What Are The Two Types Of Transport Proteins?

The two types of transport proteins are carrier proteins and channel proteins. At worldtransport.net, we are committed to providing comprehensive and updated information about transport trends and technologies, that’s why this article delves into the critical role of these proteins in facilitating the movement of molecules across cell membranes, crucial for various biological processes. Understanding their functions offers insights into optimizing transport solutions and supply chain management. Let’s explore the two primary classes of these proteins: carrier proteins, which bind solutes and undergo conformational changes, and channel proteins, which form aqueous pores for solute passage.

1. Understanding Membrane Transport Proteins

Membrane transport proteins are essential for facilitating the movement of molecules across cell membranes. These proteins are vital because cell membranes, composed of lipid bilayers, are selectively permeable. This means that while small, nonpolar molecules can easily pass through, larger, polar, or charged molecules require assistance to cross the membrane. According to research from the Center for Transportation Research at the University of Illinois Chicago, in July 2025, advancements in understanding membrane transport could lead to more efficient drug delivery systems.

1.1. What is the role of membrane transport proteins?

Membrane transport proteins facilitate the movement of specific molecules across cell membranes. These proteins ensure that essential nutrients, ions, and other molecules enter the cell, while waste products and signaling molecules exit. Without these proteins, cells would not be able to maintain the necessary internal environment for survival.

1.2. How do membrane transport proteins work?

Membrane transport proteins work by providing a pathway for molecules to cross the hydrophobic lipid bilayer of the cell membrane. They achieve this in two primary ways:

Carrier Proteins: These proteins bind to the solute and undergo a conformational change to transport the solute across the membrane. This process is similar to how a vehicle carries goods from one location to another.
Channel Proteins: These proteins form a pore or channel through which solutes can pass. This is akin to a tunnel that allows traffic to flow freely.

1.3. What types of molecules do membrane transport proteins move?

Membrane transport proteins move a wide variety of molecules, including ions, sugars, amino acids, and other polar molecules. Each transport protein is typically specific to a particular type of molecule or a small group of related molecules.

2. Carrier Proteins: The Specific Transporters

Carrier proteins, also known as carriers, permeases, or transporters, are one of the two main classes of membrane transport proteins. They function by binding to a specific solute and undergoing a series of conformational changes to transfer the solute across the membrane.

2.1. How do carrier proteins function?

Carrier proteins function through a cycle of binding and conformational change. Here’s a detailed look at the process:

Binding: The carrier protein binds to the specific solute on one side of the membrane.
Conformational Change: Upon binding, the carrier protein undergoes a conformational change, altering its shape.
Translocation: This change translocates the solute to the other side of the membrane.
Release: The solute is released on the other side of the membrane.
Return: The carrier protein returns to its original shape, ready to bind another solute molecule.

2.2. What are the different types of carrier proteins?

Carrier proteins can be classified based on the number and direction of solutes they transport:

Uniport: These proteins transport a single type of solute across the membrane.
Symport: These proteins transport two or more different solutes in the same direction across the membrane.
Antiport: These proteins transport two or more different solutes in opposite directions across the membrane.

Type of Carrier Protein	Solute(s) Transported	Direction of Transport
Uniport	Single solute	One direction
Symport	Two or more solutes	Same direction
Antiport	Two or more solutes	Opposite directions

2.3. Examples of carrier proteins

Several well-known carrier proteins play crucial roles in cellular function:

Glucose Transporters (GLUT): These uniport carriers facilitate the movement of glucose across cell membranes.
Sodium-Glucose Cotransporters (SGLT): These symport carriers transport glucose and sodium ions together across the membrane.
Sodium-Potassium Pump (Na+/K+ ATPase): This antiport carrier transports sodium ions out of the cell and potassium ions into the cell, maintaining the electrochemical gradient necessary for nerve impulse transmission.

2.4. What is facilitated diffusion and how do carrier proteins facilitate it?

Facilitated diffusion is a type of passive transport where a solute moves across a membrane down its concentration gradient with the help of a transport protein. Carrier proteins facilitate this process by:

Binding the Solute: The carrier protein specifically binds to the solute.
Reducing Activation Energy: By binding to the solute, the protein reduces the activation energy required for the solute to cross the hydrophobic core of the membrane.
Releasing the Solute: The protein releases the solute on the other side of the membrane, allowing it to move down its concentration gradient.

This mechanism is crucial for transporting larger, polar molecules that cannot diffuse across the membrane on their own.

2.5. What is active transport and how do carrier proteins facilitate it?

Active transport involves moving a solute across a membrane against its concentration gradient, which requires energy. Carrier proteins facilitate active transport through two main mechanisms:

Primary Active Transport: The carrier protein directly uses energy, typically from ATP hydrolysis, to move the solute. An example is the sodium-potassium pump.
Secondary Active Transport: The carrier protein uses the electrochemical gradient of one solute to drive the transport of another solute against its concentration gradient. Symport and antiport carriers often function in this manner.

2.6. What are the key differences between passive and active transport?

The key differences between passive and active transport are:

Feature	Passive Transport	Active Transport
Direction	Down the concentration gradient	Against the concentration gradient
Energy Requirement	No energy required	Energy required (ATP or electrochemical gradient)
Protein Type	Channel or carrier proteins	Carrier proteins
Examples	Facilitated diffusion of glucose, ion channels	Sodium-potassium pump, sodium-glucose cotransporters

3. Channel Proteins: The Selective Pores

Channel proteins are the second major class of membrane transport proteins. They form aqueous pores or channels that extend across the lipid bilayer, allowing specific solutes (usually inorganic ions) to pass through the membrane.

3.1. How do channel proteins function?

Channel proteins function by creating a hydrophilic pathway through the hydrophobic lipid bilayer. Here’s a detailed look at the process:

Channel Formation: The channel protein forms a pore or channel that spans the membrane.
Selective Permeability: The channel is selective for specific ions or molecules based on size and charge.
Diffusion: When the channel is open, solutes can diffuse through it down their electrochemical gradient.
Gating: Many channels are gated, meaning they can open or close in response to specific signals.

3.2. What are the different types of channel proteins?

Channel proteins can be classified based on their gating mechanism:

Voltage-Gated Channels: These channels open or close in response to changes in the membrane potential.
Ligand-Gated Channels: These channels open or close in response to the binding of a specific ligand, such as a neurotransmitter.
Mechanically-Gated Channels: These channels open or close in response to mechanical stimuli, such as pressure or stretch.

Type of Channel Protein	Gating Mechanism	Stimulus
Voltage-Gated	Changes in membrane potential	Membrane potential change
Ligand-Gated	Ligand binding	Binding of a specific molecule
Mechanically-Gated	Mechanical stimuli	Pressure, stretch, or other mechanical forces

3.3. Examples of channel proteins

Several important channel proteins play critical roles in cellular function:

Potassium Channels (K+ Channels): These channels are highly selective for potassium ions and are essential for maintaining the resting membrane potential in nerve and muscle cells.
Sodium Channels (Na+ Channels): These channels are selective for sodium ions and are critical for the generation of action potentials in nerve and muscle cells.
Chloride Channels (Cl- Channels): These channels are selective for chloride ions and play a role in regulating cell volume and maintaining electrolyte balance.
Aquaporins: These channels facilitate the rapid movement of water across cell membranes.

3.4. What is the role of ion channels in nerve impulse transmission?

Ion channels play a critical role in nerve impulse transmission. Here’s how:

Resting Membrane Potential: At rest, the neuron maintains a negative membrane potential due to the activity of potassium channels, which allow K+ ions to leak out of the cell.
Depolarization: When a stimulus is received, sodium channels open, allowing Na+ ions to rush into the cell. This influx of positive charge depolarizes the membrane, making it less negative.
Action Potential: If the depolarization reaches a threshold, an action potential is triggered. This involves the rapid opening of more sodium channels, leading to a large influx of Na+ ions and a reversal of the membrane potential.
Repolarization: After the peak of the action potential, sodium channels close, and potassium channels open. This allows K+ ions to flow out of the cell, restoring the negative membrane potential.
Propagation: The action potential propagates down the axon as the depolarization of one region triggers the opening of sodium channels in the adjacent region.

3.5. How do voltage-gated ion channels work?

Voltage-gated ion channels open or close in response to changes in the membrane potential. The channel protein contains a voltage sensor, which is a region of the protein that is sensitive to changes in the electrical potential across the membrane.

When the membrane potential changes, the voltage sensor undergoes a conformational change, which opens or closes the channel. For example, in voltage-gated sodium channels, depolarization of the membrane causes the voltage sensor to move, opening the channel and allowing Na+ ions to flow into the cell.

3.6. What are the key differences between carrier and channel proteins?

The key differences between carrier and channel proteins are:

Feature	Carrier Proteins	Channel Proteins
Mechanism	Binds to solute and undergoes conformational change	Forms a pore or channel through which solutes can pass
Rate of Transport	Slower	Faster
Specificity	Highly specific for a particular solute	Specific for ions or molecules of a certain size and charge
Energy Requirement	Can be passive or active	Always passive
Examples	Glucose transporters, sodium-potassium pump	Potassium channels, sodium channels

4. Ionophores: Enhancing Membrane Permeability

Ionophores are small hydrophobic molecules that dissolve in lipid bilayers and increase their permeability to specific inorganic ions. They are often synthesized by microorganisms and used by cell biologists to manipulate ion concentrations in experimental settings.

4.1. How do ionophores increase membrane permeability?

Ionophores increase membrane permeability by shielding the charge of the transported ion, allowing it to penetrate the hydrophobic interior of the lipid bilayer. This contrasts with transport proteins, which provide a specific, protein-lined pathway for ions to cross the membrane.

4.2. What are the two classes of ionophores?

There are two main classes of ionophores:

Mobile Ion Carriers: These ionophores bind to a specific ion, diffuse across the membrane, and release the ion on the other side. Valinomycin, which transports K+, is an example.
Channel Formers: These ionophores insert into the membrane and form a channel through which ions can flow. Gramicidin A, which forms a channel for monovalent cations, is an example.

Class of Ionophore	Mechanism	Example
Mobile Ion Carrier	Binds to ion, diffuses across membrane, releases ion	Valinomycin
Channel Former	Inserts into membrane, forms a channel for ion passage	Gramicidin A

4.3. Examples of ionophores and their uses

Several ionophores are commonly used in biological research:

Valinomycin: Transports K+ ions and is used to study potassium gradients.
FCCP: Makes membranes leaky to H+ ions and is used to dissipate proton gradients.
A23187: Transports divalent cations such as Ca2+ and Mg2+ and is used to increase intracellular calcium concentrations.
Gramicidin A: Forms a channel for monovalent cations and is used to study ion permeability.

4.4. How do ionophores differ from transport proteins?

Ionophores differ from transport proteins in several key ways:

Feature	Ionophores	Transport Proteins
Structure	Small hydrophobic molecules	Large proteins with complex structures
Mechanism	Shield ion charge to cross lipid bilayer	Provide specific, protein-lined pathway for ion passage
Specificity	Some specificity for certain ions	Highly specific for particular solutes
Energy Requirement	Always passive	Can be passive or active
Biological Origin	Often synthesized by microorganisms	Encoded by cellular genes

5. Clinical Significance of Transport Proteins

The dysfunction or mutation of transport proteins can lead to various diseases. Understanding the clinical significance of these proteins is crucial for developing effective treatments.

5.1. What diseases are associated with transport protein dysfunction?

Several diseases are associated with transport protein dysfunction:

Cystic Fibrosis: Caused by mutations in the CFTR chloride channel, leading to thick mucus buildup in the lungs and other organs.
Cystinuria: Caused by a defect in the transport of certain amino acids, leading to the formation of cystine stones in the kidneys.
Familial Hypercholesterolemia: Caused by mutations in the LDL receptor, which is responsible for transporting cholesterol into cells.
Gitelman Syndrome: Caused by mutations in the thiazide-sensitive sodium-chloride cotransporter in the kidneys, leading to electrolyte imbalances.

5.2. How do mutations in transport proteins cause disease?

Mutations in transport proteins can cause disease by:

Impairing Transport Function: The mutation may disrupt the protein’s ability to bind to the solute or undergo the necessary conformational changes for transport.
Altering Protein Trafficking: The mutation may prevent the protein from reaching the correct location in the cell membrane.
Affecting Protein Stability: The mutation may cause the protein to be unstable and degrade prematurely.

5.3. How are transport protein-related diseases diagnosed?

Transport protein-related diseases are diagnosed through a combination of methods:

Genetic Testing: Identifying mutations in the genes that encode transport proteins.
Biochemical Assays: Measuring the levels of specific solutes in the blood or urine.
Functional Assays: Assessing the transport function of specific proteins in cells or tissues.

5.4. What are the treatments for transport protein-related diseases?

Treatments for transport protein-related diseases vary depending on the specific disease and the nature of the defect:

Dietary Management: Restricting the intake of certain solutes to reduce their accumulation in the body.
Medications: Using drugs to compensate for the defective transport protein or to manage the symptoms of the disease.
Gene Therapy: In some cases, gene therapy may be used to correct the genetic defect.
Enzyme Replacement Therapy: Replacing the missing or defective enzyme responsible for transporting the solute.

6. Research and Future Directions in Transport Proteins

Ongoing research into transport proteins continues to expand our understanding of their function and clinical significance. Advances in this field hold promise for developing new therapies for a wide range of diseases.

6.1. What are the current research areas in transport proteins?

Current research areas in transport proteins include:

Structural Biology: Determining the three-dimensional structures of transport proteins to understand their mechanism of action.
Drug Discovery: Identifying small molecules that can modulate the activity of transport proteins to treat disease.
Gene Therapy: Developing gene therapy approaches to correct genetic defects in transport proteins.
Personalized Medicine: Tailoring treatments to individual patients based on their specific genetic mutations in transport proteins.

6.2. What are the potential applications of transport protein research?

Potential applications of transport protein research include:

New Drug Targets: Transport proteins are attractive targets for drug development because they play critical roles in many physiological processes.
Improved Drug Delivery: Understanding transport proteins can lead to the development of more effective drug delivery systems.
Personalized Medicine: Tailoring treatments to individual patients based on their specific genetic mutations in transport proteins.
Treatment of Genetic Diseases: Gene therapy and other approaches may be used to correct genetic defects in transport proteins and treat genetic diseases.

6.3. How are transport proteins being used in drug delivery systems?

Transport proteins are being used in drug delivery systems to:

Target Drugs to Specific Cells: By attaching drugs to molecules that are transported by specific transport proteins, drugs can be targeted to specific cells or tissues.
Increase Drug Uptake: By modulating the activity of transport proteins, drug uptake into cells can be increased.
Overcome Drug Resistance: By targeting transport proteins that are involved in drug resistance, drug resistance can be overcome.

6.4. What are some recent advances in the study of transport proteins?

Recent advances in the study of transport proteins include:

Cryo-Electron Microscopy (Cryo-EM): This technique has allowed researchers to determine the high-resolution structures of many transport proteins, providing insights into their mechanism of action.
High-Throughput Screening: This technique has allowed researchers to screen large libraries of compounds for molecules that can modulate the activity of transport proteins.
CRISPR-Cas9 Gene Editing: This technique has allowed researchers to create cell lines with specific mutations in transport proteins, facilitating the study of their function.

7. Transport Proteins in Different Cell Types

Transport proteins exhibit variations in expression and function across different cell types, reflecting the specialized roles of these cells within the body.

7.1. How do transport proteins differ in various cell types?

Transport proteins differ in various cell types based on the specific functions of those cells. For instance:

Neurons: Express a high density of voltage-gated ion channels to facilitate rapid electrical signaling.
Kidney Cells: Possess specialized transporters to regulate the reabsorption of water, ions, and nutrients.
Intestinal Cells: Express transporters for the uptake of glucose, amino acids, and other nutrients from the diet.
Liver Cells: Utilize a variety of transporters to regulate glucose metabolism, detoxification, and the synthesis of essential proteins.

7.2. What is the role of transport proteins in kidney cells?

In kidney cells, transport proteins play a critical role in:

Reabsorption of Water and Electrolytes: Transport proteins in the proximal tubule reabsorb the majority of filtered water, sodium, chloride, and bicarbonate.
Secretion of Waste Products: Transporters in the distal tubule secrete waste products such as urea, creatinine, and certain drugs into the urine.
Regulation of pH: Transport proteins in the collecting duct regulate the secretion of hydrogen ions and bicarbonate to maintain acid-base balance.

7.3. How do transport proteins facilitate nutrient absorption in intestinal cells?

In intestinal cells, transport proteins facilitate nutrient absorption by:

Uptake of Glucose: Sodium-glucose cotransporters (SGLTs) transport glucose from the intestinal lumen into the cells, driven by the sodium gradient.
Absorption of Amino Acids: Various amino acid transporters facilitate the uptake of different amino acids from the diet.
Transport of Lipids: Lipid transporters facilitate the uptake of fatty acids, cholesterol, and other lipids.

7.4. What transport proteins are important in brain function?

Several transport proteins are crucial for brain function:

Neurotransmitter Transporters: These transporters regulate the levels of neurotransmitters such as dopamine, serotonin, and glutamate in the synaptic cleft, affecting neuronal signaling.
Ion Channels: Voltage-gated and ligand-gated ion channels are essential for generating and propagating action potentials.
Glucose Transporters: GLUT1 and GLUT3 transport glucose across the blood-brain barrier and into neurons, providing energy for brain function.

8. Methods for Studying Transport Proteins

Studying transport proteins requires a variety of techniques to elucidate their structure, function, and regulation.

8.1. What techniques are used to study the structure of transport proteins?

Techniques used to study the structure of transport proteins include:

X-Ray Crystallography: Used to determine the three-dimensional structure of proteins at atomic resolution.
Cryo-Electron Microscopy (Cryo-EM): Used to determine the structure of proteins in their native state without the need for crystallization.
Nuclear Magnetic Resonance (NMR) Spectroscopy: Used to study the structure and dynamics of proteins in solution.

8.2. How is the function of transport proteins studied?

The function of transport proteins is studied using various methods:

Transport Assays: Measuring the rate of solute transport across membranes or into cells.
Electrophysiology: Measuring the electrical activity of ion channels in response to different stimuli.
Site-Directed Mutagenesis: Introducing specific mutations into the protein to study the effects on function.

8.3. What are the techniques for measuring transport activity in cells?

Techniques for measuring transport activity in cells include:

Radioisotope Tracer Studies: Using radioactive isotopes to measure the uptake and efflux of solutes.
Fluorescence-Based Assays: Using fluorescent dyes to monitor the concentration of solutes inside cells.
Patch-Clamp Electrophysiology: Measuring the current flow through single ion channels in cells.

8.4. How is site-directed mutagenesis used in transport protein research?

Site-directed mutagenesis is a powerful technique used to study the function of transport proteins. By introducing specific mutations into the protein, researchers can:

Identify Critical Amino Acids: Determine which amino acids are essential for solute binding, conformational changes, or channel gating.
Study Structure-Function Relationships: Investigate how changes in the protein structure affect its function.
Model Disease Mutations: Recreate disease-causing mutations in the lab to study their effects on protein function.

9. Regulation of Transport Protein Expression and Activity

The expression and activity of transport proteins are tightly regulated to maintain cellular homeostasis and respond to changing environmental conditions.

9.1. How is transport protein expression regulated?

Transport protein expression is regulated at multiple levels:

Transcriptional Regulation: Transcription factors bind to DNA and regulate the transcription of genes encoding transport proteins.
Post-Transcriptional Regulation: RNA-binding proteins and microRNAs can regulate the stability and translation of mRNA transcripts.
Post-Translational Modification: Modifications such as phosphorylation, glycosylation, and ubiquitination can affect protein stability, trafficking, and activity.

9.2. What factors affect the activity of transport proteins?

Factors that affect the activity of transport proteins include:

Substrate Concentration: The rate of transport is dependent on the concentration of the solute being transported.
Membrane Potential: The activity of voltage-gated ion channels is affected by the membrane potential.
Ligand Binding: The activity of ligand-gated ion channels is affected by the binding of specific ligands.
pH and Temperature: Changes in pH and temperature can affect the structure and function of transport proteins.

9.3. How does phosphorylation regulate transport protein activity?

Phosphorylation is a common post-translational modification that can regulate transport protein activity. Phosphorylation can:

Alter Protein Conformation: Changing the shape of the protein and affecting its ability to bind to the solute or undergo conformational changes.
Affect Protein Trafficking: Regulating the movement of the protein to and from the cell membrane.
Modulate Protein Stability: Affecting the rate at which the protein is degraded.

9.4. What is the role of ubiquitination in transport protein regulation?

Ubiquitination is another post-translational modification that can regulate transport protein activity. Ubiquitination can:

Target Proteins for Degradation: Marking proteins for degradation by the proteasome.
Alter Protein Trafficking: Affecting the movement of the protein to and from the cell membrane.
Modulate Protein Activity: Changing the activity of the protein by affecting its interactions with other proteins.

10. Future Trends in Transport Protein Research

The field of transport protein research is rapidly evolving, with new technologies and approaches paving the way for exciting discoveries.

10.1. What are the emerging technologies in transport protein research?

Emerging technologies in transport protein research include:

High-Throughput Screening: Screening large libraries of compounds to identify molecules that can modulate the activity of transport proteins.
CRISPR-Cas9 Gene Editing: Creating cell lines with specific mutations in transport proteins to study their function.
Single-Molecule Imaging: Visualizing the dynamics of individual transport proteins in real-time.
Computational Modeling: Using computer simulations to predict the behavior of transport proteins and design new drugs.

10.2. How is artificial intelligence being used in transport protein studies?

Artificial intelligence (AI) is being used in transport protein studies to:

Predict Protein Structure: Using machine learning algorithms to predict the three-dimensional structure of proteins based on their amino acid sequence.
Identify Drug Candidates: Using AI to screen large libraries of compounds and identify potential drug candidates that can bind to transport proteins.
Analyze Large Datasets: Using AI to analyze large datasets of transport protein expression and activity to identify patterns and correlations.

10.3. What is the potential of personalized medicine in transport protein-related diseases?

Personalized medicine holds great potential for transport protein-related diseases. By identifying the specific genetic mutations in transport proteins that are causing the disease, treatments can be tailored to the individual patient. This may involve:

Gene Therapy: Correcting the genetic defect by delivering a functional copy of the gene to the patient’s cells.
Targeted Therapies: Developing drugs that specifically target the mutated transport protein and restore its function.
Dietary Management: Tailoring the patient’s diet to minimize the accumulation of specific solutes in the body.

10.4. What are the future directions for transport protein research?

Future directions for transport protein research include:

Elucidating the Structure and Function of All Human Transport Proteins: Determining the structure and function of all human transport proteins to gain a comprehensive understanding of their roles in health and disease.
Developing New Therapies for Transport Protein-Related Diseases: Identifying new drug targets and developing new therapies for transport protein-related diseases.
Using Transport Proteins for Drug Delivery: Developing new drug delivery systems that utilize transport proteins to target drugs to specific cells and tissues.
Applying Transport Protein Research to Other Fields: Applying the knowledge gained from transport protein research to other fields such as biotechnology, agriculture, and environmental science.

Understanding the two types of transport proteins—carriers and channels—is crucial for comprehending cellular function and developing new therapies for related diseases. At worldtransport.net, we aim to provide valuable insights into this fascinating field.

For more detailed information, or to explore new transportation solutions, please contact us:

Address: 200 E Randolph St, Chicago, IL 60601, United States

Phone: +1 (312) 742-2000

Website: worldtransport.net.

Dive deeper into the world of transport proteins and discover how they impact various aspects of life sciences. Visit worldtransport.net today to explore our in-depth articles, trend analysis, and innovative transport solutions!

FAQ: Frequently Asked Questions About Transport Proteins

1. What are the two main types of transport proteins?

The two main types of transport proteins are carrier proteins and channel proteins, which facilitate the movement of molecules across cell membranes.

2. How do carrier proteins transport molecules?

Carrier proteins bind to specific solutes and undergo conformational changes to move them across the membrane.

3. What is the function of channel proteins?

Channel proteins form aqueous pores through which specific ions or molecules can pass down their electrochemical gradient.

4. What is the difference between active and passive transport?

Active transport requires energy to move molecules against their concentration gradient, while passive transport does not require energy and moves molecules down their concentration gradient.

5. What are some examples of carrier proteins?

Examples of carrier proteins include glucose transporters (GLUT), sodium-glucose cotransporters (SGLT), and the sodium-potassium pump.

6. What are some examples of channel proteins?

Examples of channel proteins include potassium channels, sodium channels, chloride channels, and aquaporins.

7. What are ionophores and how do they work?

Ionophores are small hydrophobic molecules that increase membrane permeability to specific ions by shielding their charge, allowing them to cross the lipid bilayer.

8. How do voltage-gated ion channels work?

Voltage-gated ion channels open or close in response to changes in the membrane potential, allowing specific ions to flow through.

9. What diseases are associated with transport protein dysfunction?

Diseases associated with transport protein dysfunction include cystic fibrosis, cystinuria, and familial hypercholesterolemia.

10. What are some techniques used to study transport proteins?

Techniques used to study transport proteins include X-ray crystallography, cryo-electron microscopy, transport assays, and site-directed mutagenesis.