Biol 1406 - DCCCD Exam 1

Define "Biology"

Biology is the scientific study of life

Distinguish between living and non-living things

Living things are characterized by eight characteristics of life, while non-living things do not exhibit the same characteristics. Living things represent a highly coordinated set of chemical and physical processes that are manifested as the phenomenon we call life.

What are the eight characteristics of life?

Specific Organization, Metabolism, Hemostasis, Growth, Movement, Responsiveness, Reproduction, and Adaptation

Specific Organization

Refers to cellular organization and to the commonality of organization shared between all living things.

Metabolism

The total or sum of all chemical activity in a living thing

Homeostasis

The maintenance of a constant internal environment

Growth

An increase in size by the addition of new living tissue; the formation of new cytoplasm and cell parts.

Movement

Movement that results from the efforts and expenditure of energy by the organism

Responsiveness

The ability to sense and respond to stimuli from the environment and from within

Adaptation

The ability of a population or species to adjust to the environment over time through genetic change. Individuals do not adapt; they acclimate as they adjust to the environment within their individual range of genetic tolerance.

energy utilization

Biological and ecological organization ranges from atoms or atomic particles to the biosphere which is all life on Earth and its physical environment.

List and Describe the levels of biological organization: Atom

Smallest or simplest particles of an individual element that exhibits its chemical and physical characteristics, i.e. hydrogen, oxygen, carbon.

List and Describe the levels of biological organization: Molecules

Any two or more atoms bonded together

List and Describe the levels of biological organization: Organelles

Cell parts such as mitochondria, chloroplast, nucleus, etc.

List and Describe the levels of biological organization: Cells

The basic unit of life. All living things are composed of cells and/or cell products.

List and Describe the levels of biological organization: Tissues

Groups of similar cells that are specialized for one, sometimes two specific functions, i.e. muscle, nerve.

List and Describe the levels of biological organization: Organs

Structures composed of two or more tissues dedicated to one to a few function, i.e. stomach, heart, liver.

List and Describe the levels of biological organization: Organ Systems

A functional unit composed of many organs dedicated to one, maybe two basic functions, i.e. digestive, respiratory, circulatory.

List and Describe the levels of biological organization: Organism

The individual, the sum of all body systems functioning in a coordinated fashion.

List and Define the ecological levels of organization: Population

The members of a single species within a defined area.

List and Define the ecological levels of organization: Community

An ecological unit composed of all populations found within a defined area.

List and Define the ecological levels of organization: Ecosystem

A self sustaining community capable of recycling nutrients from season to season. The only thing needed from the outside is energy, usually light.

List and Define the ecological levels of organization: Biome

A broad assemblage of communities characterized by a climatic factor and/or a dominant plant type, i.e. desert, coniferous forest, tropical rain forest.

List and Define the ecological levels of organization: Biosphere

All life on earth and its physical environment.

What is the scientific method?

A systematic method of problem solving not unique to science.

What are the steps of the scientific method?

- Identify or define the problem.

- Gather information about the problem.

- Formulate a hypothesis (testable question that can be answered "yes or no")

- Design and perform a single variable experiment.

- Observe and gather data on the experiment.

- Analyze data and come to a conclusion. The conclusion may or may not support the hypothesis.

What is a scientific theory?

is a concept that is accepted as a truth in the scientific community. It can not be proven nor disproved at this time, although a vast body of knowledge supports the theory (biological evolution). If a concept is proven to be a scientific fact it is referred to as a law. (Law of Gravity)

What is a scientific law?

a concise statement that summarizes the results of many observations and experiments

What is a cell?

The structural and functional unit of life

What is a prokaryotic cell and it's characteristics?

very small, no nuclear membrane, no complex membrane bound organelles. Ex: Single-cell organisms, bacteria, and archaea

What is a eukaryotic cell and it's characteristics?

relatively large, Nuclear membrane, complex membrane bound organelles. Ex: Plants and Animals, complex living things

Domain, Kingdom, Phylum, Class, Order, Family, Genus, species.

Taxonomic Groups

theory

is a concept that is accepted as a truth in the scientific community. It can not be proven nor disproved at this time, although a vast body of knowledge supports the theory

Law

If a concept is proven to be a scientific fact it is referred to as a law.

binomial nomenclature

A system for giving each organism a two-word scientific name that consists of the genus name followed by the species name

Elements

Basic substances of matter, a substance that can not be broken down into something simpler by chemical means.

Atoms

Simplest or smallest form of an element that retains the chemical and physical properties of an element.

Angstrom

A useful unit of measure for atoms is the Angstrom (A), which is 10-10 m or one ten billionth of a meter.

Atoms range from 1 to 5 Angstroms in diameter although the nucleus is only about one ten thousandth of an Angstrom. (10-4 A)

Protons and neutrons makeup the atomic nucleus.

The mass of a neutron or proton

approximately one dalton (1.67 X 10-24 grams)

four most common elements in living organisms

carbon, hydrogen, nitrogen, oxygen

Atomic number

Number of protons in an atom, determines the identity of the aton that is determins the element it represnets

Mass number

Number of protons and neutrons in an atom, each has a mass of approximately 1 Dalton, thus each is given a mass of 1.

Molecular mass

the sum of the mass number of the atoms that make up a given molecule.

Chemical symbol

Shorthand name for an element, usually composed of the first or first two letters of the English or Latin name of the element.

Isotope

Different forms of the same element that differ in their mass number, by having more or less neutrons.

Radioisotope

Unstable isotopes that emit radiation/radioactive particles.

Explain the meaning of electron orbital and relate orbitals to energy shells. Relate the number of valence electrons to the chemical properties of an element.

Orbital - A region in space in which an electron is found at least 90% of the time.

Energy level or electron shell - A region in space composed of one or more orbitals.

Valence electrons

The number of electrons in an incomplete outer energy level. Atoms will tend to gain, lose or share electrons to achieve a complete outer shell. This results in chemical bonding.

Molecule

Composed of any two or more atoms chemically bonded together.

Compound

a substance composed of molecules which contain the atoms of two or more elements in a fixed ratio

Chemical Formula

Indicates the kind of atoms and number of atoms of each element in a compound.

Structural Formula

Indicates the number, kind and location/arrangement of atoms composing a molecule of a substance

Explain the purpose and use of chemical equations

-Chemical equations illustrate the substances involved in a reaction, the products produced, the direction of the reaction and the quantities of each..

-Reversible reactions - Reactions that have the potential to proceed in both directions.

-Equilibrium is achieved when the rates of the reaction are equal in both directions.

Covalent bond

A bond that results from the sharing of electrons between the outer energy levels of two or more atoms. As a result each atom has a complete outer energy shell

Polar covalent bond

A covalent bond in which electrons are shared unequally between bonded atoms. Thus a partial positive and negative charge appears on the molecule.

Electronegativity

The attraction of an atom for electrons; this may be electrons of a covalent bond or those of another molecule. Nonmetals often have a high relative electronegativity.

Ionic bonding

Bonding that results from the gain or lose of electrons by atoms forming oppositely charged ions

Ion

Charged atoms, either negative or positive resulting from the gain or lose of electrons respectively

Cations

result from the lose of electrons thus being positively charged.

Anion

result from the gain of electrons thus being negatively charged.

Dissociation

The separation of ions from ionic bonds as the substance is dissolved.

Hydration

The attachment of water molecules to the ions of a solute.

Hydrogen bonding

Weak electrostatic attractions between hydrogen and a strongly electronegative atom such as oxygen or nitrogen.

Surface tension

Results from the attraction of water molecules to each other through hydrogen bonding. This forms a strong surface force on still water.

Capillarity

The attraction of water molecules to a wetable surface.

van der Waals forces

Weak electrical attractions that result from interactions of the electron clouds of adjacent atoms.

Hydrophobic interactions

result from the repulsion of nonpolar molecules by water.

Oxidation

the removal of electrons or H from an ion, atom or molecule.

Reduction

the addition of electrons or H from an ion, atom, or molecule.

In living cells oxidation almost always involves the removal of H, and reduction the addition of H.

Cohesion

The attraction of water molecules to other water molecules due to hydrogen bonding.

Adhesion

The attraction of water molecules to a wetable or charged surface.

Specific heat

The heat required to rase the temperature of of 1 gram of a substance 1oC.

Heat of vaporization

The heat required to vaporize 1 gram of a substance..

Universal solvent

Water is an excellent solvent for polar compounds

Ionizes to produce H+ and OH -.

Acid

An acid dissociates in solution to release H+ and an anion, the conjugate base.

A hydrogen donor

Turn blue litmus paper red

Have a sour taste

Base

Dissociates in water to produce OH- and a cation.

A proton acceptor

Turn red litmus paper blue

Are slippery to the touch

3. Explain the meaning of the pH scale.

The negative log of the H+ concentration of a solution.

Expresses the degree of alkalinity and acidity of a solution

A scale of 0 to 14; 7 is neutral, neither acid or base.

Above 7 is a base and below 7 is an acid.

At a pH of 7 the H+ concentration and the OH- concentration are equal (10-7 moles).

pH is the negative logarithm of the H+ concentration of the solution, thus the lower the pH, the higher the H+ concentration: the higher the pH, the lower the H+ concentration. Concentration is measured in moles.

The lower the pH the lower the OH- and the higher the pH the higher the OH- concentration.

The increase or decrease in H+ concentration between one pH number and the next is 10X, thus an acid of pH 5 is 10 times stronger than an acid of 6, and one of 4 is 100 times stronger than one of 6.

Explain the role of buffers.

A substance or combination of substances that resist changes in pH when an acid or base is added to a solution.