Essential Building Blocks of Life: From Atoms to Organisms

Unit 3: Lessons 1

Bioelements

Atoms are linked together to form elements. A chemical element is formed by similar atoms.

Biomolecules

Atoms are linked together to make molecules. There are two types of molecules: inorganic and organic.

Cell

This is the smallest unit of living matter that can exist freely in a medium, as it can carry out all the functions of living beings.

Multicellular Levels

• Tissue: A group of cells similar in structure that work together to perform a specific function.
• Organ: Several tissues grouped together to make a structure with a specific function.
• Organ System: A group of organs with closely related functions.
• Organism: The complete unit of the living being.

Unit 3: Lesson 2

Enzymes

Most chemical reactions in living beings would occur too slowly without enzymes. Increased temperatures would speed up the reactions, but using enzymes allows reactions to occur efficiently at 37°C. Enzymes are protein molecules with a particular shape and an active site into which the substrate fits. The reaction takes place, and end products leave the enzyme.

Catalyst

A catalyst is a substance that increases the speed of a reaction without being changed or used up in the reaction.

Cell Specialization

Specialization is the way in which cells become adapted for different functions. Specialization allows cells to become more efficient in carrying out their jobs. The disadvantage of being specialized is that cells lose the ability to perform the jobs of other cells if they are lost.

Lesson 3: The Chemicals of Living Beings

Organic Matter

Organic matter is made up of every chemical compound in which carbon (C) has chemical bonds.

Living Matter

Biomolecules are found in all living beings.

Classification of Biomolecules

• Inorganic: Water, oxygen, and salts.
• Organic: Carbohydrates (sugars and starches), lipids (fats, fatty acids, oils, cholesterol), proteins (enzymes, antibodies).

Unit 4: What is an Illness?

Health is the absence of illness, but it is not only a physical concept. Illness is an abnormal process that alters, modifies, or prevents the activity of a part of our body or the complete organism.

Gaseous Exchange

Gaseous exchange happens in the millions of air sacs in the lungs called alveoli. The structure of these alveoli makes them very efficient for gaseous exchange. Gaseous exchange occurs when oxygen diffuses from air into the bloodstream and carbon dioxide diffuses the other way. The alveoli surface should have the following characteristics:

• Thin: A single-cell lining.
• Moist: Allows gases to dissolve.
• Have a concentration gradient.
• Close to the transport system.
• Large surface area.