Unit 6: LIVING THINGS

Unit 6: LIVING THINGS

1. What makes living things special?

2. Living matter

3. Organisms are made up of cells

4. Cell types

5. Cells specialise and form groups

1. WHAT MAKES LIVING THINGS SPECIAL?

Living things consist of organic matter.

Organic matter is constituted by chemical elements which join together to form biomolecules.

• The key chemical element of organic matter is carbon (C). Other chemical elements that are abundant in living things are: hydrogen (H), oxygen (O), nitrogen (N), sulfur (S), phosphorous (P).

• There are 2 types of biomolecules: inorganic biomolecules and organic biomolecules.

INERT BEINGS River, mountain, water, rock, bag, chair…

LIVING BEINGS Lion, bird, snail, bacteria, mushroom…

CONSIST OF ORGANIC MATTER CONSIST OF INORGANIC MATTER

VOCABULARY: organic matter (materia orgánica), living beings or living things, bioelement,

biomolecule, join together (unirse), carbon (carbono), carbohydrates, lipids, proteins, provide

(aportar), energy, structural, regulatory (reguladora), nucleic acids (ácidos nucleicos),

inheritance information (información hereditaria).

THE MAIN FUNCTIONS OF BIOMOLECULES ARE:

1. Energy function, because biomolecules provide energy needed to perform life processes.

2. Structural function, because biomolecules provide the elements to form cells, tissues…

3. Regulatory function, because biomolecules participate in all the chemical reactions that occur in the cells.

Simple carbohydrate (glucose) Complex carbohydrate

Cell membrane lipid Protein

2. LIVING MATTER

All living beings have several characteristics in common:

1. They are made of cells.

2. They have a complex chemical composition.

3. They need energy to perform their life processes.

4. They grow and develop over time.

5. They reproduce by producing similar organisms.

6. They repond to environmental stimuli.

7. They adapt to their environment.

Viruses are composed of biomolecules and have a structure similar to the cell but they are not considered living beings.

A. Characteristics of living matter

B. The life processes of living things

The three fundamental life processes of living things are NUTRITION, INTERACTION AND REPRODUCTION.

ACTIVITY 4. COPY THE DEFINITION OF THE THREE FUNDAMENTAL LIFE PROCESSES FROM PAGE 61.

CELL: structural and functional unit of living beings.

CELLS VARY IN SIZE: most cells can only be seen using a microscope but others are visible to naked eye (for example: egg yolk).

According to the number of cells, THERE ARE TWO TYPES OF LIVING BEINGS:

- Unicellular living beings: bacteria, protozoan…

- Multicellular living beings: lion, pine, ant…

Human beings consist of billions of cells. THE CELLS SPECIALISE in different functions.

3. ORGANISMS ARE MADE UP OF CELLS

VOCABULARY: cell, cell membrane, cytoplasm, genetic material, jelly-like

liquid (líquido gelatinoso), nucleus (núcleo), organelle (orgánulo), chloroplast

(cloroplasto), mitochondria (mitocondria), Golgi apparatus (aparato de Golgi),

vacuole (vacuola), lysosome (lisosoma), ribosome (ribosoma), smooth

endoplasmic reticulum (retículo endoplasmático liso), rough endoplasmic

reticulum (retículo endoplasmático rugoso).

ACTIVITY 5. ACTIVITY 10 ON PAGE 62.

THE PARTS OF A CELL:

CELL MEMBRANE: layer surrounds the cell.

CYTOPLASM: jelly - like liquid inside the cell with special structures called organelles; each organelle has a specific function.

Organelles: chloroplasts, mitochondria, vacuoles, Golgi apparatus, lysosomes, ribosomes, smooth endoplasmic reticulum, rough edoplasmic reticulum, centrioles

GENETIC MATERIAL

EUKARYOTIC CELLS Bigger and more complex than

prokariotic cells.

They have one or two membranes: - animal cells have one membrane:cell membrane

- plant cells have two membranes: cell membrane

and cell wall.

Their genetic material (ADN) is

found in the nucleus, which is

surrounded by a double membrane.

The cytoplasm contains many

organelles.

There are two types: ANIMAL

CELLS and PLANT CELLS

4. CELL TYPES There are two types of cells: PROKARYOTE CELLS (células procariotas) AND EUKARYOTE CELLS (células eucariotas).

Del griego. Pro: “primitivo” o “antes de”. Karyon: “núcleo”. Eu: “verdadero”.

PROKARYOTIC CELLS

Small and simple.

They have three membranes:

cell membrane, cell wall and

capsule.

Their genetic material (ADN) is

free in the cytoplasm (they don’t

have nucleus).

BACTERIA are the most

common type of prokaryote

ACTIVITY 6. ¿CUÁLES SON LAS DIFERENCIAS ENTRE LAS CÉLULAS PROCARIOTAS Y EUCARIOTAS?

Prokariotic cell

Animal eukariotic cells

Plant eukariotic cells

ACTIVITY 7. COMPLETE THE NAMES (IN ENGLISH AND IN SPANISH) AND THE GAPS OF THE FOLLOWING IMAGE.

ACTIVITY 8. COMPLETE THE NAMES (IN ENGLISH AND IN SPANISH) AND THE GAPS OF THE FOLLOWING IMAGES.

ACTIVIDAD 9. ¿CUÁLES SON LAS PRINCIPALES DIFERENCIAS ENTRE LAS CÉLULAS ANIMALES Y VEGETALES? UTILIZA LA TABLA DE LA PÁGINA 63.

• CELL MEMBRANE: controls the exchange of substances between the cell and its environment.

• MITHOCHONDRIAS: cell organelles that provide all the necessary energy to the cell, and they obtain this energy of the nutrients.

• RIBOSOMES: cell organelles that make proteins.

• CELL WALL: rigid structure that protects the plant cell and helps maintain its shape.

• CHLOROPLASTS: cell organelles where photosynthesis occurs thanks to photosynthetic pigments (chlorophyll).

• VACUOLES: cell organelles that store different substances.

• CENTRIOLES: cell organelles that help the cell to divide.

Functions of cell membrane, cell wall and some organelles

5. CELLS SPECIALISE AND FORM GROUPS

During the development of the embryo, some cells differentiate into specialised cells. The form of cell depends on its function.

CELLS

TISSUES

ORGANS

TRACTS AND SYSTEMS

(group of organs working together to perform a specific function)

Cells with the same function group together to form tissues

Tissues group together to form more complex structures called organs

Organs group together to form tracts and systems

Muscular cell, epithelial cell, bone cell…

Muscular tissue, epithelial tissue, nerve tissue, glandular tissue…

Heart, stomach, liver, lung…

Digestive tract, circulatory tract, nervous system…

Tracts or systems

LEVEL OF ORGANISATION OF HUMAN BODY

Bioelements

Biomolecules

Organelle

Cell

Tissue

Organ

Organism

ACTIVITIES 14 AND 15 ON PAGE 64

ACTIVITIES ON PAGE 65