Biology Chapter 5 HW
1)A vesicle inside the cell fuses with the plasma membrane and releases its contents outside the cell. 2) A form of passive transport. Molecules move around the plasma membrane using a transport molecule. 3) The plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell. 4) A form of passive transport. Molecules move across the plasma membrane by crossing the lipid bilayer. 5) Requires energy from the cell. Molecules move against their concentration gradient.
1)Exocytosis 2)Facilitated Diffusion 3)Endocytosis 4)Diffusion 5)Active Transport
1. An enzyme is considered a(n) ______ because it speeds up a chemical reaction without being used up. 2. In a catalyzed reaction, a reactant is often called a(n) ______ . 3. An enzyme is specific because the shape of its ______ matches only particular reactants. 4. An enzyme speeds up reactions by lowering the ________ . 5. The _____ between an active site and its substrate often strains bonds and helps the reaction proceed. 6. A(n) ______, which is often a vitamin, binds to an enzyme and plays a role in catalysis. 7. High temperatures or changes in pH can ______ an enzyme, causing it to lose its shape and biological activity.
1. catalyst 2. substrate 3. active site 4. activation energy 5. induced fit 6. coenzyme 7. denature
1. The ideal osmotic environment for an animal cell is a(n) ___ environment. 2. An animal cell placed in a(n)___ solution will gain water, swell, and possibly burst. 3. There is a net diffusion of water out of an animal cell when it is placed in a(n) ___ solution. 4. The ideal osmotic environment for a plant cell is a(n) ____ environment. 5. A plant cell placed in a(n) ____ solution will lose water and plasmolyze. 6. A plant cell surrounded by a(n) _____ solution will be flaccid (limp).
1.isotonic 2.hypotonic 3.hypertonic 4.hypotonic 5.hypertonic 6.isotonic
Which of these is hydrophobic like the interior of the plasma membrane?
A
In cells, what is usually the immediate source of energy for an endergonic reaction?
ATP
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.
Which of these is ATP?
Adenine, Ribose, Triphosphate Group
What is the fate of the phosphate group that is removed when ATP is converted to ADP?
It is acquired by a reactant in an endergonic reaction.
Which of the following substances would have the most trouble crossing a biological membrane by diffusing through the lipid bilayer?
Na+
Most enzymes are _____.
Proteins
A group of single cell organisms collected from the ocean was brought into the lab for examination. The lab assistant was concerned that the water had become full of toxic waste products and so added clean water to the culture. All of the organisms died, and when she looked at them under the microscope, all she could see were bits and pieces of them scattered throughout the water. What likely happened?
She added water that was hypotonic to the culture of organisms, and they ruptured.
Which of these statements is TRUE with regard to this animation?
Sodium and potassium ions are transported against their concentration gradients.
Which of the following statements is true for all types of passive transport?
The concentration gradient is the driving force.
In the lab, you use a special balloon that is permeable to water but not sucrose to make an "artificial cell." The balloon is filled with a solution of 20% sucrose and 80% water and is immersed in a beaker containing a solution of 40% sucrose and 60% water. Which of the following will occur?
Water will leave the balloon.
Which of these is exhibiting kinetic energy?
a space station orbiting Earth
In your body, what process converts the chemical energy found in glucose into the chemical energy found in ATP?
cellular respiration
Glucose molecules provide energy to power the swimming motion of sperm. In this example, the sperm are changing
chemical energy into kinetic energy.
The fluid mosaic model describes the plasma membrane as consisting of
diverse proteins embedded in a phospholipid bilayer.
Small, nonpolar, hydrophobic molecules such as fatty acids
easily pass through a membrane's lipid bilayer.
The reaction ADP + P --> ATP is a(n) _____ reaction.
endergonic
This graph illustrates a(n) _____ reaction.
endergonic
Which of these reactions requires a net input of energy from its surroundings?
endergonic
"Conservation of energy" refers to the fact that _____.
energy cannot be created or destroyed but can be converted from one form to another
What is the correct label for "A"?
energy of activation
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
Identify Structure A.
glycoprotein
Which of these are by-products of cellular respiration?
heat and water
In this reaction Exergonic reaction (Part B).
heat has been released to the environment
What type of reaction breaks the bonds that join the phosphate groups in an ATP molecule?
hydrolysis
Endocytosis moves materials _____ a cell via _____. You can recognize the process of pinocytosis when _____. A white blood cell engulfing a bacterium is an example of _____. Which of the following is a typical feature of an ATP-driven active transport mechanism? When an enzyme catalyzes a reaction,
into ... membranous vesicles the cell is engulfing extracellular fluid phagocytosis The solute moves against the concentration gradient. it lowers the activation energy of the reaction.
An enzyme _____.
is an organic catalyst
As a result of its involvement in a reaction, an enzyme _____.
is unchanged
Kinetic energy differs from chemical energy in that
kinetic energy is the energy of a moving object, whereas chemical energy is the potential energy of molecules.
When molecules move down their concentration gradient, they move from where they are_______ to where they are ______ Diffusion across a biological membrane is called ______
more concentrated,less concentrated. passive transport
What name is given to the process by which water crosses a selectively permeable membrane? This cell is in a(n) _____ solution. You know that this cell is in a(n) _____ solution because the cell _____. You know that this cell is in a(n) _____ solution because it _____.
osmosis This cell is in a(n) _____ solution. hypotonic ... swelled hypertonic solution ... lost water
Facilitated diffusion is a type of _____.
passive transport
Identify Structure D.
phospholipid bilayer of membrane
Chemical energy is a form of _____ energy.
potential
Most of the functions of a cell membrane, including transport and enzymatic function, are performed by
proteins.
Which of the following enables a cell to pick up and concentrate a specific kind of molecule?
receptor-mediated endocytosis
Enzymes work by _____.
reducing activation energy
Structure A is a _____.
solute
What is the function of Structure E?
stabilization of the phospholipids
What name is given to the reactants in an enzymatically catalyzed reaction?
substrate
The transport of molecules of a particular solute from inside an animal cell across the cell membrane to the extracellular fluid always requires energy when _____.
the concentration of the solute is lower inside the cell than outside it
Osmosis is often viewed incorrectly as a process driven directly by differences in solute concentration across a selectively permeable membrane. What really drives osmosis?
the difference in water concentration across a selectively permeable membrane
What controls the direction of a molecule, such as oxygen, involved in passive transport?
the direction of the oxygen concentration gradient
Plasma membranes are selectively permeable. This means that
the plasma membrane allows some substances to enter or leave a cell more easily than others.
In this (Exergonic) reaction (Part A)
the products have less potential energy than the reactants
If placed in tap water, an animal cell will undergo lysis, whereas a plant cell will not. What accounts for this difference?
the relative inelasticity and strength of the plant cell wall
What is energy coupling?
the use of energy released from an exergonic reaction to drive an endergonic reaction
Structure A in the figure is a(n) _____.
transport protein
Structure B is a _____.
transport protein
