Chapter 1: An Introduction to Biology
o Describe the principles of biology.
Cells are the simplest units of life
• Cells=Maintain internal order separated from environment, simples unit of organization
• Cell theory: all organisms are composed of cells, cells are the smallest units of life, all
existing cells are made of preexisting cells
• Unicellular=one cell, multicellular=many cells
Living organisms use energy
• To maintain their internal organization
• Metabolism releases energy through cellular respiration which can be used to
synthesize components of cells
Living organisms interact with their environment
• Respond to environmental changes
Living organisms have mechanisms that maintain homeostasis
• Regulate (cellular metabolism) cells and bodies to maintain stable internal conditions
Living organisms grow, develop and reproduce
• Growth produces more/larger cells
The Genetic Material (DNA) provides a dynamic plan for sustaining lifePopulations of
Organisms Evolve from One Generation to the next
All life is related by an evolutionary history
Organisms follow the laws of chemistry and physics and structure determines function
• STRUCTURE DETERMINES FUNCTION
o Explain how life can be viewed at different levels of biological complexity.
1) Atoms: Smallest component of an element
2) Molecules and macromolecules: atoms bonded with each other, molecules
bonded together to form polymers (macromolecules)
3) Cells: molecules and macromolecules together form organelles enclosed in cell
4) Tissues: many cells of the same type
5) Organs: two or more types of tissues
6) Organ systems: Organs working together
7) Organism: Vary in complexity, can be singlecelled or multicellular units of life
8) Species: related group of organisms that share distinctive form and attributes in nature
9) Population: group of organisms of same species that share a space
10) Community: assemblage of populations
11) Ecosystem, Biosphere: formed by interaction of communities with physical
environment and include all places on earth
o Explain the two basic mechanisms by which evolutionary change occurs: 1) Vertical descent
• Progression of changes in a series of ancestors (lineage) depicted in a vertical diagram.
New species evolve from preexisting species by accumulation of mutations (inheritable
change in genetic material) • Accumulation of mutations can alter traits that increase chances of survival and
reproduction therefore the mutations is more likely to increase in the population via natural
2) Horizontal gene transfer.
• Genetic exchange between different species. The exchange of genetic material between
cells in Asexual species (bacteria) occurs more readily that the rare exchange between species
• Shown as a horizontal line between two different species
• These genes may be acted on by natural selection to promote changes in entire species
• Important in bacteria and early stages of life on Earth
o Outline how organisms are classified (taxonomy)
Taxonomy: grouping of species based on attempt at determining extent of relatedness of species
Dear (Domain) King (Kingdom) Philip (Phylum) Came (Class) Over (Order) For (Family) Good (Genus)
Binomial Nomenclature= Genus species
• Bacteria & Archae
Microorganisms aka prokaryotes because cell structure is simple
Differences in lipid composition, packaging of hereditary material, metabolic pathways and
regulation/production of mRNA and protein
Larger cells with membrane bound organelles that serve various functions
Cell nucleus where DNA is surrounded by membrane
8 Kingdoms: Animalia, Plantae, Fungi and the rest are termed protists
o Describe how changes in genomes and proteomes underlie evolutionary changes.
Genome: The complete genetic makeup (DNA) of an organism
• Stable information unit, encodes info for functions of organism
• Stores information needed to make, locate and modify all proteins
Proteome: complete collection of proteins made in a cell under specific conditions
• Provides continuity between generations
• Is the substrate of evolutionary change (genome mutations change alter proteome
therefore change traits of species)
Genome of every organisms has results and evidence of millions of years of evolution.
GENOMICS allows the analysis of information content of DNA sequence for entire genomes while
PROTEOMICS involves the analysis of the proteome of a single species/comparison of proteome
of different species/ comparison of proteome of different members of the same species living under
Analysis of genome shows differences in genes and analysis of proteome help understand
how various levels of biology (proteins at molecular level to higher levels) are related
o Explain how researchers study biology at different levels, ranging from molecules to ecosystems.
Reductionism: reducing a complex system to its components to understands how the parts of the
• Ecologists study species in their native environment (population/community/ecosystem)
• Anatomists and physiologists study how the structure of organisms is related to its function
(tissue/organ/organ system/organism) • Cell biologists use microscopes to learn about cell function (cellular)
• Molecular biologists study molecules and macromolecules (molecular/atomic level)
• Systems biologists study groups of molecules (all levels)
o Compare and contrast discoverybased science and hypothesis testing, and describe the scientific
1) Discovery Based Science: the collection and analysis of data without a hypothesis.
Aids knowledge of basic concepts in medicine and biology. Often leads to hypothesis testing
May have practical applications (drug companies)
Ex) study of genomes
2) Hypothesis Testing: The scientific method followed to test validity of hypothesis
(making a prediction). Objective method to gather knowledge.
I. Observations made
II. Observations lead to hypothesis
III. Experimentation is conducted
• Data collected in two ways: The experiment is done once on the control
sample and another on the experimental sample. In an ideal experiment, the
control and experimental sample differ only in one variable.
• Ex) Two groups of trees observed, only difference between them is the hours of
light they receive each day (ie. Size, composition, temperature, water amounts are
similar and adequately representative of the type of tree)
IV. Data from experiments analyzed
V. Hypothesis accepted or rejected
Chapter 2: The Chemical Basis of Life I: Atoms, Molecules, and Water
o Understand the general structure of atoms and their constituent particles.
Atoms (usually no net charge) are the smallest functional units of matter that is made of three
subatomic particles: protons (+), neutrons (electrically neutral) and electrons ().
• Protons and neutrons: at the center of the atom in the atomic nucleus (net +ive
• Electrons: In regions at various distances from the nucleus
(Number of protons and electrons are identical in an atom while the neutron number varies
o Discuss the way electrons orbit the nucleus of an atom within discrete energy levels.
Impossible to predict where an electron will be at ay given moment but they travel within regions around
the nucleus called orbitals
• Spherical orbitals= s orbitals
• Dumbbell shaped orbitals=p orbitals
• Orbitals can contain a max of two electrons, if an atom has more than two electrons
it must contain more than one orbital
• Orbitals occupy energy shells (associate with energy levels). Shell one is
closest to nucleus. More electrons around an atom mean it has orbitals in further energy shells.
Energy Shells: First= 2 electrons in one s orbital (1s) (lowest energy electrons in shell). Second=8 electron in one s
orbital (2s), and three p orbitals (2p) (progressively higherenergy electrons in shell with varying
energies within orbitals)
o Relate atomic structure to the periodic table of the elements.
Atomic Number: the number of protons in the atom. Also indicates number of electrons
• Element of periodic table are listed in order of atomic number
Rows of periodic table each have same number for energy shells
Columns from left to right have the same number of valence electrons
• This results in arrangement of elements based on similar chemical properties. Ex)
Inert/Noble gases (He, Ne, Ar) that don’t participate in reactions due to full outer shell
Elements in the same column have the same capacity to accept/donate electrons to shared bonds of
o Quantify atomic mass by using units, such as Daltons and moles.
Atomic Mass: number of protons +number of neutrons
• Measured in Daltons (Da)
Mole: 12g or Carbon=1 mole
• 1 mole of any element contains 6.022x10 atoms (Avogadro’s Constant)
o Explain how a single element may exist in more than one form, called isotopes, and how certain
isotopes have importance in human medicine.
Isotopes: atom that differs in its number of neutrons
• Found in nature are unstable= radioisotopes: lose energy through radiation by
emitting subatomic particles
• Relation to medicine: Use high energy level of radioisotopes. Localization of the radiation of
the isotope allows it to treat specific area without harming other body parts. Also radiation of these
isotopes manipulated in imaging techniques to the detect activities of cells.
o Know which elements compose most of the mass of all living organisms.
Oxygen, Carbon, Hydrogen and Nitrogen =~95% of mass of living organisms
Hydrogen & oxygen (water)=60% mass of animals, 95% mass of plants
o Compare and contrast the types of atomic interactions that lead to the formation of molecules.
Molecular Formula: ex) O
Chemical symbol for all atoms present and subscript of how many of each atom is in present in the
Compound: molecule made up of 2+ different elements
Type of bond and likelihood of it forming are dependent of the number of electrons in the outer shell of
• Types of bonds:
1. Covalent Bonds: atoms share a pair of electrons (between atoms were outer shell is
not full aka does not have 8 valence electrons aka not noble gases). Double bonds occur when
atoms share two pairs of electrons instead of one
1. PolarCovalent Bonds
o Explain the concept of electronegativity and its contribution to the polarity of some covalent bonds.
Electronegativity: Measure of atoms ability to attract electrons in a bond from another atom. • Polarity (dipole moment) created due to difference in electronegativity of two
bonded atoms. The more electronegative atom (A) will have a higher attraction for the electrons of
the other atom (B) therefore the electrons will be closer to A. (PolarCovalent Bonds)
o Understand the concepts of a chemical reaction and chemical equilibrium.
Chemical Reaction: one or more substances changed into other substances.
• Elements combine to form new compound
• Compound breaks down into + molecules
• Electrons are added/taken away from atom
Require source of energy via heat, which causes atoms and molecules to vibrate/move/collide
Require catalyst to speed of rate of reaction by lowering activation rate of reaction
Proceed in a certain direction but will reach chemical equilibrium
Occur in water environments
Chemical Equilibrium: when the rate of forward reaction is balanced by the rate of the reverse
reaction (in some cases= when all reactants converted into products)
o Compare and contrast covalent and ionic bonds with ion dipole and dipoledipole interactions.
Ion: Atom or molecule gains or loses one or more electrons to acquire a net charge
• Cations have a net positive charge
• Anions have a net negative charge
Ionic Bond: forms when a cations binds to an anions
IonDipole force: Between ions and polar molecules, Ex) when ion molecules are dissolved in
water (polar molecule)
DipoleDipole force: can occur between different polar molecules. Important type= hydrogen
bonds: between hydrogen of polar molecule and oxygen/nitrogen/fluorine of another nearby polar
o Understand the nature of hydrogen bonds and how they form in living systems.
Hydrogen Bonds are stronger than other dipoledipole bonds because oxygen/nitrogen/fluorine
are all small atoms and the covalent bond between hydrogenoxygen/ hydrogennitrogen and these
three atoms is very polar therefore the hydrogen’s will have a positive dipole mδ+e)and
oxygen/nitrogen will have a negative dipole momenδ()
• Single hydrogen bond is weak
• Significant effect on determining the physical properties of water and influencing
shape/behaviour of large biomolecule like DNA helices.
o Describe how a molecules shape is important for its ability to interact with other molecules and how
van der Waal forces contribute.
Van deer Waal forces: intermolecular forces (between molecules or between different regions of
large molecules) due to electrostatic interactions of molecules of opposite charge
• Weaker than covalent and ionic bonds because charges are smaller and distances are
• Strength of van der Waal forces is determined by the degree of he charges and the
distance between the two molecules Closer the two molecules are, the stronger the VDW force (due to more effective
electrostatic interactions) therefore two molecules that have complementary shapes can be in very
close contact (like two very flat surfaces) will be stabilized
o Describe how hydrogen bonding determines many properties of water.
Heat of vaporization: heat needed to vaporize 1 mole of any substance at its boiling point under
standard pressure (liquid to gaseous state)
Heat of fusion: the amount of energy released during process of substance going from liquid to
• For H 2 the absolute values of both^ is unusually high due to large number of hydrogen
bonds that H 2 can form in both liquid and solid st