Biology 1210 Chapter 5 Mastering Biology
In cells, what is usually the immediate source of energy for an endergonic reaction?
ATP
4. An enzyme speeds up reactions by lowering the ___________________________ .
activation energy
3. An enzyme is specific because the shape of its __________________ matches only particular reactants.
active site
aquaporins
allow water to cross the plasma membrane via facilitated diffusion.
In your body, what process converts the chemical energy found in glucose into the chemical energy found in ATP?
cellular respiration
6. A(n) ____________ , which is often a vitamin, binds to an enzyme and plays a role in catalysis.
coenzyme
The reaction ADP + P --> ATP is a(n) _____ reaction.
endergonic
"Conservation of energy" refers to the fact that _____.
energy cannot be created or destroyed but converted from one form to another.
A molecule moves down its concentration gradient using a transport protein in the plasma membrane. This is an example of
facilitated diffusion
`Which of these are by-products of cellular respiration?
heat and water
In the process of osmosis, water displays a net movement from an area of __________ water concentration to an area of __________ water concentration.
higher.... lower
What type of reaction breaks the bonds that join the phosphate groups in an ATP molecule?
hydorlysis
The ideal osmotic environment for an animal cell is a(n) _________________ environment.
isotonic
What name is given to the process by which water crosses a selectively permeable membrane?
osmosis
Diffusion across a biological membrane is called __________________________
passive transport.
A white blood cell engulfing a bacterium is an example of _____.
phagocytosis
an energy barrier
prevents the spontaneous breakdown of molecules in the cell.
Which of the following statements about ATP is true?
releases energy when one phophate group leaves ATP
You can recognize the process of pinocytosis when _____.
the cell is engulfing extra cellular fluid
As a result of its involvement in a reaction, an enzyme _____.
unchanged
You know that this cell is in a(n) _____ solution because the cell _____.
Hypotonic; swelled
According to the second law of thermodynamics, which of the following is true?
The ordering of one system depends on the disordering of another.
5. A plant cell placed in a(n) _____________________ solution will lose water and plasmolyze.
hypertonic
2. An animal cell placed in a(n)________________ solution will gain water, swell, and possibly burst.
hypotonic
4. The ideal osmotic environment for a plant cell is a(n) _________________ environment.
hypotonic
A steer must eat at least 100 pounds of grain to gain less than 10 pounds of muscle tissue. This illustrates
the second law of thermodynamics
Which of the following is an accurate comparison of active transport and facilitated diffusion?
Active transport moves solutes against their concentration gradient; facilitated diffusion moves substances down their concentration gradient.
When molecules move down their concentration gradient, they move from where they are____________________ to where they are _______________________
More concentrated; less concentrated
The concentration of solutes in a red blood cell is about 2%. Sucrose cannot pass through the membrane, but water and urea can. Osmosis would cause red blood cells to shrink the most when immersed in which of the following solutions?
a hypertonic sucrose solution
Which of these reactions requires a net input of energy from its surroundings?
endergonic
Endocytosis moves materials _____ a cell via _____.
into; membranous vesicles
An enzyme
is an organic catalyst
most enzymes are...
proteins
Enzymes work by
reducing activation energy
Which of the following statements regarding diffusion is false?
Diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated.
Which of these is exhibiting kinetic energy?
a space station orbiting Earth
The sodium-potassium pump uses energy from ATP to move sodium ions out of the cell, and potassium ions into the cell. This is an example of
active transport
Utah's Great Salt Lake has an average salinity seven times higher than that of the oceans. Very few multicellular organisms live in this harsh environment. An example is the brine shrimp, which must devote a large portion of its metabolic energy to osmoregulation. These brine shrimp must _____.
actively pump water back into their cells to counter its loss due to osmosis
Water movement is important in urine formation in the kidneys. Urine is formed when the blood is filtered by the kidneys into kidney tubules. Three figures are presented here that relate to how the kidney tubules respond to the administration of the hormone vasopressin. The direction that water flows in these figures is from the kidney tubules back into the blood.
aquaporins are inserted into the membrane as needed.
1. An enzyme is considered a(n) ___________________tbecause it speeds up a chemical reaction without being used up.
catalyst
7. High temperatures or changes in pH can ____________________ an enzyme, causing it to lose its shape and biological activity.
denature
The plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell. This describes the process of
endocytosis
A(n) _____ reaction occurs spontaneously.
exergonic
The energy for an endergonic reaction comes from a(n) _____ reaction.
exergonic
The reaction A --> B + C + heat is released in a(n) _____ reaction.
exergonic
Select the INCORRECT association.
exergonic; uphill
When two aqueous solutions that differ in solute concentration are placed on either side of a semipermeable membrane and osmosis is allowed to take place, the water will
exhibit a net movement to the side with lower free water concentration.
3. There is a net diffusion of water out of an animal cell when it is placed in a(n) ______________ solution.
hypertonic
5. The_________________ between an active site and its substrate often strains bonds and helps the reaction proceed.
induced fit
6. A plant cell surrounded by a(n) __________________solution will be flaccid (limp).
isotonic
What is the fate of the phosphate group that is removed when ATP is converted to ADP?
it is acquired by a reactant in a endergonic reaction
are able to drift about in the plasma membrane.
membrane phospholipids
In active transport
molecules move across the plasma membrane against their concentration gradient.
Chemical energy is a form of _____ energy.
potential
Which of these statements is TRUE with regard to this animation?
sodium and potassium ions are transported against their concentration gradient
2. In a catalyzed reaction, a reactant is often called a(n) ----------- .
substrate
What name is given to the reactants in an enzymatically catalyzed reaction?
substrate
For an enzyme to catalyze a reaction there must be a specific fit between the __________ and the enzyme's __________.
substrate; active site
Aspirin and other nonsteroidal anti-inflammatory drugs (NSAID) inhibit inflammation by inhibiting an enzyme in the prostaglandin pathway. However, inhibiting this enzyme also inhibits other pathways that protect the stomach from damage by stomach acid and that form blood clots. What can you conclude from this?
the enzyme is found in many different types of cells
In the reaction A → B + C + heat,
the potential energy of the products is less than that of the reactant.
Which of the following is a typical feature of an ATP-driven active transport mechanism?
the solute moves against the concentration gradient
What is energy coupling
the use of energy released from an exergonic reaction to drive an endergonic reaction
Water crosses the plasma membrane
through facilitated diffusion or diffusion.
