Concepts of Environmental Science
Environmental Systems: Elements, Organisms, and Ecosystems
The world is a complex system. A hierarchy of living organisms is evident. At the same time,
non-living things also compose the Earth. Living organisms like plants, animals, microbes, and
humans cannot exist without non-living things like water, air, and soil. Furthermore, interactions
of living organisms with each other and interactions of living things with their environment
result to the intricacy of life. No matter how complex the world may be, all of things are made up
of smaller particles, and follow the laws of Chemistry.
Matter is anything that has mass and occupies space. All living and non-living things in the
natural world are considered matter. Applying the law of conservation of mass, matter can
neither be created nor destroyed, but may be transformed form one form to another.
Elements are pure substances made from a single type of atom. Elements are the building blocks
for all of the matter in the world. The positively-charged protons, neutrally-charged neutrons,
and negatively-charged electrons make up the atom. When atoms combine, they form
compounds and molecules. Larger molecules that are important components of cells are
collectively termed as macromolecules.
Macromolecules
1. Carbohydrates – sugars; provide quick source of energy and structural component of
cells. Examples include sucrose (table sugar), glucose, and lactose (sugar in milk)
2. Lipids – fats and oils; provides insulation and lubrication; primary component of cell
membranes. Examples include palm oil, lard, and olive oil
3. Proteins – component of muscle fibres and antibodies; legumes are rich source of
proteins. Examples include amylase and haemoglobin
4. Nucleic acids – make up the genetic material of living organisms. Examples include
DNA, RNA
Hierarchy of Living Organisms
Cell Tissue Organ Organ System Organism
An organism interacts with their own species, with other species, and with the surroundings. The
hierarchy of life expands to:
Organism Population Community Ecosystem Biosphere
The cell is the fundamental unit of life.
The tissue is a group of closely associated, similar cells that work together to carry out specific
functions.
The organ is a group of tissues in a living organism that have been adapted to perform a specific
function.
The organ system is group of organs that work together to perform a certain function in an
organism's body.
The organism is the individual entity that embodies the properties of life. It may also be referred
as the species. The Species refers to all organisms of the same kind that are genetically similar
enough to breed in nature and produce live, fertile offspring.
The community includes populations of different species living in a particular area.
Ecosystems are composed of a biological community and its physical environment.
The biosphere is the worldwide sum of all ecosystems.
Environmental Systems: Elements, Organisms, and Ecosystems
The world is a complex system. A hierarchy of living organisms is evident. At the same time,
non-living things also compose the Earth. Living organisms like plants, animals, microbes, and
humans cannot exist without non-living things like water, air, and soil. Furthermore, interactions
of living organisms with each other and interactions of living things with their environment
result to the intricacy of life. No matter how complex the world may be, all of things are made up
of smaller particles, and follow the laws of Chemistry.
Matter is anything that has mass and occupies space. All living and non-living things in the
natural world are considered matter. Applying the law of conservation of mass, matter can
neither be created nor destroyed, but may be transformed form one form to another.
Elements are pure substances made from a single type of atom. Elements are the building blocks
for all of the matter in the world. The positively-charged protons, neutrally-charged neutrons,
and negatively-charged electrons make up the atom. When atoms combine, they form
compounds and molecules. Larger molecules that are important components of cells are
collectively termed as macromolecules.
Macromolecules
1. Carbohydrates – sugars; provide quick source of energy and structural component of
cells. Examples include sucrose (table sugar), glucose, and lactose (sugar in milk)
2. Lipids – fats and oils; provides insulation and lubrication; primary component of cell
membranes. Examples include palm oil, lard, and olive oil
3. Proteins – component of muscle fibres and antibodies; legumes are rich source of
proteins. Examples include amylase and haemoglobin
4. Nucleic acids – make up the genetic material of living organisms. Examples include
DNA, RNA
Hierarchy of Living Organisms
Cell Tissue Organ Organ System Organism
An organism interacts with their own species, with other species, and with the surroundings. The
hierarchy of life expands to:
Organism Population Community Ecosystem Biosphere
The cell is the fundamental unit of life.
The tissue is a group of closely associated, similar cells that work together to carry out specific
functions.
The organ is a group of tissues in a living organism that have been adapted to perform a specific
function.
The organ system is group of organs that work together to perform a certain function in an
organism's body.
The organism is the individual entity that embodies the properties of life. It may also be referred
as the species. The Species refers to all organisms of the same kind that are genetically similar
enough to breed in nature and produce live, fertile offspring.
The community includes populations of different species living in a particular area.
Ecosystems are composed of a biological community and its physical environment.
The biosphere is the worldwide sum of all ecosystems.
