8.4. EXAMPLES OF THE IMPORTANCE OF MOLECULAR SHAPE AND BONDING

What has to happen in order for you to smell something? The answer involves bonding, and molecular shape and polarity.

In order to smell something (like popcorn) a piece of it must break away and “float off.” To do this, the bonds between the particles must be _________________________

Only the bonds between ________________________ (i.e., intermolecular bonds) are weak enough to do this at room temperature. Therefore, if you can smell something, it is almost certainly a _____________________ compound …..

The molecule must float up into your nose. Once it enters your nose, it must find a receptor that is EXACTLY the right ______________ & ________________

It will fit like a “___________________ ____________________” causing the receptor to “_______________” i.e, the receptor will send a signal to your brain telling you that receptor has fired. You learned as a child that when that receptor fires, you are smelling popcorn!

This is an example of how many important ______________________ processes work. Another example of a biochemical process in which molecular shape and polarity is crucial involves how this signal (or any signal) travels to your brain.

When electrical impulses travel to your brain, they move along __________________________– (nerve cells.) Each neuron is separated from the next neuron by a gap called the ___________________________ For the impulse to cross the gap, chemicals called ___________________________ are released into the gap.

The neurotransmitters travel across the gap and find a _____________________ of just the right _______________ and ________________________This causes the receptor on the second neuron to fire, and the electrical impulse continues its journey along the second neuron to a third one The neurotransmitter then drifts back to the first neuron it came from, and is taken back into that neuron. This process is called

A lot of ‘who you are’ is a function of what goes on in your synapses! Example: one theory of depression is that it is caused (at least in part) by an insufficient amount of a neurotransmitter called __________________________ in the synapse. SSRI’s (Selective Serotonin Reuptake Inhibitors) slow down the reuptake of serotonin; so the _________________________ of serotonin in the synapse _________________________