Wednesday, March 25, 2009


While taking a practice GRE style subject test, I stumbled upon a question asking which of the organisms is not photosynthetic. My choices were cyanobacteria, diatoms, dinoflagellates, foraminifera, and rhodophyta.

I selected diatoms, because from what I remembered I thought that they were creatures that lived in rocky substances or soils, and have a crystallin look to the organism.

A first look at the organism on the left does not reveal anything that would lead it to be photosynthetic, but it is. They do indeed have chloroplasts and are photosynthetic.

The other answers that eliminated are cyanobacteria, dinoflagellates, and Rhodophyta. I eliminated cyanobacteria because I knew that organism got its name from having a cyan color, predominately because it is very photosynthetic. It is a cool organism that is a bacteria and photosynthetic at the same time. I also eliminated dinoflagellates because I distinctively remember that organism being photosynthetic. Under a light microscope it is easy to see the green color from the chloroplasts withiin that organism. The last organism that I eliminated was Rhodophyta. I remembered that this group was a reddish brown algae, and I believe all algae is photosythetic.

I was left with diatoms and Foraminifera. So what exactly is Foraminifera? They are a group of amoeboid protists that undergo a process where they take in algae, and then can temporarily use the plastids for photosynthesis and can be used by the Foraminifera. So in the end, the "forams" are not necessarily photosynthetic in it themselves, but they can use photosynthesis through algae that they take in.

I obviously did not know all of this come time of the question, but the more I look at it, it seems as if it is somewhat of a confusing question, because the "forams" at certain points are photosynthetic, but without the algae they are not. Someone that knows a lot about all five of the organisms in the question might nail this problem, but others may end up arguing with it.

Tuesday, March 24, 2009

Where does energy come from?

"The chemical reaction involved in respiration are virtually identical between prokaryotic and eukaryotic cells. In prokaryotic celss, ATP is synthesized primarily on the inner plasma membrane. Where are the corresponding reactions likely to occur in eukaryotic respiration?"

The answer to this question is on the inner mitochondrial membrane. Adenosine Triphosphate (ATP) is a high-energy molecule that stores the energy needed to accomplish just about every form of work. ATP is generated by food that we eat being oxidized. The energy taken from this process forms ATP.

Mitochondira are where ATP is manufactured. It is formed from the energy stored in food. Atp is produced through a pracess called respiration, which uses oxygen to generate energy. This process can be used to rapidly produce ATP used in the body.

Saturday, March 14, 2009

Nix the ban on stem cell research.

Not that the restrictions on stem cell research set up during the Bush administration were so much a ban, but many of the restrictions put in place were removed by way of Obama's recent executive order. The executive order allows the federal government to fund embryonic stem cell research. The major form of stem cell research previously involved use of induced pluripotent stem cell (iPSC) lines (which are derived most commonly from adult somatic cells instead of the controversy-laden embryonic lines).

Obama recognized that this switch in direction demands a certain level of ethical discretion, and as such required the NIH to develop the rules regarding medical ethics involved in the process of obtaining embryonic stem cell lines. Supporters of the executive order see promise for potentially treating some of human kind’s most devastating diseases and disorders. Some religious officials, however, disagree with the way Obama is going about furthering stem cell research. Surprise: people agree and people disagree. I’d personally like to explore some of the middle-ground options before completely nixing the conservative restrictions previously in place regarding the matter. I’m thinking it’s about time for me to do some google-searches on the practical differences between the use of iPSC versus embryonic stem cell lines. I'm also interested in seeing what others think about the policy shift.