BIOL 112-1: Chapters 1 + 2 - Properties of Life and Water

Properties of Life:

• Order

• Reproduction

• Growth and Development

• Energy Processing

• Regulation

• Response to the Environment

• Evolutionary Adaptation

Order

The highly ordered structure that typifies life 

Reproduction

The ability of organisms to produce new individuals of the same type, enabling the continuation of their species

Growth and Development

Consistent growth controlled by inherited DNA 

Energy Processing

The use of chemical energy to power activity and chemical reactions 

Regulation

The ability to control an organism's internal environment

Response to the Environment

The ability to react to external stimuli in the environment

Evolutionary Adaptation

Adaptations evolve over time, so an organism has a greater chance of survival and reproductive success

Cell

Structural and functional unit of life

Properties of cells:

• Regulate its internal environment  

• Take in and use energy  

• Respond to its environment  

• Develop and maintain its organization  

• Give rise to new cells

Unifying Themes of Biology:

• Organization

• Information

• Energy and Matter

• Interactions

• Evolution

Organization

The vast scope of biology is divided in a series of structural levels

Emergent Properties

Result from the specific arrangement and interactions among component parts (levels combined to create more functions)

Structural Levels of Biology:

1. Biosphere

2. Ecosystem

3. Community

4. Population

5. Organism

6. Organs + Organ System

7. Tissue

8. Cell

9. Organelle

10. Molecule

Biosphere

Sum of all ecosystems

Ecosystem

A large community of living organisms and their physical environment (abiotic AND biotic factors)

Community

Living organisms in a particular area

Population

A group of the same species in a particular area

Organism

Individual living thing

Organs and Organ System

A structure made of tissues and organs that have certain function

Tissue

Similar cells that have a specific function

Organelle

Performs a specific function in a cell 

Molecule

A cluster of atoms held together with chemical bonds

Element

Cannot be broken down to other substances

How many natural elements are there?

92

Compound

Different elements bonded together

How many elements are essential to human life?

About 25

What are the main 4 elements that make up organisms?

• Oxygen

• Hydrogen

• Nitrogen

• Carbon

Atom

Smallest unit of matter that still has the properties of an element

What 3 subatomic particles make up an atom?

• Protons

• Neutrons

• Electrons

Proton

Positively charged subatomic particle

Neutron

Neutral subatomic particle

Electron

Negatively charged subatomic particle

Atomic Number

Number of protons

Mass Number

Sum of protons and neutrons in the nucleus

How many electrons can the inner most electron shell hold?

2

How many electrons can the 2nd shell hold?

Up to 8

Valence Shell

Outermost shell of electrons

Isotopes

Same number of protons, different neutrons

Covalent Bonds

Electron sharing

Types of Covalent Bonds:

• Polar

• Nonpolar

Polar Covalent Bond

Electrons are pulled to the more electronegative atom

Nonpolar Covalent Bond

Equally shared electrons

Polarity

Distribution of electrical charge

Ionic Bond

Donating electrons

Ion

An atom/molecule with an electrical charge as a result from gain/loss of electrons

Cation

Positive ion

Anion

Negative ion

Hydrogen Bond

Weak attraction between hydrogen and an electronegative atom with a lone pair

Chemical Reaction

Making/breaking bonds

Cohesion

The tendency of the same type of molecules to stick to each other

Surface Tension

Measure of how hard it is to break the surface of a liquid

Adhesion

The tendency of different types of molecules to stick together 

T/F: Heat is released when hydrogen bonds form

True

Evaporative Cooling

When molecules evaporate, the surface cools down

T/F: Water is denser as a solid

False; water is denser as a liquid because hydrogen bonds are more stable (ice crystal) in a solid

Solution

A uniform liquid mixture of multiple substances

Hydrophilic

Water loving

Hydrophobic

Water fearing

What makes a solution more acidic? Basic?

H+; OH-

Buffer

Accepts/donates hydrogen ions to minimize changes in pH