Term
Which of the following is a characteristic of a carrier protein in a plasma membrane?
-It works against diffusion
-It exhibits a specificity for a particular type of molecule
-It has few, if any, hydrophobic amino acids |
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Definition
| It exhibits a specificity for a particular type of molecule |
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Term
What is the change in free energy of a system at chemical equilibrium?
-slightly increasing
-greatly decreasing
-no net change |
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Definition
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Term
According to the induced fit hypothesis of enzyme catalysis. which of the following is correct?
-A competitive inhibitor can outcompete the substrate for the active site
-The binding of the substrate depends on the shape of the active site
-The binding of the substrate changes the shape of the enzymes active site |
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Definition
| The binding of the substrate changes the shape of the enzyme's active site |
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Term
Which of the following is one of the ways that the membranes of winter wheat are able to remain fluid when it is extremely cold?
-by increasing the percentage of unsaturated phospholipids in the membrane
-By increasing the percentage of cholesterol molecules in the membrane
-By decreasing the number of hydrophobic proteins in the membrane |
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Definition
| by increasing the percentage of unsaturated phospholipids in the membrane |
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Term
Which of the following is an example of cooperativity?
-Protein function at one site affected by binding at another of its active sites
-A molecule binding at one unit of a tetramer allowing faster binding at each of the three |
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Definition
| A molecule binding at one unit of a tetramer allowing faster binding at each of the three |
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Term
Which of the following statements is a logical consequence of the second law of thermodynamics?
-Energy can be transferred or transformed, but it cannot be created or destroyed
-If the entropy of a system increases, there bust be a corresponding decrease in the entropy of the universe
-Every chemical reaction must increase the total entropy of the universe |
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Definition
| Every chemical reaction must increase the total entropy of the universe |
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Term
A chemical reaction that has a positive ΔG is correctly described as
-Endothermic
-Enthalpic
-Endergonic |
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Definition
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Term
The fact that the outer membrane of the nuclear envelope has bound ribosomes allows one to most reliably conclude that
-at least some of the proteins that function in the nuclear envelope are made by the ribosomes on the nuclear envelope
-nuclear pore complexes contain proteins
-small vesicles from the golgi fuse with the nuclear envelope |
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Definition
| at least some of the proteins that function in the nuclear envelope are made by the ribosomes on the nuclear envelope |
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Term
Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells?
-Peroxisomes
-Tight junctions
-Gap junctions |
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Definition
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Term
The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is known as
-reversible inhibition
-feedback inhibition
-metabolic inhibition |
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Definition
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Term
Of the following functions, which is the most important for the glycoproteins and glycolipids of animal cell membranes?
-A cell's ability to distinguish one type of neighboring cell from another
-Maintaining membrane fluidity at low temperatures
-Maintaining the integrity of a fluid mosaic membrane |
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Definition
| A cell's ability to distinguish one type of neighboring cell from another |
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Term
Which term most precisely describes the cellular process of breaking down large molecules into smaller ones?
-catabolism
-anabolism
-metabolism |
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Definition
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Term
Motor proteins provide for molecular motion in cells by interacting with what types of cellular structures?
-cellulose fibers in the cell wall
-cytoskeletons
-membrane proteins |
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Definition
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Term
Which of the following is (are) true for anabolic pathways?
-They consume energy to build up polymers from monomers
-They are usually highly spontaneous chemical reactions
-They do not depend on enzymes |
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Definition
| They consume energy to build up polymers from monomers |
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Term
Under which of the following conditions would you expect to find a cell with a predominance of free ribosomes?
-A cell that is producing cytoplasmic enzymes
-A cell that is constructing its cell wall or extracellular matrix |
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Definition
| A cell that is producing cytoplasm enzymes |
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Term
Which of these are not embedded in the lipid bilayer at all?
-peripheral proteins
-glycoproteins
-integral proteins |
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Definition
peripheral proteins
(PERIPHERAL...on edge of membrane) |
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Term
Which of the following types of molecules are the major structural components of the cell membrane?
-Proteins and cellulose
-Glycoproteins and cholesterol
-Phospholipids and proteins |
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Definition
| Phospholipids and proteins |
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Term
All of the following are part of prokaryotic cell except
-ribosomes
-cell wall
-ER |
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Definition
ER
(no membrane bound structures within prokaryotic cells) |
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Term
An animal cell lacking oligosaccharides on the external surface of its plasma membrane would likely be impaired in which function?
-establishing the diffusion barrier to charged molecules
-cell-cell recognition |
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Definition
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Term
When chemical, transport, or mechanical work is done by an organism, what happens to he heat generated?
-It is lost to the environment
-IT is used to power yet more cellular work |
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Definition
| It is lost to the environment |
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Term
Which of the following is a statement of the first law of thermodynamics?
-The entropy of the universe is decreasing
-Energy cannot be transferred or transformed
-Energy cannot be created or destroyed |
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Definition
| Energy cannot be created or destroyed |
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Term
Which of the following produces and modifies polysaccharides that will be secreted?
-golgi apparatus
-peroxisome
-lysosome |
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Definition
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Term
Water passes quickly through cell membranes because
-the bilayer is hydrophilic
-it moves through hydrophobic channels
-it moves through aquaporins in the membrane |
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Definition
| it moves through aquaporins in the membrane |
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Term
Which of the following is most similar in structure to ATP?
-a DNA helix
-an anabolic steroid
-an RNA molecule |
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Definition
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Term
Organelles other than the nucleus that contain DNA include
-ribosomes
-mitochondria
-chloroplasts
(pick 2) |
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Definition
| mitochondria and chloroplasts |
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Term
Ions diffuse across membranes down their
-chemical gradients
-electrical gradients
- electrochemical gradients |
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Definition
| electrochemical gradients |
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Term
What is the voltage across a membrane called
-membrane potential
-chemical gradient
-electrochemical gradient |
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Definition
membrane potential
(VOLTAGE is POTENTIAL energy) |
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Term
Which of the following possesses a microtubular structure similar to a basal body?
-peroxisome
-centriole |
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Definition
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Term
Ions can travel directly from the cytoplasm of one animal cell to the cytoplasm of an adjacent cell through
-gap junctions
-tight junctions
-desmosomes |
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Definition
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Term
Which of these are attached to the extracellular matrix?
-integrins
-transmembrane proteins
-glycoproteins |
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Definition
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Term
The sodium-potassium pump is called an electrogenic pump because
-ionizes sodium and potassium atoms
-pumps hydrogen ions out of the cell
-contributes to the membrane potential |
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Definition
| contributes to the membrane potential |
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Term
Which of the following contain the 9 + 2 arrangement of microtubules
-cilia
-centrioles
-flagella
(pick 2) |
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Definition
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Term
What structure is the site of the synthesis of proteins that may be exported from the cell?
-rough ER
-lysosomes
-plasmodesmata |
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Definition
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Term
The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and therefore abundant in liver cells?
-rough ER
-golgi
-smooth ER |
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Definition
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Term
An organism with a cell wall would have the most difficulty doing which process?
-osmosis
-diffusion
-phagocytosis |
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Definition
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Term
Which of the following is an example of potential rather than kinetic energy?
-an insect foraging for food
-a boy mowing grass
-a good molecule made up of energy-rich macromolecules |
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Definition
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Term
What kinds of molecules pass through a cell membrane most easily?
-large polar
-small and hydrophobic
-large and hydrophobic |
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Definition
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Term
Which is one of the main energy transformers of cells?
-peroxisome
-vacuole
-mitochondrion |
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Definition
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Term
Of the following molecules of the ECM, which is capable of transmitting signals between the ECM and the cytoskeleton?
-integrins
-collagen
-fibronectin |
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Definition
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Term
What are the membrane structures that function in active transport?
-integral proteins
-carbs
-peripheral proteins |
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Definition
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Term
Which of the following statements describes enzyme cooperativity?
-A substrate molecule bound to an active site affects the active site of several subunits
-Several substrate molecules can be catalyzed by the same enzyme |
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Definition
| A substrate molecule bound to an active site affects the active site of several subunits |
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