Core Biology Exam 1 Study Guide: Chapters 1-8

Chapter 1: Evolution, the 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.

• Cell: The basic unit of life.

• Tissue: Groups of similar cells performing a specific function.

• Organ: Structures composed of different tissues working together.

• Organ System: Groups of organs that perform related functions.

• Organism: An individual living entity.

• Population: Members of the same species in a given area.

• Community: All populations in a given area.

• Ecosystem: Communities plus their physical environment.

• Biosphere: All ecosystems on Earth.

Properties of Living Cells

• Order: Highly organized structures.

• Reproduction: Ability to produce offspring.

• Growth and Development: Inherited information controls growth patterns.

• Energy Processing: Use of energy to power activities.

• Response to Environment: Reacting to stimuli.

• Regulation: Maintaining stable internal conditions (homeostasis).

• Evolutionary Adaptation: Traits evolve to increase survival.

The Scientific Method

• Observation

• Question

• Hypothesis

• Experiment

• Analysis

• Conclusion

Prokaryotic vs. Eukaryotic Cells

• Prokaryotic cells: Lack a nucleus and membrane-bound organelles (e.g., bacteria, archaea).

• Eukaryotic cells: Have a nucleus and organelles (e.g., plants, animals, fungi, protists).

Three Domains of Life

• Bacteria: Prokaryotic, diverse environments.

• Archaea: Prokaryotic, often extreme environments.

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

Classification and Linnaeus

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

Emergent Properties and Homeostasis

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

• Homeostasis: Maintenance of stable internal conditions.

Chapter 2: The Chemical Context of Life

Atoms and Molecules

• Atom: Smallest unit of an element.

• Molecule: Two or more atoms bonded together.

• Atomic number: Number of protons.

• Atomic weight: Sum of protons and neutrons.

• Isotope: Atoms of the same element with different numbers of neutrons.

• Valence: Number of electrons available for bonding.

Chemical Bonds

• Covalent bonds: Sharing of electron pairs.

• Ionic bonds: Transfer of electrons.

• Hydrogen bonds: Weak attraction between polar molecules.

Polar vs. Nonpolar Covalent Bonds

• Polar covalent: Unequal sharing of electrons (e.g., H2O).

• Nonpolar covalent: Equal sharing of electrons (e.g., O2).

pH and Buffers

• pH: Measure of hydrogen ion concentration.

• Formula: $pH = -\log[H^+]$

• Buffers: Substances that minimize changes in pH.

Chapter 3: Water and Life

Properties of Water

• Cohesion: Water molecules stick together.

• Adhesion: Water molecules stick to other surfaces.

• Surface tension: Resistance of water surface to rupture.

• 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: Decreases 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 the Molecular Diversity of Life

Properties of Carbon

• Carbon: Forms four covalent bonds, allowing for diverse molecules.

• Isomers: Molecules with same formula but different structures.

Functional Groups

• OH group: Hydroxyl

• SH group: Sulfhydryl

• COOH group: Carboxyl

• CHO group: Aldehyde

• Ketone: Carbonyl group in the middle of a molecule

Acidic and Basic Groups

• Carboxyl group: Acidic, donates H+

• Amino group: Basic, accepts H+

Chapter 5: The Structure and Function of Large Biological Molecules

Polymers and Their Formation

• Polymers: Long chains of monomers.

• Dehydration synthesis: Joins monomers by removing water.

• Hydrolysis: Breaks polymers by adding water.

Types of Biological Molecules

• Carbohydrates: Monosaccharides, disaccharides, polysaccharides.

• Lipids: Fats, phospholipids, steroids.

• Proteins: Polymers of amino acids.

• Nucleic acids: DNA and RNA.

Saturated vs. Unsaturated Fats

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

• Unsaturated fats: 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 helices and beta sheets.

• Tertiary: 3D folding due to side chain interactions.

• Quaternary: Multiple polypeptides joined.

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

Chemical Reactions and Enzymes

• Activation energy: Energy required to start a reaction.

• Enzymes: Biological catalysts that speed up reactions by lowering activation energy.

• Substrate: Reactant that binds to enzyme.

• Active site: Region on enzyme where substrate binds.

• Competitive inhibition: Inhibitor competes with substrate for active site.

• Feedback inhibition: End product inhibits enzyme activity.

Enzyme Activity

• Temperature and pH affect enzyme function.

• Enzymes are specific to their substrates.

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

Additional info: Academic context and definitions have been expanded for clarity and completeness.