Facilitated diffusion across a biological membrane requires ________ and moves a substance ________ its concentration gradient.
answer
transport proteins ... down
question
The molecules responsible for membrane transport are
answer
proteins
question
Which of the following statements is true among all types of passive transport?
answer
the concentration gradient is the driving force
question
Aquaporins
answer
allow water to cross the plasma membrane via facilitated diffusion.
question
Which of the following processes can move a solute against its concentration gradient?
answer
active transport
question
Which of the following is a typical feature of an ATP-driven active transport mechanism?
answer
the solute moves against the concentration gradient
question
Which of the following statements regarding active transport is FALSE?
answer
Active transport is driven by the concentration gradient.
question
Which of the following is an accurate comparison of active transport and facilitated diffusion?
answer
Active transport moves solutes against their concentration gradient; facilitated diffusion moves substances down their concentration gradient.
question
Macrophages are white blood cells that roam the body searching for invading microbes. Inside macrophage vacuoles these invaders are destroyed. How do the microbes get inside the macrophages?
answer
Microbes are engulfed into the macrophage via phagocytosis.
question
New drugs are being developed to lower levels of circulating cholesterol. A successful drug would be one that _____.
answer
increases the rate of LDL receptor-mediated endocytosis
question
Cells acquire LDLs by
answer
receptor-mediated endocytosis.
question
Phagocytosis is to eating as pinocytosis is to
answer
drinking
question
The process of a white blood cell engulfing a bacterium is
answer
phagocytosis (eating)
question
Certain cells that line the stomach synthesize a digestive enzyme and secrete it into the stomach. This enzyme is a protein. Which of the following processes could be responsible for its secretion?
answer
exocytosis
question
Cells store energy that they use for work in the _____.
answer
arrangement of atoms within molecules
question
Light is _____ energy, which is converted by plants into molecules, which possess _____ energy.
answer
kinetic...chemical
question
Glucose molecules provide energy to power the swimming motion of sperm. In this example, the sperm are changing
answer
chemical to kinetic
question
Kinetic energy differs from chemical energy in that
answer
kinetic energy is the energy of a moving object, whereas chemical energy is the potential energy of molecules.
question
Which of the following statements regarding thermodynamics is false?
answer
An automobile engine is an example of a closed system.
question
Which of the following energy transfers is impossible in living systems?
answer
heat to light energy
question
What happens to the chemical energy that is extracted from molecules by cellular activities but that is not used for cellular work?
answer
The energy contributes to the entropy of the system
question
Which of the following processes is endergonic?
answer
the synthesis of glucose from carbon dioxide and water
question
What is the basic difference between exergonic and endergonic reactions?
answer
Exergonic reactions release energy; endergonic reactions absorb it.
question
Which of the following examples is classified as a metabolic pathway?
answer
protein synthesis
question
When a cell uses chemical energy to perform work, it uses the energy released from a(n) ________ reaction to drive a(n) ________ reaction.
answer
exergonic....endergonic
question
Which of the following statements about the ATP molecule is true?
answer
It releases energy when one phosphate group leaves ATP.
question
hypotonic
answer
when water enters the cell from the outside, cells then lyse or burst
question
hypertonic
answer
when water leaves the cell, cells shrive up
Haven't found what you need?
Search for quizzes and test answers now
Quizzes.studymoose.com uses cookies. By continuing you agree to our cookie policy
