psio

Which is most likely to be the resting membrane potential of a neuron?

-70mV

Which salt solution would be isotonic to human red blood cells?

0.9%

About 98% of plasma membrane molecules are lipids. Of this 98%, about ______ are phospholipids.

75%

Which best describes an electrical potential?

A form of potential energy that can produce current

Which of the following describes the integration center of a feedback mechanism?

A process information, relate it to other information, and makes a decision of action.

Which of the following describes primary active transport?

A solute is moved up its concentration gradient using ATP.

Which important properties of water allow it to support life?

Chemical reactivity Solvency Cohesion

Which term refers to molecules that dissolve in water? Multiple choice question.

Hydrophilic

Which factors would increase the rate of diffusion?

Increased concentration difference Decreased molecular weight of diffusing compound Increased cell surface area

Choose all that are true regarding the Na+-K+ pump.

It helps maintain the proper ion distribution across the membrane, compensating for ion leakage. It accounts for about 70% of the energy (ATP) required by the nervous system.

Which of the following contributes to the development of the resting membrane potential in neurons?

K+ is more concentrated in the ICF than in the ECF.

Which proteins do not protrude into the phospholipid layer but adhere to only one face of the membrane?

Peripheral

Which membrane type allows some things through and restricts the passage of others?

Selectively permeable

Why is sodium more concentrated in the ECF than in the ICF of most neurons?

Sodium is actively pumped out of the cell by transporter proteins.

Plasma membranes are selectively permeable. What does this mean?

Some compounds can permeate (pass through) the membrane while others cannot.

which of the following correctly defines tonicity?

The ability of a solution to cause osmosis, affecting volume and pressure in the cell

What is a protein that participates in transmembrane transport called?

a carrier

The Na+-K+ pump is a good example of which type of transport?

active

Which membrane transport process consumes ATP and uses a carrier?

active

Which process uses a carrier to move a substance against its concentration gradient using ATP?

active

Mechanisms for moving substances across the plasma membrane that require the use of cellular ATP include ______.

active transport vesicular transport

Phospholipids are ______ molecules that have a hydrophobic tail and hydrophilic head.

amphipathic ( has both polar and non-polar regions )

Which carrier transports two or more solutes in opposite directions across a cell membrane?

antiport

The movement of water in and out of the renal tubules can be increased or decreased. The tubular cells are able to do this, by changing the number of water channels, also called _____ , in their membranes.

aquapornis

Amphipathic phospholipids arrange themselves into a(n) ______ to form the plasma membrane.

bilayer

In which process does a solute bind to a carrier in the plasma membrane that then changes shape and releases the solute to the other side of the membrane?

carrier-mediated transport

What is the smallest unit of an organism that can carry out all the functions of life?

cell

Which of the following are examples of a positive feedback mechanism?

contractions during childbirth formation of a blood clot

If an antiport carrier moves solutes in opposite directions across a cell membrane without requiring energy, this is called

countertransport

Movement of gas molecules (oxygen and carbon dioxide) between the air in the lungs and the blood or between the blood and the tissues is by which process? Multiple choice question.

diffusion

What is the net movement of particles from a region of higher concentration to a region of lower concentration called? Multiple choice question.

diffusion

Without the use of energy, matter tends to flow ______.

down gradients

What is the cell or organ that directly carries out a response to a stimulus called?

effector

The vesicular transport process of discharging material from a cell is called

exocytosis

The process of using a carrier to passively transport a solute through a membrane down its concentration gradient is known as ____ diffusion.

facillitated

Facilitated diffusion is an active process that uses cellular energy to move substances against the concentration gradient.

false

The scientific method is based on an informed conjecture that is capable of being tested and potentially proven false by experimentation or data collection. True false question.

false

The greater or steeper the concentration gradient, the ______ the rate of diffusion.

faster

Smaller molecules diffuse ______ larger molecules.

faster than

Most transmembrane proteins are ______.

glycoproteins

When the concentration of a substance differs from one area to another, this creates a concentration ____.

gradient

When the concentration of a substance differs from one area to another, this creates a concentration____.

gradient

When the concentration of a substance gradually changes from one area to the next, we say it exhibits a concentration___.

gradient

Without the expenditure of energy, the net movement of matter in a physiological gradient will always be from a region of ______ concentration to a region of ______ concentration.

higher, lower

What term can be used to describe any non-polar molecule that does not dissolve in water?

hydrophobic

A cell placed into which solution will lose water by osmosis?

hypertonic

A solution that has a higher osmotic pressure than the intracellular fluid of cells and tends to cause the cells to undergo osmotic shrinkage is called a(n) _____ solution.

hypertonic

A solution that has a lower osmotic pressure than the intracellular fluid of the cell and tends to cause osmotic swelling and lysis of cells is called a(n) ___solution.

hypotonic

Cells placed in a(n) ______ solution will swell and burst due to water moving into the cell.

hypotonic

Cells can ______ the rate of osmosis by installing more aquaporins.

increase

Which part of a feedback mechanism processes information, relates it to other information, and makes a decision of action?

integrating center

Consider two solutions of different sodium concentrations separated by a selectively permeable membrane. The net movement of water across the membrane will be from the area of ______ sodium concentration to the area of ______ sodium concentration.

lower, higher

Organelles are composed of ______.

molecules

Blood pressure is controlled by a ____ feedback mechanism.

negative

Blood pressure is controlled by a_____ feedback mechanism.

negative

When some bodily changes are detected, responses are activated that reverse the change, restoring stability and preserving normal body function. This would be an example of what type of feedback?

negative

What is an anatomical structure that is composed of at least two different tissue types, has recognizable structural boundaries, and has a discrete function different from the structures around it called?

organ

What is the net flow of water down its concentration gradient through a selectively permeable membrane called?

osmosis

Which term is used to refer to a cell membrane across which there is a separation of electrical charge, so that one side is more positive and the other side is more negative?

polarized

What type of feedback is a self-amplifying cycle in which a physiological change leads to an even greater change in the same direction?

positive

Which ion has the greatest influence on the resting membrane potential of most neurons?

potassium

An electrical potential is a form of what type of energy?

potential energy

The name for a structure that is specialized to detect a stimulus is a(n)

receptor

At rest, K+ diffuses out of the cell through leak channels, resulting in a slight local accumulation of positive charge on the outside of the membrane (due to excess K+) and a slight local accumulation of negative charge on the inside of the membrane (due to decreased K+). This describes the basis of the ______ membrane potential.

resting

Which term refers to the voltage difference (electrical potential) across the plasma membrane of a neuron when it is at rest and not engaged in electrical signaling?

resting membrane potential

Which of the following assures that the ECF concentration of sodium remains much higher than the ICF concentration?

sodium-potassium pump

The ability of water to dissolve other chemicals is ______.

solvency

Which type of carrier moves two solutes through a plasma membrane in the same direction at the same time?

symport

The type of carrier protein that moves two solutes, such as glucose and sodium, in the same direction across a membrane is a(n)

symporter

An aggregation of cells and extracellular materials, which perform a discrete function, is known as a(n)

tissue

Why is it critical that the extracellular fluid have the same total concentration of non-permeating solutes as the intracellular fluid?

to avoid changes in cell volume or pressure

The concentration of solutes in a cell affects the fluid volume and pressure within the cell. This is referred to as the_____ of the solution.

tonicity

The transport of material across a cell, with capture on one side and release on the other, is by which process?

transcytosis

As long as there is an electrical potential across a cell membrane, we say that the membrane is polarized.

true

Which of the following moves large particles and fluid droplets across the cell membrane?

vesicular transport

Hydrophilic substances are soluble in

water

Hydrophobic means that a substance is insoluble in

water

Solvency, cohesion, adhesion, hydrogen bonding, chemical reactivity, and thermal stability are all important properties of ____ and account for its ability to support life.

water