Help with Vesicle Transport - GRE Subject Test: Biochemistry, Cell, and Molecular Biology

Clathrin coats are often seen trafficking vesicles from the Golgi apparatus to the plasma membrane. Clathrin protein is used to facilitate membrane invagination and vesicle formation, as well as direct vesicle release.

COPI coats are seen in vesicles headed from the Golgi apparatus back to the endoplasmic reticulum. COPII coats are seen in vesicles headed towards the Golgi apparatus from the endoplasmic reticulum.

Actin and microtubules have similar chemical properties. They maintain a nucleotide gradient (ADP/ATP for actin and GDP/GTP for microtubules) across their structures and have two distinct polarized ends. Intermediate filaments do not have either of these characteristics. For that reason, motor proteins associate with actin and microtubules as opposed to intermediate filaments. The polarity of the microtubules and actin allow the motor proteins to become oriented, transporting cargo in a particular direction along the structure. These motor proteins (such as myosin, dynein, and kinesin) are essential for vesicular transport.

Both the actin microfilament cytoskeleton and the microtubule cytoskeleton serve important functions in vesicular transport. They serve as the structures upon which motor proteins move, essentially providing a directional tract for vesicular transport. Motor proteins, such as kinesin, associate with vesicles and bring them from one area of the cell to the other along the directional filaments.

The intermediate filament cytoskeleton lacks the polarity displayed by actin microfilaments and microtubules, making it not very useful for vesicular transport.

This requires knowing that SNARE proteins are required for proper vesicle fusion to the membrane, thereby permitting exocytosis of neurotransmitters into the synaptic cleft and activating the next target; muscle in this case. Paralysis comes because the muscle is not receiving any input once the toxin has cleaved/destroyed the SNARE proteins.

Actin (microfilaments) is a cytoskeletal component, and myelin is an axon wrapping component; not molecular motors. Kinesin is a motor that moves in the plus-end direction, away from the MTOC. Dynein is the correct answer; it moves in the minus-end direction towards the MTOC.

Synaptotagmin is a calcium sensor that is associated with the vesicle to be exocytosed. In a high calcium environment, synaptotagmin becomes activated and interacts with syntaxin, a SNARE protein docked in the membrane from which the vesicle will be exocytosed. This interaction permits selective exocytosis during processes such as neurotransmission when there is a large calcium influx, indicating a message must be relayed to the next cell.

Clathrin coats are often seen trafficking vesicles from the Golgi apparatus to the plasma membrane. Clathrin protein is used to facilitate membrane invagination and vesicle formation, as well as direct vesicle release.

COPI coats are seen in vesicles headed from the Golgi apparatus back to the endoplasmic reticulum. COPII coats are seen in vesicles headed towards the Golgi apparatus from the endoplasmic reticulum.

Actin and microtubules have similar chemical properties. They maintain a nucleotide gradient (ADP/ATP for actin and GDP/GTP for microtubules) across their structures and have two distinct polarized ends. Intermediate filaments do not have either of these characteristics. For that reason, motor proteins associate with actin and microtubules as opposed to intermediate filaments. The polarity of the microtubules and actin allow the motor proteins to become oriented, transporting cargo in a particular direction along the structure. These motor proteins (such as myosin, dynein, and kinesin) are essential for vesicular transport.

Both the actin microfilament cytoskeleton and the microtubule cytoskeleton serve important functions in vesicular transport. They serve as the structures upon which motor proteins move, essentially providing a directional tract for vesicular transport. Motor proteins, such as kinesin, associate with vesicles and bring them from one area of the cell to the other along the directional filaments.

The intermediate filament cytoskeleton lacks the polarity displayed by actin microfilaments and microtubules, making it not very useful for vesicular transport.

This requires knowing that SNARE proteins are required for proper vesicle fusion to the membrane, thereby permitting exocytosis of neurotransmitters into the synaptic cleft and activating the next target; muscle in this case. Paralysis comes because the muscle is not receiving any input once the toxin has cleaved/destroyed the SNARE proteins.

Actin (microfilaments) is a cytoskeletal component, and myelin is an axon wrapping component; not molecular motors. Kinesin is a motor that moves in the plus-end direction, away from the MTOC. Dynein is the correct answer; it moves in the minus-end direction towards the MTOC.

Synaptotagmin is a calcium sensor that is associated with the vesicle to be exocytosed. In a high calcium environment, synaptotagmin becomes activated and interacts with syntaxin, a SNARE protein docked in the membrane from which the vesicle will be exocytosed. This interaction permits selective exocytosis during processes such as neurotransmission when there is a large calcium influx, indicating a message must be relayed to the next cell.

Clathrin coats are often seen trafficking vesicles from the Golgi apparatus to the plasma membrane. Clathrin protein is used to facilitate membrane invagination and vesicle formation, as well as direct vesicle release.

COPI coats are seen in vesicles headed from the Golgi apparatus back to the endoplasmic reticulum. COPII coats are seen in vesicles headed towards the Golgi apparatus from the endoplasmic reticulum.

Actin and microtubules have similar chemical properties. They maintain a nucleotide gradient (ADP/ATP for actin and GDP/GTP for microtubules) across their structures and have two distinct polarized ends. Intermediate filaments do not have either of these characteristics. For that reason, motor proteins associate with actin and microtubules as opposed to intermediate filaments. The polarity of the microtubules and actin allow the motor proteins to become oriented, transporting cargo in a particular direction along the structure. These motor proteins (such as myosin, dynein, and kinesin) are essential for vesicular transport.

Both the actin microfilament cytoskeleton and the microtubule cytoskeleton serve important functions in vesicular transport. They serve as the structures upon which motor proteins move, essentially providing a directional tract for vesicular transport. Motor proteins, such as kinesin, associate with vesicles and bring them from one area of the cell to the other along the directional filaments.

The intermediate filament cytoskeleton lacks the polarity displayed by actin microfilaments and microtubules, making it not very useful for vesicular transport.

This requires knowing that SNARE proteins are required for proper vesicle fusion to the membrane, thereby permitting exocytosis of neurotransmitters into the synaptic cleft and activating the next target; muscle in this case. Paralysis comes because the muscle is not receiving any input once the toxin has cleaved/destroyed the SNARE proteins.

Actin (microfilaments) is a cytoskeletal component, and myelin is an axon wrapping component; not molecular motors. Kinesin is a motor that moves in the plus-end direction, away from the MTOC. Dynein is the correct answer; it moves in the minus-end direction towards the MTOC.

Synaptotagmin is a calcium sensor that is associated with the vesicle to be exocytosed. In a high calcium environment, synaptotagmin becomes activated and interacts with syntaxin, a SNARE protein docked in the membrane from which the vesicle will be exocytosed. This interaction permits selective exocytosis during processes such as neurotransmission when there is a large calcium influx, indicating a message must be relayed to the next cell.

Clathrin coats are often seen trafficking vesicles from the Golgi apparatus to the plasma membrane. Clathrin protein is used to facilitate membrane invagination and vesicle formation, as well as direct vesicle release.

COPI coats are seen in vesicles headed from the Golgi apparatus back to the endoplasmic reticulum. COPII coats are seen in vesicles headed towards the Golgi apparatus from the endoplasmic reticulum.

Actin and microtubules have similar chemical properties. They maintain a nucleotide gradient (ADP/ATP for actin and GDP/GTP for microtubules) across their structures and have two distinct polarized ends. Intermediate filaments do not have either of these characteristics. For that reason, motor proteins associate with actin and microtubules as opposed to intermediate filaments. The polarity of the microtubules and actin allow the motor proteins to become oriented, transporting cargo in a particular direction along the structure. These motor proteins (such as myosin, dynein, and kinesin) are essential for vesicular transport.