Bacteria.
Vocabulary
Bacteria (Plural)-Бактерии
To provide nutrients to plants-Снабжать растения питательными веществами
Nitrogen-fixing cyanobacteria-Цианобактерии, усваивающие азот
Disease-causing-Болезнетворный, патогенный
Archaebacteria-Архибактерии
Underground-Под землей
To be alike in ...-Быть схожими в
Protein synthesis-Синтез протеина
Appearance-Внешний вид
An infolding of the plasma membrane-Впячивания цитоплазматической мембраны
To differ in ...-Различаться
A light microscope-Световой микроскоп
Metabolism-Обмен веществ
A flagellum (Pl. – flagella)-Жгутик (мн.ч. – жгутики)
A micrometer-Микрометр (10-6 степени метра)
To rotate-Вращаться
To perform a service-Выполнять функцию
A pilum (Pl. – pili)-Пили (мн.ч.)
To degrade waste-Разлагать отходы
To stick to the surface-Приклеиваться к поверхности
To add oxygen to the air-Снабжать воздух кислородом
Slime-Слизь
Rod-shaped-Палочковидный
To impart shape to ..-Придавать форму
Coma-shaped-В виде запятой
Spiral-винтообразный
Fermenting-Бродильный
An aulophyte-Симбионт
A host-Хозяин, носитель
Soil-Почва
Nodulating-Клубеньковый
A root-Корень
Predatory-Хищный
A destructor-Разрушитель
Prokaryotes fall into 3 groups : bacteria, nitrogen-fixing cyanobacteria and archaebacteria (Archaea). Bacteria are alike in appearance and size, but differ in their structure and metabolic details. Most prokaryotic cells are not wider than a micrometer (10-6 meter).
Bacteria are the most popular prokaryotic cells on Earth. They perform important services such as adding oxygen to the air, fermenting, providing nutrients to plants and degrading wastes (acting as destructors). Nearly all disease-causing prokaryotes are bacteria. Aulophytes live in organisms and are very useful. E.g. nodulating bacteria, which live in the roots of the plants, add nitrogen to the host and the soil. Predatory bacteria eat other prokaryotes.
We can find bacteria everywhere: at the bottom of the ocean, high up in the atmosphere, miles underground.
Let’s take a look at the structure of the bacteria. Bacteria are single-celled organisms that do not have their DNA in the nucleus. Instead their single chromosome(DNA) is in the region of the cytoplasm known as the nucleoid. Bacteria have ribosomes, which are responsible for the protein synthesis, and no organoids. Instead they have infoldings of the plasma membrane. You can’t see a typical prokaryotic cell without a light microscope. It’s smaller than a eukaryotic cell. Many prokaryotes have one or more flagella. They do not bend side to side, they just rotate like a propeller. Hairlike filaments pili help stick to the surface, e.g. river rocks or your teeth.
Protein filaments of the plasma membrane impart shape to the cell. Bacteria are often described by the shape. A coccus is spherical, a bacillus is rod-shaped, a spirillum is a spiral, a streptococcus is a chain of coccuses clinging together, a vibrio has coma-shaped, a staphylococcus is a mess of coccuses in the shape of grapes.
Questions:
What groups of prokaryotes do you know?
What are the common features of all bacteria? The differences?
What is the size of a bacterium?
What functions does a bacterium have?
What do destructors do?
Are there harmful bacteria?
What do aulophytes do?
What do nodulating bacteria do?
What do predators do?
Where can we find bacteria?
Describe a bacterium?
How many chromosomes does a bacterium have? What does this chromosome have? Where is the DNA chromosome?
What are ribosomes for?
Does a bacterium have any organoids? What does it have instead?
How can you see a bacterium?
How does it move?
How does it stick to surface?
Why does it stick to surface?
How do we classify bacteria?
What shape does a coccus have? A bacillus?A spirillum?A streptococcus?A vibrio?A staphylococcus?
True or false?
1. Bacteria have different shapes and the same structure.
2. Bacteria are bigger than eukaryotic cells.
3. You can’t find bacteria on Earth without a GPS navigator.
4. Bacteria help us to do our homework in Biology.
5. Bacteria are multi-celled organisms.
6. They have a lot of DNA chromosomes in the nucleus.
7. Ribosomes cook lunch for the bacteria.
8. There are infoldings of the plasma membrane in a bacterium.
9. Bacteria move using the propeller.
10. Bacteria stick to the surface with their teeth and nails.
11. All types of bacteria have a telephone number and an e-mail address, this is how we know who they are.