Discovery Institute recently released a stunning animation (different from the one above) of the mechanics of ATP synthase, a biomechanical power generator found almost ubiquitously across life. The video above offers another glimpse of the engineering prowess of this amazing molecular machine.

There exists three main types of membrane-embedded ATPases: F-type, V-type and P-type. I will discuss here the F-type ATPases (also called ATP synthase). V-type ATPases facilitate the acidification of intracellular organelles, and use the energy from adenosine triphosphate (ATP) hydrolysis to pump protons into cells and organelles (Beyenbach and Wieczorek, 2006). P-type ATPases are involved in the pumping of cations, also using the energy of ATP hydrolysis (Bublitz et al., 2011; Kuhlbrandt, 2004). The F-type ATPase discussed here is unique inasmuch as it, rather than hydrolysing ATP, actively synthesizes it using the energy from the flow of protons down an electrochemical gradient. There are also A-type ATPases which are found in archaea and perform a similar function to F-type ATPases (Bickel-Sandkötter et al., 1998).

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Atheist philosopher A.C. Grayling, whose debate with Peter S. Williams I wrote about yesterday, recently published a new book, The God Argument: The Case Against Religion and for Humanism. I was particularly interested in reading Chapter 11, which is devoted to the subject of creationism and intelligent design. The chapter contains so many errors and is so poorly researched that one hardly knows where to begin. Continue reading →

The video above features a short excerpt from a debate between well-known atheist philosopher A.C. Grayling (famous for conveniently “forgetting” having debated William Lane Craig) and Christian philosopher Peter S. Williams. Their subject: the fine-tuning of the universe’s initial conditions to support complex life, bearing on the case for intelligent design. Williams articulates the argument from specified complexity, using the analogy of an ATM bank machine. A bank pin number is a very specific combination of four digits (some banks allow more), and there is a total of ten digits (0-9) on an ATM keypad. There is thus only one four-digit combination out of a total of 10,000 (10^4) combinatorial possibilities that will allow the money to be retrieved from the machine. Since ATM machines typically allow only three attempts before denying access to one’s bank account, it is vastly more probable than not that the machine will not be cracked by chance. This is analogous to the kind of specified complexity that is of interest to ID theorists.

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The video above shows the process by which bacterial cells reproduce themselves. Looks simple, doesn’t it? It’s only a colony of cells elongating before splitting in two. Don’t be fooled — appearances can be deceiving. As is so common throughout biology, the apparent simplicity at the macro level masks remarkable complexity at the micro or molecular level.

In eukaryotes, cell division occurs by either meiosis (sex cells) or mitosis (somatic cells). Bacteria, however, undergo neither of those processes (they are asexual and contain no membrane-enclosed organelles or nuclei). Bacterial cell division occurs by a process known as binary fission. Rod-shaped bacteria (e.g. Escherichia coli or Salmonella typhimurium) elongate to twice their original length. This is followed by invagination of the cell membrane, and the formation of a septal ring in the middle (Vicente et al., 2006; Weiss, 2004). The elongated bacterial cell splits down the middle, forming two daughter cells. Some bacteria exhibit variations on this mechanism. For example, inCaulobacter, no septum is formed (Poindexter and Hagenzieker, 1981) and its division is asymmetrical(Judd et al., 2003).

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