Term
| Consider a U-tube with two compartments, A and B, separated by a selectively permeable membrane. |
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Definition
| Water will flow until the hydrostatic pressure of the water on the higher side equals the osmotic pressure. |
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Term
| Molecular oxygen, O2, enters cells by: |
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Definition
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Term
Which statement about the sodium-potassium pump is FALSE?.
a. It pumps 3 Na+ ions out and 2 K+ ions in during each cycle
b. It hydrolyzes ATP to provide the energy
c. It operates whenever the internal Na+ concentration exceeds the external Na+ concentration.
d. It is an electrogenic pump |
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Definition
| . It operates whenever the internal Na+ concentration exceeds the external Na+ concentration. |
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Term
| The sodium-potassium pump is called an electrogenic pump because it |
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Definition
| contributes to the membrane potential |
|
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Term
| Why was the 1935 sandwich model of the membrane eventually rejected? |
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Definition
| Because it put hydrophobic material in contact with water and hydrophilic material out of contact. |
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Term
| Membrane glycolipids and glycoproteins both contain |
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Definition
|
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Term
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Definition
| the amino acid at the carboxyl end of the polypeptide |
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Term
| Large particles or large volumes of fluid can be brought into the cell by |
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Definition
|
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Term
| In each cycle, the sodium-potassium pump uses the energy of ATP to: |
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Definition
| pump 3 Na+ out of the cell and 2 K+ into the cell |
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Term
| The sodium-potassium pump creates a transmembrane electrical potential so that cell interiors are about: |
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Definition
|
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Term
| Exergonic reactions don't necessarily proceed quickly from reactant to product. The reason is: |
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Definition
| An energy barrier intervenes for which some considerable activation energy must be supplied |
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Term
| In biological systems, ATP functions by |
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Definition
| providing the energy necessary for an endergonic reaction by coupling it with an exergonic reaction |
|
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Term
| Which cellular macromolelcules are continually being degraded and resynthesized? |
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Definition
|
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Term
| In the equation DG = DH - TDS, what does H refer to: (D means delta) |
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Definition
| enthalpy, i.e., the heat released from the system (which is also equal to the bond energy of the system) |
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Term
| The text described the addition of ammonia to the amino acid glutamate to form another amino acid, glutamine. It gave the free energy change as + 3.4 kcal/mole. Therefore |
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Definition
| . this is an endergonic reaction, so energy must be added by covalent coupling to ATP hydrolysis |
|
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Term
| Suppose that an enzyme E has both a substrate X and an allosteric inhibitor Y. Then, the higher the concentration of Y gets, |
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Definition
| the slower the catalysis of X |
|
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Term
| Which cellular macromolelcules are continually being degraded and resynthesized? |
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Definition
|
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Term
| Red blood cells in a hypotonic solution will tend to: |
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Definition
|
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Term
| The difference between "simple diffusion" and "facilitated diffusion" is: |
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Definition
| Facilitated diffusion uses a transport protein to increase the diffusion down the concentration gradient. |
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Term
| The endoplasmic reticulum of muscle cells is called sarcoplasmic reticulum (SR), and serves a special function as a repository of Ca+2 ions. The Ca+2 is sequestered (withdrawn) inside the SR because of the action of an ATP-dependent Ca+2 pump in the SR membrane. Ca+2 rushes out during a muscle contraction. What can be said about the state of the cell when the muscle is NOT contracting? |
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Definition
| Any leakage of Ca+2 that occurs will be outward, from SR to cytosol, because of the direction of the electrochemical gradient. |
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Term
| The rate of diffusion to equilibrium for a solute X is faster ... |
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Definition
| ...The higher the Temperature |
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Term
| A virus, such as HIV, enters cells by: |
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Definition
|
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Term
| The movement of a substance across a biological membrane against its concentration gradient with the help of energy input is called |
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Definition
|
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Term
| Ions tend to diffuse across membranes down their ___ gradients |
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Definition
|
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Term
| Exergonic reactions don't necessarily proceed quickly from reactant to product. The reason is: |
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Definition
| An energy barrier intervenes for which some considerable activation energy must be supplied. |
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Term
All of the following cellular activities require ATP except
Choose one answer.
a. protein synthesis
b. sodium ion movement out of the cell
c. cytoplasmic streaming
d. exocytosis
e. movement of oxygen into cell |
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Definition
| movement of oxygen into cell |
|
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Term
| Pepsin is an enzyme whose rate of reaction is highest at about pH 2. That is a [H+] of |
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Definition
|
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Term
|
Definition
|
|
Term
| Suppose that an enzyme E has both a substrate X and an allosteric inhibitor Y. Then, the higher the concentration of Y gets, |
|
Definition
| the slower the catalysis of X |
|
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Term
| Biochemists use this equation of J. Gibbs (where D means delta) to predict the spontaneous direction of metabolic reactions: |
|
Definition
|
|
Term
| Under normal cellular conditions, (i.e., not "standard" conditions), the free energy change when ATP is hydrolyzed to ADP and phosphate is about |
|
Definition
|
|
Term
| If one plots the reaction rate of an enzyme versus temperature, the curve reaches a peak and then drops off rapidly. The reason for the initial rise is: |
|
Definition
| more thermal energy is available so more reactants can reach the transition state |
|
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Term
|
Definition
| speed up reactions so that they can occur at body temperatures |
|
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Term
| Dynamic turnover of proteins refers to: |
|
Definition
| the constant degradation and new synthesis of the proteome |
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Term
| What is the value of feedback inhibition? |
|
Definition
| it matches production to need |
|
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Term
| Dynamic turnover of proteins refers to: |
|
Definition
| the constant degradation and new synthesis of the proteome |
|
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Term
| The direction of energy flow in the biosphere is primarily |
|
Definition
| Solar energy --> chemical bond energy --> heat |
|
|
Term
| The text described the addition of ammonia to the amino acid glutamate to form another amino acid, glutamine. It gave the free energy change as + 3.4 kcal/mole. Therefore, |
|
Definition
| this is an endergonic reaction, so energy must be added by covalent coupling to ATP hydrolysis |
|
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Term
| The energy released during the oxidation of a mole of glucose is ___ compared to the energy released during the hydrolysis of ATP. |
|
Definition
|
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Term
| Currently scientists are identifying proteins that use ATP as an energy source by |
|
Definition
| determining if the protein has a known ATP-binding site. |
|
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Term
All of the following are functions of membrane proteins except
Choose one answer.
a. cell-cell recognition
b. protein synthesis
c. signal transduction
d. intercellular joining
e. transport |
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Definition
|
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Term
| Substances enter cells selectively because of the presence in membranes of: |
|
Definition
|
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Term
| Which of the following substances would be expected to be MOST permeable through a lipid bilayer? |
|
Definition
| a gas molecule such as O2 |
|
|
Term
| In each cycle, the sodium-potassium pump uses the energy of ATP to: |
|
Definition
| pump 3 Na+ out of the cell and 2 K+ into the cell |
|
|
Term
| The sodium-potassium pump is called an electrogenic pump because it |
|
Definition
| contributes to the membrane potential |
|
|
Term
| On the left side of a selectively permeable membrane is a 0.1 M solution. On the right side is a 0.3 M solution. Osmotic force will cause water to move |
|
Definition
|
|
Term
| Which of the following is an example of active transport? |
|
Definition
| Na+ and K+ movement through the sodium-potassium pump |
|
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Term
|
Definition
| a protein with oligosaccharide attached |
|
|
Term
| During ___, materials are moved across the plasma membrane against their concentration gradient. |
|
Definition
|
|
Term
| Which statement about the sodium-potassium pump is FALSE? |
|
Definition
| It operates whenever the internal Na+ concentration exceeds the external Na+ concentration |
|
|
Term
| When researchers fused a human cell with a mouse cell |
|
Definition
| they were able to visualize the membrane proteins of the two species rather quickly intermingling |
|
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Term
| Potassium ion, K+, enters cells by: |
|
Definition
|
|
Term
| In the cyclic action of the sodium-potassium pump, the next step, after the binding of sodium ions to the internal face of the pump, is: |
|
Definition
| a. The phosphorylation of the pump on its internal face |
|
|
Term
| Substances enter cells selectively because of the presence in membranes of: |
|
Definition
|
|
Term
| In the Na/K pump, the import of potassium ions is triggered by: |
|
Definition
| the dephosphorylation of the pump |
|
|
Term
| The fluidity of the membrane is demonstrated by all of the following EXCEPT which |
|
Definition
| flip-flop of phospholipids between the two faces of a membrane |
|
|
Term
| Currently scientists are identifying proteins that use ATP as an energy source by |
|
Definition
| determining if the protein has a known ATP-binding site. |
|
|
Term
| The text described the addition of ammonia to the amino acid glutamate to form another amino acid, glutamine. It gave the free energy change as + 3.4 kcal/mole. Therefore, |
|
Definition
| this is an endergonic reaction, so energy must be added by covalent coupling to ATP hydrolysis |
|
|
Term
| Under normal cellular conditions, (i.e., not "standard" conditions), the free energy change when ATP is hydrolyzed to ADP and phosphate is about |
|
Definition
|
|
Term
| If one plots the reaction rate of an enzyme versus temperature, the curve reaches a peak and then drops off rapidly. The reason for the initial rise is: |
|
Definition
| more thermal energy is available so more reactants can reach the transition state |
|
|
Term
| Which of the following metabolic processes is exergonic |
|
Definition
| C6H12O6 + 6 O2 --> 6 CO2 + 6 H2O |
|
|
Term
| If one plots the reaction rate of an enzyme versus pH, one will tend to find a peak |
|
Definition
| at the pH at which the enzyme normally functions |
|
|
Term
| The catalytic rate of some enzymes is modified by the binding of non-substrate molecules to a site distant from the active site. Such enzymes are called: |
|
Definition
|
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Term
| I showed two pictures of cheetahs, one showing a cheetah eating a deer, the other showing the cheetah running hard and giving off heat and breathing out CO2 and H2O vapor. These two pictures represent the two laws of thermodynamics; more specifically ... |
|
Definition
| 1st law - transfer of energy from deer to cheetah; 2nd law - useful energy becoming useless energy of heat and CO2 and H2O |
|
|
Term
| In biological systems, ATP functions by |
|
Definition
| providing the energy necessary for an endergonic reaction by coupling it with an exergonic reaction |
|
|
Term
| Biochemists use this equation of J. Gibbs (where D means delta) to predict the spontaneous direction of metabolic reactions: |
|
Definition
|
|
Term
| If one plots the reaction rate of an enzyme versus temperature, the curve reaches a peak and then drops off rapidly. The reason for the initial rise is: |
|
Definition
| more thermal energy is available so more reactants can reach the transition state |
|
|
Term
| In enzyme catalysis the reactant is called the ___ and it binds to the ___. |
|
Definition
|
|
Term
| The important difference for us between combustion and cellular respiration is: |
|
Definition
| . combustion releases energy as heat, whereas cellular respiration releases energy as ATP |
|
|
Term
| What is the name given to the process in which solutes are moved across a membrane against their concentration gradient? |
|
Definition
|
|
Term
| Large particles or large volumes of fluid can be brought into the cell by |
|
Definition
|
|
Term
| According to the second law of thermodynamics, |
|
Definition
| each energy transfer increases the level of disorder in a system. |
|
|
Term
| Reactions that release free energy are |
|
Definition
| exergonic, and spontaneous |
|
|
Term
| Enzymes speed up the reactions by |
|
Definition
| lowering the activation energy necessary to initiate the reaction. |
|
|
Term
| Which of the following factors may alter the function of an enzyme? |
|
Definition
| pH, temperature, and cofactors |
|
|
Term
| Currently, scientists are identifying proteins that use ATP as an energy source by |
|
Definition
| determining if the protein has a known ATP binding site. |
|
|
Term
| the synthesis of large molecules from smaller components is called |
|
Definition
|
|
Term
| Membranes in the eukaryotic cell have a thickness of about |
|
Definition
|
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