Pearson, as an active contributor to the biology learning community, is pleased to provide free access to the Classic edition of The Biology Place to all educators and their students.
The purpose of the activities is to help you review material you have already studied in class or have read in your text. Some of the material will extend your knowledge beyond your classwork or textbook reading. At the end of each activity, you can assess your progress through a Self-Quiz.
To begin, click on an activity title.
Lab 2 Enzyme Catalysis
Mitosis and Meiosis
Plant Pigments and Photosynthesis
6-I Bacterial Transformation
6-II DNA Electrophoresis
Genetics of Organisms
Population Genetics and Evolution
10-I Cardiovascular Fitness
10-II Heart Rate in Daphnia
Biomembranes I: Membrane Structure and Transport
Biomembranes II: Membrane Dynamics and Communication
Cardiovascular System I: The Beating Heart
Cardiovascular System II: The Vascular Highway
Cell Structure and Function
DNA Structure and Replication
From Gene to Protein: Transcription
From Gene to Protein: Translation (Protein Synthesis)
Plant Structure and Growth
Properties of Biomolecules
Restriction Enzyme Digestion of DNA
The lac Operon in E. coli
Concept 5: Proteins
The most abundant and diverse molecules found in living cells are proteins.
Proteins are macromolecules, ranging from simply large to enormous. Proteins typically make up about half the total weight of biomolecules in a cell (excluding water).
Proteins play a wide variety of functional roles, including:
- enzymes as catalysts, such as ribonuclease, that accelerate specific chemical reactions up to 10 billion times faster than they would spontaneously occur; one cell may contain some thousand different types of enzymes at one time
- structural materials, including keratin (the protein found in hair and nails) and collagen (the protein found in connective tissue)
- specific binding, such as antibodies that bind specifically to foreign substances to identify them to the body's immune system
- specific carriers, including membrane transport proteins that move substances across cell membranes, and blood proteins, such as hemoglobin, that carry oxygen, iron, and other substances through the body
- contraction, such as actin and myosin fibers that interact in muscle tissue
- signaling, including hormones such as insulin that regulate sugar levels in blood