Midterm 1 - Misc. Questions Flashcards
What is the correct definition of an ion?
An ion is an atom or molecule with a net electrical charge.
What is true about proteins in terms of their composition?
Proteins are strings of amino acids.
Where are proteins synthesized in eukaryotic cells?
Proteins are synthesized outside the nucleus in the ribosomes.
What do microtubules do?
Microtubules are needed to transport vesicles within the cell.
Microtubules serve as tracks for motor proteins to transport vesicles (small sacs containing proteins) within the cell, facilitating communication and nutrient distribution essential for cellular function.
What can be said about multicellular organisms?
Multicellular organisms are either made of all eukartyotic or all prokaryotic cells, but never both. Complex multicellular organims are made of eukaryotic cells.
Cerebral Cortex, Hippocampus, Amygdala, Cerebellum
Unlike the brains of humans, which of the above structures is absent in the brains of other mammals like mice?
TRICK question - all these brain structures (Cerebral Cortex, Hippocampus, Amygdala, Cerebellum) are present in both mice and humans.
What is the structure of the gene that encodes the voltage-gated sodium channel found in neurons?
The gene is a string of nucleic acids.
What is the leak potassium channel found in neurons?
The leak potassium channel is a two-way door through which potassium can leave and enter the cell
What is the function of the gene promoter for the leak potassium channel?
It regulates when and in which cells the leak potassium channel gene is read.
Gene promoters are sections of DNA that regulate gene expression. They are not the genes themselves.
Of the following, which ion carries a negative charge when dissolved in water?
Sodium, Potassium, Calcium, Hydrogen
Trick question: NONE OF THE ABOVE!
At its resting membrane potential, how is a neuron charged relative to the extracellular space?
The neuron is negatively charged relative to the extracellular space.
What is the primary job of the voltage-gated potassium channel in neurons?
To quickly restore the resting membrane potential after an action potential.
When the membrane potential of a neuron is exactly 0 mV during an action potential, what is true?
The concentration of sodium ions inside and outside the cell are equal.
In a neuron sitting at rest (about -70 mV), how does the force of diffusion affect sodium ions moving into the axon at the peak of an action potential (about +40 mV)?
The force of diffusion encourages sodium ions to move into the axon at rest and out of the axon at the peak of an action potential.
Diffusion is driven by concentration gradients, and there is always 15 times more sodium outside a neuron than inside of it.
Which of the following requires molecules of ATP to function?
Voltage-gated sodium channels, Leak potassium channels, Ionotropic receptors, Metabotropic receptors, Sodium-potassium pump
Sodium-potassium pump
How is the density of sodium ions at the peak of an action potential?
At the peak of an action potential, the density of sodium ions is greater inside the cell than outside the cell.
What does it mean when action potentials are described as “all or none”?
There is no such thing as a strong or weak action potential.
What would most likely happen if you introduced a mutation that tripled the length of each segment of myelin sheath on an axon?
Action potentials would not propagate all the way down the myelinated axon.
What triggers neurotransmitter release from the presynaptic membrane?
An influx of calcium ions into the axon terminal.
What is true about every single glutamate receptor in the brain?
Every glutamate receptor is excitatory.
Which process might mediate depolarization when neurotransmitters activate postsynaptic metabotropic receptors?
The closing of open potassium ion channels.
What would happen to a neuron’s membrane potential if the concentration of potassium ions in the extracellular space was artificially increased?
Potassium ions would be less likely to leave through leak channels, so the membrane would depolarize.
What is generally true about the autoreceptors expressed by neurons?
They are usually inhibitory.
What is the correct order of the following from smallest to largest in size:
(1) Carbon atom
(2) Synaptic vesicle
(3) Voltage-gated sodium channel
(4) Neuropeptide
(5) Amino acid
1, 5, 4, 3, 2 (carbon atom, amino acid, neuropeptide, voltage-gated sodium channel, synaptic vesicle).
- A carbon atom is a single atom.
- A typical amino acid is about 20 atoms.
- A neuropeptide is short string of amino acids (about 600 atoms).
- Ion channels are proteins, which are long strings of amino acids (about 10,000 atoms).
- A synaptic vesicle can hold over 5000 neurotransmitters and has many proteins embedded in its membrane (about 100,000 atoms in total).
When looking at a fixation point with an image flashed in your left periphery, what happens to the information from the right side of your left eye at the optic chiasm?
The information crosses over to the right hemisphere.
In a split-brain patient, if an image is shown in their left periphery while staring at a fixation point, what would they be able to do?
They would be able to write what they saw with their left hand, which is controlled by the right hemisphere of the brain. However, they would not be able to verbally answer about what they saw, because the information processed in the right hemisphere cannot be communicated verbally.
If a split-brain patient sees the word “fork” in their left periphery and “screwdriver” in their right periphery, what are they likely to verbally say and pick up with their left hand?
They would verbally answer “screwdriver” and pick up a “fork.”
Why would a split-brain patient who laughs at the word “laugh” make up a reason for laughing according to Gazzaniga’s Interpreter Theory?
The patient’s left hemisphere is creating a narrative to explain the behavior.
Which of the following statements is false about Gazzaniga’s Interpreter Theory?
- Consciousness is only located in the left hemisphere.
- The function of consciousness is storytelling.
- Free will is an illusion.
- Human consciousness directly controls behaviour
Human consciousness directly controls behaviour
Gazzaniga’s Interpreter Theory believes that while human consciousness plays a role in decision-making and behavior, it does not directly control all behaviors, which are also influenced by unconscious processes, reflexes, and external factors.
What term refers to Descartes’ argument that our body exists in a physical realm while our mind exists in a separate immaterial realm?
Mind-body dualism.
Which atoms or molecules primarily compose cells?
Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur.
The cell membrane is similar to what structure and consists of what?
It is similar to a liposome and consists of a phospholipid bilayer.
What is a liposome?
A liposome is a small, spherical vesicle made of phospholipid bilayers that encapsulates water-soluble substances.
It protects and transports hydrophilic molecules (like drugs).
It is commonly used in pharmaceuticals to improve drug solubility and reduce toxicity, as well as in cosmetics for ingredient delivery.
It mimics cell membranes in structure but is artificial and lacks complex proteins.
What is an important difference between prokaryotic and eukaryotic cells?
Prokaryotic cells have free-floating DNA, while eukaryotic cells have DNA contained in the nucleus.
Which component of the cell is responsible for creating proteins?
Ribosome.
What is an implication of Gazzaniga’s Interpreter Theory?
An implication of Gazzaniga’s Interpreter Theory is that consciousness is localized in the right hemisphere.
How can a sensory neuron differentially encode weak or strong sensory input?
By varying the amount of time between each action potential, the number of sodium ions that enter with each action potential, the time it takes for the action potential to travel along a section of axon, and the frequency of subthreshold depolarizations.
If we replace all K+ leak channels with Na+ leak channels, what would the resting membrane potential be close to?
Approximately -40mV.
What would most likely happen if action potentials were triggered simultaneously in the cell body and axon terminal of a neuron?
The action potentials would pass each other, propagating up to the cell body and down to the axon terminal.
How are forces acting on chloride ions in a neuron with a higher concentration of chloride ions inside than outside at rest?
The diffusion force is pulling chloride into the cell, and the electrostatic force is pushing chloride out of the cell.
What would happen if chloride leak channels were introduced to a neuron with a higher concentration of chloride inside?
The resting membrane potential will increase (become less negative).
What do we expect to observe after a neuron at rest receives an EPSP that brings the membrane voltage to -60mV?
An influx of Na+ ions.
What is true at 0mV during the depolarization phase of the action potential?
The diffusion and electrostatic forces acting on sodium ions are equal.
