Chemistry Option D

Functioning of Penicillin

1. There is a sterically strained beta lactam ring in the structure of penicillin

2. This ring opens up and binds and incapacitates

3. The transpeptidase enzyme which is responsible for forming the cross-linking protein chains in the bacterial cell wall

4. Because the cell wall is weak, the osmotic pressure of surrounding water causes it to rupture and die

Differences between Morphine and Diamorphine

1. Morphine features 2 hydroxyl groups whereas diamorphine has 2 ester groups

2. This makes diamorphine less polar than morphine

3. As a result, Diamorphine can cross the lipid blood-brain barrier more easily and rapidly (thus making it more potent)

Therapeutic index

The ratio between the Toxic Dose and Effective Dose for 50% of the population (TD50/ED50).

Therapeutic window

The range of dosage over which a drug causes a therapeutic effect without creating toxic side effects for 50% of the population

Effective Dose 50 (ED50)

Minimum dosage required to produce the desired therapeutic effect in 50% of animals

Lethal Dose 50 (LD50)

Minimum lethal dosage that causes death in 50% of animals; the lower the number, the more toxic the substance

Toxic Dose 50 (TD50)

A dosage that causes a toxic effect in 50% of the population.

Synergistic effect

A tyoe of drug interaction whereby moderate side effects of multiple drugs can cause a severe risk (eg. Aspirin and Alcohol causing stomach bleeding)

Drug bioavailability

the fraction of the administered dose that is absorbed into the bloodstream

Functioning of Aspirin

Aspirin works by:

1. Going to the site of pain or injury

2. Inhibiting the production of the prostaglandins molecule (synthesized by the COX enzyme) which is responsible for signalling pain to the brain

Effects of Aspirin

1. Mild analgesic (Pain reduction)

2. Antipyretic (Fever reduction)

3. Anti-inflammatory (Swelling reduction)

Opiates

Compounds that are derivatives of morphine and have similar physiological effects

Strong analgesics

Compounds that bind to the opioid receptors in the brain, thus blocking out pain signals from reaching the brain.

Blood-Brain Barrier

Lipid layer that separates the brain from the bloodstream

Antacids

1. Any substance, generally a base or basic salt, which neutralizes stomach acid so the pH level returns to the desired level

2. Used to relieve acid indigestion, upset stomach and heartburn

Side effects of Antacids

1. Production of CO₂ gas which causes bloating

2. Reduces phosphate concentration in stomach

3. Affects electrolytic balance

Functioning of Omeprazole

1. Omeprazole is a compound which binds and inhibits the gastric proton pump enzyme

2. Which is responsible for signalling to the stomach cells to secrete more acid

3. As a result, the secretion of HCl stomach acid is reduced for a prolonged period of time

Functioning of Ranitidine

1. Ranitidine is a compound that binds to the H2-histamine receptors on the stomach lining cells

2. It is responsible for signaling for the secretion of stomach acid

3. By binding to these receptors, Ranitidine blocks our histamines from binding to the receptors, thus preventing acid secretion for a short amount of time

Steps of viral infection

1. Capsid shel binds to cell receptors

2. Viral particles cross the membrane or inject their genome into cells

3. The viral genome gets translated and duplicated in the cell

4. Newly made viruses leave the cell to infect other cells

Functioning of Oseltamivir and Zanamivir

1. The compound goes to infected cells and binds to and inhibits the neuraminidase enzyme which is responsible in the budding process of viral release

2. This traps the virus inside the cell until it eventually dies

HIV

Human Immunodeficiency Virus

AIDS

Auto Immunodeficiency Syndrome

Why HIV is hard to treat

1. HIV rapidly makes new viruses and mutates

2. HIV can integrate its viral DNA in host cells and remain dormant

3. HIV is a retrovirus

Low Level Waste

Waste that contains low radioactivity and short half-life times

High Level Waste

Waste that contains high radioactivity and long half-life times

LLW disposal method

1. LLW is stored in a container and buried until its radioactivity is decayed

2. Then it is incinerated and disposed of

HLW disposal method

1. HLW is cooled down with water for many years

2. Then it can be recycled

Main type of environmental waste

Organic solvents

Common organic solvents

Benzene, Chloroform, Dichloromethane

Problems with Organic solvents

1. Toxic for the environment

2. Highly flammable

3. Creates vapour that contributes to the greenhouse effect

Green chemistry alternatives

1. Solvent free reactions

2. Fewer step synthesis (atom economy)

3. Enzyme catalysts

   1. Such as Shikimic Acid which is a precursor to Oseltamivir and can be produced from genetically engineered E. Coli

Taxol

A drug commonly used to treat different forms of cancer

Chiral Auxiliary

An optically active substance that is temporarily incorporated into an organic synthesis so that it can be carried out asymmetrically with the selective formation of a single enantiomer

What is used to measure the purity of Taxol

Polarimeter

Functioning of Taxol

1. Taxol binds to the tubulin of rapidly multiplying cancer cells

2. This prevents cells from undergoing mitosis

3. Which eventually leads to cell death from killer T cells

Radiotherapy

The use of radioactive substances to cause genetic errors in cancerous cells to kill cancer cells

Side effects of radiotherapy

1. Hair loss

2. Nail damage

3. Secondary cancer

Targeted alpha therapy (TAT)

1. Used for treatment in cancers that have spread

2. Alpha emitting nuclides (Ac-225) are attached to antibodies that target the spread cancer cells

3. The alpha particles are released and damage the genetic material of cancer cells, killing them

Boron neutron capture therapy

1. Used in the treatment of neck and brain cancers

2. Non radioactive boron-10 is taken and accumulates at cancer cells

3. Patient is irradiated with neutrons that are captured by boron atoms, forming boron-11

4. Boron-11 is an alpha emitter with kills the cancer cells

Gamma radiation therapy

Uses low doses of gamma radiation multiple times to target a specific cancerous region

Reasons for using Tc-99 in radiodiagnostic

1. The compound is versatile and can be incorporated into many compounds

2. It has a perfect half-life such that it is long enough for imaging but short enough to not cause prolonged radioactive exposure

3. It releases gamma rays and electrons which are not very harmful

Functioning of fractional distillation

1. continuous evaporation and condensation

2. increased surface area in column helps condensation

3. most volatile component collected first

Functioning of simple breathalyzer

1. A glass tube filled with acidified potassium dichromate is blown into

2. If alcohol touches the dichromate, it reduces, causing the solution to turn green

Functioning of fuel cell breathalyzer

1. Ethanol is oxidized at the platinum anode

2. Electrons flow through the external circuit, creating current

3. The higher the alcohol concentration, the higher the current

Reduction: O₂ + 4H⁺ → 2H₂O
Oxidation: C₂H₅OH + H₂O → CH₃COOH + 4H⁺ + 4e^-

Gas chromatography

A detection technique where the sample is evaporated and carried by an inert gas to create bands of vapor which can be analyzed on a chromatograph.