Essential Cell Biology 5th edition

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Contents
Ion Channels Randomly Snap Between Open and Closed States 407
Different Types of Stimuli Influence the Opening and Closing of Ion Channels 408
Voltage-gated Ion Channels Respond to the Membrane Potential 409
ION CHANNELS AND NERVE CELL SIGNALING 410
Action Potentials Allow Rapid Long-Distance Communication Along Axons 411
Action Potentials Are Mediated by Voltage-gated Cation Channels 411
Voltage-gated Ca 2+ Channels in Nerve Terminals Convert an Electrical Signal into a Chemical
Signal 416
Transmitter-gated Ion Channels in the Postsynaptic Membrane Convert the Chemical Signal
Back into an Electrical Signal 417
Neurotransmitters Can Be Excitatory or Inhibitory 418
Most Psychoactive Drugs Affect Synaptic Signaling by Binding to Neurotransmitter
Receptors 419
The Complexity of Synaptic Signaling Enables Us to Think, Act, Learn, and Remember 420
Light-gated Ion Channels Can Be Used to Transiently Activate or Inactivate Neurons in Living
Animals 421
ESSENTIAL CONCEPTS 422
QUESTIONS 424
CHAPTER 13
How Cells Obtain Energy from Food 427
THE BREAKDOWN AND UTILIZATION OF SUGARS AND FATS 428
Food Molecules Are Broken Down in Three Stages 428
Glycolysis Extracts Energy from the Splitting of Sugar 430
Glycolysis Produces both ATP and NADH 431
Fermentations Can Produce ATP in the Absence of Oxygen 433
Glycolytic Enzymes Couple Oxidation to Energy Storage in Activated Carriers 434
Several Types of Organic Molecules Are Converted to Acetyl CoA
in the Mitochondrial Matrix 438
The Citric Acid Cycle Generates NADH by Oxidizing Acetyl Groups to CO 2
438
Many Biosynthetic Pathways Begin with Glycolysis or the Citric Acid Cycle 441
Electron Transport Drives the Synthesis of the Majority of the ATP in Most Cells 446
REGULATION OF METABOLISM 447
Catabolic and Anabolic Reactions Are Organized and Regulated 447
Feedback Regulation Allows Cells to Switch from Glucose Breakdown to
Glucose Synthesis 447
Cells Store Food Molecules in Special Reservoirs to Prepare for Periods of Need 449
ESSENTIAL CONCEPTS 451
QUESTIONS 452