How Prokaryotes Impact Humans

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  • 0:01 What Is a Prokaryote?
  • 0:50 Prokaryotes: Friends or Foes?
  • 1:34 Beneficial Prokaryotes
  • 3:30 Harmful Prokaryotes
  • 4:27 Differentiating Bacteria
  • 5:12 Lesson Summary
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Lesson Transcript
Instructor: Angela Hartsock

Angela has taught college Microbiology and has a doctoral degree in Microbiology.

In this lesson, we will discuss the beneficial and harmful ways that prokaryotes can impact humans. We will define the terms prokaryote, symbiosis, mutualistic bacteria, and pathogenic bacteria.

What Is a Prokaryote?

You may happy to hear that you have a lot more friends than enemies. We're not talking about people, but rather the microscopic bacteria that are with you 24 hours a day, and they've totally got your back - some are even on your back. And, there are trillions of them.

What we're talking about here are prokaryotes, single-celled microscopic bacteria and archaea. Archaea are very similar to bacteria and until recently were believed to actually be bacteria, though they have a slightly more complex structure. For the purposes of this lesson, we'll group them together with bacteria.

One of the prokaryote's defining characteristics is that it doesn't have a nucleus, the cell's core that holds the DNA, or other membrane-bound organelles. Instead, the prokaryote's DNA floats around in the gooey center of the cell.

Prokaryotes: Friends or Foes?

Prokaryotes live on your body and in your environment. Some types of these organisms are harmful and can make us sick, while others help protect us and can even be used by doctors to improve our overall health.

So, for the most part, prokaryotes are our friends. We live in symbiosis, which is when two different species live in close association. We can break the word symbiosis down into its two parts: sym which means together and biosis which means living. So, symbiosis simply means living together.

You can think about these symbiotic associations just like you think about other relationships in your life. They can be mutually beneficial or they can be toxic. Let's look first at how prokaryotes may affect you.

Beneficial Prokaryotes

Once upon a time, we used to think of bacteria as simply bad things that caused disease. But scientists have since discovered a huge number of prokaryotes that live in mutually beneficial relationships with the human body, which means both parties benefit from the relationship.

These are referred to as mutualistic bacteria, bacterial species that live in symbiosis with a human host in a mutually beneficial relationship. These beneficial prokaryotes are found in many parts of the body, including the skin, mouth, nasal cavity, ears, vagina, stomach, and intestines. We call the collection of microorganisms that live in association with the human body normal flora or more technically, human microbiota.

How do these mutualistic bacteria benefit us? They ward off disease-causing organisms by competing for space and nutrients on and inside the body. They train our immune system so it's ready when our bodies are attacked, and they aid in digestion and supply us with vitamins. They can also affect the way our metabolism works and help our bodies become less susceptible to conditions like obesity and diabetes.

Scientists and doctors can even utilize prokaryotes to help the human body. Bacteria are used to make antibiotics that can be helpful in treating infections, as well as insulin for diabetes management. Bacteria can also be used to ferment foods, making some of the delicious and nutritious edibles we know and love, like kimchi and cheese. Have you ever eaten yogurt? Yogurt is often enhanced with probiotics, which are mutualistic bacteria that travel through your digestive system and into your intestines, where they contribute to gut health.

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