Chlorophyll and questions?, page 1

Originally posted by Cearbhall
Chlorophyll is the basis of all life! Give it up for chlorophyll. Without it nothing on this planet would survive. Plants are awesome indeed. They support and nuture this world and we need more. Plant a tree and contribute please.

While chlorophylls role is certainly acknowledged, and being a vegetarian, I am all for plants as well. However believe it or not, most of the planets photosynthesis is not performed by plants, rather it's performed by photosynthetic microorganisms, so give it up for pond scum!!

My question is why didn't mammals or other creatures with hemoglobin, evolve like plants? Why hemoglobin?

I am not sure that I can answer this question the way you would like, but I do have some interesting info. Hemoglobin is not just a molecule present in higher organisms with blood. The porphyrin synthesis pathways are present throughout many phyla. Plants actually possess hemoglobin as do certain yeasts and other fungi. While not my personal belief, it would probably be stated that the endosymbiotic event that endowed progenitor photosynthetic organisms with a chloroplast occured after the endosymbiotic that endowed progenitor non-photosynthetic organisms and photosynthetic organisms with mitochondria. However, most evolutionary theory relies on primary producers evolving first.

Why not chlorophyll? It would of been so easy for everything to have chlorophyll? What are the benefits of having hemoglobin (iron) than chlorophyll (magnesium)?

Again, it's not necessarily an issue or either or, but why not both. Certainly photosynthesis endows organisms with a great ability, creation of one's own food. While I've not done the calculations, perhaps it is not efficient enough to fuel a warm blooded organism such as yourself. I've not done the calculation here either, but I would imagine that the surface to volume ratio of most photosynthetic organisms is higher than that of non-photosynthetic organisms... multicellular organisms that is. Certainly motility and the ability to gather your own food also provide advantages. Perhaps in the presence of abundant vegetable material, motility becomes and advantage. For example if an area is saturated with vegetation, many resources are being used from the earth, and the competition for that pool of resources is intense. If an organism existed that could consume the vegetation, it would provide an advantage in that environment; it could eat plants rather than competing for scarce photosynthetic resources. Of course, we would be talking about this most likely on the level of a single cell. For a single cell endowed with both catabolic and anabolic pathways this is no great feat.

Do plants and animals/insects have anything in common with plants?

Absolutely!! How long of a list do you want? Obviously cellular life, and all the structures, organelles and biomolecules that go along with it, many biochemical pathways, ie: glycolysis are universal, the one's that are not universal are generally represented multiple times, the genetic code is nearly universal, biosynthesis and degradation pathways are pretty much the same.

Are plants more complex than animals?

This of course depends on what you mean by complex. Certainly animals have very complex organ and circulation systems. Myself, I would say that those are more complex than in plants, but I would bet there are many plant biologists that would love to string me up for it. However the process of photosynthesis, and the structure of the photosynthetic reaction center are some of the most amazing and complex structures I've ever 'seen.' They are amazing, absolutely and totally perfectly architecture at the Angstrom level. Of course mitochondria have similarly engineered electron transport pathways. But in my opinion the photosynthetic pathways are more complex than the catabolic pathways like glycolysis and oxidative phosphorylation.

I'd like some good thought out answers please. Do we have and bio chemists, biologists, geneticists majors here?

Not sure if this is thought out enough for you... ask if you need clarification.