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 group

1. WHAT MAKES LIVING THINGS SPECIAL?

Living things consist of organic matter.

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

Chemical elements join together

Molecules

The chemical elements that form living beings are called BIOELEMENTS.

- Carbon (C): key chemical element of organic matter or living matter(elemento químico característico de la materia orgánica o materia viva)

- Other bioelements that are abundant in living things:

Hydrogen (H), Oxygen (O), Nitrogen (N), Phosphorus (P) and Sulfur (S).

Chlorine (Cl), Sodium (Na), Calcium (Ca), Iron (Fe)

Bioelements

Carbohydrates(glúcidos)

Lipids(lípidos o grasas)

Proteins(proteínas)

join together

Vitamins

Nucleic acids

Inorganic biomolecules

Biomolecules

Organic biomolecules

Water(H2O)

Mineral salts

The molecules that form living beings are calledBIOMOLECULES. There are two types of biomolecules:inorganic biomolecules and organic biomolecules.

Simple carbohydrate (glucose) Complex carbohydrate

Cell membrane lipid Protein

ACTIVITY 5 ON PAGE 60

ACTIVITY. COMPLETE THE TABLE

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 of a livingbeing, 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 andreproduction.

NUTRITION INTERACTION REPRODUCTION

ACTIVITY 8 ON PAGE 61.

3. ORGANISMS ARE MADE UP OF CELLS

Louse

Worm

Bacteria

Mushroom

• CELLS VARY IN SIZE: some cells can only be seen using a microscope but

others are visible to neked eye (for example: egg yolk).

• There are UNICELLULAR (bacteria, protozoan…) and MULTICELLULAR living

things (lion, pine, ant…).

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

functions.

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, mitochodria, vacuoles, Golgi apparatus,

lysosomes, ribosomes, smooth endoplasmic reticulum, rough edoplasmic

reticulum, centrioles

GENETIC MATERIAL

3. ORGANISMS ARE MADE UP OF CELLS

ACTIVITY 10 ON PAGE 62.

Multicelllular: many cells.

Unicellular: one cell.

Organelle: special structure of the celllocated in the cytoplasm and which hasa special function.

Cytoplasm: jelly-like liquid inside the cellcontaining organelles.

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 TYPESThere 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

Prokariotic cell

Animal eukariotic cells

Plant eukariotic cells

ACTIVITY 12 ON PAGE 63.

The main differences between prokaryotes andeukaryotes are:

1. Prokaryotic cells are small and simple but eukaryoticcells are bigger and more complex.

2. Prokaryotic cells have 3 membranes and eukaryoticcells have 1 or 2 membranes.

3. The material genetic in proKaryotic cells is free in thecytoplasm but in eukaryotic cells it is found in thenucleus.

4. Eukaryotic cells contain more organelles thatprokaryotic cells.

ACTIVITY. WHAT ARE THE MAIN DIFFERENCES

BETWEEN ANIMAL AND PLANT CELLS? YOU HAVE

TO USE THE TABLE ON PAGE 63.

1. The cell wall and chloroplasts are found only

in plant cells.

2. Centrioles and lysosomes are found only is

animal cells.

3. Plant cells have a big vacuole and animal cells

have many vacuoles but very small.

ACTIVIDAD. COMPLETE THE NAMES (IN

ENGLISH AND IN SPANISH) OF THE FOLLOWING

IMAGE AND ANSWER THE QUESTIONS.

ACTIVITY. COMPLETE THE NAMES (IN ENGLISH AND IN SPANISH) OF THE

IMAGES AND ANSWER THE QUESTIONS.

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

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

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

• RIBOSOMES: cell organelles that make proteins.

• CHLOROPLASTS: cell organelles where photosynthesis occurs thanksto 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 ANDFORM GROUPS

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

CELLS

TISSUES

ORGANS

TRACTS AND SYSTEMS

(group of organs working togetherto 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

Macromolecules

Organelle

Cell

Tissue

Organ

Organism

ACTIVITY 14 AND 15 ON PAGE 64

ACTIVITIES ON PAGE 65

VOCABULARY

1. Organic matter, living beings, bioelement, biomolecule, join together,

carbon, carbohydrates, lipids, proteins, provide, energy, strutural,

regulatory, nucleic acids, inheritance information.

2. Perform, environmental stimuli, grow, survive, interaction, perceive.

3. Cell, cell membrane, cytoplasm, genetic material, jelly-like liquid,

nucleus, organelle, chloroplast, mitochondria, Golgi apparatus, vacuole,

lysosome, ribosome, smooth endoplasmic reticulum, rough endoplasmic

reticulum.

4. Prokaryotic cell, eukaryotic cell, cell wall, capsule, animal cell, plant

cell, optical microscope, electron microscope.

5. Development, specialised cell, tissue, organ, tract, system.