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I. Bacteria (plural) - Bacterium (single)

Very small organisms - they can only be seen through a microscope.

A thousand bacteria lined up would be just one millimeter long.

Unicellular - made of just one cell.

They have no cell nucleus, nor do they have most other cell organelles.

Some information here comes from: Simple English Wikipedia

The simplest organisms on Earth. They have existed on Earth for billions of years.

There are more individual bacteria than any other type of organism on the planet!

Most bacteria live in the ground or in water. Some live deep in the Earth, in cracks between rocks.

Many bacteria live inside, or on the skin of, other organisms - even humans.

II. Uses of bacteria

1. Gut bacteria help us digest our food.

2. Other bacteria help us ferment food.

What is fermentation?

Using bacteria (or yeast) to convert carbohydrates to other chemicals.

Only happens in anaerobic conditions (very low amount of oxygen)

Bacteria turns some carbs into alcohols, carbon dioxide gas, or other organic acids

Foods made with bacteria

Fermentation of milk makes cheese and yogurt.

Fermentation of cacao (chocolate) beans, and coffee beans, helps them achieve their desired flavors.

Sauerkraut is finely cut cabbage that has been fermented by bacteria.

Salami is a type of sausage — ground meat stuffed into a casing — which is not cooked, but is instead allowed to ferment with bacteria, before being dried and made edible. (This includes pepperoni)

Prince George's Community College, Karl J. Roberts, Ph. D. Professor of Biology



III. Reproduction of bacteria

They divide in half and creating two "daughter" cells. -> Mitosis

Each daughter is identical in shape to the parent, but smaller.



IV. Bacteria (and Archaea) - their version of sex, and evolution

Bacteria do not have "males" or "females".

(The same is true for Archaea)

They do not have sexual intercourse.

However, bacteria exchange DNA with other bacteria cells.

This allows bacteria to randomly mix up their genes.

This makes each daughter cell slightly different from the parent.

So, in a way, this is sort of like sex - genes can get randomly shuffled.

But why do this?

If the environment that they live in changes, then some bacteria may die. In fact, if they all had the same genes, then all could die!

But if their genes are different, then even though some may die, others may live.

The cells that live pass on their genes to their offspring. These new, mutant, genes become more common.

The cell that die do not pass on their genes; those genes become less common.

Therefore, as time goes by, the remaining bacteria change. This is evolution.

It's not just bacteria: All forms of life on Earth have changes in their DNA, as time goes by.

All forms of life undergo evolution.

V. Archaea are very small, single-celled organisms.

That they can only be seen through a microscope.

They have no nucleus, nor most other organelles.

The word Archaea comes from the Ancient Greek ἀρχαῖα, meaning "ancient things".

They look so much like bacteria, that until recently we thought that they were bacteria.

But when we learned how their genes worked, we discovered that they were very different.

Their DNA is more similar to plants and animals than to a bacterium!?

They way they process chemical reactions in their cells is more plant-like or animal-like than bacteria-like.

As such, they do not belong in the bacteria category - and they do not belong in the animal, plant or fungus category - they are in their own domain (special group.)

Most live in extreme environments, places where we once thought no life could exist.

The environments in which they live are much like Earth's environment billions of years ago, back when it was young.

The three families of Archaea

1. Methanogens: “methane-makers”

Use only CO2 (carbon dioxide), H (Hydrogen) and N (Nitrogen) to produce energy.

They give off methane gas.

They live in swamps, marshes, gut of cattle, termites, etc.

They can't breathe normal air, because they are poisoned by oxygen!

These are decomposers; and can be used in sewage treatment. They may someday be used to produce methane as fuel!

2. Extreme Halophiles: “salt lovers” - Require extremely salty water.

Even the ocean is not salty enough! Some prefer up to 30% salt concentrations!

Live in the Dead Sea (Israel), the Great Salt Lake (Utah), and salt evaporation ponds all over the world.

Some get energy from photosynthesis, like plants. But they do not have chlorophyll like plants.

Instead, they have a special colored molecule, a pigment, in their cells called bacteriorhodopsin.

It absorbs energy from light, and transfers the energy into molecules in the cell.

3. Extreme Thermophiles: “heat / cold lovers”

Some prefer temperatures above 60°C (up to 110°C for hyperthermophiles!), while some prefer to live near or below freezing. (Many will die at room temperature).

Live in hot sulfur springs, Yellowstone Park, near volcano vents, deep sea hydrothermal vents, deep sea “black smokers”, geothermal power plants.

Some are specialized to live in the cold ocean waters around Antarctica, and under the polar ice caps. ("north pole".)

Name: Biology: The Living Environment Date:

Bacteria

I. Bacteria (plural) - Bacterium (single)

Very small organisms - they can only be seen through a microscope.

_____________________ bacteria lined up would be just _________________________

Unicellular - made of _______________________

They have no _________________ nor do they have most other cell organelles.

Some information here comes from: Simple English Wikipedia

The simplest organisms on Earth. They have existed on Earth for _________________

There are more individual bacteria than any other type of organism on the planet!

Most bacteria live in the ground or in water. Some live _______________________, in cracks between rocks. Many bacteria live inside, or on the skin of, other organisms - even humans.

II. Uses of bacteria

1. Gut bacteria help us ________________________.

2. Other bacteria help us ferment food.

What is fermentation?

Using bacteria (or yeast) to convert carbohydrates to other chemicals.

Only happens in anaerobic conditions (_____________________________________)

Bacteria turns some carbs into ________________ carbon dioxide gas, or other organic acids

Foods made with bacteria

Fermentation of milk makes ____________________________.

Fermentation of cacao (chocolate) beans, and coffee beans, helps them achieve their desired flavors.

Sauerkraut is finely cut cabbage that has been ____________________________.

Salami is a type of sausage — ground meat stuffed into a casing — which is not cooked, but is instead allowed to ferment with bacteria, before being dried and made edible. (This includes pepperoni)

Prince George's Community College, Karl J. Roberts, Ph. D. Professor of Biology



III. Reproduction of bacteria

They divide in half and creating two "daughter" cells: _________

Each daughter is ____________ to the parent, but smaller.



Name: Biology: The Living Environment Date:

Bacteria

IV. Bacteria (and Archaea) - their version of sex, and evolution

Bacteria do not have ____________________________

(The same is true for Archaea)

They do not have _________________________

However, bacteria exchange DNA with other bacteria cells.

This allows bacteria to ____________________________.

This makes each daughter cell slightly different from the parent.

So, in a way, this is sort of like sex - genes can get randomly shuffled.

But why do this?

If the environment that they live in changes, then

______________________________

In fact, if they all had the same genes, then ____________

______________________________

But if their genes are different, then even though some may die, _______________________________

The cells that live pass on their genes to their offspring. These new genes become _________________

The cell that die do not pass on their genes; those genes become ________________________

Therefore, as time goes by, the remaining bacteria change. This is __________________,

It's not just bacteria: All forms of life on Earth have changes in their DNA, as time goes by.

All forms of life undergo evolution.

Name: Biology: The Living Environment Date:

Bacteria

V. Archaea are very small, single-celled organisms.

Can only be seen through _________________

They have no nucleus, nor most other organelles.

The word Archaea comes from the Ancient Greek ἀρχαῖα, meaning ___________________

They look so much like bacteria, that until recently we thought _____________________________

But when we learned how their genes worked, we discovered that they were very different.

Their DNA is more similar to _________________________ than to a bacterium!?

They way they process chemical reactions in their cells is more plant-like or animal-like than bacteria-like.

As such, they do not belong in the bacteria category - and they do not belong in the animal, plant or fungus category - they are in their own ____________________ (special group.)

Name: Biology: The Living Environment Date:

Archaea

Most Archaea live in extreme environments, places where we once thought no life could exist.

The environments are much like Earth's environment ________________________, back when it was young.

The three families of Archaea

1. Methanogens: “methane-makers”

Use only CO2 (carbon dioxide), H (Hydrogen) and N (Nitrogen) to produce energy.

They give off methane gas.

They live in swamps, marshes, gut of cattle, termites, etc.

They can't breathe normal air, because ____________________________________!

These are decomposers; and can be used in sewage treatment.

They may someday be used to _______________________________

2. Extreme Halophiles: “salt lovers” - Require __________________________.

Even the ocean is not salty enough! Some prefer up to ____________ concentrations!

Live in the Dead Sea (Israel), the Great Salt Lake (Utah), and salt evaporation ponds all over the world.

Some get energy from _____________________________. But they do not have chlorophyll like plants.

Instead, they have a special colored molecule, a pigment, in their cells called bacteriorhodopsin.

It absorbs energy from light, and transfers the energy into molecules in the cell.

3. Extreme Thermophiles: “heat / cold lovers”

Some prefer temperatures above 60°C (up to 110°C for hyperthermophiles!), while some prefer to live near

or below freezing. (Many will _________________________________).

Live in hot sulfur springs, Yellowstone Park, near volcano vents, deep sea hydrothermal vents, deep sea “black smokers”, geothermal power plants.

Some are specialized to live in the cold ocean waters around Antarctica, and under the polar ice caps. ("north pole".)

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