Practice quiz #1 Phys

During osmosis through a selectively permeable membrane….

Water moves down its concentration gradient and moves to an area of higher solute concentration

A (blank) is a protein that transports two substances in opposite directions across a membrane

antiporter

Define diffusion

Passive movement of substances from higher to low concentration

A cell is placed in a solution and it expands?

The cell was hypotonic

Two compartments are operated by a selectively permeable membrane. In which direction will osmosis occur if the right compartment has less solute?

Left

Pumps are integral proteins that are involved, specifically, in the process of….

Active transport

One function of a membrane protein is to serve as a…

Structure

The supporting cells that form myelin in the peripheral nervous system are the …

Schwann cells

An ion found in highest concentration inside an unstimulated ( resting) cell is …

-70mv

During transmission at chemical synapses, which event occurs immediately after the depolarization of the axon terminal.

Opening voltage gated channels

( blank) are responsible for carrying electrical information into a neuron.

At rest, K+ enters the cell through ( blank) channels.

leakage

Which is improperly impaired?

Answer- terminal- insulates axon

If Na+ and K+ leak across the membrane of a resting cell, then how can those ions be restored to their original location?

Secondary Active transport

If V-rest was -70 mv and some sodium entered the cell, then would the value become less negative or more negative?

answer - less negative

Does secondary active transport occur in the absence of primary active transport? Yes or no and why or why not?

No because primary active transport has to occur first before secondary active transport can occur.

Why does sodium not accumulate inside the cell in a resting neuron?

Na+ is not permeable.

The peak of the action potential is closest to the equilibrium potential for

Answer- Sodium ions

During the falling phase (repolarization) of the action potential

Answer- Na+ channels open

Action potential in myelinated axons are produced only at the…

Nodes of Ranvier

What does +66mv represent?

Equilibrium potential

What does -55mv represent?

Threshold potential

Conduction in electrical synapses is ( blank), while conduction in chemical synapses is ( blank).

1. bi directional

2. un-directional

During the ( blank), a neuron cannot be simulated to generate another action potential.

refractory period

Plasma has a solute concentration equal to about 300 most. Which of the following os hyper osmotic to plasma?

Answer- 450mOsm

Descibe the two conditions required for osmosis to occur

1. must be a difference in concentration

2. has to be

The type of summation of electrical information that can result when more than one presynaptic neurons synapse on one synaptic neuron is referred to as ( blank) summation.

spatial

Which example of a greed potential can drive the resting membrane potential of cell further from threshold?

Inhibitory post synaptic inhabitation