21st January 2014
10.00 p.m. to 10.30 p.m.
Biotechnology Tutorials (Handouts)
What I did:
Just last week, Dr Tan completed a lecture on Prokaryotic cells, following up after the lecture on Eukaryotic cells. As a result, I also decided to follow up on my research on these two types of cell structures as it was truly tempting to make two English Language Independent Learning Logs on science-related articles. Like the previous ILO, I also started of this new research with wikipedia before digging into more content-based sites.
What I have learnt:
After doing some read-up, I found out that prokaryotic cells or prokaryotes were as, if not more interesting than eukaryotes as they were much more ‘microbial’ both in size and in meaning. Prokaryotic cells simply referred to bacteria and they are very simple and small in structure. Talking about small, they really are small, with a diameter ranging from 0.2-2.0 micrometers and the length ranging from 2.0-8.0 nanometers.
Things I have learnt about Prokaryotes:
Eukaryotic cells are cells that do not have specialized organelles to perform necessary life functions, which meant they have a large cytoplasm which perform all of the cellular functions. They have different shapes which are also a component of the scientific name. There is the bacilli, which are rod-shaped, the spirilla which are corkscrew in shape, the cocci which are spherical and the vibrios which are curved rods. These shapes are the characteristic shape of the cell. Below are the different parts of a prokaryotic cell.
Cell membrane: Phospholipid bilayer with proteins interspersed (permeability barrier)
Cell wall: Porous and peptidoglycan which maintains characteristic shape of cell
Cytoplasm: Contain the nuclear region and ribosomes to perform life functions
Nucleoid: Consist mainly of DNA molecules storing genetic information codes
Plasmid: Small circular double stranded DNA carrying advantageous genes
Ribosomes: Synthesize proteins
Glycocalyx: Polysaccharide layer for attachment to surfaces and protection
Flagellum: Movement of cell in response to stimuli
Fimbria: Short protrusions on cell surface to adhere to environment
Pilus: Hair like hollow projection for exchange of genetic material