Bio 201 final exam study questions
The movement of molecules from a region of higher concentration to a region of lower concentration is called: _______
diffusion
When one oxygen atom shares two pairs of electrons with another oxygen atom, O2 is formed via a(n)
double covalent bond.
After ATP donates a phosphate group in a coupled reaction, it becomes ADP. The ADP can be converted back to ATP in a(an) ________ reaction
endergonic
The free energy (G) of the reactants for a particular reaction is 100 kcal/mol and the free energy (G) of the products is 50 kcal/mol. This reaction is
exergonic
Choose the pair of terms that correctly completes this sentence: Catabolism is to anabolism as _____________ is to ___________________.
exergonic; endergonic
A series of enzymes catalyze the reactions A> B >C> D. Substance "D" binds to the enzyme that converts A to B and decreases the activity of the enzyme. What is going on here?
feedback inhibition
Cellular membranes are mosaic and
fluid
The complete genetic composition of an organism is called its
genome.
Which compound has the highest free energy and produces the most ATP when oxidized?
glucose
Which of the following processes will occur in the presence or absence of oxygen?
glycolysis
A disaccharide, such as maltose, consists of two molecules of glucose linked by what type of bond?
glycosidic
Scientists unearth a Wooly Mammoth from the Siberian Ice Sheath and discover that a eukaryotic "amoeba"-like cell is still alive. Which component of the cell membrane might contribute to maintaining the fluidity of plasma membranes under freezing conditions?
high levels of unsaturated fatty acid tails within the lipid bilayer
Which of the following solutions has the greatest concentration of hydroxide ions [OH-]
household bleach at pH 12
Which of the following represents an abundant element found in living organisms?
hydrogen
What is the chemical mechanism by which cells break down polymers?
hydrolysis
The major class of macromolecules that stores energy and makes up the major component of plasma membranes are
lipids
A red blood cell placed in a hypertonic solution will ____
lose water and shrivel up.
Which one of the following pairs is mismatched?
lysosome-protein synthesis
The cytoskeletal structure(s) that are composed of actin and regulate cell shape, cell movement, and muscle contraction include
microfilaments.
Cyanide binds and impairs one of the molecules involved in the production of ATP. Which organelle does cyanide act upon?
mitochondria
Cyanide binds and impairs one of the molecules involved in the synthesis of ATP. The target organelle for cyanide must be
mitochondria.
At the end of glycolysis, glucose has been broken down into
pyruvate
What substance produced from the oxidation of glucose in the cytosol gets oxidized more completely in the mitochondria?
pyruvate
The route that most accurately describes secretory protein movement through the endomembrane system would be
rough endoplasmic reticulum→vesicles→ Golgi apparatus→vesicles →plasma membrane.
Glycogen is to animal cells as ________ is to plant cells.
starch
The ATP made during glycolysis is generated by
substrate-level phosphorylation.
Which of the following statements best represents the relationships between the light reactions and the Calvin cycle?
The light reactions provide ATP and NADPH to the Calvin cycle, and the Calvin cycle returns ADP, Pi, and NADP+ to the light reactions.
Which is an immediate effect of blocking the activity of mitochondrial ATP synthase?
The pH in the space between the mitochondrial membranes would decrease
When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs? ______
The pH of the matrix increases
This nitrogenous base is found in RNA but not DNA.
Uracil
You measure the amount of enzyme activity in the presence of compound X and note that as you add more substrate the amount of enzyme activity increases. This indicates that the compound X is an
competitive inhibitor.
Tritiated hydrogen (3H) differs from hydrogen (1H) in that
) 3H has 2 more neutrons than 1H
Your liver produces 90% of the cholesterol found in your body. When cholesterol levels get too high, the first enzyme in the pathway of cholesterol synthesis is inhibited. This is an example of
Feedback inhibition
Which of the following represents a reactant in the light reaction of photosynthesis?
H2O
Some bacteria can use sulfur instead of oxygen as a final electron acceptor. What would they produce during anaerobic respiration?
H2S
What would be an expected feature of a plasma membrane that had no integral membrane proteins?
the membrane would be unable to transport sodium ions
The portion of an amino acid that makes the amino acid unique among the 20 different amino acids is
the side chain or R-group.
Placing celery sticks in fresh water will make them more turgid and harder. This is because
the celery is hypertonic to fresh water
Most carbon dioxide from catabolism is released during _______
the citric acid cycle
______ is a polymer of glucose
Cellulose
Oxygen has an atomic number of 8. What is the valence of an oxygen atom?
2
The equation, 6CO2 + 6H2O > C6H12O6 + 6O2, describes which of the following processes?
photosynthesis
Based on your knowledge of the polarity of water molecules, the solute molecule in the center of the water molecules is most likely _____
positively charged
Amphipathic molecules
possess both hydrophilic and hydrophobic properties.
Prokaryotes, such as bacterial cells, differ from eukaryotes in that eukaryotes
possess membrane-bound organelles.
Water diffuses through certain organs such as the kidneys and bladder much faster than would occur by passive diffusion through a lipid bilayer alone. What accounts for this more rapid rate of water transport in these organs?
presence of aquaporin channels for facilitated diffusion of water
Altering the three-dimensional structure of an enzyme might
prevent the substrate from binding the enzyme's active site.
Ribosomes are the structures in the cell that produce
proteins
The nucleus of an atom is composed of ________________A) protons.
protons and neutrons.
Two "magic" solutions are sold by a research supply company. "Magic Solution A" promises to extract all proteins, including integral membrane proteins, from the plasma membrane. "Magic Solution B" promises to simply extract all peripherally associated membrane proteins. What is the likely composition of "Magic Solution A" and "Magic Solution B"?
"Solution A" is a membrane solubilizing detergent, "Solution B" is a high salt buffer that disrupts hydrogen bonds and ionic interactions.
In mitochondria, exergonic redox reactions ____________
. provide the energy that establishes the proton gradient
What is the valence of an atom with an atomic number of 9
1
Calcium has an atomic number of 20 and an atomic mass of 40. Therefore, a calcium atom must have ______
20 protons
A phospholipid has ________ fatty acids attached to glycerol, whereas a fat has ________.
2; 3
A region on one DNA strand has the sequence 5'ATCCG3'. What is the sequence on the complementary strand of DNA?
3'TAGGC5'
How many electrons does sulfur have in its valence shell?
6
Which of the following are produced during the citric acid cycle?
ATP, NADH, and FADH2
Which bond is a peptide bond?
C
Which molecule contains an aldehyde group?
C
The molecular formula of a polysaccharide that is made up of 4 glucose (C6H12O6) monomers is _____
C24H42O21
Proteins are largely responsible for the traits of living organisms, while ________ provides the blueprint for the organization, development, and function of living things.
DNA
Which of the following best describes the flow of information in eukaryotic cells?
DNA → RNA → proteins
In the biochemical regulation of metabolic pathways, how might one overcome the effect of a competitive inhibitor on enzyme activity?
Increase the amount of substrate for the enzyme.
What would your predict about the following reaction? Pi+ ADP --> ATP
It has a change in free energy that is greater than 0.
Which of the following is not true of water?
It is a relatively poor solvent.
What feature of genetic mutations can eventually lead to the evolution of new species?
Mutations produce changes in the DNA sequence of a gene.
In addition to ATP, what are the end products of glycolysis?
NADH and pyruvate
The purpose of the light reactions is to produce
NADPH and ATP
Which of the following statements about metabolism is NOT TRUE
Protein synthesis is a catabolic process.
Which of the following is TRUE of active transport but is NOT true of facilitated diffusion?
Requires metabolic energy in the form of ATP
Plasma membrane phospholipids are labeled with a fluorescent tag and then the phospholipids in one area are bleached with a laser beam to eliminate the fluorescent signal. What would one observe after the cell is incubated for a few minutes?
The bleached molecules would diffuse laterally through the membrane and intermix with unbleached molecules.
A researcher decides to test the scientific validity of the common phrase "An apple a day keeps the doctor away." What would be a valid hypothesis to investigate this specific question?
The daily consumption of a single apple does not change the number of visits to the doctor.
How is a gradient of H+ ions formed across the inner mitochondrial membrane?
The electron transport chain uses energy from the transfer of an electron donated by NADH to pump H+ across the inner mitochondrial membrane against its electrochemical gradient.
Select the statement that is true when comparing solutions with a pH of 6 and a pH of 8.
The solution with a pH of 6 has a 100 times higher concentration of hydrogen ions than a solution with a pH of 8.
In a PET scan, a patient is injected with radioactively labeled glucose. Cells take up the radioactive glucose and the scanner detects levels of radioactivity in various parts of the body. This is a measure of the amount of glucose uptake. Cancer cells are often in an environment with low oxygen concentration and they take in high amounts of glucose. Why would a low oxygen environment lead to high glucose uptake?
They rely more on glycolysis which is less efficient than oxidative phosphorylation.
The addition of a strong acid like HCl to an aqueous solution would result in
a decrease in pH
Which of the following descriptions best fits the class of molecules known as nucleotides?
a nitrogenous base, a phosphate group, and a pentose sugar
A series of enzymes catalyze the reaction X > Y > Z > A. Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of the enzyme. Substance A functions as ______
a non-competitive inhibitor
If orange juice has a pH of 4, then it can be described as
an acidic solution
In photosynthesis, carbon dioxide gas is reduced and combined to form glucose. This is an example of
anabolism
Fats and fatty acids
are insoluble in water.
Polysaccharides and proteins are similar in that they ____
are synthesized from monomers by dehydration reactions.
Which portion of the photosynthetic apparatus absorbs light?
both photosystem I and photosystem II
How can a living cell increase the rate of a chemical reaction?
by using a catalyst.
An example of a non-polar covalent bond is the bond between ______
carbon and hydrogen in methane (CH4).
Which molecule passes through a lipid bilayer most readily?
carbon dioxide
A comparison of mitochondria and chloroplasts shows that
both generate ATP via an H+electrochemical gradient.
When one atom loses an electron to another atom, it results in the formation of
cations and anions that can form ionic bonds.
Where does the Calvin cycle occur
chloroplast stroma
What type of bonding is likely to occur between two water molecules or strands of DNA?
covalent
FtsZ, MreB, and CreS proteins regulate the shape and structure of bacterial (prokaryote) cells. These proteins are homologous to the ________ in eukaryotes.
cytoskelaton
A dehydration reaction
is used to form polymers
The plasma membrane Na+/K+-ATPase pump
is used to generate sodium and potassium gradients across the membrane.
What would be the likely outcome of a silent mutation within a transcription factor?
no effect would be observed
Carbon and hydrogen have similar electronegativities and combine together to form hydrocarbon molecules. What type of bonds form between these atoms?
nonpolar covalent
An amino acid is to a protein as a ________ is to a nucleic acid.
nucleotide
Cellular respiration produces the most energy in the form of ATP from which of the following?
oxidative phosphorylation
The process that produces protein from mRNA is called
translation
Which membrane component is important for allowing large, charged molecules to pass through the membrane?
transmembrane proteins
In order to visualize the fine structure of viruses and cytoskeletal filaments at 10-25 nanometers in diameter the type of microscopy that would be most effective is
transmission electron microscopy.