LEARNSMART CHAPTER 4
A cell with a 0.5M concentration of salt inside it is placed into a solution. The cell begins to shrink. What is the possible concentration of salt outside the cell?
5.0 M
When a system reaches concentration equilibrium
Molecules continue to move but do not exhibit net movement in any direction
What would use a contractile vacuole to rid itself of excess water?
Parameclum
Proteins found on either the external or internal side of the membrane
Peripheral
The plasma membrane is described as a "fluid-mosaic." What does it consist of?
Phospholipids, cholesterol, and proteins
The form of endocytosis in which vesicle form around liquids or very small particles is called
Pinocytosis
Pinocytosis and receptor-mediated endocytosis serve much the same function. What is the difference between these two processes?
Pinocytosis is less selective
Which of the following are considered membrane-assisted transport?
Pinocytosis, phagocytosis, and exocytosis
Which structure controls the movement of substances into and out of the cell?
Plasma membrane
When a plant is placed in a hypertonic solution, its cells lose water and its cytoplasm shrinks; this form of osmosis in plant cells is called
Plasmolysis
The soidum-potassium pump moves sodium ions to the outside of the cell and potassium ions to the inside of the cell. Both ions are moved against their concentration gradient. This type of transport is called
Active transport
What junction is a cellular junction that has intracellular filaments mechanically connecting the cytoplasmic membrane of adjacent cells
Adhesion junction
Which type of membrane protein may have a hormone like insulin bind to it?
Receptor protein
Which form of bulk transport is highly selective?
Receptor-mediated endocytosis
Secretion that occurs only in response to a specific signal is called
Regulated secretion
Which types of molecules are more likely to be able to diffuse across a plasma membrane?
Small, uncharged, and nonpolar
A solution contains both a _______ and a ________
Solute and Solvent
Factors that will influence the rate of diffusion
Temperature, electrical currents, pressure, and molecular size (NOT LIGHT)
Which of the following are needed to complete active transport of molecules?
Carrier protein, plasma membrane, and energy
What is true about all carrier proteins?
Carrier proteins aid in both facilitated transport and active transport; carrier proteins are specific to a single type of molecule
What is the role of enzymatic plasma proteins?
Catalyzing metabolic reactions near plasma membrane
Which of the following is an example of active transport?
Cell pumps H+ ions into the mitochondrial intermembrane space, which allows H+ into the matrix.
A newly transplanted organ is rejected by the immune system of the host. Which protein is responsible for the rejection?
Cell recognition protein
The major component of the plant cell wall is
Cellulose
Both carrier and _____ proteins are involved in passive transport of molecules through the cell membrane
Channel
The lipid molecule that stiffens and strengthens the plasma membrane and helps regulate its fluidity is known as
Cholesterol
General term for transporting materials into a cell by the formation of a vesicle
Endocytosis
A vesicle fuses with the plasma membrane as secretion occurs and macromolecules move out of the cell during
Exocytosis
Two transport mechanisms that lead to the formation of a vesicle inside the cell
Exocytosis and Endocytosis
The protective meshwork of proteins and polysaccharides located externally to the cell is called
Extracellular Matrix
Which are a passive process?
Facilitated transport and diffusion
Diffusion is defined as the movement of molecules from ____ concentration to ___ concentration
HIGH ; LOW
Marine animals compensate for the hypertonic environment by
Increasing/decreasing the amount of urea in its blood until it is isotonic with its environment, excreting salt across their gills, and by secreting salt in tears from a gland near their eye
What serves to separate the internal environment of a cell from its external envrionment, allowing the cell to maintain homeostasis
The plasma membrane
Which type of protein would more likely be able to function as a channel through the plasma membrane?
Integral protein
Which part of the plasma membrane is nonpolar?
Interior, where the fatty acid tails are located
A solution that is equal in solute concentration to that of the cytoplasm of a cell and causes a cell to neither lose nor gain water by osmosis
Isotonic
Why does the sodium potassium pump require energy?
K+ and Na+ are moved against their concentration gradients
Which type of membrane transport leads to the formation of vesicles?
Membrane assisted transport
Which direction do the phosphate heads of the phospholipids in the plasma membrane face?
Towards (?)
Which of the following best explains why a hypotonic solution causes a cell to swell
Water rushes into the cell
What best explains why a hypertonic solution causes a cell to shrink?
Water rushes out of the cell
After inhalation, oxygen gas is more concentrated in the ____ and diffuses into the ____
alveoli ; blood
Channel proteins located in the plasma membrane for the passage of water are called
aquaporins
Cell receptor proteins are involved in
binding signaling molecules to bring out physiological changes
The gradual increase or decrease in concentration from one point to another constitutes a
concentration gradient
The shrinking or shriveling of animal cells placed in a hypertonic solution is called
crenation
If salt diffuses from an area of high concentration to an area of low concentration, the salt is moving
down its concentration gradient
The MHC cell recognition molecules are
glycoproteins
The cytolysis of red blood cells is specifically called
hemolysis
Turgor pressure is increased in a plant cell when it is placed in a
hypotonic solution
A solution that has a lower solute concentration to that of a cytoplasm of a cell is
hyptotonic
Osmosis is defined as the
movement of water across a selectively permeable membrane
The general term for the pressure that may build in a cell as a result of osmosis is called
osmotic pressure
The plasma membrane is described as being selectively
permeable
Engulfment of a bacterium by a white blood cell occurs via
phagocytosis
The channels located in the cell wall of plants which enable adjacent cells to readily exchange materials are called
plasmodesmata
In the cell signaling pathway, the series of relay proteins that ends in the activation of a targeted protein is called the
transduction pathway