Column: How our cells strategize to keep up alive
Wait, what? Is that even possible? Apparently it is. Over half of you is water, and we know that we constantly replace that. Another large percentage of you is protein, and as you may recall,
. We even disassemble and replace our ribosomes and large organelles such as mitochondria, which are made primarily of protein.constantly replacing their seemingly permanent structures and old battered molecular machines with new ones. The only ones they don’t replace are our massive chromosomes. Instead, we have machines that swarm along them looking for problems and fixing them.
What if the damage to a cell is too great to repair? We have a fallback plan for that too. We simply destroy the entire cell, chop it up into recyclable units, and make a fresh one. On average, you replace most of your cells, which amounts to about 330 billion cells a day. Those that work in the harshest conditions are retired most frequently. The damage to many cells in your intestines, which are exposed to harsh acids, is so predictable that they commit planned suicide and are replaced.
So, in addition to using reliable machines, our cells have a three-pronged motto to stay alive: ceaselessly check for errors, constantly repair, and continually replace. In a way, your body is like a major New York highway—always open and always under repair.by Dan Levitt. To be published by HarperCollins on Jan. 24, 2023. Copyright © 2023 by Daniel Levitt. All rights reserved.
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