Concept explainers
Introduction:
Cells are regarded as the simplest unit (structural and functional) of life. Cellular membrane, nucleus, and cytoplasm are the three major components of a cell. Cellular membrane, which surrounds the entire cell, is composed of phospholipids and proteins. The nucleus is bound by a nuclear membrane, and it possesses the genetic material of the cell. Cytoplasm consists of organelles, cytoskeleton (filaments and tubules), and inclusion bodies. Protoplasm denotes all living material that are present in the cell enclosed by the cellular membrane (inside and outside the nucleus).
Want to see the full answer?
Check out a sample textbook solutionChapter 3 Solutions
LSC (CONCORDIA UNIV ST PAUL) BIO 315/316: B&N DPF Connect with APR and Phils Online Access for Anatomy and Physiology: The Unity of Form and Function 180 Day Access ENTRP
- How are transmembrane potentials maintained in a leaky membrane?arrow_forwardWhat is the result of opening a membrane ion channel?arrow_forwardWhich of these answers explains why synaptic vesicles only releasee their neurotransmitter cargo in response to a signal? A) the necessary Rab proteins are not synthesized until an action potential arrives B) vesicle formation at the trans-Golgi network cannot occur in the absence of plasma membrane depolarization C) an additional protein, synaptotagmin, makes vesicle fusion dependent on the calcium concentration D)a plasma membrane transporter is needed to actively pump neurotransmitter into the synaptic cleft. These are inactive until membrane depolarizationarrow_forward
- What would happen in each of the following cases where something related to intracellular transport is altered? Assume in each case that the protein involved is a soluble protein, not a membrane protein. State where each protein would be located and explain each of your answers. You add a signal sequence (for the Golgi) to the N-terminal end of a normally cytosolic protein. You change the hydrophobic amino acids in an ER signal sequence into other, hydrophobic, amino acids.arrow_forwardWhat is the structure of the translocation channel that allows transfer of proteins across the membrane bilayer? In particular, is the channel so narrow that proteins can pass through only in an unfolded state, or will it accommodate folded protein domains?arrow_forwardThe resting membrane potential is established by? The Na+/K+-ATPase pumping Na+ into the cell and K+ out of the cell The Na+/K+-ATPase pumping K+ into the cell and Na+ out of the cell A larger diffusion of K+ out of the cell compared to diffusion of Na+ into the cell A larger diffusion of K+ into the cell compared to diffusion of Na+ out of the cell a) and d) b) and c)arrow_forward
- What is membrane potential and how is this created?arrow_forwardThe sodium Na+/Glucose symport moves sodium and glucose across the plasma membrane. A) Describe was is meant by a symport. Include in your answer whether a symport is an example of a channel protein or a carrier protein. B) Why does the Na+/Glucose transporter work in only one direction? C) Describe how glucose can be both actively and passively transported into an out of the same cell. Include in your description how localization of transport proteins allows for these two different types of transport to occur in the same cell.arrow_forwardWhat are the three types of coated vesicles involved in membrane trafficking. Name three types and briefly explain their role in the transport of materialarrow_forward
- SNAT2 (a membrane protein) determines the cell’s content of most amino acids. It acts as a symport (or co-transporter) of Na+ and amino acids. On the outside of the cell, the Na+ concentration is higher than the inside. The amino acid concentration on the inside of the cell is higher than the outside. When both Na+ and an amino acid bind to the SNAT2 membrane channel on the outside of the cell, there is a conformational change allowing the energy from electrochemical gradient of Na+ for the transport of the amino acid into the cell. a. Draw this scenario and label your representations of Na+, amino acids, SNAT2, and the membrane. b. What kind of transport is this, simple diffusion, facilitated, diffusion, active transport, 1o active transport, or 2o active transport? Explain your choice. Thanksarrow_forwardWhich type of membrane transporter could move molecules against their concentration gradient (low to high) a) Carrier proteins b) Leak channel proteins c) Ligand-gated channel proteins d) All of the abovearrow_forwardFor each type of membrane transport, know the following:– Is a transporter protein required? If so, what type?– Is there an energy requirement, and if so, what is the energy source?– What is the relative rate of solute transport based on molecule type? On concentration gradient?– What are examples of the types of solutes transported by carriers and channels?arrow_forward
- Human Physiology: From Cells to Systems (MindTap ...BiologyISBN:9781285866932Author:Lauralee SherwoodPublisher:Cengage Learning