CHEM 2701 – Lab 6 – Organic II
Chemistry II for Pre-Health Sciences (online)
____/23 marks (6% of final grade)
Rationale
Organic molecules may look like 2D objects when drawn on paper. But just like you learned about VSEPR (i.e. tetrahedral, trigonal pyramidal etc.) in CHEM 1701, molecules have a 3D shape. In this lab you will get a chance to build organic molecules to see their 3D shape come to life. You will also explore applications of amines and amides in healthcare.
Learning objectives
The following learning objectives are covered in this lab.
· CLO 8 Prepare for and conduct laboratory experiments to investigate scientific questions using appropriate techniques.
· LO 4.30 Identify the amine and amide functional groups in organic compounds
· LO 4.31 Name common examples and uses of amines and amides (i.e. neurotransmitters)
· LO 4.32 Discuss the importance of hydrogen bonding in amines and amides
Procedure & Observations
· Be sure to review the lab in its entirety before beginning.
· Throughout the lab you are required to photograph parts of your experiment and include these photos in your final submission.
Handing in your la
When complete, submit your work to the appropriate folder in DC Connect under Activities Assignments.
Other notes
· A maximum 10% penalty may be applied for spelling, grammar and mechanics.
· When rounding final answers, apply the rounding rules as discussed in this course.
· Make sure all answers are in full sentences using appropriate scientific terminology.
· Note how many marks are associated with a question and use that as a guide when structuring your response.
Materials
Soft materials to act as “atoms” and a more sturdy material to join the atoms and to represent bonds as you build molecules in this lab. Below are some suggestions but please use whatever you already have at home. Do not go out to a store to purchase materials. Practice social distancing. If you are struggling with finding materials at home, email me and I will suggest some alternatives.
· toothpicks (or some other object for connecting, even a hair pin will work)
· ~10 small marshmallows of one color [or raisins, candy, cereal, beans of one color etc.]
· ~20 small marshmallows of a second color [or raisins, candy, cereal, beans of a second color etc.]
· ~20 small marshmallows of a third color [or raisins, candy, cereal, beans a third color etc.]
Experiment 1 – Building Organic Models [14 marks]
Background: The following functional groups learned in this course do not contain oxygen: alkane, alkene, alkyne. The following functional groups learned in this course do contain oxygen: amide, alcohol, ca
oxylic acid, aldehyde, ketone, ester, ether.
Materials
Remember you can use something other than marshmallows – anything you have at home – the items just have to have the right texture to build molecules below.
· toothpicks (or some other object for connecting, even a hair pin will work)
· ~10 small marshmallows of one colo
· ~20 small marshmallows of a second colo
· ~20 small marshmallows of a third colo
Procedure
1. [1 mark] Each of your marshmallows (or other material) will represent an element. Identify which element each of your materials will represent.
Ca
on atoms (C)
Hydrogen atoms (H)
Oxygen atoms (O)
2. Use your toothpicks and marshmallows (or other items) to build each of the organic molecules below.
3. As you work, complete the table below to provide the missing information for each organic molecule.
a. Identify the functional group (i.e. alkene, alcohol etc.)
. Provide the IUPAC name
c. Write the condensed formula
d. Write the molecular formula (CxHy)
e. Identify the bond type (i.e. single, double, triple)
4. Photograph each molecule and include the photo below.
Data and Analysis
1. [3 marks] Use your materials to build each molecule shown below. Then record the information indicated and photograph your molecules. Insert photos below. Click directly on the photo space holder to insert your photo.
Table 1: Functional groups without oxygen
Functional group
IUPAC name
Condensed formula
Molecular formula
Bond type
Photo of molecule
CH3 – CH = CH2
propyne
propane
2. [1 mark] As you add more bonds between ca
ons, what happens to the number of hydrogen atoms in the molecule? Comment in 1-2 sentences.
3. [1 mark per row = 4 marks] Use your materials to build each molecule shown below. Then record the information indicated and photograph your molecules. Insert photos below. Click directly on the photo space holder to insert your photo.
Table 2: Functional groups with oxygen
Functional group
Common name
IUPAC name
Structural formula
Photo of molecule
acetone
formaldehyde
isopropyl alcohol
OH
|
CH3 – CH – CH3
formic acid
4. [3 marks] How are a ca
onyl group and hydroxyl group similar? How are they different? Comment in 2-3 sentences.
Ca
onyl
Hydroxyl
What it looks like
Similarity
Difference
5. Ru
ing alcohol often contains a mixture of isopropyl alcohol and ethanol. The structural formula for isopropyl alcohol is provided in Table 2: Functional groups with oxygen above.
a. [1 mark] Draw the structural formula for ethanol.
. [1 mark] Which alcohol, isopropyl alcohol or ethanol, would you expect to be more soluble in water? Why? [HINT: consider the length of each alcohol].
Experiment 2 – Amines and Amides in Health [6 marks]
Procedure
1. Refer to the printed resources in the lab 6 assignments folder for additional information to complete this section.
2. Summarize the function of each molecule in 1-2 points.
Data and Analysis
1. [1 mark per row = 5 marks] Record all information below.
Molecule
Common name
Function
2. [1 mark] What is the key difference between the amine and amide functional group?
Experiment 3 – Hydrogen Bonding in Amines and Amides [3 marks]
Background: The presence of nitrogen in amines and amides results in polarity in these molecules. The polarity allows these molecules to take part in hydrogen bonding. The N-H bond is not as polar as the O-H bond thus the hydrogen bonding seen is not as strong.
The ability of amines and amides to take part in hydrogen bonding is important for maintaining the structure of proteins and DNA. Hydrogen bonding holds nitrogenous base pairs together in the DNA double helix.
Hydrogen bonding between neighboring amides
Hydrogen bonding between neighboring amines
Data and Analysis
1. [1 mark] Highlight/circle the hydrogen bonds in the nucleotide base pairing below.
[HINT: there are two hydrogen bonds]
2. [1 mark] Which nitrogenous base, adenine and thymine, contains an amide? __________________
3. [1 mark] What do you think would happen if hydrogen bonding did not happen in DNA?
CHEM 2701 – Lab 6 – Organic II Page 4 of 4
Lab 6 – Organic II – Amines and Amides in Health
CHEM 2701 – Pre-Health Chemistry II (standard)
Overview
• Amines and amides are abundant in nature.
• They are a major component of proteins and enzymes, nucleic acids, drugs and much more.
Amines
• A class of functional group containing a nitrogen (N) atom bonded to ca
on atoms (C)
Amides
• A class of functional group containing a nitrogen (N) atom bonded to a ca
onyl group (C = O)
Examples of Amines and Amides
Many drugs and hormones contain amines, amides or both.
Common name Description Molecular formula
Trimethylamine
Responsible for the odor of
otting fish
Putrescine
Very strong smell, found in
otting flesh; partially
esponsible for the odor of urine
and bad
eath
NH2 – CH2 – CH2 – CH2 – CH2 – NH2
Morphine Painkille
Heroin
More powerful than morphine.
Crosses the blood
ain ba
ier
more readily than morphine.
Cocaine
Stimulant made from the coca
plant. Causes large amounts of
dopamine to build up in the
ain. Feelings range from
sensations of energy and
alertness to i
itability and
paranoia.
Caffeine
Blocks adenosine receptors in
the
ain. Adenosine in the
ain
helps humans feel tired. When
adenosine receptors are
locked, you feel more alert.
Melatonin
A naturally occu
ing hormone
eleased by the pineal gland.
Triggered in darkness. Causes
drowsiness.
Urea
Crystalline compound; main
product in the
eakdown/metabolism of
proteins; excreted in urine
Dopamine
A hormone and
neurotransmitter. Role in motor
control, motivation and arousal.
Parkinson’s disease, a condition
esulting in “resting tremors” and
motor impairment, results when
the dopamine production
pathway in neurons is reduced.