Textbook Question
Describe the role of summation in postsynaptic cells.
Ch. 43 - Animal Nervous Systems
Freeman8th EditionBiological ScienceISBN: 9780138276263
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Table of contents
- Ch. 1 - Biology: The Study of Life13
- Ch. 2 - Water and Carbon: The Chemical Basis of Life14
- Ch.3 - Protein Structure and Function10
- Ch.4 - Nucleic Acids and the RNA World10
- Ch. 5 - An Introduction to Carbohydrates10
- Ch. 6 - Lipids, Membranes, and the First Cells11
- Ch. 7 - Inside the Cell10
- Ch. 8 - Energy and Enzymes: An Introduction to Metabolism10
- Ch. 9 - Cellular Respiration and Fermentation11
- Ch. 10 - Photosynthesis12
- Ch. 11 - Cell-Cell Interactions12
- Ch. 12 - The Cell Cycle8
- Ch. 13 - Meiosis12
- Ch. 14 - Mendel and the Gene23
- Ch. 15 - DNA and the Gene: Synthesis and Repair15
- Ch. 16 - How Genes Work16
- Ch. 17 - Transcription, RNA Processing, and Translation16
- Ch. 18 - Control of Gene Expression in Bacteria16
- Ch. 19 - Control of Gene Expression in Eukaryotes12
- Ch. 20 - The Molecular Revolution: Biotechnology, Genomics, and New Frontiers15
- Ch. 21 - Genes, Development, and Evolution12
- Ch. 22 - Evolution by Natural Selection16
- Ch. 23 - Evolutionary Processes13
- Ch. 24 - Speciation15
- Ch. 25 - Phylogenies and the History of Life13
- Ch. 26 - Bacteria and Archaea15
- Ch. 27 - Diversification of Eukaryotes16
- Ch. 28 - Green Algae and Land Plants16
- Ch. 29 - Fungi18
- Ch. 30 - An Introduction to Animals9
- Ch. 31 - Protostome Animals15
- Ch. 32 - Deuterostome Animals17
- Ch. 33 - Viruses16
- Ch. 34 - Plant Form and Function16
- Ch. 35 - Water and Sugar Transport in Plants16
- Ch. 36 - Plant Nutrition13
- Ch. 37 - Plant Sensory Systems, Signals, and Responses16
- Ch. 38 - Flowering Plant Reproduction and Development16
- Ch. 39 - Animal Form and Function17
- Ch. 40 - Water and Electrolyte Balance in Animals16
- Ch. 41 - Animal Nutrition16
- Ch. 42 - Gas Exchange and Circulation16
- Ch. 43 - Animal Nervous Systems16
- Ch. 44 - Animal Sensory Systems16
- Ch. 45 - Animal Movement11
- Ch. 46 - Chemical Signals in Animals16
- Ch. 47 - Animal Reproduction and Development16
- Ch. 48 - The Immune System in Animals16
- Ch. 49 - An Introduction to Ecology15
- Ch. 50 - Behavioral Ecology16
- Ch. 51 - Population Ecology16
- Ch. 52 - Community Ecology20
- Ch. 53 - Ecosystems and Global Ecology17
- Ch. 54 - Biodiversity and Conservation Ecology18
Chapter 43, Problem 3
In a neuron, what creates the electrochemical gradient favoring the outflow of K+ when the cell is at rest?
a. Na+/K+-ATPase
b. Voltage-gated K+ channels
c. Voltage-gated Na+ channels
d. Ligand-gated Na+/K+ channels
Verified step by step guidance1
Understand the concept of electrochemical gradient: It is the combination of electrical and chemical gradients that influence the movement of ions across a membrane.
Identify the role of Na+/K+-ATPase: This enzyme actively transports 3 Na+ ions out of the neuron and 2 K+ ions into the neuron, using ATP. This creates a concentration gradient with more Na+ outside and more K+ inside the cell.
Recognize the resting membrane potential: At rest, the inside of the neuron is negatively charged relative to the outside, primarily due to the activity of Na+/K+-ATPase and the presence of negatively charged proteins inside the cell.
Consider the movement of K+ ions: The concentration gradient created by Na+/K+-ATPase favors the outflow of K+ ions, as there is a higher concentration of K+ inside the cell compared to outside.
Evaluate the options: Na+/K+-ATPase is responsible for maintaining the concentration gradient that favors the outflow of K+ when the neuron is at rest, making it the correct answer.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Electrochemical Gradient
An electrochemical gradient is a gradient of electrochemical potential, usually for an ion that can move across a membrane. It consists of two parts: the electrical potential and a difference in the chemical concentration across a membrane. In neurons, this gradient is crucial for the movement of ions like K+ and Na+, influencing the cell's resting membrane potential.
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04:51
Concentration Gradients and Diffusion
Na+/K+-ATPase Pump
The Na+/K+-ATPase pump is an essential membrane protein that uses ATP to transport three Na+ ions out of the cell and two K+ ions into the cell. This active transport mechanism helps maintain the resting membrane potential by creating a high concentration of K+ inside the cell and a high concentration of Na+ outside, contributing to the electrochemical gradient.
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06:57Primary Active Transport: Na+/K+ Pump
Resting Membrane Potential
The resting membrane potential is the voltage difference across the neuronal membrane when the cell is not transmitting a signal. It is typically around -70 mV in neurons, primarily due to the differential distribution of ions, especially K+ and Na+, across the membrane, maintained by the Na+/K+-ATPase pump and selective permeability to K+.
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10:31Membrane Potential
Related Practice
Textbook Question
Which ion most readily leaks across a neuron's membrane, helping to establish the resting potential?
Textbook Question
Which of these statements about myelination in neurons is/are correct? Select True or False for each statement.
T/FIt speeds propagation by increasing the density of voltage-gated channels all along the axon.
T/FMultiple sclerosis is characterized by disrupted myelination of certain neurons in the central nervous system.
T/FIt speeds propagation by preventing cations from leaking out across the membrane as they spread down the axon.
T/FIt is more commonly observed in vertebrates than in invertebrates.
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Textbook Question
Explain the difference between a ligand-gated K+ channel and a voltage-gated K+ channel.
Textbook Question
Which of the following brain regions is responsible for the formation of new memories?
a. Brainstem
b. Cerebellum
c. Frontal lobe
d. Hippocampus