Download How the living matter is organized

How the living matter is organized
1.- Levels of organization
2.- What are living beings made of?
3.- Cell structure and function
1.- Levels of organization
The organization of life
Living matter is very complex. This is one of the characteristics which most differenciates
it from inert or inanimate matter. We can discover several levels of complexity which are
known as Levels of organization. Each level of organization gives the matter which
makes it up certain properties which cannot be found in lower levels.
Types of levels of organization
We can find the following levels of organization in living matter:
Atom: is the smallest particle that mantains its physical and chemical properties. Ex:
oxygen, nitrogen.
Molecule: when two or more atoms are bonded together. Ex: water, carbon dioxide.
Macromolecule: when two or more molecules are bonded together to form large
molecules. Ex: proteins, lipids, carbohydrates.
Organelles: several macromolecules bonded together form these building blocks of a
cell. Ex: mitochondria, nucleus.
Below this level begins what scientists consider living or alive
Cells: the smallest unit of life, a cell is a collection of organelles functioning together. Ex:
bacteria, animal, plant cell.
Tissues: a collection of cells working together to perform a specific job. Ex: epithelial,
connective.
Organs: two or more types of tissues that work together to complete a specific task. Ex:
heart, stomach.
Systems: several organs working in unison to achieve a common goal. Ex: digestive,
cardiovascular.
Organism: several organ systems functioning together. Ex: human.
Population: groups of individual organisms of the same species living in the same zone
and at the same time. Ex: a swarm of bees.
Community: populations of different species of organisms.
Ecosystem: the physical components of environment (abiotic factors), all organisms
living in an area (biotic factors) and their interactions. Ex: a tropical rain forest.
Biome: a collection of ecosystems with similar climates. Ex: desert, tundra.
Biosphere: all tha biomes on the planet Earth. Ex: the Earth`s living occupants.
1 Å (angstrom) = 0,1 nm
1 nm (nanometre) = 0,001 µm
1µm (micron) = 0,001 mm
1mm = 0,001 m
1 m = 0,001 Km
Units of measurement for the levels of organization
Scale of life:
from the smallest to the biggest
2.- What are living beings made of?
Oxygen
Chemical compounds in cells
Elements: an element is any substance that cannot be broken
down into simpler substances. Oxygen and nitrogen are examples
of elements. The smallest unit of an element is called atom. An
element is made up of only one kind of atom. The elements found
in living things include carbon, hydrogen, oxygen, nitrogen,
phosphorus, and sulfur.
Water Molecule
Hydrogen
A water molecule is
made up of one atom of
oxygen and two atoms of
hydrogen.
Compounds: when two or more elements combine chemically,
they form a compound. Carbon dioxide is a compound made up of
the elements carbon and oxygen. Most elements in living things
occur in the form of compounds. The smallest unit of many
compounds is called a molecule. A molecule of carbon dioxide
consists of one carbon atom and two oxygen atoms. Water is
another compound. Each water molecule is made up of two
hydrogen atoms and one oxygen atom.
Organic and Inorganic Compounds: many of the compounds
found in living things contain the elelment carbon. Most
compounds that contain carbon are called organic compounds.
Some important groups of organic compounds found in living things
are carbohydrates, lipids, proteins, and nucleic acids. As you
know, many of these compounds are found in the foods you eat.
This is not surprising, since the foods you eat come from living
things. Compounds that don´t contain the element carbon are
called inorganic compounds. Water and sodium chloride (table
salt), are familiar examples of inorganic compounds. Organisms
contain many inorganic compounds as well as organic compounds.
Carbon Dioxide Molecule
The air bubbles contain
carbon dioxide. A carbon
dioxide molecule has one
atom of carbon and two atoms
of oxygen.
Oxygen
Carbon
Inorganic compounds
1. Water
There is no life without water. In fact, more than half
of our body is liquid water. Some beings, like jelly fish,
are made up of 96 % of water, whereas seeds only
have 20 %.
Mostly water
About two-thirds of the
human body is water.
Water palys many important roles in cells. For
example, most chemical reactions in cells involve
substances that are disolved in water. Also, water
molecules themselves take part in many chemical
reactions in cells. Most chemical reactions within
cells could not take place without water.
Water also helps cells keep their size and shape. In
fact, a cell without water would be like a balloon
without air. In addition, because water changes
temperature slowly, it helps keep the temperature of
cells from changing rapidily.
2. Mineral salts
9They make up the hard and solid parts of living beings (skeletons and shells).
9Many mineral salts are in dissolutions in the form of ions and they take part in chemical
reactions.
9They maintain the salinity of the body.
9They allow the transmission of nervous impulses.
9They form part of significant molecules such as hemoglobin.
Shells of molluscs
They are made up of a mineral salt known as calcium carbonate.
Skeletons
They are made up of a mineral salt
known as calcium phosphate.
Organic compounds
Monosaccharides: a single unit of sugar (simple sugars), they are the smallest carbohydrates. The
common monosaccharides are:
1. Carbohydrates
They are organic compounds of
carbon, hydrogen and oxygen.
Functions of carbohydrates:
9Primary among those is that
they serve as energy sources for
both plants and animals
9Source of carbon in metabolic
processes
9Storage form of energy
9Structural elements of cells and
tissues
Glucose (C6H12O6): it is the
main sugar used by cells to
produce energy and it is often
referred to as blood sugar.
Fructose / Galactose: both are
absorbed and converted into
glucose by the liver. Sources of
fructose include fruit and honey.
Ribose: ribose and its related
deoxyribose are the building
blocks of nucleic acids (RNA
and DNA).
Disaccharides: are formed by two monosaccharides linked together (double sugars). The common
disaccharides are:
On the basis of the chemical
complexity carbohydrates are
classified as ...
Lactose: it is found in the milk.
It has a glucose and a galactose
sugar.
Maltose: it is composed of two
glucose molecules. It is known
as beer sugar.
Sucrose: it is composed of
glucose and fructose. It is the
table sugar.
Polysaccharides: formed of long chains of monosaccharide units linked together. The common
polysaccharides are: starch (storage form of energy in plants made up of glucose units), glycogen
(storage form of energy in animals made up of many glucose units), cellulose ( it is a constituent of plant
cell walls and it is not digestable because we lack enzymes for it). Chitin ( some insects make their
skeletons with this carbohydrate).
2. Lipids
3. Proteins
Lipids are a group of very different substances, including oils, fats, waxes, cholesterol.
They are organic compounds of carbon, hydrogen, oxygen and, in some cases,
small amounts of phosphorous.
They are large organic molecules made of of carbon, hydrogen,
oxygen, nitogen, and, in some cases, sulfur. Protein molecules are
made up of smaller molecules called amino acids. Although there
are only 20 common amino acids, cells can combine them in
different ways to form thousands of different proteins.
Functions of lipids:
9Like carbohydrates, lipids are energy-rich organic compounds. Lipids contain even
more energy than carbohydrates. Cells store energy in lipids for later use.
9They are structural elements of cells. Cell membranes are made mainly of lipids.
4. Nucleic Acids
Nucleic acids are very long organic
molecules made of carbon, hydrogen,
oxygen, nitrogen and phosphorous.
Nucleic acids contain the instructions
that cells need to carry out all the
functions of life.
There are two kinds of nucleic acids.
Deoxyribonucleic acid, or DNA, is the
genetic material that carries information
about an organism and is passed from
parent to offspring. The information in
DNA also directs all the cell`s functions.
Most of the DNA in a cell is found in the
chromatin in the nucleus. Ribonucleic
acid, or RNA, plays an important role in
the production of proteins. RNA is found
in the cytoplasm as well as in the
nucleus.
DNA
molecule
sugar
Functions of proteins:
9Much of the structure of cells is made up of proteins. Proteins form
parts of cell membranes. Proteins also make up many of the
organelles within the cell.
9The proteins known as enzymes perform important functions in the
chemical reactions that take place in cells. An enzyme is a type of
protein that speeds up a chemical reaction in a living thing.
9They carry substances from one part of the body to another. For
example, haemoglobin transprts oxygen in the blood.
9Inmune protection: the antibodies that allow us to defend
ourselves from viruses and bacteria are proteins.
bases
Chain of amino acids
Phosphate
group
Protein molecule
3.- Cell Structure and function
An overview of cells
You are made of cells. All living things are made
up of one or more cells. Cells are the smallest
units of structure and function in living
things. This means that cells form the parts of an
organism and carry out all of an organism’s
processes, or functions. Some functions in
organisms include:
9Obtain food and oxygen
9Perform chemical reactions (make energy)
9Eliminate carbon dioxide and wastes
9Synthesize proteins and cell components
9Control exchange of materials
9Adapt, respond to environmental changes
9Reproduce (except nerve and muscle)
Cells are involved in all these functions.
Types of cells
There are several ways to classify cells, but the main division is between
prokaryotic and eukaryotic cells. There are big differences between them:
Prokaryotic
Eukaryotic
9Simple cells
9Small cells
9Do not have a nucleus
9No membrane-bound organelles
9More primitive than eukaryotic
9They only form unicellular organisms
9Ex: bacteria
9Complex cells
9Larger cells
9Do have a true nucleus
9Membrane-bound organelles
9Evolved from Prokaryotic
9They can form both unicellular and multicellular
organisms
9Ex: animal, plant, fungi, protozoans
Organisms that exist as single cells are called
unicellular and organisms that are made up of
groups of cells working together are called
multicellular.
Principles of the Cell Theory:
9All living things are made of one or more
cells.
9Cells are the basic unit of structure and
function in organisms
9Cells come only from the reproduction of
existing cells.
Prokaryotic Cell
Animal (Eukaryotic) Cell
Looking inside cells
Enter the cell
All cells contain three basic parts:
Cell Membrane:
9Cell membrane: forms the outside boundary of the cell.
9Nucleus: the cell’s control center, directing all of the cell’s
activities.
9Cytoplasm: a gel-like fluid between the cell membrane
and the nucleus. Many cell’s specialized structures or cell
organelles are found in the cytoplasm.
9It surrounds the cell and separates the cytoplasm of the cell from its environment.
9Protects the cell and controls what enters and leaves. Cell membranes are
selectively permeable only allowing certain materials to enter or leave. Food and
oxygen enter the cell through the cell membrane. Harmful waste products leave
the cell through the cell membrane. It also prevents harmful materials from
entering the cell.
9It is made up of lipids and proteins.
Cell Wall:
The cell wall is a rigid layer that surrounds the cell membrane of plant cells and
prokaryotic cells (bacteria). It is made mostly of a strong material called cellulose.
The cell wall provides and maintains the shape of these cells and serves as a
protective barrier.
The cell membrane is made up
of two lipid layers
Cell Membrane
A channel in the cell membrane.
It is made up of certain proteins
whose function is to control the
movement of food and water into
the cell.
The Nucleus
This is the largest and most easily visible structure in a
cell. As you sail inside the cell, a large, oval structure
comes into view. This structure acts as the “brain” of the
cell.
Nuclear envelope: notice in figure that the nucleus is
surrounded by a membrane called the nuclear envelope.It
is a double-membrane structure that protects the nucleus.
Materials pass in and out of the nucleus through pores in
the nuclear envelope.
Nucleolus: This is a spherical structure in which
ribosomes are made. Ribosomes are the organelles
where proteins are produced. Proteins are important
chemicals in cells.
Nucleoplasm: the viscous liquid within nucleus. It is
similar to the cytoplasm found outside the nucleus. It
contains the chromatin, which is composed of DNA and
proteins.The chains of DNA contain the genetic
information of the cell, in other words, instrunctions for
carrying out the cell’s activities.
Organelles in the cytoplasm
Mitochondria: most of the cell’s energy is produced within these rod—
shaped organelles. They convert energy in food molecules to energy the
cell can use to carry out its functions.
Endoplasmic Reticulum: a network of membranes that stores, separates
and transports substances within the cell.
Chloroplasts
ƒRough Endoplasmic Reticulum: close to the nucleus and in contact with
the nuclear envelope. It has ribosomes attached to its membranes and
makes proteins to be secreted by the cell.
ƒSmooth Endoplasmic Reticulum: more distant from the nucleus and
with no ribosomes. It makes lipids, processes carbohydrates and modifies
toxic chemicals in the cell.
Endoplasmic
Reticulum
Ribosomes: these small tiny ball-like structures function as factories to
produce proteins. Ribosomes may be attached to the Endopalsmic
Reticulum, or they may float in the cytoplasm.
Mitochondria
Golgi Apparatus: flattened sacs and tubes where protein molecules are
stored, changed, packaged and distributed throughout the cell.
Chloroplasts: only the cells of plants and some other organisms have
these organelles. Green oval-shaped structures that capture energy from
sunlight and use it to produce food for the cell (photosynthesis).
Chloroplasts make leaves green.
Vacuoles: large water-filled sacs floating in the cytoplasm. They are the
storage areas of cells. Most plant cells have one large vacuole. Some
animal cells do not have vacuoles; others do. Vacuoles store food and
other materials needed by the cell. Vacuoles can also store waste
products.
Lysosomes: are small, round structures containing chemicals that break
down certain materials in the cell.
Ribosomes
Golgi
Apparatus
Plant and Animal Cells