Biology Diffusion, Osmosis, Phagocytosis etc.
During one cycle, the sodium-potassium pump binds and moves...
3 Na+ and 2 K+
T/F The molecules in a solid lump of sugar do not move.
False
T/F Unlike simple diffusion, facilitated diffusion requires energy expenditure by the cell
False
Lysosomes are membrane-bound vesicles that arise from the...
Golgi Apparatus
Which of the following cells will be expected to contain the most active lysosomes?
Phagocytosing white blood cell
A phagosome containing the engulfed bacteria combines with a lysosome containing enzymes to produce a phagolysosome
True
T/F A 5% urea solution is hypotonic to a 10% urea solution
True
T/F A sodium channel is formed by a channel protein
True
T/F Complement factor C3b coats a bacterium and binds to C3b receptors on phagocytes, making bacterium more susceptible to being phagocytized
True
T/F Diffusion is one of the processes whereby materials are exchanged between a cell and its environment
True
T/F Facilitated diffusion requires a specific transporter for a specific molecule
True
T/F If a cell is placed in an isotonic medium, there will be no net movement of water
True
T/F Lysosomes function in the destruction and recycling of old organelles
True
T/F The enzymes found in the lysosomes were formed in the endoplasmic reticulum
True
T/F The sodium channels in the cell membrane have receptor sites for acetylcholine
True
T/F the binding and release of sodium or potassium ions are due to conformational changes in the protein
True
T/F the sodium-potassium pump is a trans-membrane protein
True
Phagocytes are attracted to...
phospholipids released by injured cells, components of the complement system, chemical products of microorganisms
A red blood cell placed in a hypertonic medium will...
shrink
Which of the following will pass through a cell membrane most easily
small nonpolar molecules
When sodium channels open...
sodium ions diffuse through and enter the cell
The sodium-potassium pump functions to pump...
sodium ions out of the cell and potassium ions into the cell
Facilitated diffusion is used to transport...
sugars and amino acids
the rate of diffusion is affected by which of the following?
temperature, size of molecules, and steepness of the concentration gradient
When sugar is mixed with water, equilibrium is reached when...
the dissolved sugar molecules are evenly distributed throughout the solution
When the acetylcholine binds to the receptor sites...
the sodium channels open
When the acetylcholine receptor sites are not occupied...
the sodium channels remain closed
Osmosis is best defined as the movement of...
water molecules across a membrane from an area of high water concentration to an area of lower concentration
A lysosome...
contains lysozyme and proteases which digest bacteria
In phagocytosis the digested contents are eliminated by...
exocytosis
The lysosome contains_______ enzymes
hydrolytic
Facilitated diffusion occurs
in either direction depending on the concentration gradient of the molecule
What is the source of energy used to power the sodium-potassium pump?
breakdown of ATP
Facilitated diffusion requires
lipid carriers
Simple diffusion is defined as the movement of...
molecules from areas of higher concentration to areas of lower concentration
