General Biology Semester 1 Final Study Guide: Chapters 1–6

Chapter 1: Introduction to Biology

Properties of Life

• Order: Highly organized structures in living organisms.

• Evolutionary adaptation: Populations evolve over generations to adapt to their environment.

• Regulation: Homeostasis maintains stable internal conditions.

• Energy processing: Organisms obtain and use energy.

• Growth and development: Controlled by inherited information.

• Response to the environment: Reacting to stimuli.

• Reproduction: Ability to produce offspring.

Levels of Biological Organization

• Biosphere

• Ecosystems

• Communities

• Populations

• Organisms

• Organs/Organ systems

• Tissues

• Cells

• Organelles

• Molecules

Structure and Function

• Structure correlates with function at all levels of organization.

• Example: Bird wings are adapted for flight.

Energy Flow and Chemical Cycling

• Energy flows through an ecosystem, usually entering as light and exiting as heat.

• Chemicals are recycled within an ecosystem.

Genetic Information

• DNA: The molecule of inheritance; encodes genes.

• Gene expression: DNA → RNA → Protein.

• Genome: The entire set of genetic instructions.

• Proteome: The entire set of proteins expressed by a cell or tissue.

Feedback Regulation

• Organisms use feedback mechanisms to regulate internal processes (e.g., sweating to cool the body).

Evolution

• Descent with modification explains unity and diversity of life.

• Charles Darwin proposed natural selection as the mechanism of evolution.

Natural Selection

• Individuals with inherited traits best suited to their environment are more likely to survive and reproduce.

Chapter 1: Scientific Methods

Science and Inquiry

• Science: From Latin meaning "to know"; a way of learning about the natural world.

• Inquiry: The search for information and explanations.

Scientific Method Steps

1. Observation

2. Question

3. Hypothesis

4. Prediction

5. Experiment

6. Analysis

7. Conclusion

Types of Data

• Qualitative: Descriptions (e.g., color, shape).

• Quantitative: Numerical measurements (e.g., weight, height).

Graphs

• Bar graph: Categorical vs. numerical data.

• Scatter plot: Numerical vs. numerical data.

• Line graph: Continuous data (e.g., time series).

Hypotheses and Variables

• Hypothesis: A testable explanation for an observation.

• Independent variable: Manipulated by the experimenter.

• Dependent variable: Measured outcome.

• Control group: Used for comparison.

Experimental Error and Theory

• Experimental error can arise from uncontrolled variables.

• A theory is broader in scope than a hypothesis and supported by a large body of evidence.

Chapter 2: Chemistry Review

Atoms and Molecules

• Atoms are made of protons, neutrons, and electrons.

• Atomic number: Number of protons.

• Mass number: Protons + neutrons.

• Isotopes: Atoms with the same number of protons but different neutrons.

Chemical Bonds

• Covalent bonds: Sharing of electrons.

• Ionic bonds: Transfer of electrons.

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

• Non-polar covalent: Equal sharing (e.g., O2).

Chapter 3: Water Chemistry

Properties of Water

• Water is polar; forms hydrogen bonds.

• Exists naturally as solid, liquid, and gas.

Four Key Properties

• Cohesion and Adhesion: Water molecules stick to each other and other substances.

• Moderation of Temperature: High specific heat and heat of vaporization.

• Expansion upon Freezing: Ice is less dense than liquid water.

• Versatility as a Solvent: Dissolves many substances.

Acids, Bases, and pH

• Acid: Increases H+ concentration.

• Base: Reduces H+ concentration.

• pH scale: 0–14; below 7 is acidic, above 7 is basic.

Chapter 4: Carbon and Molecular Diversity

Organic Chemistry

• Study of carbon-based molecules.

• Carbon forms four covalent bonds; can create large, complex molecules.

Isomers

• Structural isomers: Different covalent arrangements.

• Cis-trans isomers: Same covalent bonds, different spatial arrangements.

• Enantiomers: Mirror images.

Functional Groups

• Common groups: Hydroxyl, Carbonyl, Carboxyl, Amino, Sulfhydryl, Phosphate, Methyl.

Adenosine Triphosphate (ATP)

• Main energy currency of the cell.

• Hydrolysis of ATP releases energy.

Chapter 5: The Structure and Function of Large Biological Molecules

Macromolecules

• Carbohydrates: Sugars and polymers of sugars.

• Lipids: Fats, phospholipids, steroids.

• Proteins: Polymers of amino acids; perform many cellular functions.

• Nucleic acids: DNA and RNA; store and transmit genetic information.

Carbohydrates

• Monosaccharides: Simple sugars (e.g., glucose).

• Polysaccharides: Starch, glycogen, cellulose, chitin.

Lipids

• Fats: Glycerol + fatty acids; energy storage.

• Phospholipids: Main component of cell membranes.

• Steroids: Four fused carbon rings (e.g., cholesterol).

Proteins

• Amino acids: 20 types; linked by peptide bonds.

• Levels of structure: Primary, secondary, tertiary, quaternary.

• Protein shape determines function.

Nucleic Acids

• Nucleotides: Monomers (A, T, C, G, U).

• DNA: Double helix; stores genetic information.

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

Chapter 6: A Tour of the Cell

Cell Types

• Prokaryotes: No nucleus; bacteria and archaea.

• Eukaryotes: Nucleus and membrane-bound organelles.

Cell Structures and Functions

• Plasma membrane: Selective barrier.

• Nucleus: Contains DNA.

• Ribosomes: Protein synthesis.

• Endoplasmic reticulum (ER): Protein and lipid synthesis.

• Golgi apparatus: Modifies and packages proteins.

• Lysosomes: Digestion of macromolecules.

• Vacuoles: Storage and support in plant cells.

• Mitochondria: Site of cellular respiration; ATP production.

• Chloroplasts: Site of photosynthesis in plants.

• Peroxisomes: Breakdown of fatty acids and detoxification.

• Cytoskeleton: Structural support; movement.

• Cell wall: Protection and support in plants, fungi, and some protists.

Microscopy

• Light vs. electron microscopes; magnification and resolution.

Endosymbiotic Theory

• Mitochondria and chloroplasts originated from engulfed prokaryotes.

Biological Tests

• Biuret test: Proteins

• Sudan III test: Lipids

• Diphenylamine test: Nucleic acids

• Iodine test: Carbohydrates