Blood vessels produce chemical reactions that control glucose levels:

https://www.sciencedaily.com/releases/2016/11/161114103909.htm

Research led by a Johns Hopkins University biologist demonstrates the workings of a biochemical pathway that helps control glucose in the bloodstream, a development that could potentially lead to treatments for diabetes.

***

It has been known for some time that neurons and the pancreatic beta cells, or β-cells, that reside in clusters called islets of Langerhans and produce insulin, have many similarities in molecular makeup and signaling receptors. Receptors are proteins on cell surfaces that respond to particular chemicals and have critical roles in biochemical pathways. Both neurons and pancreatic β-cells have the receptors for neurotrophins. (my bold)

***

It turns out that NGF performs a function in the mature pancreas that has nothing to do with supporting neurons. Specifically, the research team traced a chain of biochemical signals showing that elevated blood glucose causes NGF to be released from blood vessels in the pancreas, and that the NGF signal then prompts pancreatic β-cells to relax their rigid cytoskeletal structure, releasing insulin granules into the blood stream. Although β-cells also make NGF, Kuruvilla and her team found that it was the NGF released from the blood vessels that is needed for insulin secretion. (my bold)

Using genetic manipulation in mice and drugs to block NGF signaling in β-cells, they were able to disrupt distinct elements of this signaling sequence, to show that this classical neuronal pathway is necessary to enhance insulin secretion and glucose tolerance in mice. Importantly, Kuruvilla and colleagues found that NGF's ability to enhance insulin secretion in response to high glucose also occurs in human β-cells.

Comment: This is another example of a system that cannot develop in small steps. It must appear all put together. Also look at the bolded portions describing how receptors receive information and how a chain of molecular reactions produce directions for results. All automatic, no thought involved.

Cells are constantly being replaced after old tired ones are removed under tight controls:

https://www.sciencedaily.com/releases/2019/02/190211105405.htm

"Cellular death is vital for health. Without it, we could develop autoimmune diseases or cancers. But a cell's decision to self-destruct is tightly regulated, so that it only happens to serve the best interests of the body. Now researchers have discovered a novel role for a signaling molecule that was once considered a dispensable player, a discovery that could inform fields of research as diverse as cancer, autoimmunity, and in-utero development.

***

"Years ago, researchers in the field discovered receptors on the surfaces of cells they called "death receptors." These molecules would send the cell into a cascade of cellular reactions that ended in death. Soon after, three molecules were discovered that contained "death domains," areas on the molecule that directly interacted with the death receptors and helped relay the message. These molecules proved so essential that without them mice lacking these death-domain molecules died young. At least that was the case in two of the three molecules.

"Of the three major death-relaying molecules, RIPK1, FADD, and TRADD, it seemed TRADD was less essential. Without FADD, mice died in utero. Without RIPK1, mice die shortly before or after birth. Without TRADD, mice seemed to do just fine. TRADD had a death domain -- it clearly was connected to cell-death pathways -- but its main purpose was unclear.

***

"Through the work of Dr. Zhang and others, it became clear that the roles of these molecules wasn't simply to turn on the death signal. Rather, in certain combinations they could protect a cell from death, rather than spur suicide.

"Through the work of first author and postdoctoral fellow John Dowling, their most recent paper, the researchers showed that TRADD serves a dual function. In cells lacking the RIPK1 protein, having two copies of the gene TRADD or no copies of it would result in cell death. On the other hand, when only one copy of TRADD gene was present in cells lacking RIPK1, the cells tended to turn off the death signal, and promote cell survival.

"'The work sheds new light on the regulation of cell death and survival," said Dr. Zhang. "In certain contexts, such as in cells that have naturally low RIPK1 expression, TRADD could drive death or promote survival.'"

Comment: Another very precise feedback mechanism with go or no go decisions about life and death. This cannot be developed or adjusted stepwise, but must be put in place all at once or cell death will not be properly controlled. This is irreducibly complex and must be designed from the beginning.

DAVID: If you can find the intelligence you think your version of God put onboard then you win! [...]

dhw: [...] If you can find the 3.8-billion-year computer programme or a signed statement from God that he dabbles, then you win! But of course those would be absolute proof, which is impossible, whereas you will not even consider my hypothesis until I can provide absolute proof, which is impossible. That’s what we call double standards.

DAVID: Not so fast. You are sitting atop your picket fence which looks down on two sides, neither of which you accept. That is your double standard of disbelief. I am not forbidden to make a choice, and have. Just as you reject both sides, I've rejected one!

You are misrepresenting both my position and the meaning of double standards! Firstly, I do not have disbelief, and I do not reject both sides. I am an agnostic. That means I neither believe nor disbelieve in God. In terms of how evolution works, I offer a theistic hypothesis which I actually find more convincing than your own, though I would not go so far as to call it a belief. As regards double standards, although I accept the possibility of God’s existence, you accuse me of wanting absolute proof, which is impossible. However, you refuse even to consider the possibility of cellular intelligence without absolute proof, which is also impossible. Your hypothesis does not require absolute proof, but mine does. Double standards.

A new complex mechanism is described:

https://phys.org/news/2019-05-mechanism-accessing-dna.html

"It has been unclear, however, how repair proteins work on DNA tightly packed in chromatin, where access to DNA damage is restricted by protein packaging. Using cryo electron microscopy, researchers from the Thomä group at the Friedrich Miescher Institute for Biomedical Research (FMI) have identified a new mechanism whereby repair proteins detect and bind to damaged DNA that is densely packed in nucleosomes.

"Ultraviolet (UV) light damages DNA, producing small lesions. These UV lesions are first detected by a protein complex known as UV-DDB and—once the lesions have been identified—the rest of the DNA repair machinery swings into action. The question is, how can UV-DDB bind to lesions when the DNA is coiled around the histone protein core of the so-called nucleosome (the basic unit of chromatin—the DNA packaging of eukaryotic chromosomes)?

"To gain access, UV-DDB was previously thought to require the assistance of additional proteins that shift the nucleosome. Researchers from the group led by Nicolas Thomä have now found that additional proteins are not necessarily needed to detect UV-induced lesions; instead, the UV-DDB complex takes advantage of the intrinsic dynamics of nucleosomal DNA. The DNA repair factor appears to catch the UV lesions when they are temporarily accessible.

"In their study published in Nature, the scientists determined various three dimensional (3-D) structures of UV-DDB bound to lesions at different locations around the nucleosome, using cryo-electron microscopy—a technique that allows the 3-D structure of biomolecules to be visualized with atomic detail. The researchers concluded that damage detection strategies depend on where the DNA lesion is located. In the case of "accessible" lesions, which can be directly contacted, UV-DDB binds to the lesion tightly. The recognition of "occluded" lesions (facing the histone protein core of the nucleosome) requires additional steps: UV-DDB binds the UV lesions when they are exposed temporarily through the natural dynamics of the nucleosome. One of the lead authors, Syota Matsumoto, explains: "To visualize what happens at the molecular level, imagine a piece of string wrapped around a spool, which becomes accessible when it is pulled forwards or backwards a little bit."

"The researchers called the mechanism of DNA damage read-out "slide-assisted site-exposure." This new mechanism operates independently of chromatin remodelers and does not require chemical energy to slide or dislodge nucleosomes.

"Thomä comments: "In the past, nucleosomes were thought to be a major obstacle for DNA-binding proteins. In our study, we show that they are not, and that the system is tailored to bind UV lesions wherever they are. What makes this study really powerful is the fact that the mechanism we identified could very well be used by many other types of DNA-binding proteins. Accessing nucleosomal DNA is not only fundamental for DNA repair, but is relevant for all proteins that bind to chromatin. With our study, we define a previously unknown strategy for protein access to chromatinized DNA templates."

Comment: Just as in the last entry, the earliest life forms had to have these defenses for life to continue. Only design fits these requirements.

A group of proteins that anchor cell shape and nucleus position are identified:

https://phys.org/news/2019-08-fundamental-properties-cells-affect-tissue.html

"...Virginia Commonwealth University researchers, in collaboration with researchers from the University of Florida, identify a fundamental factor in maintaining a stable multicellular structure: the LINC complex.

"The LINC complex—a group of proteins known as the nuclear linker of nucleoskeleton to cytoskeleton—anchors the nucleus to the cell. The study, using 3-D culture models of cell clusters known as acini, suggests that mechanically disrupting the LINC complex destabilizes the clusters.

"'If these main connections that help anchor the nucleus are disrupted, the cells try their best to compensate in order to keep things normal," said Vani Narayanan, a doctoral candidate in the Department of Biomedical Engineering in the VCU College of Engineering and lead co-author of the study. "Unfortunately, this compensation becomes over-compensation. Various proteins that should ideally remain in nominal amounts within the cell for proper cellular function get unregulated, causing rapid movement of cells within the acinus, abnormal cell division and migration and, hence, the system collapses."

***

"'The mechanics of the cells affect how tissue structures form," said Daniel Conway, Ph.D., associate professor in the Department of Biomedical Engineering and co-author of the study. "If you change the mechanical properties of individual cells, they lose the ability to form more complex tissue or to stay organized. ... The structures actually aren't that stable, [therefore] disruptions in physical connections between or within cells can result in these structures collapsing.'"

Comment: This shape-holding structure must have been designed as multicellular forms appeared in evolution. Otherwise how did they maintain proper functions?

A very complex new aspect of photosynthesis regulation is found:

https://phys.org/news/2020-01-ancient-iron-sulfur-based-mechanism-electron-photosynthes...

"[Research] professor[s] of biochemistry, have shown that the chloroplast sensor kinase (CSK) protein is equipped with an evolutionarily conserved iron-sulfur cluster. The cluster helps it to sense the presence of electrons and thereby send signals to the gene expression machinery in plant chloroplasts to turn photosystem genes on and off.

"'CSK is an ancient protein found in both cyanobacteria and chloroplasts. More than a billion years ago a cyanobacterium took up residence inside a eukaryotic host cell and became the chloroplast of plants and algae," Puthiyaveetil said. "By examining the cyanobacterial, plant and diatom CSK proteins, we've discovered that CSK uses an iron-sulfur cluster to sense the electron transport, assessing how well the electrons are flowing, and make adjustments in the relative abundance of plant photosystems to keep photosynthesis working correctly and protect the plant from oxidative stress."

***

"During photosynthesis, plants turn sunlight into energy via two photosystems. Photosystem I utilizes long wavelength light efficiently while photosystem II prefers mostly short wavelength light, with the two photosystems connected by the plastoquinone pool. As the systems work, photosystem II sends electrons into the plastoquinone pool while photosystem I removes and utilizes them.

"But if a plant is exposed to shorter wavelength light, the electron balance can be lost. In that case, photosystem II would send electrons into the plastoquinone pool, but photosystem I wouldn't be able to draw them efficiently. Those electrons could linger in the plastoquinone pool and produce dangerous free radicals.

"'The two photosystems are like two photovoltaic cells connected in series," Puthiyaveetil said. "They should convert light energy at equal rates for optimal electron transport. If the electron transport is not balanced, you get free radicals that can damage the plant's photosynthetic machinery and hurt or kill the plant."

"Purdue scientists determined that CSK's iron-sulfur cluster acts as a sort of magnet for those extra electrons. When the plastoquinone pool becomes reduced, meaning it has excess electrons, those electrons leak into CSK and turn off its kinase activity.

"When kinase activity is interrupted, CSK stops transferring phosphate groups to the chloroplast gene expression machinery, turning on photosystem I genes and increasing its amount and therefore activity in short wavelength light. In essence, when CSK's kinase activity is on, it serves as a brake pedal for photosystem I gene expression.

"The CSK is redox-reactive, meaning it's using the iron and sulfur to sense the electron flow, and that's keeping the two photosystems working at the same rate in photosynthesis.

"The findings illuminate an elegant regulatory mechanism in the photosynthetic processes of plants. It's possible, Puthiyaveetil said, that one day this regulatory circuit could be modified to increase photosynthetic efficiency in crop plants by improving light capture in shaded conditions." (my bold)

Comment: Photosynthesis is a vital source of the level of oxygen now present in this atmosphere. Without it evolution could not have passed beyond the very small animal stage.
Note my bold: without this precise regulatory system photosynthesis would not work. It is so complex is cannot be built by step by step testing of each advance, that is, it is irreducibly complex, a logical concept introduced by Dr. Behe, one of the leading scientists in the ID group, of whom there are many with important papers in publication. Such design requires a designing mind behind it to create it all at once. Any Darwin approach fails to explain it. How long would it take to develop it by chance?

Another complexity of photosynthesis:

https://phys.org/news/2020-06-small-protein-electrons-photosystems-involved.html

"By utilizing solar energy to turn carbon dioxide into sugars, while also generating molecular oxygen from water, photosynthesis provides the basis for both plant and animal life. These two processes are carried out by distinct, but functionally connected complexes called photosystems I and II (PSI and PSII). In cyanobacteria, algae and plants, these photosystems—all of which employ chlorophyll pigments to capture light energy—are embedded in specialized lipid membranes called thylakoids. Moreover, the thylakoids that contain PS I and PSII differ in their organization, which effectively enables the two systems to convert light of different wavelengths into chemical energy.

"The functional link between the two reaction complexes is provided by soluble proteins that serve as electron transporters. Biologists led by Professor Dario Leister (Chair of Plant Molecular Biology) at LMU's Biocenter, in collaboration with international colleagues, have now taken a closer look at the role of one of these proteins—plastocyanin, a small copper-containing protein. Their findings, which appear in the journal PNAS, reveal that the efficacy of electron transport is critically dependent on the architecture of the membrane systems. "Function shapes" The functional link between the two reaction complexes is provided by soluble proteins that serve as electron transporters. Biologists led by Professor Dario Leister (Chair of Plant Molecular Biology) at LMU's Biocenter, in collaboration with international colleagues, have now taken a closer look at the role of one of these proteins—plastocyanin, a small copper-containing protein. Their findings, which appear in the journal PNAS, reveal that the efficacy of electron transport is critically dependent on the architecture of the membrane systems. "Function shapes architecture," says Leister.

"So the courier's level of performance depends on the architecture of the thylakoids. Both the tower blocks and the walkways between them are congested. Not only the membranous structures, but the aqueous phase that surrounds them, is densely packed with proteins and small molecules. "And that reduces the mobility of the couriers significantly," Leister notes.

"Earlier work done by his research group had shown that the architecture of the thylakoids has a crucial impact on the efficiency of photosynthesis under fluctuating light intensities. "When light levels are low, thylakoid membranes have to be stacked in order to maintain the efficiency of photosynthesis, and only land plants can perform this trick," he says. "Furthermore, to make things easier for the couriers, the width of the individual tower blocks must be restricted. These architectural specifications are observed in essentially all plants.'"

Comment: Unpeeling the layers of the onion shows how complexly the process of photosynthesis is designed. Not by chance.