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