Cellular Form and Function chapter 3 (Hwrk questions)

False

A cell's second messengers serve to transport material through the plasma membrane.

ligands

A molecule that binds specifically to a receptor site of another molecule.

isotonic, 0.9%

A patient was severely dehydrated, losing a large amount of fluid. The patient was given intravenous fluids of normal saline. Normal saline is _______to your blood cells and is about _______NaCi.

...

A receptor protein in the plasma membrane will not bind to just any chemical in the extracellular fluid, but only to certain ones. That is to say, the receptor exhibits SPECIFICITY

higher - shrink

A red blood cell is placed in a hypertonic solution. The concentration of the solutes in the solution is HIGHER than the concentration of solutes in the intracellular fluid and will cause the cell to SHRINK

A 5% urea solution is hypotonic to a 10% urea solution. A) True B) False

A) True

Facilitated diffusion requires a specific transporter for a specific molecule. A) True B) False

A) True

If a cell is placed in an isotonic medium, there will be no net movement of water. A) True B) False

A) True

If the material the cell takes in is liquid, the process is termed pinocytosis. A) True B) False

A) True

Low-density lipoprotein is brought into the cell by receptor-mediated endocytosis. A) True B) False

A) True

The binding and release of sodium or potassium ions are due to conformational changes in the protein. A) True B) False

A) True

The sodium-potassium pump is a trans-membrane protein. A) True B) False

A) True

What is the source of energy used to power the sodium-potassium pump? A) breakdown of ATP B) formation of ATP C) transport of ATP by the pump D) breakdown of GTP E) transport of GTP by the pump

A) breakdown of ATP

Simple diffusion is defined as the movement of A) molecules from areas of higher concentration to areas of lower concentration. B) molecules from areas of lower concentration to areas of higher concentration. C) water molecules across a membrane. D) gas molecules across a membrane. E) gas or water molecules across a membrane.

A) molecules from areas of higher concentration to areas of lower concentration.

Exocytosis is a process by which cells A) release substances from the cell through pores in the cell membrane. B) release substances from the cell via vesicles. C) release substances from the cell via carrier proteins. D) bring in substances from the outside via vesicles. E) bring in substances from the outside via pores in the cell membrane.

A) release substances from the cell through pores in the cell membrane.

The sodium-potassium pump functions to pump A) sodium ions out of the cell and potassium ions into the cell. B) sodium ions into the cell and potassium ions out of the cell. C) sodium and potassium ions into the cell. D) sodium and potassium ions out of the cell. E) sodium and potassium ions in both directions across the cell membrane.

A) sodium ions out of the cell and potassium ions into the cell.

Facilitated diffusion is used to transport A) sugars and amino acids. B) H2O and O2. C) CO2 and O2. D) CO2 and H2O. E) sugars and H2O.

A) sugars and amino acids

Which of the following statements about receptor-mediated endocytosis is TRUE? A) it is used to transport material out of the cell B) it is not specific C) it involves clathrin-coated pits D) it involves transport of material into the cell through pores in the cell membrane E) none of the above

C) it involves clathrin-coated pits

A red blood cell placed in a hypertonic medium will A) expand. B) burst. C) shrink. D) have no change in shape. E) become a white blood cell.

C) shrink.

When sugar is mixed with water, equilibrium is reached when A) molecules of sugar stop moving. B) water and sugar molecules are moving at the same speed. C) the dissolved sugar molecules are evenly distributed throughout the solution. D) there are the same number of water molecules as dissolved sugar molecules. E) two tablespoons of coffee are added.

C) the dissolved sugar molecules are evenly distributed throughout the solution.

MICROVILLI

Cells lining the small intestines are specialized for absoption of nutrients. their plasma membrane has MICROVILLI

Centrioles; microtubules

Centrioles play an important role in cell division, and they are made of microtubules

During one cycle, the sodium-potassium pump binds and moves. A) 1 Na+ and 2 K+. B) 2 Na+ and 2 K+. C) 2 Na+ and 3 K+. D) 3 Na+ and 2 K+. E) 3 Na+ and 3 K+.

D) 3 Na+ and 2 K+.

Facilitated diffusion occurs A) into the cell only. B) out of the cell only. C) in either direction depending on the temperature. D) in either direction depending on the concentration gradient of the molecule. E) in either direction depending on the size of the molecule.

D) in either direction depending on the concentration gradient of the molecule.

Certain white blood cells engulf microorganisms and bring them in to digest them. This process is best described as A) pinocytosis. B) osmosis. C) receptor-mediated exocytosis. D) phagocytosis. E) diffusion.

D) phagocytosis.

cases of carrier mediated transport

Facilitated diffusion and active transport have in common that both are cases of carrier-mediated transport.

Flagella; cilia; microvilli

Flagella provide motility to a cell, cilia act as sensory "antnna" in many cells, and microvilli increase the cells surface area

GLYCOPROTEINS - id tags

GLYCOPROTEINS act like identification tags in the glycocalyx that enable the body ot distinguish its own cells from foreign and diseased cells

...

Gates respond to all these stimuli fluid except WATER IN THE EXTRACELLULAR FLUID Gates do respond to Physical deformations of the plasma membrane ligands changes in electrical potential (voltage) across the plasma membrane chemical messengers

False

If a cell doubled in diameter, it would have twice as much cytoplasm to maintain

osmolarity; tonicity

OSMOLARITY describes the number of particles of a solute in solution, whereas TONICITY is the ability of a solution to affect the fluid volume in a cell

false

One example of pinocytosis is the uptake of low-density lipoproteins (LDL'S) by endothelial cells FALSE

Peroxisomes

PEROXISOMES decompose fatty acids, and detoxify alcohol, free radicals, and drugs

Pinocytosis

PINOCYTOSIS - brings nonspecific material into a cell

Particles can leave cell by the following simple diffusion active transport exocytosis an antiport system

Particles can leave a cell by any of these means except PINOCYTOSIS

Phospholipids

Phospholipids are the most abundant molecules in plasma membrane

PUMPS

Pumps consume ATP when transferring solutes fro one side to the other side of the plasma membrane.

TRUE

Ribosomes are made of proteins and RNA

SMOOTH ER

Smooth ER is NOT involved in protein synthesis

symport; cotransport

Sodium and glucose are transported together from the intestinal lumen into an intestinal cell. The carrier is a SYMPORT and the process is called COTRANSPORT

The Golgi complex; rough ER

THE GOLGI COMPLEX synthesize (s) carbohydrates and put(s) finishing touches on proteins synthesized at ROUGH ER

False

The Golgi complex makes peroxisomes but not lysosomes

True

The Na+-K ATPase is a counter-transport antiport carrier, which always requires energy.

SQUAMOUS

The flat-shaped cells found covering the skin are SQUAMOUS

True

The most important advantage of transmission electron microscopes (TEM) over light microscopes (LM) is its higher resolution

True

The nucleus is the largest organelle in most cells

False

The sodium-glucose transport protein (SGLT) is one example of an active transport process involving a uniport carrier

UP ; ACTIVE TRANSPORT

The sodium-potassium (Na+-K) pump transports both sodium and potassium UP their concentration gradients in a process called ACTIVE TRANSPORT

RIBOSOMES - NOT MEMBRANOUS

These are all membranous organelles except RIBOSOMES

C. all cells occupy space.

These generalizations constitute the modern cell theory except A. an organism's structure and all of its functions are ultimately due to the activities of its cells. B.all cells come only from preexisting cells. C. all cells occupy space. D. all organisms are composed of cells and cell products. E. the cell is the basic structural and functional unit of life.

hydrophobic; hydrophilic

Transmembrane proteins that make up enzymes in the plasma membrane are made up of hydrophilic and hydrophobic regions. Most amino acids embedded in the membrane are _____, while most amino acids facing the extracellular fluid are _____.

ACTIVE TRANSPORT

Transport of Na+ from a place of low concentration to a place of higher concentration

Diffusion is one of the processes whereby materials are exchanged between a cell and its environment. A) True B) False

True

water will pass down its concentration gradient from solution B to A.

Two solutions are separated by a selectively permeable membrane. If solution A has a higher concentration of a nonpermeating solute than solution B, then:

Smooth endoplasmic reticulum

organelle that synthesizes steroids in the ovary and stores calcium in muscle cells

The molecules in a solid lump of sugar do not move. A) True B) False

FALSE

Fusiform cells - thick middle tapered ends

FUSIFORM cells are thick in the middle and tapered toward the end.

TEM PRODUCES HIGHER RESOLUTIONS

Although the transmission electron microscope (TEM) can magnify more than a light microscope, even at identical magnifications the TEM has the advantage of PRODUCING HIGHER RESOLUTION

smooth endoplasmic reticulum

Among other functions, hepatocytes (liver cells) are specialized in detoxifying drugs or other chemicals. Hepatocytes have large amounts of SMOOTH ENDOPLASMIC RETICULUM

Unlike simple diffusion, facilitated diffusion requires energy expenditure by the cell. A) True B) False

B) False

Facilitated diffusion requires A) enzymes. B) carrier proteins. C) lipid carriers. D) carbohydrate carriers. E) lipid or carbohydrate carriers.

B) carrier proteins.

Which of the following will pass through a cell membrane most easily? A) small polar molecules B) small nonpolar molecules C) large polar molecules D) large nonpolar molecules E) large neutral molecules

B) small nonpolar molecules

True

Both the nucleus and the mitochondrion are surrounded by two layers of unit embranes

Osmosis is best defined as the movement of A) molecules from an area of high concentration to an area of lower concentration. B) molecules from an area of low concentration to an area of higher concentration. C) water molecules across a membrane from an area of low water to an area of higher concentration. D) water molecules across a membrane from an area of high water concentration to an area of lower concentration. E) water molecules inside a container.

D) water molecules across a membrane from an area of high water concentration to an area of lower concentration.

The rate of diffusion is affected by which of the following? A) temperature B) size of molecules C) steepness of the concentration gradient D) A and B E) A, B and C

E) A, B and C

kinases adds phospate groups to regulate other enzymes

In its second-messenger role, cAMP activates enzymes called KINASES, whose job is to regulate other enzymes by adding phospate groups to them

FALSE

In the plasma membrane, glycolipids and glycoproteins face toward the cytoplasm, while peripheral proteins always face toward the ECF.

TRANSCYTOSIS

Insulin is taken up by endocytosis by endothelial cells lining capillaries, and then transported across the cell to the other side where it is released. This transport is called TRANSCYTOSIS

True

Ligand-gated channels are membrane proteins that open or close in reponse to the binding of chemicals - t or f

FALSE

Microvilli and cilia differ in their function but have the same internal structure

HYDROPHOBIC; HYDROPHILIC

Most amino acids embedded in the membrane are HYDROPHOBIC, while most amino acids facing the extracellular fluid are HYDROPHILIC

muscle = mitochondria

Muscle cells contain numerous MITOCHONDRIA to serve their high demand for ATP.

Osmosis; aquaporins

Water flows through a selectively permeable membrane in a process called OSMOSIS, but water molecules cross the membrane more easily through channels of transmembrane proteins called aquaporins

Protein synthesis

What function would immediately cease if the ribosomes of a cell wall destroyed

Volume and surface relationship

What limits how large a cell can be? Most human cells range from 10 to 15 micrometers in diameter

LYSOSOME

What organelle is most active in causing programmed cell death

Active Transport

Which of the following processes could occur only through the plasma membrane of a living cell

Phagocytosis

White blood cells engulf bacteria by means of Phagocytosis

Filtration; hydrostatic pressure

___________is the process in which ________forces water and small solutes such as salts through narrow clefts between capillary cells.

Receptors

________are membrane proteins that bind to signals by which cells communicate

centrioles; microtubules

_____play an important role in cell division and they are made of microtubules