Transcript Organic Molecules and the Beginning of Life

In This Lesson:
Organic
Molecules and
Early Earth
(Lesson 7 of 9)
Today is Monday,
September 28th, 2015
• Pre-Class:
– What kind of snake is this?
– Get a strip of paper from
the Turn-In Box. Don’t
write on it!
– Please also get a SMALL
paper towel for your
partner/table if you do not
already have one.
http://scienceblogs.com/zooillogix/.jpg
Spitting Cobra
http://www.kingsnai.co.za/attachments/Image/spitting_20cobra.jpg
Spitting Cobra (Naja genus)
http://1.bp.blogspot.com/_7eeP4sigHj0/RoZLtjJ5FI/AAAAAAAAA2A/rO5s1ObCQsc/s400/spit.png
http://www.bio.davidson.edu/people/midorcas/animalphysiology/we
bsites/2005/Koike/fangcomp.jpg
Today’s Agenda
• Find out what snake venom is.
– This will lead us into our next topic.
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New note format recommendation.
BioScale addition
Challenge Questions
Arts and crafts
Learn organic molecules in overview form.
How life began on Earth…
• Where is this in my book?
– Academic: P. 44 and following…
– Honors: P. 34 and following…
By the end of this lesson…
• You should be able to identify the basic
characteristics of the four types organic
molecules.
• You should be able to describe the lifegenerating conditions of the early Earth.
Organizing Your Notes
• For this lesson, there are some “big idea”
bits of info, followed by details.
• It might be a good idea to take a front/back
blank page and label it “Organic
Molecules.”
• Front: Big Idea Notes
• Back: Graphic Organizer
Snake Venom
• What could such a powerful substance as snake
venom (or lizard/bee venom or primate/bird
poison) be composed of?
http://www.newinfo2day.com/wp-content/uploads/2009/03/slow-loris.jpg
http://www.japanprobe.com/2007/01/slow-loris.jpg
Protein
• Snake venom is actually, as scientists
commonly put it, a “cocktail” of proteins.
– In other words, a whole bunch mixed together.
• Brings new meaning to the phrase “pick your
poison.”
• Snake Venom and Blood video
Okay, so what’s protein?
• Well?
• Scientists classify protein as one of four
kinds of organic molecules.
• How big are we talking, here?
– http://learn.genetics.utah.edu/content/begin/
cells/scale/
– Scale of the Universe
• BioScale!
But first…
• Some challenge questions…
• Grab yo’ whiteboards.
Organic Molecules
• Remember when we said that the elements are
the substances that make up EVERYTHING in
the known universe?
• Well, organic molecules (sometimes called
macromolecules) are the types of molecules
that make up EVERYTHING that’s alive.
– In fact, they also make up some stuff that isn’t alive.
Organic Molecules
Concept Map
• For now, leave a lot of room around this
concept map as we will repeatedly return
to it throughout the lessons.
• On this page, you’ll start your concept map,
and take down the key facts I’ll be giving
on the back of your concept map sheet.
Key Notes (Slide 1 of 2)
• Organic molecules mainly have elements
from the first three rows of the Periodic
Table.
• Carbon and hydrogen are always included.
– Remember what we said a few lessons ago –
carbon’s ability to form long chains and big
molecules helps it support life.
• Can be classified into four main groups,
each as important as the other.
Key Notes (Slide 2 of 2)
• Each of these has a basic unit (called a
monomer).
• Each also has a complex unit that is made
of groups of monomers (called a polymer).
• You will have to know the names of the
building blocks, the bigger units, roughly
what they’re made of, and what they do.
But for now…
• Let’s start by getting the concept of
monomer/polymer down, shall we?
• Think of polymers like chains, and
monomers like individual links in those
chains.
Polymer 
http://blogs.dallasobserver.com/cityofate/Zinc-Chain.jpg
 Monomer
Monomers & Polymers
Arts & Crafts
• Find the strip of paper you picked up at the
beginning of class. On this, once we begin,
write your name and the term “Monomer”
on one side.
• Divide the masking tape strip at your lab
tables into small sections and use it to link
your strips into chains, leaving one link
OPEN.
• Then, link to other groups’ chains!
Looking at some
real examples…
• Let’s take a look at the four kinds of organic
molecules and we’ll identify each one’s
monomer and polymer.
Carbohydrates
• Composed of carbon, hydrogen, and
oxygen.
• Monomer: Monosaccharide (simple sugar)
• Polymer: Disaccharide (two simple sugars
put together) or polysaccharide (many
sugars put together)
– Fun Fact: A disaccharide is an example of a
two-monomer chain known as a dimer.
Examples of Carbohydrates
• Monosaccharides: Glucose,
fructose.
• Disaccharides: Sucrose, maltose.
• Polysaccharides: Starch, cellulose,
chitin, glycogen.
• Important in: Plant structure,
animal energy, insect
exoskeletons.
Chitin exoskeleton
http://www.backyardnature.net/pix/exoskel1.jpg
Lipids
• Lipids are fats, phospholipids, steroids,
hormones, pigments, and waxes (non-polar!).
• Monomer: Well…about that…
– For now let’s just remember this:
• Fat is composed of 3 fatty acid chains and a glycerol
molecule. This is called a triglyceride, but it is not a
true monomer.
• Polymer: No true polymer, but we’ll say fats,
phospholipids, pigments, waxes (as above).
• Important in: Cell membranes, energy,
hormones.
A Little More About Lipids
• Some examples include:
– Saturated Fats (solid at
room temp.)
– Unsaturated Fats (liquid
(oil) at room temp.)
– Cholesterol
– Testosterone, estrogen,
progesterone, and other
excesses in this room.
Chef Boyardee Chicken Alfredo
with Pasta
http://blog.foodfacts.com/wp-content/uploads/2009/06/food-label-with-ingredients2.jpg
Proteins
• Monomer: Amino acid.
• Polymer: Polypeptide.
• Important in: Enzymes,
cell structures, some
hormones, viruses,
making more proteins,
lots of other stuff.
• Examples:
Phenylalanine,
tryptophan (amino
acids), catalase.
http://www.dreamviews.com/community/showthread.php?t=52863
Nucleic Acids
• Monomer: Nucleotide (A, T, G, C)
• Polymer: Nucleic Acid
• Important in: Reproduction, heredity,
protein creation.
• Examples: DNA, RNA.
http://puesoccurrences.files.wordpress.com/2009/07/dna_500.jpg
Big Picture?
• These organic molecules come together to
accomplish complex tasks for the body/cell.
• A good example is how the human body handles
blood sugar after a meal:
– Your stomach enzymes (protein) break down
carbohydrates into simple sugars.
– First, blood glucose (monosaccharide) levels rise.
– The hormone insulin (lipid) is released by the
pancreas to store the excess sugar in the liver as
glycogen (polysaccharide).
– The stored glycogen can then be used later when
another hormone called glucagon (lipid) is released.
Wait one second…
• So we’ve got all these organic molecules
and they’re the basis for life, right?
• Where’d they come from?
– Guesses?
Old Earth
• With a partner, take 1.14 minutes and try
to think of how organic molecules may
have formed on Earth.
– Hint: “They just formed” doesn’t count.
• We will discuss your thoughts when the
1.14 minutes are up. We need actual “first
this, then this” sorts of stuff for the board.
Oparin-Haldane Model
• The Early Earth:
– Earth was a “primordial soup” made of organic
molecules that were formed when volcanoes
erupted or lightning struck.
– At least, these were the thoughts of A.I. Oparin
and J.B.S. Haldane back in the ‘20s.
The Miller-Urey Experiment
• In 1953, Stanley Miller
and Harold Urey
decided to try and
prove the OparinHaldane model.
Harold Urey
http://www.amnh.org/education/resources/rfl/web/essaybooks/earth/images/urey_01.jpg
Stanley Miller
Cooking with Urey and Miller
• Ingredients: Methane,
nitrogen gas, ammonia, water
and water vapor, hydrogen
gas.
• Directions: Preheat oven to
“Lightning.”
• Makes enough servings of
organic molecules for life.
What They “Cooked”
• Sure enough, Miller and Urey found amino
acids (protein monomers), fatty acids (lipid
monomers), and some hydrocarbons after
their experiment.
• But was it accurate?
The Lerman Model (1986)
• We now know that Miller and Urey used some
gases that may not actually have been present
when organic molecules were forming.
• Louis Lerman formed the Bubble Model in
response.
– Volcanic eruptions in the ocean formed molecules in
bubbles, which rose to the surface, went into the
atmosphere, and reacted to form more complex
organic molecules.
• How old is life on Earth as estimated?
– 4.5 billion years. Give or take…
For scale…
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Bill Bryson – Earth History in a Day
Early Life – NOVA
Elements of Life – NOVA
Cosmos – Cosmic Calendar
CrashCourse – History of Life on Earth
But then there’s the
Big Question:
• Are organic molecules alive?
– Are you eating living things when you eat
lipids, proteins, and carbohydrates?
• What is the most basic and smallest living
unit?
– This to be answered in greater detail later in
the year.
Closure
• Exclusion Brainstorming!
• With your partner, figure out which of the
items on the list DOES NOT belong there/fit
in.
– Remember from Sesame Street?
• Write it on your whiteboard.
Exclusion Brainstorming
• Example 1:
– Carbohydrates, water, lipids, nucleic acids
• Answer: Water – not an organic molecule.
• Example 2:
– Glucose, chitin, starch, triglyceride
• Answer: Triglyceride – not a carbohydrate.
• Example 3:
– Amino acid, fatty acid, protein, polypeptide
• Answer: Fatty acid – not a protein.
Exclusion Brainstorming
• Example 4:
– Steroid, maltose, pigment, testosterone
• Answer: Maltose – not a lipid.
• Example 5:
– Monosaccharide, nucleotide, amino acid,
polypeptide
• Answer: Polypeptide – not a monomer.
• Example 6:
– Triglyceride, fatty acid, oil, steroid
– TRICK QUESTION – they’re all lipids.
Your First Assignment…
• …is to put together everything we’ve covered so far.
• You’re going to make a mini-poster (on a standard
sheet of paper).
• On it you will put information on a certain compound
that we will see later in this semester.
• Things to include:
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Element Composition
Protons, Neutrons, Electrons of each element
Type of bond (if ionic, covalent, or hydrogen)
Electron configuration
Polarity (we’re getting there)