin B5
How about Vitamin A and B5?
Vitamin A
Vitamin C
Vitamin D2
Vitamin EVitamin B5
The polarity of water molecules, and the resulting hydrogen bonds among molecules,give water properties that support life on Earth• Cohesion• Temperature moderation• Solvent of life
Thanks, Water!
Today’s Exit Ticket
• Draw two water molecules connected by a hydrogen bond.
• Label the covalent and hydrogen bonds.
• Your drawing should be detailed enough to show the electrons within each H20 molecule.
• Draw a triangle ( ) around the electrons that are shared in the two molecules
