8

Yes, photosynthesis provides nearly all of the ocean's biomass and energy. The best is to study oceanic food chains and webs. It looks like there aren't enough plants in the ocean because they don't form huge reserves of foliage and branches... 10% of land plant mass dies and is replaced every year, and 100% of oceanic plants die and are replaced every week:...


7

Short answer All marine life needs energy to survive and reproduce. "Heterotrophic" organisms get their energy from eating other organisms and digesting the molecules of their tissues for driving cellular respiration/function. Ultimately, though, entire ecosystems and food webs are dependent on the non-biotic energy (e.g., sunlight) captured by &...


5

Summary Enzymes catalysing oxido-reductive reactions (oxidoreductases) do so with the aid of non-protein molecules (prosthetic groups or cofactors) at their active sites. The three main types of such prosthetic groups or cofactors are iron–sulphur clusters, derivatives of flavin (FAD and FMN) and nucleotide derivatives of nicotinamide (NAD and NADP). The ...


4

It is all about energy. It is estimated to take 5000 square meters of plants to feed the average person in the developed world, while the same source gives the lowest possible for a human under ideal conditions at 700 square meters. In comparison, the average person covers less than 1 square meter. While there is a lot of waste (animals are able to eat ...


4

The emergence of photosynthesis has occurred rather independently in multiple organisms. One way of looking at this is to look at the taxonomic distribution of photosynthesis reaction centers, which points to 5-10 origins according to current data (mostly in bacteria). That number has some big error bars as we are talking about very deep, old branches of the ...


3

Question and Scope of Answer The question is about metaphors and semantics relating to the carbon stoichiometry of the reactions producing dihydroxyacetone phosphate from carbon dioxide. I have decided to provide a clarification of the carbon stoichiometry, ignoring hydrogen and oxygen stoichiometry (even though I find the reduction and energetics more ...


3

You're looking at a version of the Calvin cycle that has been simplified to consider 3 "turns" all together as the steps necessary to produce one 3-carbon product. A hint is that you see three CO2 molecules entering rather than one. You can look for another diagram that has a one-carbon version, like at https://en.m.wikipedia.org/wiki/Calvin_cycle ...


3

The plant uses light to produce energy but also as a signal of how and when to grow (phototropism, photoperiodism). In the context of your question I'll first cover light-harvesting in photosynthesis and then phototropism. Tl;DR Blue and red light are important for plant growth. Red light is the main one in photosynthesis and if a plant is exposed to another ...


2

Im going to expand my comment into an answer because the discussion was just too interesting. the conclusion at the bottom of the review cited is: "Current evidence suggests that the earliest photosynthetic organisms were anoxygenic, that all photosynthetic RCs have been derived from a single source, and that antenna systems and carbon fixation pathways ...


2

The light harvesting complexes use light energy to "lift" electrons to a higher energy state from which they can be used to reduce organic molecules (by way of an electron transport chain and NADPH), leaving a "hole" or cation behind in the LHC and thereby oxidizing it. If these complexes were not re-reduced by something, they would ...


2

I think the crux of the answer is only hinted at in WYSIWYG's answer. The crux of photosynthesis is partitioning coupled reactions. Photosynthesizing plant cells have sub-cellular structures called chloroplasts; their membranes are especially important for the compartmentalization of different functions and chemical processes for the entirety of ...


1

A very basic kind of photosynthesis can be realized in E.coli by expressing a rhodopsin (Kim et al., 2017). Rhodopsins are membrane proteins that can pump ions (including protons) across the membrane and generate a transmembrane potential. When coupled to ATP synthase, rhodopsins can cause ATP generation in the presence of light. In an earlier work, Hara et ...


1

The rationale behind CAM photosynthesis, as opposed to C3 photosynthesis, is to partition the "light" and "dark" reactions temporally to avoid production of phosphoglycolate by RuBisCO in the presence of oxygen. During photosynthesis, molecular oxygen is produced in the photosynthetic electron transport chain, or the "light" ...


1

In the process of photosynthesis light is used as as a source of energy to generate sugar from carbon and water. A by-product is oxygen. This process can be broken into two cycles: light reaction and Calvin cycle. In the light reaction energy from photons is transformed into usable energy and reducing agents (ATP, NADPH) and water is used as a source of ...


1

The number of stomata on the leaf is the limiting factor. Light causes the stomata to open, more so with increasing light intensity. Once all the stomata are fully open, the transpiration rate rate cannot increase any further (for a given set of temperature and relative humidity conditions).


1

As you already mentioned N and P are major components of important biomolecules. In Sterner & Elser, ecological Stoichiometry, 2002, fig 2.2 demonstrates the percentage of N and P in biomolecules. As you can imagine these biomolecules are important and require forms of P and N to be consumed for an organism to function. Animals are limited by nutrients ...


Only top voted, non community-wiki answers of a minimum length are eligible