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Molecules and cells

Molecules and cells

Glucose
Glucose. Martin LaBar. Flickr (CC BY-NC)

Let's see what types of living organisms exist on Earth.

ORGANIC COMPOUNDS

They are chemical combinations that include carbon, for example, sugar, fats, proteins and nucleic acids. These compounds are found in all living things.

INORGANIC COMPOUNDS

They are chemical combinations which don't contain carbon, for example, water, salt, etc. We can find these compounds in living things or in inert matter.

CELLS

They are the basic units of every living organism. All cells are made from the same major organic molecules: nucleic acids, proteins, carbohydrates and lipids.

Cells have different parts which carry out different vital functions: nutrition, reproduction, interaction.

PROKARYOTIC CELLS

They are primitive cells whose genetic material is dispersed in the cytoplasm because they don't have a nucleus, for example, bacteria. They are single-cell organisms.

EUKARYOTIC CELLS

They are plant or animal cells that have a nucleus and organelles and are enclosed by a plasma membrane, for example, protists, fungi, plants and animals. They may be single-cell organisms such as protists or multicellular organisms such as animals, plants and fungi.

SINGLE-CELL ORGANISM

They consist of only one cell which senses the environment, gathers nutrients and reproduces asexually. Amoebas, bacteria

and plankton are single-cell organisms.

MULTICELLULAR ORGANISMS

They are made up of many cells which are specialized in different functions. Animals, plants and fungi are multicellular organisms.
Cell types
Cell types. Kelvin13. Wikipedia. (Public Domain)

Activity 1

1. Listen and write the words.
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Activity 2

2. Choose the right word to make correct statements.
a. The different parts of a cell carry out these functions: , reproduction and interaction.
Koli bacteria
Koli bacteria. Geralt. Pixabay. (Pixabay Licence)
b. Organic compounds include molecules.
c. A is an example of single-cell organism.
d. The genetic material in a cell is dispersed in the because it has not got a nucleus.
e. doesn't contain carbon molecules.
f. are an example of eukaryotic cells.

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Activity 3

3. Choose the corresponding letter to make correct sentences.
1. Inorganic compounds are combinations of chemical elements... a. ... eukaryotic, single-cells organisms.
2. Cells have different parts... b. ... which include carbon.
3. Organic compounds are combinations of chemical elements... c. ... which don't contain carbon.
4. Prokaryotic cells are primitive cells... d. ... prokaryotic, single-cell organisms.
5. Bacteria are... e. ... which carry out different vital fuctions.
6. Plankton are... f. ... whose genetic material is dispersed in the cytoplasm.
7. Animals, plants and fungi are... g. ... multicellular organisms.

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Extra activity

Watch this video about animal cells and answer the questions on the right.

A typical animal cell. Wisc-online.  YouTube. (YouTube standard)

 1. Why are plants and animal cells different?
2. Which are the three main parts of an animal cell?
3. What is one of the differences between blood cells and liver cells?
4. Which element is related to muscle contractions?
5. Where can DNA be found?