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Homework 3: an essay about bacteria
Bacteria are tiny living things with a simple setup inside their cells. They
are unique because their DNA is shaped in circles, which helps them live
and make more bacteria. These tiny organisms can survive in different
places by using oxygen or not and by eating different kinds of food.
Scientists sort bacteria into three groups based on their shape: spiral, rod-
like, and round. This helps us understand where they live and how they
act. For example, some known bacteria are Streptococcus mutans,
Clostridium botulinum, and Treponema pallidum, each with its unique
shape and lifestyle.
Bacteria have seven main parts in their cell, including a protective layer
called the capsule, a rigid cell wall, tiny ribosomes for making proteins, a
nucleoid holding their DNA, flagella and pili for moving and sticking to
things, and a jelly-like substance called cytoplasm. These parts help the
bacteria live, grow, and interact with their environment.
When it comes to making more of themselves, bacteria do something
called binary fission, where one cell splits into two. This can happen very
fast, sometimes in just 20 minutes, depending on the conditions they're
in.
Bacteria can also survive tough times by making endospores, a kind of
safety capsule for their DNA that helps them endure extreme heat, cold,
or dryness. Bacillus subtilis is a bacteria that's really good at this, even
surviving boiling water.
Bacteria play different roles in nature. Some are parasites that live off
other living things, some feed on dead stuff, and others help break down
dead materials into simpler substances. These jobs are crucial for keeping
the environment healthy.
To keep harmful bacteria in check, especially in food, we use methods like
canning, pasteurization, and drying out food. We also use chemicals called
antiseptics and disinfectants to kill bacteria on our skin and on surfaces.
Not all bacteria are bad, though. Some help decompose things, returning
nutrients to the soil, which helps plants grow. Others help animals digest
food, or are used by scientists to make medicines and other important
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substances. Bacteria even help treat sewage and are a key part of making
healthy dairy products like yogurt.
In conclusion, bacteria are everywhere and play vital roles in nature and
human life. They can be harmful or helpful, but understanding their
diverse roles shows how important they are to our world and well-being.
