The Tao of the The Tao of the Molecular World Molecular World

A hands on approach to A hands on approach to understanding the mantra of understanding the mantra of

molecules in real life.molecules in real life.

Today we are going to: Today we are going to:

Check out some of the forces acting Check out some of the forces acting on and between macromolecules.on and between macromolecules.

Think about how the chemical Think about how the chemical structures of biomolecules manifest structures of biomolecules manifest as properties -even behaviors - in as properties -even behaviors - in cells. cells.

Or most importantly…Or most importantly…

Today will be a nuts and bolts Today will be a nuts and bolts exercise in order to challenge your exercise in order to challenge your own particular brand of creativity own particular brand of creativity and your ability to link these and your ability to link these molecular concepts with the real molecular concepts with the real world. world.

Translated…Translated…

There is a lot of stuff in this room There is a lot of stuff in this room arraigned in different groupings.arraigned in different groupings.

There are no real instructions…There are no real instructions…

And it’s up to you to figure some And it’s up to you to figure some stuff out based on what you already stuff out based on what you already know about biology and chemistry.know about biology and chemistry.

So why don’t I help jump-So why don’t I help jump-start your thinking before start your thinking before

we begin…we begin… Sulfur hexafluoride is about Sulfur hexafluoride is about

5X heavier than air and 35X 5X heavier than air and 35X heavier than helium.heavier than helium.

Inhaling helium makes your Inhaling helium makes your voice pitch higher as it voice pitch higher as it allows you vocal chords to allows you vocal chords to vibrate faster, SF6 is so vibrate faster, SF6 is so dense, inhaling it would dense, inhaling it would make your voice much make your voice much lower. lower.

Sulfur Hexafluoride is great example of molecular properties we cannot see but do indeed exist!

ChemLancer, Youtube.com

One moreOne more

TheTvelvethMonkey, Youtube

It’s easy to live in a world It’s easy to live in a world and not realize the and not realize the

principles that govern it.principles that govern it. Again, the properties of molecules and Again, the properties of molecules and

their interactions with one another are their interactions with one another are real things and they are amazing at that!real things and they are amazing at that!

This example also dispels the myth that This example also dispels the myth that in order to have “weight” or be counted in order to have “weight” or be counted as an effective molecule you must be as an effective molecule you must be large… we just saw a gas behave much large… we just saw a gas behave much like water. like water.

Why?Why?

Think about H2O, think about the types Think about H2O, think about the types of bonds and interactions between of bonds and interactions between polar and non polar molecules.polar and non polar molecules.

Do we all know enough about bonds, Do we all know enough about bonds, polarity and partial negative and polarity and partial negative and positive charges at this point? (Psst, positive charges at this point? (Psst, you’ll need a basic understanding to you’ll need a basic understanding to work out some of today’s fun stuff)work out some of today’s fun stuff)

BondingBonding A Covalent bondA Covalent bond: is a shared pair of electrons: is a shared pair of electrons

Hydrogen bondsHydrogen bonds: : Hydrogen interaction--partial(+) H Hydrogen interaction--partial(+) H atom attracted to partial(-) oxygen or nitrogenatom attracted to partial(-) oxygen or nitrogen

Greasy:Greasy: ( = hydrophobic = non-polar) ( = hydrophobic = non-polar) ‘bond’‘bond’: water : water doesn’t play well with others, excludes them.doesn’t play well with others, excludes them.

Ionic bondIonic bond: : + or – charge due to electron gain or loss + or – charge due to electron gain or loss

What about the 4 big guns What about the 4 big guns of biological science?of biological science?

Lipids = greasy water shedders: Lipids = greasy water shedders: barriersbarriers

Nucleic acids = picky pairers: Nucleic acids = picky pairers: informationinformation

Amino acids = diverse shapes, surfaces Amino acids = diverse shapes, surfaces & sizes: machines& sizes: machines

Carbohydrates = rich fuel: energyCarbohydrates = rich fuel: energy

Static electricity and Static electricity and balloons to mess up your balloons to mess up your

hair.hair. You don’t really have to mess up You don’t really have to mess up

your hair, a shirt or your neighbors your hair, a shirt or your neighbors hair should do just fine.hair should do just fine.

What is ‘static cling’?What is ‘static cling’?

How could we use it to investigate How could we use it to investigate these claims about oil & water?these claims about oil & water?

Use your nose…Use your nose…

What do you notice?What do you notice? What does the What does the factfact of smelling tell you of smelling tell you

about involvement of molecules?about involvement of molecules? What does smelling What does smelling differentdifferent things tell things tell

you?you?

CC1010HH1414OO

This is the formula for This is the formula for bothboth smells. smells. What can you conclude?What can you conclude?

Hmm, what about starch..Hmm, what about starch.. Why does bread get stale? Is it simply a loss of Why does bread get stale? Is it simply a loss of

water?water?

What if you knew that bread will stale even in a What if you knew that bread will stale even in a moist environment, and stales most rapidly at moist environment, and stales most rapidly at temperatures just above freezing.temperatures just above freezing.

What if you knew, that simply placing the bread What if you knew, that simply placing the bread in the microwave (without water) would freshen in the microwave (without water) would freshen it up once more?it up once more?

So then what is it about bread (or starch) that So then what is it about bread (or starch) that causes this? causes this?

A hint I suppose… but why, A hint I suppose… but why, why, why?why, why?

Fun with eggsFun with eggs

A lipid bilayer surrounds the contents of A lipid bilayer surrounds the contents of an eggan egg

What effect will this have on big molecules?What effect will this have on big molecules? Charged molecules?Charged molecules? Small or uncharged molecules?Small or uncharged molecules?

Where might you expect to see a Where might you expect to see a membrane in biology?membrane in biology?

So then, today’s So then, today’s challengeschallenges

Figure out unknownsFigure out unknowns Demonstrate what you knowDemonstrate what you know

Unknowns--What’s weird? Can you explain Unknowns--What’s weird? Can you explain it?it?

A funny ‘liquid’A funny ‘liquid’

A funny solidA funny solid

Demonstrating that you get it (x2)Demonstrating that you get it (x2)

Size MattersSize Matters

Surface tension manifestsSurface tension manifests

Hydrophobicity & your worldHydrophobicity & your world

Heat helps (molecular movement, brownian Heat helps (molecular movement, brownian motion)motion)

Homework for next weekHomework for next week

Homework: Tao write-up, see Homework: Tao write-up, see handouthandout

I think that is it but I will email right I think that is it but I will email right away if I missed something. away if I missed something.

The rubrics for all written The rubrics for all written assignments are available on the assignments are available on the main course page after you click on main course page after you click on your session (47).your session (47).

Pay attention to these, once you Pay attention to these, once you know what you are being graded on, know what you are being graded on, your work will become much more your work will become much more focused.focused.

Taking care of businessTaking care of business