Bio 1310 chapter 5
Which of the following statements regarding thermodynamics is false
An automobile engine is a closed system because it does not exchange energy and matter with its surroundings
Which of the following statements regarding diffusion is true?
Diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated.
Frequently, transplanted organs are rejected by the recipient's body. How is this reaction related to plasma membranes?
Each person has a unique set of carbohydrate chains attached to his or her plasma membranes.
Which of the following statements regarding enzyme function is false?
Enzymes are used up when they catalyze a chemical reaction so must be synthesized for each new chemical reaction.
Which statement regarding enzyme function is true?
Excessive salt ions can cause an enzyme to denature.
What is the basic difference between exergonic and endergonic reactions?
Exergonic reactions release energy; endergonic reactions absorb it
Which of these statements describes what occurs in facilitated diffusion?
Facilitated diffusion of solutes occurs through protein pores in the membrane.
In a theoretical world where all things are possible, how could you increase the amount of energy that could be stored in a molecule of ATP?
Increase the negative charge of each phosphate group
Which of the following statements about ATP is true?
It releases energy when one phosphate group leaves ATP.
The eukaryotic cell has multiple membrane-enclosed compartments. This evolutionary innovation provides what advantage to the cell?
The different membrane-enclosed spaces allow different parts of the cell to perform specific functions
According to the second law of thermodynamics, which of the following is true?
The ordering of one system depends on the disordering of another
plasma/cell membrane
a semi-permeable layer around the cell made up of phospholipids
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
Which of the following processes can move a solute against its concentration gradient?
active transport
passive diffusion
also known as active transport- requires a specific protein to cross the membrane but no energy
simple diffusion
also known as active transport- requires energy but no protein to cross the membrane
Membrane phospholipids
are able to drift about in the plasma membrane
Heating inactivates enzymes by
changing the enzyme's three-dimensional shape
mitochondria
contains cell's DNA, creates energy for the cell
The fluid mosaic model describes the plasma membrane as consisting of
diverse proteins embedded in a phospholipid bilayer
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
isotonic
equal amount of solute in both the solution and the cell and osmosis does not need to happen, no net flow of water
A molecule moves down its concentration gradient using a transport protein in the plasma membrane. This is an example of
facilitated diffusion
You are working in the medical tent at an Ironman triathlon. A finisher comes into the tent and appears to be suffering from hyponatremia. Which of the following would be best for you to do?
give them sodium
You are a high school soccer coach. One of your players appears to be overheated. Which of the following would be best for you to do?
have them sit in the shade
Which of the following direct energy transfers is impossible in living systems?
heat to light energy
hypertonic solution
higher concentration of solute in the solution, water leaves the cell to dilute the solution, cell membrane deflates
A plant cell placed in what kind of solution will lose water and plasmolyze.
hypertonic
There is a net diffusion of water out of an animal cell when it is placed in what kind of solution.
hypertonic
An animal cell placed in what solution will gain water, swell, and possibly burst.
hypotonic
The ideal osmotic environment for a plant cell is what kind of environment.
hypotonic
Some protozoans have special organelles called contractile vacuoles that continually eliminate excess water from the cell. The presence of these organelles tells you that the environment
is hypotonic to the protozoan
A plant cell surrounded by what kind of solution will be flaccid (limp).
isotonic
The ideal osmotic environment for an animal cell is what kind of environment
isotonic
hypotonic solution
lower concentration of solute in the solution, water goes inside the cell to dilute, cell membrane expands
The mechanism of enzyme action is to
lower the energy of the activation of a reaction
In active transport
molecules move across the plasma membrane against their concentration gradient
eukaryote characteristics
multicellular organisms, contain DNA, mitosis
organelles
organized structure within the cell
Hyponatremia is the result of what process
osmosis
The process of a white blood cell engulfing a bacterium is
phagocytosis
The transfer of a phosphate group to a molecule or compound is called
phosphorylation.
an energy barrier
prevents the spontaneous breakdown of molecules in the cell
Most of a cell's enzymes are
proteins
prokaryote characteristics
single celled organisms, no DNA, binary fission
For an enzyme to catalyze a reaction there must be a specific fit between the __________ and the enzyme's __________.
substrate, active site
ENdocytosis
the cell ENgulfs a molecule or substance outside of it's membrane
EXocytosis
the cell EXcretes substance
chloroplast
the differing organelle between animal and plant cells
Osmosis can be defined as
the diffusion of water
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 the reaction A → B + C + heat,
the potential energy of the products is less than that of the reactant.
Which of the following statements is true of an exergonic reaction, but NOT true of an endergonic reaction?
the potential energy of the products is less than the potential energy of the reactants
The active site of an enzyme is
the region of an enzyme that attaches to a substrate.
Which of the following processes is endergonic?
the synthesis of glucose from carbon dioxide and water
Water crosses the plasma membrane
through facilitated diffusion or diffusion