 |
 |
Life spans
Name: kelly trina
Status: N/A
Age: N/A
Location: N/A
Country: N/A
Date: Around 1993
Question:
Why do all living things have to die?
Replies:
A very good question, and one that has many answers! I know that
younger people especially are concerned about death. If living things did not
die, there would not be evolution, there would not be procreation (what!? a
world without sex!), there would not be people, cats, cows, dogs or frogs,
trees, grass, or dandelions: the only life would be very simple one-cell
plants and animals. It may be possible in the near future to greatly extend
the human life span. Maybe. Hope this helps on a very difficult subject.
Jade
A fundamental reason why living things eventually die is that
they are unable to make enough properly functioning enzymes. This means that
reactions required to sustain life - convert ingested food into energy, make
new structural protein and lipids to replace worn out membranes, synthesize
the mRNA needed to make these proteins and enzymes, etc., these reactions
andmany more cannot take place at all or are so inefficient that they are not
useful. The reason cells begin to lose their ability to make these essential
enzymes is that DNA, which "codes" for all enzymes in the cell, is always
accumulating errors. The cell is able to repair these errors, but not at 100%
accuracy. So eventually misrepaired errors in DNA are so great in number that
the cell's function is affected. This results in cell death (from any number
of reasons, depending on what enzymes are affected by the DNA errors).
Dr. Pam
Click here to return to the Biology Archives
| |
Update: June 2012
|
|
