Weekly Reflections - Week 4

I directly go for the week 4 reflections because this is my first class because I’m a second intake students. So this would be my first reflection of this course subject that is Cellular and Developmental Biology. So, what was I study in this week ? Of course it’s about Cell Theory about prokaryotic and eukaryotic cell and also virus along with their characteristics. What is remarkable about this week topic is that the cells itself where a bunch of scientists were tried to discover the origin and theory about that cells.  Scientist that involved in the discovery of cell is Robert Hooke, Anton van Leeuwenhoek, Matthias Jakob Schleiden, Theodore Schwann and last but not least is Rudolph Carl Virchow. All this scientists worked hard to discover and study about cells and as a results they come out with different kinds of theories. So, is cell living cells or not? That is some of  an exceptions to cell theory were discovered by the scientists. They found that mitochondria and chloroplast is a subcellular organelles which carry info and replicate independently but differ with multinucleated single cell such as muscle cells and fungal hyphae. Suddenly earth evolved and introduced modern cell theory which has additional of 4 statement. The first is the cell contains hereditery information which is passed on from cell to cell during cell division. Secondly, all cells are basically the same in chemical composition and metabolic activities. Thirdly, all basic chemical and physiological functions are carried out inside the cells such as movement, digestion, homeostasis and else. Last but not least, cell activities depends on the activities of subcellular structures within the cell such as organelle, nucleus and plasma membrane.  At the same time, I found that there are two basic types of cells that is Prokaryote and Eukaryote cell where both of this cells are living things. Prokaryotic cells were divided into two domain that is Eubacteria and the other one is Archaeabacteria. On a eukaryotic cells only has one domian that is Eucarya. More than that, I’ve identified that prokaryotic cell structure and it’s functions including cell wall that provides a rigid framework that support and maintain its shape and keeps it from bursting under hypotonic conditions which is known as their protection, capsules that slime-like layers that surrounds the cell wall, bacterial cell membrane, nucleoid region that contain genetic material genes that is DNA, flagella to moving the cell through a liquid environment and respond to food or poison, pili hairlike structures play a role in exchange og genetic information, endospores that is produced by certain bacteria when starved and can germinate under favorable condition, plasmids are extra-chromosomal DNA,small and circular that are often have genes that code for catabolic enzymes,genetic exchanges and for antibiotic resistance, ribosomes as a workbench for protein synthesis that is receive and translate genetic instructions for the information of specific proteins.

Next, Dr. Parameswari also tought me about viruses that is including prions and also viroids. What I learned about viruses is not a living things because it is only can survive in a host cell. Without a host cell, viruses are nothing. This is because viruses only consist of two major parts that is protein coat alled capsid and hereditary material which is DNA or RNA. Unfortunately, when these viruses found a host, they can be infect animals, plants, human and even bacteria. There are two types of cycle included in their reproductive  cycle in two days which is Lytic Cycle and also Lysogeny Cycle. This viruses can be classified according to their genetic material, shape, symmetry of the capsid, presence or absence of the envelope and the type of the host they selected.  I also got that viruses that infect bacteria is called bacteriophages. What i knoew about prions is an infectious agent that is composed primarily of protein and propagate by transmittinga mis-folded protein state known as abnormal prion proteins. Prions usually infections in both humans and animals directly causes some diseases including Alzheimer and Parkinson.  Apart of prions, there is also viroids which is a small circular RNA molecules without a protein coat and it is typically infect plants that lead to some diseases that losses in agriculture horticulture worldwide.

At the end of this week lecture, Dr. Paramesari gave us an activity in the class on this topic which is doing a Venn Diagram on differences and similarities of prokaryote and eukaryote cells. Not only that, she also ask each group to do some flyers of Most Wanted and Unwanted Bacteria. I did really loves an activity after a lecture as wall as it can tougher and also sharpen our understanding on every topics.