b) Histamine – amine groups

a)  Give the chemical formula for this compound.

C5H9N3

b) Circle the amine functional groups in histamine.

(circled in red on diagram)

c) Which part (or parts) of the molecule make the compound water-soluble?

The amine groups contribute to the solubility of the molecule due to the highly electronegative nature of nitrogen atom that makes the molecule polar and so able to interact with the polar water molecules.

2. Antihistamines are widely used drugs for treating symptoms of allergies caused by reactions to histamines compound. This class of drugs competes with histamines, occupying receptor sites on cells normally occupied by histamines.

a) Give the chemical formula for this compound.

C16H21N3

b) What similarities do you see between this structure and that of histamine that would allow for antihistamine to compete with histamine.

Ethylamine moiety (-CH2-CH2-N-)

3. Consider this statement. “Drugs can be broadly classed into 2 groups: those that produce a physiological response in the body and those that inhibit growth of substances that cause infections.” 

Drugs that illicit physiological response:

Estrogen, amphetamine, morphine

Drugs that inhibit growth of infection-causing substances:

Penicillin, aspirin, antibiotic (Keflex)

4. Herbal or alternative medicines are not regulated in the same way as prescription or OTC medicines. In particular, the issues of concern are identification and quantification of active ingredient, quality control in manufacture, and side effects when herbal remedy is used in conjunction with another alternative/prescription medicine.

a) What do you think is the evidence from herbal supplement manufacturers that address these issues?

All prescription and non-prescription are regulated in the US by the Food and Drug Administration (FDA). However, herbal and alternative medicines are treated more like special foods, and not considered as drugs. Therefore herbal and alternative medicines will not be put under the same strict safety and effectiveness measurements as prescription or OTC medicines. Prescription or OTC medicines are considered unsafe until proven safe, whereas herbal and alternative medicines are considered safe until proven unsafe. Hence, herbal supplement manufacturers are not required to put their products under clinical trials to find potential risks and interactions with drugs or other substances.

b) Do  you know anything about Singapore’s legislation on the topic?

Under the health science authority (HSA) of Singapore, the requirements of drugs in Singapore are as follows:

(a)  Traditional medicinal materials do not contain any substances controlled under the Poisons Act and other prohibited substances such as Pangamic acid including its salts, Danthron, Suprofen including its salts and Rhodamine B.

(b)  The heavy metal contents of the traditional medicinal materials do not exceed the following limits: Arsenic (5 ppm), Copper (150 ppm), Lead (20 ppm) and Mercury (0.5 ppm).

(c)  The labels and packaging materials of the traditional medicinal materials (if any) do not stipulate any of the 19 diseases/conditions specified in the Schedule of the Medicines (Advertisement and Sale) Act, namely, blindness, cancer, cataract, drug addiction, deafness, diabetes, epilepsy or fits, hypertension, insanity, kidney diseases, leprosy, menstrual disorders, paralysis, tuberculosis, sexual function, infertility, impotency, frigidity, conception and pregnancy.

SPMS Tutorial Room 7, 1.30 PM, 2 hours

Team members who attended and members who missed the meeting with clarification on their reasons for missing it.

All members in attendance.

Topics discussed (briefly)

1. Complete LAMS assignment
2. Discussion on blog site and video progress

Tasks to be done before the next meeting and who has been assigned/agreed on doing them.

1. Finish up individual parts and consolidate everything on Google Docs by 2/04/2017.

Problems arising if any

Nil.

Plan of action

1. Complete individual blog content by 2/04/2017 on Google Docs (Everyone)
2. Think about content for the videos from individual content (Everyone)

Image Reference:

Improve your meeting ROI. (2017). 71.0 KB. Retrieved February 22, 2017, from http://www.workboard.com/master-team-meetings/. 

LT 23, 3.00 PM, 30 minutes

Team members who attended and members who missed the meeting with clarification on their reasons for missing it.

All members in attendance.

Topics discussed (briefly)

1. Update on progress of the blogs
2. Brief discussion on content for each part of the blog

Tasks to be done before the next meeting and who has been assigned/agreed on doing them.

Nil. Just progress on the blog content on individual parts. (Everyone)

Problems arising if any

Nil.

Plan of action

1. Complete blog content by 29/03/2017

Image Reference:

Improve your meeting ROI. (2017). 71.0 KB. Retrieved February 22, 2017, from http://www.workboard.com/master-team-meetings/. 

LT 23, 3.00 PM, 15 minutes

Team members who attended and members who missed the meeting with clarification on their reasons for missing it.

All members were present.

Topics discussed (briefly)

1. Discussion on the topic to be chosen for the blog.
2. Briefly discussed the required tasks of the blog.

Tasks to be done before the next meeting and who has been assigned/agreed on doing them.

1. Email Professor Felipe on chosen topic (Consequences of Climate Change) – (Junnesha)

Problems arising if any

Nil.

Plan of action

1. Email Professor Felipe on chosen topic (Consequences of Climate Change) by 17/02/2017.

Image Reference:

Improve your meeting ROI. (2017). 71.0 KB. Retrieved February 22, 2017, from http://www.workboard.com/master-team-meetings/. 

LT 23, 3.00 PM, 30 minutes

Team members who attended and members who missed the meeting with clarification on their reasons for missing it.

All members in attendance.

Topics discussed (briefly)

1. Confirmation from Prof about the chosen topic (Consequences of Climate Change)
2. Discussion of tasks required for each part of the blog (intro, explanation and references, etc.)
3. Discussed and assigned parts of the blog to members
4. Improve aesthetics of blog and add required tabs

Tasks to be done before the next meeting and who has been assigned/agreed on doing them.

1. Improve aesthetics of blog and add required tabs (Junnesha & Johanna)

Problems arising if any

Nil.

Plan of action

1. Improve aesthetics of blog and add required tabs (by 1/3/2017)

Image Reference:

Improve your meeting ROI. (2017). 71.0 KB. Retrieved February 22, 2017, from http://www.workboard.com/master-team-meetings/. 

Answer: When you stretch the plastic bag, the plastic bag narrows and “necks down”. The molecules of the plastic bag will become aligned to each other in a parallel manner and in the direction of the pull. When you alter the molecule alignment, the process is not reversible and will eventually break when it is pulled for a continued period.

However, in the case of the paper, the paper does not react the same way as the plastic bag when it is pulled. When it is pulled, the paper instead tears instead of stretching to any extent. This is because of the cellulose molecules that are held far more rigidly in place in paper that cannot be freely aligned such as the molecules of the plastic bag.

2) When Styrofoam packing peanuts are immersed in acetone (the primary component in some nail-polish removers), they dissolve. If the acetone is allowed to evaporate, a solid remains. The solid still consists of Styrofoam, but now it is solid and much denser. Explain. Hint: Remember that Styrofoam is made with foaming agents.

Answer: Styrofoam packing peanuts are made of 98% air. When it is immersed in the acetone, the acetone will allow the gases of the foaming agent to escape, leaving behind a denser Styrofoam piece. Therefore, it is more solid and much denser because the gases have been removed.

3) Consider Spectra, Allied-Signal Corporation’s HDPE fiber, used as liners for surgical gloves. Although the Spectra liner has a very high resistance to being cut, the polymer allows a surgeon to maintain a delicate sense of touch. The interesting thing is that Spectra is linear HDPE, which is usually associated with being rigid and not very flexible.

a. Suggest a reason why branched LDPE cannot be used in this application.

b. Offer a molecular level reason for why linear HDPE is successful in this application.

Answer:

a. Branched LDPE are not packed in a linear or crystal structure. This means that there is less intermolecular forces as the instantaneous-dipole induced-dipole attraction is less. Therefore, LDPE is usually lower in tensile strength but higher ductility. Therefore, it cannot be used in surgical gloves as it is not strong enough and may be too “flimsy” like a plastic bag.

b. Linear HDPE has a low degree of branching and is mostly made up of linear molecules where intermolecular forces are stronger than highly branched polymers. Therefore, HDPE has high tensile strength. However, in order for it to be flexible enough to be used in surgical gloves, only a thin liner of HDPE is used. This ensures the gloves are strong enough to be resistant to cuts and at the same time, flexible enough for use as gloves (fit into surgeons hands, stretched, etc.).

4) A Teflon ear bone, fallopian tube, or heart valve? A Gore-Tex implant for the face or to repair a hernia? Some polymers are biocompatible and now used to replace or repair body parts.

a. List four properties that would be desirable for polymers used within the human body.

b. Other polymers may be used outside your body, but in close contact with it. For example, no surgeon is needed for you to use your contact lenses—you insert, remove, clean, and store them yourself. From which polymers are contact lenses made? What properties are desirable in these materials? Either a call to an optometrist or a search on the Web may provide some answers.

c. What is the difference in the material used in “hard” and “soft” contact lenses? How do the differences in properties affect the ease of wearing of contact lenses?

Answer:

a. (1) Non-toxic, (2) Lack of reactivity in body fluids, (3) Lack of solubility in body fluids and (4) stability over time of intended use. We can also consider the costs and the ease of implantation.

b. In the market, there are different types of contact lenses that are made of different kinds of polymers. Polymethyl methacrylate (PMMA), one of the earliest polymers used for rigid gas permeable lenses, is structurally similar to Lucite and plexiglas. Silicone-acrylate materials now are more commonly used under trade names such as Kolfocon. Newer rigid gas permeable (RGP) polymers contain fluorine: fluoro-silicone-acrylate polymers and fluoro-silicones. Polymacon (38% water) is typical of the polymers used for soft lenses and is a polymer of 2-hydroxyethyl methacrylate (HEMA). Other methacrylates include hioxifilcon (48% water) and methafilcon (55% water) or even lidofilcon (70% water). Manufacturers’ websites are good sources of information. Desirable properties include being nontoxic, permeable to oxygen, comfortable to wear, and inexpensive. Also desirable is the ability to conform to the shape of the eye and to be easily cleaned (if not disposable).

c. Polymethyl methacrylate (PMMA) are typically used in hard contact lenses. This is a rigid non-gas permeable plastic which may reduce the oxygen supply to eyes when it is used. On the other hand, soft contact lenses are made of silicone, a flexible and gas permeable plastic. This allows sufficient oxygen to reach the eye, making it more comfortable and less painful on the eyes.

2a) LDPE cannot be used in this application because it does not have the required strength.

2b) The molecules of HDPE must line up in a way that produces the required strength. Using a thin liner of HDPE allows sufficient flexibility.

3)  When the piece of plastic is stretched, the strip narrows and “necks down.” The molecules become aligned parallel to each other and in the direction of the pull. This alteration of the three-dimensional structure is not reversible, and if the pulling continues, the plastic breaks. When the same pulling force is applied to a piece of paper, the paper tears rather than stretching to any significant extent. The cellulose molecules in paper are held far more rigidly in place, and are not free to become aligned.

4a) The benefits for polymers intended for use in the body should far outweigh any risks. The two main properties are (1) stable over time of intended use and (2) non-toxic. Other factors to consider are low cost, lack of solubility in body fluids, lack of reactivity in body fluids, and the ease of implantation.

4b)  Several different types of contact lenses are on the market and each uses a different type of polymer. Polymethyl methacrylate (PMMA), one of the earliest polymers used for rigid gas permeable lenses, is structurally similar to Lucite and plexiglas. Silicone-acrylate materials now are more commonly used under trade names such as Kolfocon. Newer rigid gas permeable (RGP) polymers contain fluorine: fluoro-silicone-acrylate polymers and fluoro-silicones. Polymacon (38% water) is typical of the polymers used for soft lenses and is a polymer of 2-hydroxyethyl methacrylate (HEMA). Other methacrylates include hioxifilcon (48% water) and methafilcon (55% water) or even lidofilcon (70% water). Manufacturers’ websites are good sources of information. Desirable properties include being nontoxic, permeable to oxygen, comfortable to wear, and inexpensive. Also desirable is the ability to conform to the shape of the eye and to be easily cleaned (if not disposable)

4c) As mentioned in the previous part, hard contact lenses are typically made of PMMA, a rigid non-gas permeable plastic. The soft contact lenses that replaced them are made of silicone, which is flexible and allows oxygen to reach the eye. Because of these properties, the soft lenses tend to be more comfortable.

1. Mammoth Cave National Park in Kentucky is in close proximity to the coal-fired electric utility plants in the Ohio Valley. Noting this, the National Parks Conservation Association (NPCA) reported that this national park had the poorest visibility of any in the country.

• The NPCA reported “the average rainfall in Mammoth Cave National Park is 10 times more acidic than natural.” From this information and that in your text, estimate the pH of rainfall in the park.
• What is the connection between coal-fired plants and poor visibility?

• Coal-fired plants release sulfuric acid, which forms tiny droplets. These droplets are suspended in air, forming aerosols which do not absorb sunlight. Instead, aerosols reflect sunlight and reduce visibility.
• Since the rainfall is 10 times more acidic than natural, it contains 10 times H⁺ ion concentration. The pH, therefore, falls by 1. The average pH of rain is 5-6, so the pH of rainfall in the park is 4-5.

2. Here are examples of what an individual might do to reduce acid rain. For each, explain the connection to producing acid rain.

• Hang your laundry to dry it.
• Walk, bike, or take public transportation to work.
• Avoid running dishwashers and washing machines with small loads.
• Add additional insulation on hot water heaters and pipes.
• Buy locally grown and locally produced food.

Reducing acid rain is possible by reducing the electricity and vehicle usage. Electricity generation in power plants requires the burning of fossil fuels and coal, same as vehicles which run on fossil fuels. The combustion of fossil fuels and coal emits SOx and NOx gases which could react and cause the acid rain. Therefore, reducing both usage could reduce acid rain. The following activities could reduce acid rain by reducing electricity and vehicle usage.

• Hanging laundry to dry it reduces the electricity used in a household.
• Walking, cycling or taking public transportation reducing the usage of private vehicles.
• Avoid running dishwasher and washing machines with small loads to reduce the electricity usage.
• Adding additional insulation prevents heat loss in water heaters and pipes, therefore it reduces the electricity used.
• Buying locally grown and produced food cuts the transportation process in buying food from other places which means avoiding more vehicle usage.

3.

• Name three observable properties generally associated with acids and bases.
• Give names and chemical formulas for five acids and five bases.

4. The concerns of acid rain vary across the globe. Many countries in North America and Europe have websites dealing with acid rain. Either search to locate one (“Canada, acid rain”) or use these links to websites in Canada, the UK, or Europe. What are the issues in Singapore? Does the acid deposition originate outside or inside the Singapore’s borders?

URLs:

http://www.ec.gc.ca/

http://www.ukawmn.ucl.ac.uk/

http://www.grida.no?

http://www.nea.com.sg?

Just like any other countries, Singapore faces the threat of acid rain, especially since Singapore has low basic content of soil, the neutralization of acidity is low. The acid deposition itself originates outside and inside Singapore. One of the transboundary sources is the forest fires in neighbouring country, Indonesia, which release high level of carbon dioxide and sulfur dioxide which react with water producing carbonic acid and sulfuric acid. The industry and urban areas in Singapore also produce gases which cause acid rain.

The effects of acid rain in Singapore are seen in the increase of acidity of streams and the higher risk of extinction faced by native species in Singapore. The number of several Singapore native species such as Singapore freshwater crab have declined drastically.

Fat-soluble vitamins are non-polar so as to interact with non-polar lipid molecules while water-soluble vitamins would have polar properties enabling interaction with polar water molecules. Similar polarity properties with the solvents are important to allow the vitamins to dissolve and be transported to the respective regions within the body.

This phenomenon is also known as “thermal inertia”. This is due to energy being emitted as longwave radiation because the earth and its atmosphere has characteristic temperatures. The Earth stays hot even after energy leaves it’s surface because it’s still emitting the energy it had absorbed earlier.

2. Decide and explain whether the statement, “This winter has lowered my concerns about global warming”, is correct or incorrect. Explain.

This statement is incorrect as increasing snowfall is actually caused by warmer temperatures due to global warming because more evaporating water from water bodies on earth was available for precipitation.

Cold weather is also due to air moving from higher pressures to lower pressures around the world. Artic oscillations push cold wet and snowy weathers to parts of the earth with lower pressures, resulting in colder winters.

3. One of the first radar devices developed during the WWII used microwave radiation of a specific wave range that triggers the rotation of water molecules. Why was the design not successful?

Absorption of microwave radiation by water in the atmosphere interferes with the detection of the intended object.

4. Now that you have studied air quality, stratospheric ozone depletion and global warming, which do you believe poses the most serious problem for you in the short run and in the long run?

In the short run, air quality is believed to pose the most serious problem as it affects the most important human survival necessity, that is to breathe. For example, air pollutions like the haze causing a surge in PSI values would lead to respiratory problems or even death.

In the long run, global warming is believed to pose the most serious problem as it is destructing the planet we all live in. For example, the melting ice caps causing a rise in sea levels leads to floods and droughts. Also, extreme weather conditions and excessive deforestation affects our land and would eventually lead to our planet being unsuitable for human survival.