hehe .. thats a pretty entertaining name. pronounced similarly to "fungi" (more like "fong guy") and depending on the characters in the traditional writing (風改?) it could potentially transliterate to "crazy change"bob b said:
*grin*
Cell Trends
- Thread starter bob b
- Start date
*grin*
aharvey
New member
Oh no, no, no, stipe. SUTG is providing the perfect counterpoint to bob's "thread." Since bob won't do anything more than serve as the mouthpiece for creationsafari, which doesn't exactly allow for critical consideration of its absurd pronouncements, SUTG is providing the next best thing: actual responses of heavyweights in the "field" of ID when forced to do what bob won't.stipe said:
aharvey
New member
Oh no, no, no, stipe. SUTG is providing the perfect counterpoint to bob's "thread." Since bob won't do anything more than serve as the mouthpiece for creationsafari, which doesn't exactly allow for critical consideration of its absurd pronouncements, SUTG is providing the next best thing: actual responses of heavyweights in the "field" of ID when forced to do what bob won't. Look at it this way: just like bob, SUTG is merely copying and pasting what ID proponents have to say, in their own words, about the concept of irreducible complexity.stipe said:
whoa .. deja vu. they played the same tune at the last wedding i was at ...
...
i know .. we should have a competition ... jackjack posts one quote of ID people saying stupid things every time bob posts a piece about cell complexity from now on.
see who runs out first.
just as long as he gets his own thread.
...
i know .. we should have a competition ... jackjack posts one quote of ID people saying stupid things every time bob posts a piece about cell complexity from now on.
see who runs out first.
just as long as he gets his own thread.
Rotating Gate in the Cell Membrane a “Beautiful Design” 02/12/2002
Another gateway into the cell has been explored, and it’s a beauty, say the three biochemists who describe it in the Proceedings of the National Academy of Sciences Feb 12 online preprint. This one is called KcsA, a potassium ion channel that is critically important for nerve impulses in humans, but also is used by bacteria. KcsA is one of many membrane proteins that are subjects of intense scrutiny by biochemists. It is so effective, it can let in 10,000 potassium (K+) ions for every unwanted sodium ion (Na+), even though sodium ions are smaller but have same charge.
How the KcsA channel does this was a surprise. Apparently, four helical rod-shaped parts rotate clockwise in such a way as to keep parts of the gate rigid while allowing other parts to flex. To picture this in a simplified way, visualize four chopsticks hanging vertically, forming a square looking from the top down. Each stick has a pivot point about 1/3 of the way down, allowing it to rock. The bottom ends of the sticks are bundled together in the shape of an inverted teepee, in such a way that as each stick pivots, the bottoms trace out a circle. Moving in concert, they cause a rotary motion that allows the potassium ions funnelling into the stiff upper part, the “selectivity filter” wide berth as they exit into the interior of the cell. The selectivity filter, like a one-way ID-checking turnstile, attracts positive potassium ions but keeps unwanted molecules out.
The authors explain how only a clockwise rotation allows the gate to work. They did not state the rotation rate of the gate, but it must be phenomenal; the throughput of KcsA is an astonishing 100 million ions per second, very near the diffusion limit. The authors apparently could not help expressing a little awe in their otherwise straightforward scientific paper; they used the word “design” twice: “The interplay of the two pivot points is a beautiful design by nature for solving the gating problem of KcsA,” and “The swinging rotational motion of TM2 helices with two pivot regions is an exquisite design by nature to ensure an effective gating of KcsA without having to loosen up the structural integrity near the intracellular side of channel in the open state.”
It’s hard not to gasp at what scientists are discovering every week in cellular biology. Who would have thought that your muscles, nerves, and brain functions are made possible by such wondrous mechanisms as these? Who can continue to believe that such molecular motors and machines could ever self-organize without intelligent design?
Another gateway into the cell has been explored, and it’s a beauty, say the three biochemists who describe it in the Proceedings of the National Academy of Sciences Feb 12 online preprint. This one is called KcsA, a potassium ion channel that is critically important for nerve impulses in humans, but also is used by bacteria. KcsA is one of many membrane proteins that are subjects of intense scrutiny by biochemists. It is so effective, it can let in 10,000 potassium (K+) ions for every unwanted sodium ion (Na+), even though sodium ions are smaller but have same charge.
How the KcsA channel does this was a surprise. Apparently, four helical rod-shaped parts rotate clockwise in such a way as to keep parts of the gate rigid while allowing other parts to flex. To picture this in a simplified way, visualize four chopsticks hanging vertically, forming a square looking from the top down. Each stick has a pivot point about 1/3 of the way down, allowing it to rock. The bottom ends of the sticks are bundled together in the shape of an inverted teepee, in such a way that as each stick pivots, the bottoms trace out a circle. Moving in concert, they cause a rotary motion that allows the potassium ions funnelling into the stiff upper part, the “selectivity filter” wide berth as they exit into the interior of the cell. The selectivity filter, like a one-way ID-checking turnstile, attracts positive potassium ions but keeps unwanted molecules out.
The authors explain how only a clockwise rotation allows the gate to work. They did not state the rotation rate of the gate, but it must be phenomenal; the throughput of KcsA is an astonishing 100 million ions per second, very near the diffusion limit. The authors apparently could not help expressing a little awe in their otherwise straightforward scientific paper; they used the word “design” twice: “The interplay of the two pivot points is a beautiful design by nature for solving the gating problem of KcsA,” and “The swinging rotational motion of TM2 helices with two pivot regions is an exquisite design by nature to ensure an effective gating of KcsA without having to loosen up the structural integrity near the intracellular side of channel in the open state.”
It’s hard not to gasp at what scientists are discovering every week in cellular biology. Who would have thought that your muscles, nerves, and brain functions are made possible by such wondrous mechanisms as these? Who can continue to believe that such molecular motors and machines could ever self-organize without intelligent design?
Presto! Prestin Wins the Gold in Molecular Motor Race 02/21/2002
A “new type of molecular motor, which is likely to be of great interest to molecular cell biologists” has been discovered. Named prestin, this protein motor, made up of 744 amino acid units, is a speed demon, ferrying negative ions across cell membranes in millionths of a second. It appears to function as part of the mechanical amplifier in the cochlea, helping the ear to achieve its “remarkable sensitivity and frequency selectivity.” Nature Molecular Biology Reviews describes the unique features of this biological machine:
"Prestin is a new type of biological motor. It is entirely different from the well-known and much-studied classical cellular motors in that its function is not based on enzymatic processes, but on direct voltage-to-displacement conversion. The action of prestin is also orders of magnitude faster than that of any other cellular motor protein, as it functions at microsecond rates."
Prestin has an external voltage sensor that causes it to respond. Its action apparently mediates changes in length of the outer hair cells of the cochlea, greatly amplifying the responsiveness of vibrations reaching the inner ear. The illustration in the article shows how the cochlear amplifier works to provide variable, automatic, amplitude-dependent response. The “gain” on low-level signals can be 1000-fold, but intense signals are not amplified. This allows the brain to hear very faint signals but not get saturated by loud ones.
Update 02/26/2002: A paper in the Proceedings of the National Academy of Sciences describes prestin further and finds that it is dependent on regulation by thyroid hormone.
Interesting that other cellular motors are called “classical”: the whole field of molecular motors is almost brand new. Every time a motor is found in living cells is cause for astonishment. There are hundreds of them. This one goes directly from voltage to force, without requiring other enzymes. If it is true that prestin is crucial in the inner ear amplifier system, it is another one of a host of finely-crafted parts that enable us to hear, by converting mechanical waves in the air to electrical signals sent to the brain.
Sound begins as miniscule pressure waves in the air. These are first channeled by the outer ear into a tunnel, where they set up vibrations in the eardrum, then are transmitted mechanically through three lever-action bones to the inner ear, then are amplified by hair cells in the cochlea (each responding to its own characteristic frequency), which open and close ion channels that send electrical pulses down the auditory nerves. The brain, then, sorts out all this information to determine frequency, amplitude, direction, and meaning.
Delays in hearing could be dangerous. The rapid response of prestin and all the other components of our amazing sound system helps us to hear in real time. Scientists are just now beginning to understand the details of operation of the long-mysterious cochlea, with its keyboard-like rows of inner hair cells and outer hair cells that expand and contract in perpendicular directions. It is far more wondrous than we could have imagined; who would have thought it included direct-drive motors with microsecond response?
A “new type of molecular motor, which is likely to be of great interest to molecular cell biologists” has been discovered. Named prestin, this protein motor, made up of 744 amino acid units, is a speed demon, ferrying negative ions across cell membranes in millionths of a second. It appears to function as part of the mechanical amplifier in the cochlea, helping the ear to achieve its “remarkable sensitivity and frequency selectivity.” Nature Molecular Biology Reviews describes the unique features of this biological machine:
"Prestin is a new type of biological motor. It is entirely different from the well-known and much-studied classical cellular motors in that its function is not based on enzymatic processes, but on direct voltage-to-displacement conversion. The action of prestin is also orders of magnitude faster than that of any other cellular motor protein, as it functions at microsecond rates."
Prestin has an external voltage sensor that causes it to respond. Its action apparently mediates changes in length of the outer hair cells of the cochlea, greatly amplifying the responsiveness of vibrations reaching the inner ear. The illustration in the article shows how the cochlear amplifier works to provide variable, automatic, amplitude-dependent response. The “gain” on low-level signals can be 1000-fold, but intense signals are not amplified. This allows the brain to hear very faint signals but not get saturated by loud ones.
Update 02/26/2002: A paper in the Proceedings of the National Academy of Sciences describes prestin further and finds that it is dependent on regulation by thyroid hormone.
Interesting that other cellular motors are called “classical”: the whole field of molecular motors is almost brand new. Every time a motor is found in living cells is cause for astonishment. There are hundreds of them. This one goes directly from voltage to force, without requiring other enzymes. If it is true that prestin is crucial in the inner ear amplifier system, it is another one of a host of finely-crafted parts that enable us to hear, by converting mechanical waves in the air to electrical signals sent to the brain.
Sound begins as miniscule pressure waves in the air. These are first channeled by the outer ear into a tunnel, where they set up vibrations in the eardrum, then are transmitted mechanically through three lever-action bones to the inner ear, then are amplified by hair cells in the cochlea (each responding to its own characteristic frequency), which open and close ion channels that send electrical pulses down the auditory nerves. The brain, then, sorts out all this information to determine frequency, amplitude, direction, and meaning.
Delays in hearing could be dangerous. The rapid response of prestin and all the other components of our amazing sound system helps us to hear in real time. Scientists are just now beginning to understand the details of operation of the long-mysterious cochlea, with its keyboard-like rows of inner hair cells and outer hair cells that expand and contract in perpendicular directions. It is far more wondrous than we could have imagined; who would have thought it included direct-drive motors with microsecond response?
sorry .. i understood all the words .. i just couldnt put them together correctly.aharvey said:
i think i understand you now. youre asking why i think bob is allowed to post crap in here while sutg is not allowed to post crap.
i think thats because i want to read bobs crap .. and id prefer not to have to scroll past sutgs crap to do so ... if he decided to take my advice itd be an unlikely piece of altruism on his part after i smote him and asked kinda rudely.
aharvey
New member
Not exactly. They are not equally crappy, and any objective observer would agree that defended positions are less crappy than undefended ones. Anyways, my point was that SUTG is providing something relevant to this topic that bob is not.stipe said:
It's not really "advice" that you're offering, is it?stipe said:
i used the 'cr' word to indicate what each of us thought of the posts we didnt like .. i think youll find that bob gets to define what is relevant to the topic he defined ... simply by posting. what right would i have to go into a thread sutg started and tell him that my responses to his question were more relevant to his question than his original post?aharvey said:
oh sorry .. do i have to put "may i advise you to" in front of "get your own thread" for it to be advice?aharvey said: