Microorganisms 6th. Grade

Microorganisms & Health

Miss Ma. Carolina B.Science 6th. Grade - April 2021

Investigate and identify some benficial and harmful microorganisms for health (bacterias, virus and fungi), and propose measures to take care and hygiene of the body.

Objective

Important facts of the videos

Class discussion.

Bacterias

Activity

See the following pictures and answer the questions below (write the question and complete answer in your copybook). 1. Where can we find these organisms? 2. How can we observe these organisms?

Virus

Fungi

What are microorganisms?

Microorganisms are very small living things which are impossible to see with the naked eye and only be observed with a microscope. Bacteria and fungi are examples of microorganisms.

1. BACTERIA: are unicellular organisms (formed by a single cell) that come in different shapes: -elongated -conical -espherical Some of them can cause serious diseases.

MICROSCOPE

2. FUNGI: can be unicellular or pluricellular organisms. -Yeast (unicellular) -Mushrooms (pluricellular) Some cause diseases and others harmless or even, play an important part in some processes that are beneficial. 3. VIRUS: they are not considered to be microorganisms, because of their small size and their ability to reproduce easily. They do not have the characteristics typical of living things. Some of them can cause serious diseases in human beings.

beneficial Microorganisms to human beings

1. Microorganisms in the body

-Most of the bacteria live in the digestive tract (100 billion). These are called bacterial flora. -Examples: Escherichia coli and Staphylococcus aureus. -Roles of bacterial flora in the body: a. Facilitate digestion of certain foods that are not digested in the small intestine (plant fiber). b. Producing vitamin K, that participates in the blood clotting process. c. Facilitates the absorption of some mineral salts (calcium and iron) that protects us from invasion of microorganisms that cause diseases.

Escherichia coli

2. Microorganisms in food

-Microorganisms participate in the preparation of these products through a chemical process called fermentation.-In fermentation, microorganisms transform one substance into another. -Some examples: 1. Bacteria Lactobacillus and Lactococcus, which are naturally present in milk, are involved in the preparation of yogurt and cheese. 2. Fungus called Saccharomyces cerevisiae is involved in the preparation of bread. This is a unicellular fungus that is added to dough to make it fluff up and rise.

Saccharomyces cerevisiae

3. Microorganisms in antibiotics

-Antibiotics are a group of medicines which destroy the bacteria that cause diseases. -In 1928, Scottish doctor Alexander Fleming was preparing vaccines in his lab, he observed that a culture of a bacterial strain had been contaminated by the presence of a fungus called Penicillium notatum. Fleming realized that there was a bacteria-free area arounfd the fungus. -He supposed that this fungus was preventing the groth of bacteria or causing them to die. *PENICILLIN was invented because of this discovery. Is one of the most commonly used antibiotics in the world for fighting bacterial illnesses.