the basis of life

2. What do you remember?
1. What living beings can you see in this photo?
2. What common characteristics do living beings have?
3. What are the vital functions of living beings?
4. What is the basic unit of life?

4. What are the vital functions?
They are the specific actions that support life:
1. Nutrition: process in which living beings obtain the
matter and the energy necessary for life.
2. Interaction: process in which living beings relate with
their surrounding environment.
3. Reproduction: process by which new living beings are
produced.

5. Activity 1. What vital functions are these?

7. They are the building blocks of life, and perform
important functions in living organisms. There
are two types:
1. Organic biomolecules: are exclusive to living beings:
carbohydrates, lipids, proteins and nucleic acids.
2. Inorganic biomolecules: are not exclusive to living
beings, but they are essential for life: water and
mineral salts.

8. Organic biomolecules
Carbohydrates: the most abundant and soluble
in water, are made up of molecules called
monosaccharides. Some of them restore energy,
but others are structural components. Ex. Sucrose,
cellulose, starch.

9. Lipids: insoluble in water, they perform lots of
functions. Some of them restore energy, and
others have structural functions. Ex: oil,
cholesterol, wax, phospholipids.

10. Proteins: are macromolecules with complex
structures, made up of chains of smaller
molecules called amino acids. They carry out
many different functions.

11. Nucleic acids are macromolecules formed by
the union of smaller molecules called
nucleotides. They are found in the genetic
material of cells, and there are two types:
Deoxyribonucleic acid (DNA) found in the cell
nucleus. It contains the genetic material.
Ribonucleic acid (RNA) found in the cytoplasm, it
participates in the synthesis of proteins.

12. Inorganic Biomolecules
 Water: is the most abundant substance in living beings,
about the 65% of our bodies. All chemical reactions
occur in aquatic media, it transports substances and
regulates the body temperature.
 Mineral salts form structures such as bones and teeth,
take part in chemical reactions and are necessary for
the transmission of nervous impulses.

13. Activity 2. Classify these substances and explain their
functions.
1. Starch
2. Cholesterol
3. Cellulose
4. Wax
5. Haemoglobin
6. Collagen
7. Antibodies
8. Phospholipids

15. WHAT ARE CELLS?
They are the structural and functional units of all living
beings. They have three basic structures:

16. Cell membrane: the thin layer which separates the
inside of the cell from its surrounding environment.
Cytoplasm: the gelatinous, semi-transparent fluid
which fills most cells. It contains structures called
organelles, which are responsible for cell functions.
Nucleus : carries the genetic (hereditary) material of
living things which is passed from one generation to the
next.

17. According to the location of their genetic material, cells can be:
1. Prokaryotic: the genetic material is dispersed in the cytoplasm).
Bacteria are prokaryotic organisms.
2. Eukaryotic: the genetic material is enclosed in the nucleus). Ex:
Animals and Plants are eukaryotic organisms.

18. Main differences between Animal and Plant cells

19. Activity 3. Complete the chart comparing animal and
vegetal cell.
Animal Cell Vegetal Cell
Shape
Rigid Cell Wall
(Made of cellulose)
Cell Membrane
Chloroplasts.
(Organelles which
absorb the Sun’s
energy)
Vacuoles
(Organelles that
accumulate
substances)

21. What is Cellular Nutrition?
In involves all the processes in which cells obtain
matter and energy to perform vital functions.
Cells take nutrients from food (lipids, carbohydrates,
proteins, water, etc). Once inside the cell, the nutrients
suffer chemical processes called cellular metabolism.

22. There are two types of metabolic reactions:
- Catabolism: proccesses in which complex substances
are degradated into simpler ones. They produce energy.
- Anabolism: processes in which simple substances
produce complex ones. They require energy.

23. Types of Cellular Nutrition:
Depending on the type of nutrients, cellular nutrition can
be Autotrophic or Heterotrophic.
Autotrophic: it takes place in cells which make their
own organic matter from inorganic matter using an
energy source. Depending on the energy source used,
two processes can occur:
- Photosynthesis: if energy comes from the sun (for
example in plants and algae).
- Chemosynthesis: if energy comes from chemical
reactions, (for example in some bacteria).

24. Water + Mineral Salts + CO2 + Sunlight  O2 + Glucose

25. o Heterotrophic: characteristic of cells which feed on
organic matter produced by other living beings.
It takes place in the cells of animals, fungi, protozoa and
many bacteria.

26. What is cellular respiration?
Once cells have nutrients, respiration takes place.
It describes the metabolic reactions in a cell to
obtain energy from those organic molecules
(glucose). It can occur with or without oxygen
(fermentation).
Cellular respiration occur in mitochondria.

27. What is cellular division?
It is a process by which the parent cell divides
into two or more cells called daughter cells.
In Unicellular living things, cellular division
replicates an entire organism. This can occur by two
processes:
 Binary Fission.
 Multiple Fission.

29. • In Pluricellular organisms, cellular division
results in an increase in the number of cells of an
organism.