Sexual Reproduction in Human

It took me quite a while to memorise the diagrams, but now I can identify the parts of a male and female reproduction system , and recite the menstrual cycle. I was interested to find out more about embryonic stem cells, so here:
It refers to extracting the inner cell mass, killing the embryo.

Embryonic stem cells are distinguished by two distinctive properties:
their pluripotency, and
their ability to replicate indefinitely.

ES cells are pluripotent, that is, they are able to differentiate into all derivatives of the three primary germ layers: ectoderm, endoderm, and mesoderm. These include each of the more than 220 cell types in the adult body. Pluripotency distinguishes embryonic stem cells from adult stem cells found in adults; while embryonic stem cells can generate all cell types in the body, adult stem cells are multipotent and can only produce a limited number of cell types. Human ES cells measure approximately 14μm while mouse ES cells are closer to 8μm .

This means that embryonic stem cells are very versatile. It makes it useful for cancer patients, but the argument is that killing a life for this is wrong.

This is where science and morals clash. Sometimes the most powerful is the most innocent. I do not support embryonic stem cell research. This is because this may lead to scientists thinking that as long as the baby does not feel the pain, it is alright and may lead to even more morally questionable methods being developed. Lab babies are possible, but not without two human parents. Thus the parents have the right to refuse. We have the choice to refuse this. Even if cancer patients are dying we whould not be exchanging another's life for theirs. It goes against human rights. I think humans need to rethink respect for each other.

Reproduction is an interesting subject. How creation is done, a unique being is formed, but at the same time, somewhere in the world, someone ones to take it apart in the name of science.

Enzyme that could boost super long-term memories

Increased levels of one natural brain enzyme supercharge rat memories, a study suggests. And it's not just new, short-term memories. The enzyme -- called PKM-zeta -- gives rats better recall of old remembrances. In a number of recent studies, researchers showed that they could make rats forget a range of old learned behaviors by blocking the protein in the brain. Rodents with too little PKM-zeta, for instance, didn't know to avoid liquids that had made them sick in the past. On the other hand, when the scientists increased this enzyme, rats that had this could remember unpleasant tastes that they had been given to experience 4 days before better than control rats without the increase. However, how this enzyme helps the retrieval of this memory is unknown. PKM-zeta seems to be a brain gardener. The enzyme waters and arranges neurons, keeping the connections between these memory-storing cells flowing. Even momentary disruptions to PKM-zeta can obliterate many long-term memories seemingly for good. This is a very powerful enzyme that could help Alzheimer's or trauma victims to control their memory. I feel that this could be an artificial boost that is very powerful for people who need powerful memory, like soldiers, old people or young children.

Brief intro to bonding

A covalent bond is a form of chemical bonding that is characterized by the sharing of pairs of electrons between atoms, and other covalent bonds. In short, the stable balance of attractive and repulsive forces between atoms when they share electrons is known as covalent bonding. Instead of giving electrons, the atom merges its electrons so that they form 2 or 8. To read more go to http://www.visionlearning.com/library/module_viewer.php?mid=55

What I have been learning in Science Class

In Science class, I have been learning about the theory about atoms-what they are made of, their electronic configuration and so on. Atoms are interesting to learn about as they make everything up on earth. Even earth itself.

Firstly, we learnt about the anatomy of an atom. An atom is said to contain a dense nucleus of protons and neutrons surrounded by electrons in orbitals.

Only the electrons are involved in chemical reactions. Electrons are tiny particles that carry a negative charge. They move in orbits around the nucleus. There are rules to orbiting.

1. The electron shell closest to the nucleus can only have up to two electrons.

2. Subsequent shells can have up to eight electrons.

3. For any atom belonging to an element after calcium(Ca), the third shell onwards can hold up to eighteen electrons.

The protons are fixed. They carry a positive charge. Atoms of an element carry a specifically defined number of protons. The neutrons have no charge. They are said to be neutral.

In chemical bonding, electrons interact. There are two kinds of bonding, chemical and covalent. In chemical bonding, an atom loses its electrons to another atom so that they both reach a stable electronic configuration of 2 or 8. Then they can form a compound, like sodium chloride or magnesium oxide. More will be shown in the next post.

Welcome and Introduction

Welcome to this blog, I am Timothy Leong. As of 2011 I am in 2O3, Hwa Chong Institution. This is a Science E-portfolio, a platform whereby I can post matters that are related to Science, e.g lessons, new advancements in technology, etc. This is mostly a blog of information-bites, which are (small)but interesting posts.

Welcome again.

Technology- the all-new stretchy solar cells

This is a stretchable solar cell. It can withstand stretching up to 30% when pulled from both ends. This could lead to robotic skin that are durable and can pick up sensory details from the environment.The device's electrode is made from a unique liquid metal called eutectic gallium-indium, which conforms to a surface as it lengthens and relaxes. "Eutectic" refers to a mix of elements or compound that remains liquid at lower temperature than either of its components does alone.

This is good as solar cells eliminate the need for a battery cell or charging. Also, its stretchability is good as it can withstand damage from wear and tear like scratching, grazing... this is not commercially available yet, but I think it will be very useful when it comes out. I think it can be used for:

- Robots in space

- Shopping centre walls

- Cars