Bio hw Ch 3

______ is an enzyme which converts ATP to cyclic AMP.

Adenylate cyclase

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

Antiport

What are the membrane channels that allow the movement of water across a membrane called?

Aquaporins

Within the plasma membrane, most transmembrane proteins will be comprised of what type of regions?

Both hydrophobic and hydrophilic

Which of the following is a function of the glycocalyx?

Cell adhesion

What are glycoprotein compounds on the cell surface that allow the body to distinguish the body's cells from foreign cells called?

Cell-identity markers

Which group of glycoproteins found on the cell's surface allow the body to recognize the cell as one of its own?

Cell-identity markers

Water and electrolytes can cross a cell membrane through which of the following?

Channels

Cells that line the intestine are taller than they are wide and therefore described as what?

Columnar

What is a cell that is equally tall as it is wide called?

Cuboidal

______ is formed from ATP and is the most common second messenger.

Cyclic AMP

Voltage-regulated gates respond to changes in what across the plasma membrane?

Electrical potential

True or false: Facilitated diffusion is an active process that uses cellular energy to move substances against the concentration gradient

False Facilitated diffusion is a passive process that does not use cellular energy.

Down a gradient

From a region of high to low concentration

Cell receptors are sometimes linked to which type of intracellular peripheral protein?

G

Which cellular structure is critical for identifying your body's own healthy cells from transplanted tissue?

Glycocalyx

Which organelle plays a role in immunity, transplant compatibility, cell adhesion, and protection?

Glycocalyx

Which pressure allows for the filtration of fluid from blood vessels into the extracellular fluid?

Hydrostatic Reason: Hydrostatic pressure is the pressure that a fluid exerts on the walls of the vessel in which it is contained.

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

Hypertonic

Which factors would increase the rate of diffusion?

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

What is the name of the structure at the end of the long pointer that allows ions to pass through the cell membrane?

Ion channel

What are integral proteins of the cell membrane that allow ions to pass through called?

Ion channels

When cells are placed in which solution, there is no change in cell volume or shape?

Isotonic

As the molecular weight of a substance increases, what happens to its diffusion rate?

It decreases.

As a membrane surface area increases, what happens to it's diffusion rate?

It increases.

As temperature increases, what happens to the rate of diffusion?

It increases.

A second messenger ultimately might activate an enzyme that adds a phosphate to yet another cellular enzyme. What is this enzyme that causes phosphorylation of others called?

Kinase

What is most useful unit of measurement for cell size?

Micrometer

Which of the following molecules can readily diffuse through a cell membrane?

Nonpolar molecules Lipid-soluble molecules Hydrophobic molecules

The number of milliosmoles of solute per liter of water is used to express the osmotic concentration of a solution, also known as what?

Osmolarity

At tissue capillary beds, fluid leaves the capillaries by filtration while it moves back into the capillaries by which process?

Osmosis

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

Osmosis

Which of the following are examples of passive transport?

Osmosis Filtration Passive diffusion Facilitated diffusion

Which membrane protein is not integral to the plasma membrane and is often attached to the cytoskeleton?

Peripheral

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

Peripheral

The plasma membrane is made up of phospholipids and which of the following?

Protein

When all carriers have bound ligand and no further ligand can be transported they are said to be what?

Saturated

Cyclic AMP is an example of which of the following?

Second messenger

What are three mechanisms of carrier-mediated transport?

Secondary active transport Primary active transport Facilitated diffusion

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

Selectively permeable

Plasma membranes are selectively permeable. What does this mean?

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

A carrier protein binds and transports only its particular ligand. What quality does this demonstrate?

Specificity

What are cells, like adipose cells, that are round in appearance described as?

Spheroidal

The cell shape shown in the figure is

Stellate

Which of the following correctly defines tonicity?

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

As a solute concentration rises, its rate of transport through a membrane increases up to the point where all the carriers are saturated. This point of saturation is called what?

The transport maximum

What is a protein that extends through the cell membrane called?

Transmembrane

When all carriers are saturated, the transport of the molecule levels off at a rate called what?

Transport maximum

What is a carrier that carries only one type of solute called?

Uniport

Reverse osmosis uses a mechanical pressure to drive water through a membrane ______ its concentration gradient.

against

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

amphipathic

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

bilayer

The cell shape shown in the image is

columnar

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

countertransport

The cell shape indicated by the pointer is

cuboidal

Oxygen passes into the bloodstream across the membranes in the lung by the process of _____

diffusion

Passive mechanisms of membrane transport ______.

do not require ATP

What is the fluid located between cells called?

extracellular fluid

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

faster

The rate of diffusion across the cell membrane is ______ at high temperatures than at low temperatures.

faster

Smaller molecules diffuse ______ larger molecules.

faster than

In blood capillaries, blood pressure forces fluid through gaps in the capillary wall in a process called

filtration

Up a gradient

from a region of low to high concentration

A membrane coating called the ____ is chemically unique in everyone but identical twins.

glycocalyx

Coming from words that mean "sugar coat", the layer of carbohydrates coating a cell membrane is called the

glycocalyx

Components of the plasma membrane called ______ help form the glycocalyx.

glycolipids

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

The greater the concentration of a nonpermeating solute present in a solution, the ______ the osmotic pressure of that solution.

higher

The physical force generated by a liquid, such as blood or tissue fluid, is known as _____ pressure.

hydrostatic

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

hypertonic

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

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

The rate of diffusion is increased by ______ the surface area of the cell membrane.

increasing

The fluid contained inside a cell is known as ______ fluid.

intracellular

Squamous cells

line the esophagus

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 Reason: Remember that water moves by osmosis from a high water, yet low solute concentration to a low water, yet high solute concentration.

Larger molecules diffuse through the cell membrane ______ than smaller molecules.

more slowly

What are the longest human cells?

nerve and muscle

Examples of stellate cells are_____

nerve cells

The _____ of a solution is the number of milliosmoles per liter of solution.

osmolarity

The movement of specifically water from an area of higher concentration to an area of lower concentration across a semipermeable membrane is called ____

osmosis

The majority of the plasma membrane can be described as a bilayer of _____ with associated proteins.

phospholipid

The fluidity of the plasma membrane is primarily provided by the ______.

phospholipids

What drives filtration through a membrane?

physical pressure

Mechanical pressure can be applied to one side of a membrane in order to drive water through the membrane against its concentration gradient. This process is called _____ osmosis.

reverse

The cell shape shown in the figure is

spheroidal

The cell shape shown in the figure is

squamous

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

symport

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

A hydration sphere consists of a solute particle surrounded by _____ molecules.

water

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

0.9%

What is a protein that participates in transmembrane transport called?

A carrier

What do voltage-gated ion channels open in response to?

A change in membrane potential

Water molecules can form a loose reversible relationship with a solute particle by assembling into what?

A hydration sphere

The binding of a molecule to a cell-surface receptor may result in the activation of another molecule within the cell which, in turn, causes an alteration in cell function. What is this molecule within the cell called?

A second messenger

The heart generates pressure that drives fluid out of the capillaries and into the spaces between cells. What is this process called?

Capillary filtration

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 net movement of particles from a region of higher concentration to a region of lower concentration called?

Diffusion