The resting potential of a cell is roughly –70mV. When the potential rises above this level, the cell is considered "depolarized." When the potential delves below this level, the cell is considered "hyperpolarized." If the cell is depolarized above –55mV, the threshold potential, then an action potential is triggered.

Hyperpolarization occurs because potassium channels are slow to open and close, and thus the cell polarizes itself beyond its usual membrane potential. After an action potential depolarizes a cell there is a build-up of positive charge in the cell interior. The late opening of potassium channels causes an abrupt rush of potassium out of the cell, propelled by its electrochemical gradient. This rush lowers the cell potential below its normal resting state, resulting in hyperpolarization. The cell then returns to its resting state via repolarization. Sodium is removed from the cell and potassium is reintroduced through action of the sodium-potassium pump.

The resting potential of a cell is roughly –70mV. When the potential rises above this level, the cell is considered "depolarized." When the potential delves below this level, the cell is considered "hyperpolarized." If the cell is depolarized above –55mV, the threshold potential, then an action potential is triggered.

Hyperpolarization occurs because potassium channels are slow to open and close, and thus the cell polarizes itself beyond its usual membrane potential. After an action potential depolarizes a cell there is a build-up of positive charge in the cell interior. The late opening of potassium channels causes an abrupt rush of potassium out of the cell, propelled by its electrochemical gradient. This rush lowers the cell potential below its normal resting state, resulting in hyperpolarization. The cell then returns to its resting state via repolarization. Sodium is removed from the cell and potassium is reintroduced through action of the sodium-potassium pump.

Monosynaptic reflexes do not require a neuron between the pre-synaptic and post-synaptic neuron, and do not require input from the brain. These reflexes can be triggered even in brain-dead individuals. The knee-jerk reflex is an example of a monosynaptic reflex.

The accommodation reflex is used to adjust the focus of the eye. The acoustic reflex reduces sound intensity by adjusting the bones of the middle ear. The suckling reflex is the complicated reflex of an infant mammal being able to breast feed. Somatic reflexes are a broad category simply involving muscle reflexes. Some of these reflexes involve input from the brain, while others (like the knee-jerk reflex) do not.

Neurotransmitters and hormones are both chemical signals, but hormones are used in the endocrine system, released from glands into the blood, while neurotransmitters are released from the axon terminals of neurons to signal other neurons. Signals travel across neurons as electrical signals caused by the movement of large numbers of atomic ions across the membrane via protein channels. Charged proteins would be too large to quickly move through the channels in such large numbers.

Monosynaptic reflexes do not require a neuron between the pre-synaptic and post-synaptic neuron, and do not require input from the brain. These reflexes can be triggered even in brain-dead individuals. The knee-jerk reflex is an example of a monosynaptic reflex.

The accommodation reflex is used to adjust the focus of the eye. The acoustic reflex reduces sound intensity by adjusting the bones of the middle ear. The suckling reflex is the complicated reflex of an infant mammal being able to breast feed. Somatic reflexes are a broad category simply involving muscle reflexes. Some of these reflexes involve input from the brain, while others (like the knee-jerk reflex) do not.

Neurotransmitters and hormones are both chemical signals, but hormones are used in the endocrine system, released from glands into the blood, while neurotransmitters are released from the axon terminals of neurons to signal other neurons. Signals travel across neurons as electrical signals caused by the movement of large numbers of atomic ions across the membrane via protein channels. Charged proteins would be too large to quickly move through the channels in such large numbers.

The brain is often divided into four lobes based on anatomy and physiology: the frontal lobe, parietal lobe, occipital lobe, and temporal lobe. Each lobe controls various aspects of cognition and motor skills. The frontal lobe is associated with reasoning, speech, movement, and emotions. The parietal lobe is associated with orientation and recognition. The occipital lobe is associated with visual processing. The temporal lobe is associated with auditory processing and memory.

Broca's area is a small region of the frontal lobe located in the left hemisphere. This region of the brain is responsible for generating speech and articulation. Damage to this region of the frontal lobe could cause speech impairment. In contrast, Wernicke's area is located in the temporal lobe and is associated with comprehension of speech.

Spastic muscle activity is not related to the brain, but results from injury to motor neurons spanning from the spinal cord to the limbs.

The ventral root of the spinal cord is located anteriorly, while the dorsal root is located posteriorly. Afferent neurons enter the spinal cord through the dorsal root, carrying signals from the body to the brain. Efferent neurons exit the spinal cord from the ventral root before interfacing with their target muscles.

Phototaxis is movement (taxis) in response to light (photo). Movement towards a source is positive; movement away from a source is negative. "Positive phototaxis" would be used to describe movement toward a light source.

The question states that the person is malnourished. This means that he/she is not getting enough nutrients and energy to fuel the body, which directly affects the production of ATP. The correct answer will be a protein that requires energy to transport the molecules (active transport).

Out of the three proteins presented in the question, only one uses ATP to transport molecules: the sodium-potassium pump. It requires ATP because the pump transports sodium (Na) and potassium (K) ions against their respective concentration gradients. The leak channels and the voltage-gated channels use facilitated diffusion and the electrochemical gradients of the ions as the driving force for transport.

Eventually, as ion concentrations fluctuate in the individual, all three types of proteins may be affected, but only as an indirect consequence. Malnourishment will directly affect the available ATP, reducing functionality of the sodium-potassium pump.