How does oil & dirt get washed away with soap?Written by Dr. George Grant
We use soap each day in our lives in form of detergents, shampoo, shower crème, hand soap or bar soap. We are so used to using soap that we rarely stop and wonder how this wonderful compound manages to help us clean ourselves day after day. Have you ever thought about what would happen if there were no soap? How else can we rid dirt off our bodies or our clothes?
Most of time, dirt comes in form of grease or oil which sticks itself onto surfaces and will not come off if only water is just used. This is because oil and grease are non-polar, which means that oil molecules are not charged and therefore are not attracted to polar substances such as water. Because of this, oil tends to stick with its own molecules or other non-polar substances.
On other hand, water is a polar substance which is made up of one positive and one negative charge, and therefore is a fragmented substance. With this, water dissolves salt easily because salt is made up of charged ions in which positive charge will be attracted to negative ions in water.
Due to fact of nature of oil and water, you will see that oil will not dissolve in water but remain clustered on surface. Also, oil and grease will stick onto plates and cutlery during cleaning, and no amount of water can completely remove it. That’s when soap comes in. All it takes is just one layer of soap with water and oil will be removed. How does this happen?
Well, soap is a unique substance of potassium fatty acid salts, produced through a chemical reaction called saponification. Its molecules are made up of a hydrocarbon chain, which is non-polar, as well as a carboxylate molecule which is polar. Therefore, non-polar part of soap – hydrocarbon chain, is not attracted to water but to oil (lipophilic). On other hand, carboxylate molecules which are negatively charged, are attracted to positively charged water molecules (hydrophilic).
The fertilization process and implications of test tube babiesWritten by Dr.Richard Waller
Through wonders of science, infertile couples who were previously unable to bear children, due to reasons such as blocked fallopian tubes, low sperm count, low egg quantities or advanced age of mother, are now able to conceive through in-vitro fertilization. The results are babies known as test-tube babies which are technically conceived outside womb.
In a natural scenario, conception of a baby occurs when ovum, travels from ovaries, through fallopian tube to be fertilized by sperm of father during sexual intercourse. From this point on, fertilized egg will travel down towards uterus and during process division of cells will occur until it reaches its final destination at wall of uterus. However, in cases of block fallopian tubes, eggs are unable to travel from ovaries to uterus and conception cannot happen.
Developed in United Kingdom by Dr. Patrick Steptoe and Dr. Robert Edwards, process of in-vitro fertilization involves removing eggs from ovaries of mother and combining them with sperm of father in a lab environment. The fertilized egg is then placed back into uterus of mother after 3 to 5 days and will remain there to grow till birth. Because of low success pregnancy rate of this procedure, a few eggs are placed in uterus to increase odds of success. With this process, statistics have shown that rates of multiple births have increased where 24 percent of in-vitro fertilization births have produced twins.
The first test-tube baby, Louise Brown, who was born on 25th July 1978, marked hope for other infertile couples to have a baby through this procedure. However, many others were concerned about ethical issues surround this. One major area of concern was fact that as egg is located outside womb for a few days while cells multiplied before being put back inside uterus, health issues affecting this baby is unknown. Indeed, research has been shown that test-tube babies have a higher chance of birth defects and low birth weight, and researchers still have not been able to determine reason for this.