General Biology Exam 1 Study Guide: Scientific Method, Digestion, Membranes, and Cells

Exam 1 Preparation: General Biology

Overview

This study guide covers foundational topics in General Biology, including the scientific method, biological themes, digestion and absorption, membrane structure and function, and cell types. It is designed to help students prepare for Exam 1, which covers Chapters 1, 2, 6, 7.1, and 41.

Themes in Biology & The Scientific Method

Key Concepts in Biology

• Biology is the scientific study of living things.

• Major themes include organization, information, energy and matter, interactions, and evolution.

The Scientific Method

• Scientific method: A systematic approach to inquiry involving observation, hypothesis formation, experimentation, and analysis.

• Hypothesis: A testable statement that explains observations and can be supported or refuted by experiments.

• Prediction: A logical statement about what will happen if the hypothesis is correct.

• Experiment: A controlled procedure to test a hypothesis.

• Variable: Any factor that can be changed or controlled in an experiment.

• Control group: The group in an experiment that does not receive the experimental treatment and is used for comparison.

Analyzing Results

• Write a sentence describing the results shown in a graph.

• Describe the main theme in biology illustrated by a research study.

• Define controlled variable and identify controlled variables in an experimental design.

• Describe the trend in a graph.

• Identify how central tendency is presented in a graph.

• Evaluate whether results are statistically significant, based on authors' report of p values.

• Make an inference based on experimental data.

Distinguishing Results and Inferences

• Result: Direct observation or measurement from an experiment.

• Inference: A logical interpretation or conclusion based on results.

Digestion & Absorption (Ch 41)

Digestive System Structure and Function

• Distinguish regions of the alimentary canal and accessory glands by function: digestion, secretion, or absorption.

• Accessory glands: salivary glands, liver, pancreas, gallbladder.

• Major digestive tract sections: mouth, stomach, duodenum.

• Accessory organs secrete enzymes and aid in digestion.

• Identify types of biomolecules: carbohydrates, proteins, lipids, nucleic acids.

Enzymes and Digestion

• List types of enzymes secreted in each digestive compartment.

• Describe the process of chemical digestion and absorption for carbohydrates, proteins, and lipids.

• Explain how absorption occurs for different molecules: water, glucose, amino acids, fats.

Absorption Mechanisms

• Describe structure of gastrointestinal cavities and alimentary canals in relation to Fick's Law of Diffusion.

• Explain how structure of the intestinal lining enhances surface area (e.g., villi, microvilli).

• Trace digestion and absorption of each component of a meal through the human digestive tract.

• Explain the function of tight junctions in epithelia in relation to digestion and absorption.

• Predict the effect of an increase or decrease in each variable in Fick's Law of Diffusion on nutrient uptake.

Fick's Law of Diffusion

• Describes the rate of diffusion across a membrane:

$\text{Rate of diffusion} = \frac{(k \cdot A \cdot (P_2 - P_1))}{D}$

• Where k is the diffusion constant, A is the surface area, P2 - P1 is the difference in partial pressure, and D is the distance.

Lipids & Cell Membranes (Ch 6)

Types of Lipids

• Identify the type of lipid based on a structural diagram: fat, phospholipid, or steroid.

• Know the functions of fats, phospholipids, and steroids.

• Draw a saturated and an unsaturated hydrocarbon.

• Distinguish between saturated and unsaturated fatty acids.

• Explain why lipids are not polymers.

Cell Membrane Structure

• Explain the fluid mosaic model of cell membrane structure.

• Define selective permeability: the ability of the membrane to allow some substances to cross more easily than others.

• Define active transport and passive transport.

• Explain how Na+-K+ ATPase creates an ion gradient across the cell membrane.

• Define diffusion and osmosis, giving examples of substances that cross the membrane by each process.

• Explain facilitated diffusion and how water crosses the cell membrane (e.g., via aquaporins).

• Predict changes in intracellular solute concentrations and cellular volume if the cell adds or removes certain types of transport proteins or ions from the membrane.

Osmosis and Diffusion

• Osmosis: Movement of water across a selectively permeable membrane from low solute concentration to high solute concentration.

• Diffusion: Movement of molecules from an area of high concentration to low concentration.

Macromolecules: Carbohydrates, Proteins, Nucleic Acids (Ch 5)

Carbon Skeletons and Functional Groups

• Draw the general structural formula of the 3 types of carbon skeletons.

• Identify each of the 6 functional groups within a biomolecule, given a structural diagram.

• Name the properties of each functional group: polar, non-polar, acid, base, negative charge.

Miller Experiment

• Explain the hypothesis, results, and significance of Miller's experiment on the origin of organic molecules.

Cells (Ch 7)

Prokaryotic vs. Eukaryotic Cells

• Compare structure of prokaryotic and eukaryotic cells.

• List the 4 characteristics shared by all cells: plasma membrane, cytoplasm, DNA, ribosomes.

Experimental Design and Data Interpretation

Variables and Graphs

• Given variables in an experiment, identify the independent and dependent variables and graph the relationship between them.

• Practice writing experimental descriptions and drawing graphs.

Vocabulary and Key Terms

Below is a table of important vocabulary terms to know for the exam. Students should be able to define each term and use it in context.

Term	Definition
adaptation	A heritable trait that increases an organism's fitness in a particular environment.
alimentary canal	The digestive tract from mouth to anus.
basal lamina	A layer of extracellular matrix on which epithelium sits.
bile	A digestive fluid produced by the liver that emulsifies fats.
diffusion	Movement of molecules from high to low concentration.
osmosis	Diffusion of water across a selectively permeable membrane.
phagocytosis	Cellular process of engulfing solid particles.
facilitated diffusion	Passive movement of molecules across a membrane via transport proteins.
active transport	Movement of substances against a concentration gradient using energy (ATP).
prokaryote	Cell lacking a nucleus and membrane-bound organelles.
eukaryote	Cell with a nucleus and membrane-bound organelles.
endocytosis	Process by which cells take in substances by engulfing them in a membrane.
exocytosis	Process by which cells expel substances using vesicles.

Practice and Application

• Practice drawing and labeling diagrams of cell membranes, digestive tracts, and graphs of experimental data.

• Be able to explain the relationship between structure and function in biological systems.

• Apply vocabulary and concepts to new scenarios, such as predicting the outcome of an experiment or explaining a biological process.

Additional info: Some content was expanded for clarity and completeness, including definitions and explanations of key terms and processes.