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Biology 1 - Test 2
60 questions from my second Bio 1 test
41
Biology
12/10/2010

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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
Definition
It exhibits a specificity for a particular type of molecule
Term
What is the change in free energy of a system at chemical equilibrium?
-slightly increasing
-greatly decreasing
-no net change
Definition
no net change
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
Definition
The binding of the substrate changes the shape of the enzyme's active site
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
Definition
by increasing the percentage of unsaturated phospholipids in the membrane
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
Definition
A molecule binding at one unit of a tetramer allowing faster binding at each of the three
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
Definition
Every chemical reaction must increase the total entropy of the universe
Term
A chemical reaction that has a positive ΔG is correctly described as
-Endothermic
-Enthalpic
-Endergonic
Definition
Endergonic
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
Definition
at least some of the proteins that function in the nuclear envelope are made by the ribosomes on the nuclear envelope
Term
Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells?
-Peroxisomes
-Tight junctions
-Gap junctions
Definition
Gap junctions
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
Definition
feedback inhibition
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
Definition
A cell's ability to distinguish one type of neighboring cell from another
Term
Which term most precisely describes the cellular process of breaking down large molecules into smaller ones?
-catabolism
-anabolism
-metabolism
Definition
catabolism
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
Definition
cytoskeletons
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
Definition
They consume energy to build up polymers from monomers
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
Definition
A cell that is producing cytoplasm enzymes
Term
Which of these are not embedded in the lipid bilayer at all?
-peripheral proteins
-glycoproteins
-integral proteins
Definition
peripheral proteins

(PERIPHERAL...on edge of membrane)
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
Definition
Phospholipids and proteins
Term
All of the following are part of prokaryotic cell except
-ribosomes
-cell wall
-ER
Definition
ER

(no membrane bound structures within prokaryotic cells)
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
Definition
Cell-cell recognition
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
Definition
It is lost to the environment
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
Definition
Energy cannot be created or destroyed
Term
Which of the following produces and modifies polysaccharides that will be secreted?
-golgi apparatus
-peroxisome
-lysosome
Definition
golgi apparatus
Term
Water passes quickly through cell membranes because
-the bilayer is hydrophilic
-it moves through hydrophobic channels
-it moves through aquaporins in the membrane
Definition
it moves through aquaporins in the membrane
Term
Which of the following is most similar in structure to ATP?
-a DNA helix
-an anabolic steroid
-an RNA molecule
Definition
an RNA nucleotide
Term
Organelles other than the nucleus that contain DNA include
-ribosomes
-mitochondria
-chloroplasts
(pick 2)
Definition
mitochondria and chloroplasts
Term
Ions diffuse across membranes down their
-chemical gradients
-electrical gradients
- electrochemical gradients
Definition
electrochemical gradients
Term
What is the voltage across a membrane called
-membrane potential
-chemical gradient
-electrochemical gradient
Definition
membrane potential

(VOLTAGE is POTENTIAL energy)
Term
Which of the following possesses a microtubular structure similar to a basal body?
-peroxisome
-centriole
Definition
centriole
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
Definition
gap junctions
Term
Which of these are attached to the extracellular matrix?
-integrins
-transmembrane proteins
-glycoproteins
Definition
integrins
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
Definition
contributes to the membrane potential
Term
Which of the following contain the 9 + 2 arrangement of microtubules
-cilia
-centrioles
-flagella
(pick 2)
Definition
cilia and flagella
Term
What structure is the site of the synthesis of proteins that may be exported from the cell?
-rough ER
-lysosomes
-plasmodesmata
Definition
rough ER
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
Definition
smooth ER
Term
An organism with a cell wall would have the most difficulty doing which process?
-osmosis
-diffusion
-phagocytosis
Definition
phagocytosis
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
Definition
a food molecule...
Term
What kinds of molecules pass through a cell membrane most easily?
-large polar
-small and hydrophobic
-large and hydrophobic
Definition
small and hydrophobic
Term
Which is one of the main energy transformers of cells?
-peroxisome
-vacuole
-mitochondrion
Definition
mitochondrion
Term
Of the following molecules of the ECM, which is capable of transmitting signals between the ECM and the cytoskeleton?
-integrins
-collagen
-fibronectin
Definition
integrins
Term
What are the membrane structures that function in active transport?
-integral proteins
-carbs
-peripheral proteins
Definition
integral proteins
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
Definition
A substrate molecule bound to an active site affects the active site of several subunits