BSCI170 Quizzes
During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a ∆G of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be the ∆G for the new reaction?
-20 kcal/mol
Starting with citrate, which of the following combinations of products would result from three acetyl CoA molecules entering the citric acid cycle?
3 ATP, 6 CO2, 9 NADH, and 3 FADH2
If one strand of a DNA molecule has the sequence of bases 5′-ATTGCA-3′, the complementary RNA synthesized by using it as a template will be ________.
3′-UAACGU-5′
For each mole of glucose (C6H12O6) oxidized by cellular respiration, how many moles of CO2 are released in the citric acid cycle (see the accompanying figure)?
4
Referring to the figure, what bases will be added to the primer as DNA replication proceeds?
5′ A, G, A, C, G, A, C 3′
How many electrons are involved in a triple covalent bond?
6
Which of the following statements is the most current description of a gene?
A DNA sequence that is expressed to form a functional product: either RNA or polypeptide
The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following statements to be true?
A gene from one organism can theoretically be expressed by any other organism.
Which of the following can be attributed to water's high specific heat?
A lake heats up more slowly than the air around it.
Which of the following is an example of potential rather than kinetic energy?
A molecule of glucose
Which of the following effects can occur because of the high surface tension of water?
A raft spider can walk across the surface of a small pond.
During the elongation phase of translation, which site in the ribosome represents the location where a codon is being read?
A site
Which of the following statements is most likely true of a protein that cotransports glucose and sodium ions into the intestinal cells of an animal?
A substance that blocks sodium ions from binding to the cotransport protein will also block the transport of glucose.
A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is ________.
AAA
In the absence of oxygen, yeast cells can obtain energy by fermentation, which results in the production of which of the following sets of molecules?
ATP, CO2, and ethanol (ethyl alcohol)
Protein kinase is an enzyme that functions in which of the following ways?
Activates or inactivates other proteins by adding a phosphate group to them
What is the name of the thermodynamic barrier that must be overcome before products are formed in a spontaneous reaction?
Activation Energy
Which of the following provides the best evidence that cell-signaling pathways evolved early in the history of life?
Signal transduction molecules identified in distantly related organisms are similar.
The oxygen released by photosynthesis is produced by which of the following processes?
Splitting water molecules
What component of amino acid structure varies among different amino acids?
The components of the R group
What happens to a glucose molecule when it loses a hydrogen atom as the result of an oxidation-reduction reaction?
The glucose molecule is oxidized.
Which of the following statements correctly describes the difference between the leading and the lagging strands of DNA during DNA replication?
The leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction.
In an experimental situation, a student researcher inserts an mRNA molecule into a eukaryotic cell after she has removed its 5′ cap and poly-A tail. Which of the following processes would you expect her to find to have occurred?
The molecule is digested by enzymes because it is not protected at the 5′ end.
What happens when electrons are passed from one atom to a more electronegative atom?
The more electronegative atom is reduced, and energy is released.
In bacteria, DNA will be found in which of the following?
The nucleoid
Which of the following statements correctly describes the difference between ATP and the nucleotides used during DNA synthesis?
The nucleotides have the sugar deoxyribose; ATP has the sugar ribose.
A beaker contains 100 milliliters (mL) of NaOH solution at pH = 13. A technician carefully pours into the beaker 10 mL of HCl at pH = 1. Which of the following statements correctly describes the result of this mixing?
The pH of the beaker's contents will decrease.
Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes?
The phosphodiester linkages of the polynucleotide backbone would be broken.
What does it mean to say that a signal is transduced?
The physical form of the signal changes as it passes from the cell membrane to the ultimate intracellular target.
How do phospholipids interact with water molecules?
The polar heads interact with water; the non polar tails do not.
Which of the following statements is true for a system at chemical equilibrium?
The system can do no work.
Hormones are chemical substances produced in one organ that are released into the bloodstream and affect the function of a target organ. Which of the following conditions is required for the target organ to respond to a particular hormone?
The target organ must have receptors that recognize and bind the hormone molecule.
Which of the following characteristics is directly related to the coding of a single amino acid during the process of translation?
The three-base sequence of mRNA
Which of the following is a major difference between RNA and DNA?
The type of sugar
Why are lipids and proteins free to move laterally in membranes?
There are only weak hydrophobic interactions in the interior of the membrane.
Why are carbohydrates and fats frequently considered high-energy foods?
They contain many electrons associated with hydrogen atoms
What role do phosphatases play in signal transduction pathways?
They inactivate protein kinases to turn off signal transduction.
In sickle-cell disease, as a result of a single amino acid change, the hemoglobin tetramers associate with each other and assemble into large fibers. Based on this information alone, we can conclude that sickle-cell hemoglobin exhibits ________.
altered primary structure and altered quaternary structure; the secondary and tertiary structures may or may not be altered
For a protein to be an integral membrane protein, it would have to be ________.
amphipathic, with at least one hydrophobic region
Atoms have no electric charge because they have ________.
an equal number of protons and electrons
Thalidomide and L-dopa (see figure) are examples of pharmaceutical drugs that occur as enantiomers, or molecules that ________.
are mirror images of one another
Starch and cellulose ________.
are polymers of glucose
Accuracy in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the ________.
binding of the anticodon to the codon and the attachment of amino acids to tRNAs
Caffeine is an inhibitor of phosphodiesterase. Therefore, the cells of a person who has recently consumed coffee would have increased levels of which of the following molecules?
cAMP
According to the fluid mosaic model of cell membranes, phospholipids ________.
can move laterally along the plane of the membrane
An animal cell lacking carbohydrates on the external surface of its plasma membrane would likely be impaired in which function?
cell-cell recognition
Water molecules can form hydrogen bonds with ________.
compounds that have polar covalent bonds
Saturated fats ________.
contain more hydrogen than unsaturated fats that consist of the same number of carbon atoms
A carbon atom is most likely to form what kind of bond(s) with other atoms?
covalent
Cooking oil and gasoline (a hydrocarbon) are not amphipathic molecules because they ________.
do not have a polar or charged region
CAM plants keep stomata closed in the daytime, thus reducing the of water. They can do this because they ________.
fix CO2 into organic acids during the night
Which of the following sequences describes the path by which electrons travel downhill energetically in aerobic respiration?
glucose → NADH → electron transport chain → oxygen
Testosterone and estradiol are male and female sex hormones, respectively, in many vertebrates. In what way(s) do these molecules differ from each other? Testosterone and estradiol ________.
have different functional groups attached to the same carbon skeleton
Humans can digest starch but not cellulose because ________.
humans have enzymes that can hydrolyze the α-glycosidic linkages of starch but not the β-glycosidic linkages of cellulose
The membranes of winter wheat are able to remain fluid when it is extremely cold by ________.
increasing the proportion of unsaturated phospholipids in the membrane
If the cytoplasm of a cell is at pH 7, and the mitochondrial matrix is at pH 8, then the concentration of H+ ions ________.
is 10 times higher in the cytoplasm than in the mitochondrial matrix
According to the central dogma, what s the intermediate molecule involved in the flow of information in a cell that should go in the blank? DNA → ________ → Proteins
mRNA
Which of the following molecular structures contain codons?
mRNA
Which of the following molecules are required for the process of translation?
mRNA, tRNA, and rRNA
Bonds between two atoms that are equally electronegative are ________.
nonpolar covalent bonds
A covalent chemical bond is one in which ________.
outer-shell electrons of two atoms are shared so as to satisfactorily fill their respective orbitals
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by ________.
polar covalent bonds
Based on your knowledge of the polarity of water molecules, the solute molecule depicted is most likely ________.
positively charged
The structural level of a protein least affected by a disruption in hydrogen bonding is the __________.
primary level
The chemical reaction illustrated above ________.
results in a peptide bond
Which of the following domains of life are classified as prokaryotes?
Bacteria and Archaea
In eukaryotic cells, transcription cannot begin until _____________
several transcription factors have bound to the promoter.
An electron loses potential energy when it __________________.
shifts to a more electronegative atom
A compound contains hydroxyl groups as its predominant functional group. Therefore, this compound ________.
should dissolve in water
The solutions in the two arms of this U-tube are separated by a membrane that is permeable to water and glucose but not to sucrose. Side A is half-filled with a solution of 2 M sucrose and 1 M glucose. Side B is half-filled with 1 M sucrose and 2 M glucose. Initially, the liquid levels on both sides are equal.
side A is isotonic to side B
A research team is working on the design of a new drug for the treatment of lung cancer. To be most effective, this drug must specifically enter the cytoplasm of lung cells while not entering the cells of other tissues. Which of the following characteristics would likely enhance the specificity of this drug?
similarity of the drug molecule to other molecules normally transported lung cells
What kinds of molecules pass through a cell membrane most easily?
small and hydrophobic
A spaceship is designed to support animal life for a multiyear voyage to the outer planets of the solar system. Plants will be grown to provide oxygen and to recycle carbon dioxide. Since the spaceship will be too far from the sun for photosynthesis, an artificial light source will be needed. Suppose a plant has a unique photosynthetic pigment and the leaves of this plant appear to be reddish yellow. What wavelengths of visible light are absorbed by this pigment?
Blue and Violet
Which of the following graphs most likely describes the effect of pH on the function of the enzyme catalase in human cells? Note: The x-axis is pH and the y-axis is enzyme activity.
C
Which of the following best summarizes the relationship between dehydration reactions and hydrolysis?
Dehydration reactions assemble polymers; hydrolysis reactions break polymers apart.
Some photosynthetic organisms contain chloroplasts that lack photosystem II, yet are able to survive. Which of the following approaches would be the best way to detect the lack of photosystem II in these organisms?
Determine whether they produce O2 in the light.
Which of the following characteristics is most likely to be associated with an enzyme that catalyzes two different chemical reactions?
Either the enzyme has two distinct active sites or the substrates involved in the two reactions have very similar structures.
Why does the oxidation of organic compounds by molecular oxygen to produce CO2 and water release free energy?
Electrons are being moved from atoms that have a lower affinity for electrons (such as C) to atoms with a higher affinity for electrons (such as O).
A chemical reaction that has a positive value for ΔG is best described as ________.
Endergonic
Which of the following statements describes the first law of thermodynamics?
Energy cannot be created or destroyed.
Which of the following statements about enzyme function is true?
Enzymes increase the rate of chemical reactions by lowering activation energy barriers.
Which of the following investigators was (were) responsible for the discovery that in DNA from any species, the amount of adenine equals the amount of thymine, and the amount of guanine equals the amount of cytosine?
Erwin Chargaff
Which of the following is a major difference between prokaryotic cells and eukaryotic cells?
Eukaryotic cells have membrane-bound organelles, while prokaryotic cells do not.
The figure illustrates the energy states associated with the reaction A + B ↔ C + D. Which of the following terms best describes the forward reaction in the figure?
Exergonic, ∆G < 0
The relationship between catabolism and anabolism is most similar to the relationship between which of the following pairs of terms?
Exergonic; Endergonic
Which of the following is not true of RNA processing?
Exons are cut out before mRNA leaves the nucleus.
Which of the following statements describes the process of transformation in bacteria?
External DNA is taken into a cell, becoming part of the cell's genome.
Identical heat lamps are arranged to shine on two identical containers, one containing water and one methanol (wood alcohol), so that each liquid absorbs the same amount of energy minute by minute. The covalent bonds of methanol molecules are nonpolar, so there are no hydrogen bonds among methanol molecules. Which of the following graphs correctly describes what will happen to the temperature of the water and the methanol?
Fig. B
Which of the pairs of molecular structures shown depict enantiomers (enantiomeric forms) of the same molecule?
Fig. C
Which of the following illustrations is not a structural isomer of an organic compound with the molecular formula C6H14? For clarity, only the carbon skeletons are shown; hydrogen atoms that would be attached to the carbons have been omitted.
Fig. C c-c=c-c c c
Which of the following are compounds?
H2O and CH4, but not O2
What type of bonding is responsible for maintaining the shape of the tRNA molecule shown in the figure?
Hydrogen bonding between base pairs
In his work with pneumonia-causing bacteria and mice, Griffith found that .......
some substance from pathogenic cells was transferred to nonpathogenic cells, making them pathogenic.
A salamander relies on hydrogen bonding to stick to various surfaces. Therefore, a salamander would have the greatest difficulty clinging to a ________.
surface of hydrocarbons
In the polymerization of DNA, a phosphodiester bond is formed between a phosphate group of the nucleotide being added and which of the following atoms or molecules of the last nucleotide in the polymer?
the 3' OH
The complexity and variety of organic molecules are due to ________.
the chemical versatility of carbon atoms
The partial negative charge in a molecule of water occurs because ________.
the electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus
In the term trace element, the adjective trace means that...
the element is required in very small amounts
In an ethane (C2H6) molecule, each carbon atom is bonded to ________ hydrogen atoms.
three
A tripeptide has ________.
three amino acids and two peptide bonds
You briefly expose bacteria undergoing DNA replication to radioactively labeled nucleotides. When you centrifuge the DNA isolated from the bacteria, the DNA separates into two classes. One class of labeled DNA includes very large molecules (thousands or even millions of nucleotides long), and the other includes short stretches of DNA (several hundred to a few thousand nucleotides in length). Which two classes of DNA do these different samples represent?
Leading strands and Okazaki fragments
Which of the following statements is true for lipids?
Lipids mix poorly with water.
In E. coli, there is a mutation in a gene called dnaB that alters the helicase that normally acts at the origin of replication. Which of the following events would you expect to occur as a result of this mutation?
No replication fork will be formed.
The figure shows the absorption spectrum for chlorophyll a and the action spectrum for photosynthesis. Why are they different?
Other pigments absorb light in addition to chlorophyll a.
Which of the following statements describes a primary function of both alcohol fermentation and lactic acid fermentation?
Oxidation of NADH to NAD+
Carbon dioxide (CO2) is released during which of the following stages of cellular respiration?
Oxidation of pyruvate to acetyl CoA and the citric acid cycle
Which of the following processes is driven by chemiosmosis?
Oxidative phosphorylation
The activity of adenylyl cyclase is essentially the opposite of which of the following enzymes?
Phosphodiesterase
In the initial step in carbon fixation, a molecule of CO2 is attached to RuBP to produce a six-carbon molecule, which is immediately split to produce two molecules of 3-phosphoglycerate. After phosphorylation and reduction produce glyceraldehyde 3-phosphate (G3P), what more needs to occur to complete the Calvin cycle?
Regeneration of RuBP
In the fractionation of homogenized cells using differential centrifugation, which of the following will require the greatest speed to form pellets at the bottom of the tube?
Ribosomes
Transcription in eukaryotes requires which of the following molecules in addition to RNA polymerase?
Several transcription factors
A heat-killed, phosphorescent (light-emitting) strain of bacteria is mixed with a living, non-phosphorescent strain. Further observations of the mixture show that some of the living cells are now phosphorescent. Which of the following observations would provide the best evidence that the ability to phosphoresce is a heritable trait?
Phosphorescence in descendants of the living cells
Under what conditions do photosynthesis and cellular respiration occur in plants?
Photosynthesis occurs only in the light, and cellular respiration occurs in both the dark and the light.
If you disrupt all hydrogen bonds in a protein, then what level of structure will be preserved?
Primary structure
Examination of a cell by transmission electron microscopy reveals a high density of ribosomes in the cytoplasm. This observation suggests that this cell is actively producing large amounts of which of the following molecules?
Proteins
What is the electron acceptor in the following reaction? Pyruvate + NADH + H+ → Lactate + NAD+
Pyruvate
Which of the following processes occurs during transcription?
RNA is synthesized
In eukaryotes, there are several different types of RNA polymerase. Which type is involved in transcription of mRNA for a globin protein
RNA polymerase II
Which of the following statements best describes the termination of transcription in prokaryotes?
RNA polymerase transcribes through the terminator sequence, causing the polymerase to separate from the DNA and release the transcript.
Which electron carrier(s) function in the citric acid cycle?
NADH and FADH2
In carbohydrates, the ratio of hydrogen (H) to oxygen (O) is ________.
2:1
If glucose is the sole energy source, what fraction of the carbon dioxide exhaled by animals is generated only by the reactions involved in the oxidation of pyruvate to acetyl CoA?
1/3
A solution with a pH of 2 has how many more protons in it than a solution with a pH of 4?
100 times more
Substrate-level phosphorylation accounts for approximately what percentage of the ATP formed by the reactions of glycolysis?
100%
How many molecules of water are released during the polymerization of a 20 monomer-long cellulose molecule?
19
Starting with one molecule of glucose, glycolysis results in the net production of which of the following sets of energy-containing products?
2 NADH, 2 pyruvate, and 2 ATP
During glycolysis, for each molecule of glucose oxidized to pyruvate __________________.
2 molecules of ATP are used, and 4 molecules of ATP are produced
Which of the following is true during a typical cAMP-mediated signal transduction event?
Adenylyl cyclase is activated after the hormone binds to the cell and before phosphorylation of proteins occurs.
Which kind of metabolic poison would most directly interfere with glycolysis?
An agent that closely mimics the structure of glucose but is not metabolized
Which of the following events accompanies absorption of energy by chlorophyll molecules of the reaction-center complex?
An electron is excited
Which of the following statements is an important consequence of the first law of thermodynamics for a living organism?
An organism ultimately must obtain all of the necessary energy for life from its environment.
Which of the following types of reactions would decrease the entropy within a cell?
Anabolic Reactions
Which of the following statements correctly describes a distinction between autotrophs and heterotrophs?
Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic.
What is the difference between covalent bonds and ionic bonds?
Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between charged atoms.
The molecular formula for glucose is C6H12O6. What would be the molecular formula for a molecule made by linking three glucose molecules together by dehydration reactions?
C18H32O16
Which of the summary statements below describes the results of the following reaction? C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy
C6H12O6 is oxidized and O2 is reduced.
Which of the following categories includes all others in the list?
Carbohydrate
About 25 of the 92 natural elements are known to be essential to life. Which 4 of these 25 elements make up approximately 96% of living matter?
Carbon, Hydrogen, Nitrogen, Oxygen
Which parts of the amino acids X and Y are involved in the formation a peptide bond of the following peptide? X—Y
Carboxyl group of X and amino group of Y
A cell has enough available ATP to meet its needs for about 30 seconds. What is likely to happen when an athlete exhausts his or her ATP supply?
Catabolic processes are activated that generate more ATP.
You would like to lose weight. Which of the following should be your preferred food group?
Cellulose and Fructose
Which organelle often takes up much of the volume of a plant cell?
Central Vacuole
Which polysaccharide is an important component in the structure of many animals and fungi?
Chitin
Which structure below is independent of the endomembrane system?
Chloroplast
HIV is the virus that causes AIDS. In the mid-1990s, researchers discovered an enzyme in HIV called protease. Once the enzyme's structure was known, researchers began looking for drugs that would fit into the active site and block it. If this strategy for stopping HIV infections were successful, it would be an example of what phenomenon?
Competitive Inhibition
Which of the following conditions may be overcome by increasing the substrate concentration in an enzymatic reaction with a fixed amount of enzyme?
Competitive Inhibition
In DNA replication, the resulting daughter molecules contain one strand of the original parental DNA and one new strand. What is the explanation for this phenomenon?
DNA replication is semiconservative.
The activity of various enzymes at various temperatures (a) and at various pH (b) Which curves on the graphs may represent the temperature and pH profiles of an enzyme taken from a bacterium that lives in mildly alkaline hot springs at temperatures of 70°C or higher?
Curves 3 and 5
You have just sequenced a new protein found in mice and observe that sulfur-containing cysteine residues occur at regular intervals. What is the significance of this finding?
Cysteine residues are involved in disulfide bridges that help form tertiary structure.
Hershey and Chase set out to determine what molecule served as the unit of inheritance. They completed a series of experiments in which E. coli was infected by a T2 virus. Which molecular component of the T2 virus actually ended up inside the cell?
DNA
Which of the following facts did Hershey and Chase make use of in trying to determine whether DNA or protein is the genetic material?
DNA contains phosphorus, whereas protein does not.
A biochemist isolates, purifies, and combines in a test tube a variety of molecules needed for DNA replication. When she adds some DNA to the mixture, replication occurs, but each DNA molecule consists of a normal strand paired with numerous segments of DNA a few hundred nucleotides long. What has she probably left out of the mixture?
DNA ligase
In E. coli, which enzyme catalyzes the elongation of a new DNA strand in the 5' → 3' direction?
DNA polymerase III
The lagging strand is characterized by a series of short segments of DNA (Okazaki fragments) that will be joined together to form a finished lagging strand. The experiments that led to the discovery of Okazaki fragments gave evidence for which of the following ideas?
DNA polymerase is an enzyme that synthesizes leading and lagging strands during replication only in one direction.
Why does testosterone, a lipid-soluble signaling molecule that crosses the membranes of all cells, affect only target cells?
Intracellular receptors for testosterone are present only in target cells.
What is the most likely mechanism by which testosterone functions inside a cell?
It binds with a receptor protein that enters the nucleus and activates expression of specific genes.
Which of the following statements about the electron transport chain is true?
It consists of a series of redox reactions
Why is glycolysis considered to be one of the first metabolic pathways to have evolved?
It does not involve organelles or specialized structures, does not require oxygen, and is present in most organisms.
Which of the following statements describes a characteristic feature of a carrier protein in a plasma membrane?
It exhibits specificity for a particular type of molecule.
Which of the following statements about the evolution of life on Earth, from simple prokaryote-like cells to multicellular eukaryotic organisms, is true?
It has occurred in accordance with the laws of thermodynamics and resulted in a substantial decrease in the entropy of the planet.
Which of the following statements correctly describes a ribozyme?
It is an RNA with catalytic activity.
When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated?
It is lost to the environment.
What happens to the free energy released as electrons are passed from photosystem II to photosystem I through a series of electron carriers?
It is used to establish and maintain a proton gradient.
Which of the following statements describes what happens to a molecule that functions as the electron donor in a redox or oxidation-reduction reaction?
It loses electrons and loses potential energy.
Within a double-stranded DNA molecule, adenine forms hydrogen bonds with thymine, and cytosine forms hydrogen bonds with guanine. What is the significance of the structural arrangement?
It permits complementary base pairing.
What is the function of the nuclear pore complex found in eukaryotes?
It regulates the movement of proteins and RNAs into and out of the nucleus.
Which of the following statements best describes the primary role played by oxygen in cellular respiration?
It serves as the final acceptor for electrons from the electron transport chain.
Energy released by the electron transport chain is used to pump H+ ions into which location in eukaryotic cells?
Mitochondrial intermembrane space
Which of the following structures is common to both plant and animal cells?
Mitochondrion
In his transformation experiments, what phenomenon did Griffith observe?
Mixing a heat-killed pathogenic strain of bacteria with a living nonpathogenic strain can convert some of the living cells into the pathogenic form.
The rate of an enzyme-catalyzed reaction as a function of varying reactant concentration, with the concentration of enzyme constant In the figure above, why does the reaction rate plateau at higher reactant concentrations?
Most enzyme molecules are occupied by substrate at high reactant concentrations.
The free energy for the oxidation of glucose to CO2 and water is -686 kcal/mol, and the free energy for the reduction of NAD+ to NADH is +53 kcal/mol. Why are only two molecules of NADH formed during glycolysis when it appears that as many as a dozen could be formed?
Most of the free energy available from the oxidation of glucose remains in two pyruvates, one of the products of glycolysis.
To sustain high rates of glycolysis under anaerobic conditions, cells require __________________.
NAD+
Which of the following statements about NAD+ is true?
NAD+ is reduced to NADH during glycolysis.
What is meant by the description "antiparallel" regarding the two strands that make up the DNA double helix?
The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand.
Which of the following statements about the 5′ end of a polynucleotide strand of RNA is correct?
The 5′ end has a phosphate group attached to the number 5′ carbon of ribose.
Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large, complex, undigested lipids. Which cellular organelle is most likely defective in this condition?
The Lysosome
What makes lipids/fats hydrophobic?
The presence of relatively non polar C-H bonds
How does the primary transcript in the nucleus of a eukaryotic cell compare to the functional mRNA?
The primary transcript is larger than the mRNA.
Which of the following provides the information necessary to stipulate the 3-D shape of a protein?
The sequence of amino acids in the polypeptide chain
It became apparent to Watson and Crick after completion of their model that the DNA molecule could carry a vast amount of hereditary information. Which of the following characteristics of DNA is responsible for this?
The sequence of bases
If your muscle cells used alcoholic fermentation instead of lactic acid fermentation, which of the following might occur?
You might become drunk when sprinting to catch a bus.
The process of cellular respiration, which converts simple sugars such as glucose into CO2 and water, is an example of _____.
a catabolic pathway
The molecule shown is ________.
a hexose
Which of the following descriptions best fits the class of molecules known as nucleotides?
a nitrogenous base, a phosphate group, and a sugar
The relation between an amino acid and a polypeptide is similar to the relation between ________.
a nucleotide and nucleic acid
Consider the following, which represents the structural formula for carbon dioxide. O=C=O Each line in the covalent bonds connecting carbon and oxygen in carbon dioxide represents ________.
a pair of shared electrons
Differences among organisms are caused by differences in the ________.
types and relative amounts of organic molecules synthesized by each organism