Core Biology Exam 1 Study Guide: Chapters 1-8

Chapter 1: Evolution, Themes of Biology, and Scientific Inquiry

Organizational Levels in Biology

Biology can be studied at various organizational levels, each representing increasing complexity in living systems.

• Biosphere: All environments on Earth that support life.

• Ecosystem: All living and nonliving components in a particular area.

• Community: All organisms in an ecosystem.

• Population: Individuals of a species living in an area.

• Organism: Individual living entity.

• Organ System/Organ: Body parts that perform specific functions.

• Tissue: Group of similar cells performing a function.

• Cell: Fundamental unit of life.

• Organelle: Functional components within cells.

• Molecule: Chemical structure of two or more atoms.

Properties of Living Cells

• Order: Highly ordered structure.

• Reproduction: Ability to produce offspring.

• Growth and Development: Inherited information controls growth.

• Energy Processing: Use of chemical energy to power activities.

• Response to Environment: React to environmental stimuli.

• Regulation: Maintain internal environment (homeostasis).

• Evolutionary Adaptation: Traits evolve to suit environment.

Scientific Method

• Observation

• Question

• Hypothesis

• Experiment

• Analysis

• Conclusion

Prokaryotic vs. Eukaryotic Cells

• Prokaryotic cells: No nucleus, smaller, simpler (e.g., bacteria, archaea).

• Eukaryotic cells: Nucleus, membrane-bound organelles (e.g., plants, animals, fungi, protists).

Three Domains of Life

• Bacteria: Prokaryotic, diverse environments.

• Archaea: Prokaryotic, extreme environments.

• Eukarya: Eukaryotic, includes plants, animals, fungi, protists.

Classification and Linnaeus

• Carl Linnaeus: Developed binomial nomenclature (genus and species).

Emergent Properties & Homeostasis

• Emergent properties: New properties arise at each level of organization.

• Homeostasis: Maintenance of stable internal conditions.

Chapter 2: The Chemical Context of Life

Atoms and Elements

• Atom: Smallest unit of matter, consists of protons, neutrons, electrons.

• Atomic number: Number of protons.

• Atomic weight: Sum of protons and neutrons.

• Isotope: Atoms of same element with different neutron numbers.

• Valence: Number of electrons in outer shell.

Chemical Bonds

• Covalent bond: Sharing of electron pairs.

• Ionic bond: Transfer of electrons.

• Hydrogen bond: Weak attraction between polar molecules.

Electronegativity and Polarity

• Electronegativity: Atom's ability to attract electrons.

• Polar covalent bond: Unequal sharing of electrons.

• Nonpolar covalent bond: Equal sharing of electrons.

pH and Buffers

• pH: Measure of hydrogen ion concentration.

• $pH = -\log[H^+]$

• Buffer: Substance that minimizes changes in pH.

Chapter 3: Water and Life

Properties of Water

• Cohesion: Water molecules stick together.

• Adhesion: Water molecules stick to other substances.

• Surface tension: Measure of how difficult it is to break the surface.

• Specific heat: Amount of heat needed to change temperature.

• Heat of vaporization: Energy required to convert liquid to gas.

Water as a Solvent

• Hydrophilic: Substances that dissolve in water.

• Hydrophobic: Substances that do not dissolve in water.

Acids, Bases, and pH

• Acid: Increases H+ concentration.

• Base: Reduces H+ concentration.

Water's Role in Life

• Moderates temperature, dissolves nutrients, supports chemical reactions.

• Prevents freezing in cells due to hydrogen bonding.

Chapter 4: Carbon and Molecular Diversity of Life

Properties of Carbon

• Carbon: Forms four covalent bonds, basis of organic molecules.

• Isomers: Compounds with same formula, different structures.

Functional Groups

• Hydroxyl (-OH): Alcohols.

• Sulfhydryl (-SH): Thiols.

• Carboxyl (-COOH): Acids.

• Amino (-NH2): Bases.

• Phosphate (-PO4): Energy transfer.

• Methyl (-CH3): Nonpolar.

Acidic and Basic Groups

• Carboxyl groups are acidic; amino groups are basic.

Chapter 5: Structure and Function of Large Biological Molecules

Polymers and Monomers

• Polymers: Long chains of monomers.

• Monomers: Building blocks (e.g., amino acids, monosaccharides).

Types of Biological Molecules

• Carbohydrates: Sugars and polymers (monosaccharides, disaccharides, polysaccharides).

• Lipids: Fats, phospholipids, steroids.

• Proteins: Polymers of amino acids.

• Nucleic acids: DNA and RNA.

Saturated vs. Unsaturated Fats

• Saturated: No double bonds, solid at room temperature.

• Unsaturated: One or more double bonds, liquid at room temperature.

DNA vs. RNA

• DNA: Double-stranded, stores genetic information.

• RNA: Single-stranded, involved in protein synthesis.

Protein Structure

• Primary: Sequence of amino acids.

• Secondary: Alpha helix, beta sheet.

• Tertiary: 3D folding.

• Quaternary: Multiple polypeptides.

Enzymes

• Enzymes: Proteins that catalyze reactions by lowering activation energy.

Chapter 8: Introduction to Metabolism (pp. 152-159)

Chemical Reactions and Enzymes

• Activation energy: Energy required to start a reaction.

• Catalyst: Substance that speeds up reactions without being consumed.

• Enzyme: Biological catalyst.

Enzyme Activity

• Substrate: Reactant acted on by enzyme.

• Active site: Region where substrate binds.

• Competitive inhibitor: Binds active site, blocks substrate.

• Noncompetitive inhibitor: Binds elsewhere, changes enzyme shape.

• Feedback inhibition: End product inhibits pathway.

Temperature and pH Effects

• Enzyme activity is affected by temperature and pH; optimal conditions vary by enzyme.

Bond Type	Strength	Example
Covalent	Strong	H2O, O2
Ionic	Moderate	NaCl
Hydrogen	Weak	Between water molecules

Additional info: Some explanations and definitions were expanded for clarity and completeness, including the scientific method steps, properties of water, and enzyme inhibition mechanisms.