bio semester 1 t&q
If acid rain has lowered the pH of a particular lake to pH 4.0. What is the hydrogen ion concentration of the lake
10^-4 M
If a DNA sample were composed of 20% guanine, what would be the percentage of cytosine?
20
The following question refers to the essential steps in meiosis described below.1. formation of four new nuclei, each with half the chromosomes present in the parental nucleus 2. alignment of homologous chromosomes at the metaphase plate3. separation of sister chromatids4. separation of the homologs; no uncoupling of the centromere 5. synapsis; chromosomes moving to the middle of the cell in pairsWhich of the steps take(s) place in both mitosis and meiosis?
3
Which of the following is the simpli!ed balanced equation for the generation of sugar from sunlight, water, and CO2?
6CO2 + 6H2O--> C6H12O6 + 6O2
Which of the following statements correctly describes an organism's genome?
A genome is a complete set of all of an organism's genes.
Which of the following statements best describes the critical role that ATP plays in cellular metabolism?
ATP serves as an energy shuttle in the cell, coupling exergonic and endergonic reactions.
Figure 6.4 illustrates various aspects of the free-energy change (ΔG) for the reaction A + B ↔ C + D. Which of the following represents the EA of the reaction WITH AN ENZYME
B
The unlettered circle at the top of Figure 9.1 shows a diploid nucleus with four chromosomes that have not yet replicated. There are two pairs of homologous chromosomes, one long and the other short. One haploid set is black, and the other is gray. The circles labeled A-E show various combinations of these chromosomes. What is the correct chromosomal condition for a nucleus at prophase of mitosis?
B
Which of the following statements about the relationship between photosynthesis and cellular respiration is correct?
Cellular respiration is catabolic and photosynthesis is anabolic
Which of the following presents a correct interpretation of the changes in chromosome number depicted in Figure 1 ?
Chromosomes enter metaphase containing two chromatids attached by a centromere. During anaphase, the chromatids are separated, each becoming a chromosome. Cytokinesis distributes the chromosomes into two separate cells.
Reinforces animal cell's shape ans size; can function in movement
Cytoskeleton
Figure 6.4 illustrates various aspects of the free-energy change (ΔG) for the reaction A + B--> C + D. Which of the following represents the ΔG of the reaction in Figure 6.4?
D
The unlettered circle at the top of Figure 9.1 shows a diploid nucleus with four chromosomes that have not yet replicated. There are two pairs of homologous chromosomes, one long and the other short. One haploid set is black, and the other is gray. The circles labeled A-E show various combinations of these chromosomes. Which image displays the chromosomal composition of one daughter nucleus at telophase of mitosis?
E
A scientist claims that Elysia chlorotica, a species of sea slug, is capable of photosynthesis.Which of the following observations provides the best evidence to support the claim?
Elysia chlorotica grows when exposed to light in the absence of other food sources.
Which of the following is true of enzymes?
Enzymes increase the rate of chemical reaction by lowering activation energy barriers.
At puberty, an adolescent female body changes in both structure and function of several organ systems, primarily under the influence of changing concentrations of estrogens and other steroid hormones. How can one hormone, such as estrogen, mediate so many effects?
Estrogen binds to specific receptors inside many kinds of cells, each of which have different responses to its binding.
Which of the following statements is a logical consequence of the second law of thermodynamics?
Every chemical reaction must increase the total entropy of the universe.
Stimulatory proteins are encoded by tumor suppressor genes.
False
In the figure above, which numbered segment(s) of the cycle represent a period during which chromosomes are replicated?
II only
Aminolevulinate dehydratase (ALAD) is an enzyme that relies on zinc as a coenzyme. A zinc ion binds to the ALAD active site, where it forms favorable interactions with the side chains of three amino acids. Researchers have found that substituting a lead ion for a zinc ion in the ALAD active site causes inhibition of ALAD. Which of the following statements best helps explain how the lead ion causes inhibition of ALAD?
It changes the three-dimensional structure of the active site so that ALAD is no longer compatible with its substrate.
If a cell has completed the first meiotic division and is just beginning meiosis II, which of the following statements describes the genetic or chromosomal contents of this cell?
It has half the amount of DNA of the cell that began meiosis.
Which of the following is the most comprehensive definition of metabolism in living organisms?
Metabolism consists of all the energy transformation reactions in an organism
Which of the following is the best explanation for the fact that most transduction pathways have multiple steps?
Multiple steps provide for greater possible amplification of a signal.
Non-membranous structure located within the nucleus and responsible for the production of ribosomes.
Nucleolus
which of the following molecules would you expect to diffuse through the lipid bilayer of a plasma membrane most rapidly?
O2
Studded with ribosomes; Modifies proteins that are destined for other parts of the cell
Rough ER
At the end of which phase does the cell have two complete sets of chromosomes?
S
A student calculated the average surface-area-to-volume ratio of four different types of human epithelial cells. Simple squamous: 9Simple cuboidal: 6Simple columnar: 4Simple spherical: 3Based on the data, which type of cell would be best suited for the lining the alveoli of the lungs, where diffusion of carbon dioxide and oxygen must occur very rapidly?
Simple squamous cells
Modifies and assembles lipids for shipment to other parts of the cell; synthesizes membranes
Smooth ER
Which of the following statements about humans is true?
The 23rd pair, the sex chromosomes, determines whether the person is female (XX) or male (XY).
According to the induced "t hypothesis of enzyme catalysis, which of the following is correct?
The binding of the substrate changes the shape of the enzyme's active site.
The figure above shows an organelle typically found in eukaryotic cells. Which of the following best describes the function of the double membrane system of this organelle?
The inner membrane has specialized proteins that create a hydrogen ion concentration gradient between the intermembrane space and the matrix.
Immediately after a membrane receptor protein binds to its ligand, which of the following processes occurs?
The membrane receptor protein undergoes a conformational (shape) change.
Calculate the water potential of a cell with no cell wall that has a 0.5M sucrose concentration and is at 27°C and describe what would happen to this cell if placed in a solution with a water potential of -3.0 bars? Will the cell shrivel OR swell?
The water potential of the cell is -12.5 bars.Due to the net movement of water the cell will SWELL.
The value for water potential in root tissue was found to be -3.3 bars. If you place the root tissue in a 0.2 M solution of sucrose at 20°C in an open beaker, what is the water potential of the solution, AND in which direction would the net "ow of water be? (Answer by #lling in the blanks below) The water potential of the solution is _ bars. (*round your answer to the nearest tenth only! For example, 9.1 or 4.2) The net "ow of water will be _ the root tissue. (into OR out of) Water potential = Solute potential + Pressure potential Ψ = Ψs + ΨpThe solute potential (ψS) = - iCRT, where i is the ionization constant, C is the molar concentration, R is the pressure constant (R = 0.0831 liter bars/mole-K), and T is the temperature in K (273 + °C). Common ionization constants: sucrose (i=1), glucose (i=1), NaCl (i=2) The pressure potential (ψp) = 0 for pure water in an open container. The ψp = 1 for a plant cell (turgor pressure). QUESTION: The value for water potential in root tissue was found to be -3.3 bars. If you place the root tissue in a 0.2 M solution of sucrose at 20°C in an open beaker, what is the water potential of the solution, AND in which direction would the net "ow of water be? (Answer by #lling in the blanks below)
The water potential of the solution is -4.9 bars. (*round your answer to the nearest tenth only! For example, 9.1 or 4.2) The net flow of water will be outside the root tissue. (into OR out of)
If cell cycle regulators DO NOT function properly an organism may end up with too few or too many cells.
True
When a signal is amplified, one active relay protein is able to activate several relay proteins in the next step of the pathway. This allows for one signal to cause several responses within a cell at the same time
True
which of the following is a correct example of cohesion
a drop of water spilled on a table forms a drop on the table, rather than spreading out over the surface
What is a cleavage furrow?
a groove in the plasma membrane between daughter nuclei
a nucleotide is composed of
a nitrogenous base, a phosphate group, and a pentose sugar
Intact cells of two unknown cell types were placed into solutions with dIFFerent concentrations of NaCl.Type I cells swelled and burst in the solution with the lowest concentration of NaCl. Type II cells swelled but did not burst in the solution with the lowest concentration of NaCl. Which of the following descriptions of cell type I and cell type II are most consistent with the data?
a. A
Which of the following describes a metabolic consequence of a shortage of oxygen in muscle cells?
a. A buildup of lactic acid in the muscle tissue due to fermentation
Which of the following statements correctly summarizes a redox reaction that occurs in photosynthesis?
a. CO2 is reduced to form glucose.
Which of the following are responsible for regulating the progression from one phase of the cell cycle to the next?
a. Checkpoint proteins
Which of the following is the "resting, nondividing stage" that some cells remain in?
a. G0
Why does ice float in liquid water?
a. Hydrogen bonds stabilize and keep the water molecules of ice farther apart than the water molecules of liquid water.
Which of the following statements about diffusion is correct?
a. It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration.
Which of the following molecules would you expect to diffuse through the lipid bilayer of a plasma membrane most rapidly?
a. O2
Which type of membrane protein would likely be most easily removed in a laboratory experiment?
a. Peripheral membrane proteins
A student placed a semipermeable membrane inside a U-shaped channel with two chambers, as shown. The membrane permits the movement of water but not salt. The student wants to vary the rate of osmosis that occurs across the membrane. Which of the following experimental designs will result in the fastest net rate of water movement into chamber A?
a. Placing salt water in chamber A and distilled water in chamber B
Which of the following represents the stages of cell communication (C,E and F) in the correct order
a. Reception, Transduction, Response
The following questions refer to an experiment in which a dialysis-tubing bag is filled with a mixture of 3% starch and 3% glucose and placed in a beaker of distilled water. After 3 hours, glucose can be detected in the water outside the dialysis-tubing bag, but starch cannot. Which of the following best describes the condition expected after 24 hours?
a. The bag will contain more water than it did in the original condition
Which statement about cholesterol molecules is true?
a. They alter the fluidity of the membrane.
The figure above illustrates a eukaryoic cell. Which of the following best describes how the three structures indicated by the arrows work together?
a. To synthesize and isolate proteins for secretion or for use in the cell
A scientist designed an experiment to test an artificial membrane that mimics the phospholipid bilayer of a cell. The scientist built a tube that was divided by an arti#cial membrane and #lled with distilled water. The scientist put a known amount of a protein into the water on one side of the membrane. After some time, the scientist measured the concentration of the protein on either side of the membrane but found that there had been no change. Which of the following experimental changes would allow the scientist to observe transport of a solute across the arti#cial membrane?
a. Use a small, nonpolar solute instead of a protein
A scientist designed an experiment to test an artificial membrane that mimics the phospholipid bilayer of a cell.The scientist built a tube that was divided by an artificial membrane and filled with distilled water. The scientist put a known amount of a protein into the water on one side of the membrane. After some time, the scientist measured the concentration of the protein on either side of the membrane but found that there had been no change.Which of the following experimental changes would allow the scientist to observe transport of a solute across the artificial membrane?
a. Use a small, nonpolar solute instead of a protein
Which of the following solutions would PURE water move toward the most?
a. Water potential of -2.8
If a hospital patient is mistakenly given an IV of pure water instead of a saline solution (isotonic to blood) the patient's red blood cells will
a. absorb water and eventually burst.
Oxidation and reduction
a. always occur together.
The data were obtained from a study of the length of time spent in each phase of the cell cycle by cells of three eukaryotic organisms designated beta, delta, and gamma. The best conclusion concerning delta is that the cells
a. are actually in the G0 phase.
The centromere is a region in which
a. chromatids remain attached to one another until anaphase.
which of the following is the key characteristic that is ultimately responsible for the unique chemical properties of each element
a. each element has a unique number of protons
The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is most precisely described as
a. feedback inhibition.
Binding of the signaling molecule epinephrine to its receptor results in
a. increased concentrations of cyclic AMP in the cytoplasm.
Water can move quickly through the plasma membrane of some cells because
a. it moves through aquaporin channel proteins.
Which of the following enzymes adds a phosphate group to target proteins in signal transduction pathways that involve a phosphorylation cascade?
a. kinase
The enzyme peroxidase is found in many organisms. It catalyzes the breakdown of hydrogen peroxide into water and oxygen gas. The rate of peroxidase activity at different pH values was assessed by students in the lab. The students' results are shown in graph 1.
a. lower than the level at pH 9
The cytoplasmic side of a cell membrane is negative in charge relative to the extracellular side. What is the voltage across a cell membrane called?
a. membrane potential
Which structure is common to plant and animal cells?
a. mitochondrion
A proper relationship between an enzyme and its function is illustrated by which of the following?
a. phosphatase: removal of a phosphate group
When a neuron responds to a particular neurotransmitter by opening gated ion channels, the neurotransmitter is serving as which part of the signal pathway?
a. signal molecule
Where does the Calvin cycle take place?
a. stroma of the chloroplast
You can fill a glass of water to just slightly above the rim without it spilling over the glass. What property of water best explains this phenomenon?
a. surface tension
Which of the following types of signaling is represented in Figure 5.5?
a. synaptic
The reactions in photosynthesis that produce the molecular Oxygen (O2) take place in
a. the light reactions alone
A student is looking through his light microscope (~450 X) at a squashed and stained onion root tip. Some, but not all, of the cells have clearly visible chromosome strands. When the cell has just completed telophase, which of the following does he see?
a. two new nuclei with chromatin
ATP is composed of -
adenine, ribose, 3 phosphate groups
-NH2
amino
which functional group can act as a base
amino
What is the term for the programmed death of cells?
apoptosis
ibuprofen is a drug commonly used to relieve inflammation and pain. It is a mixture of two enantiomers, which are molecules that
are mirror images of one another
Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. How is lactose classified?
as a disaccharide
The ΔG for a particular enzyme-catalyzed reaction is -20 kcal/mol. If the enzyme is removed, what will be the ΔG for the noncatalyzed reaction?
b. -20 kcal/mol
If a sexually reproducing organism has a diploid number of 36, how many individual chromosomes would any of its gametes have?
b. 18 chromosomes
Which of the following is a statement of the first law of thermodynamics?
b. Energy cannot be created or destroyed.
Following activation of a receptor, which sequence below represents the correct order in which components will be involved in a signaling pathway that utilizes the second messenger cAMP?
b. G protein --> adenyl cyclase --> cAMP --> protein kinase
Which of the following statements correctly describes the differences between sexual and asexual reproduction?
b. In sexual reproduction, o"spring vary genetically from their siblings and both parents.
Which statement describes the chromosome shown in Figure 5.2?
b. It is made up of two sister chromatids.
Which of the following statements best explains how the energy in a photon of light is stored in a molecule of the sugar G3P?
b. Light energy energizes electrons to make ATP and NADPH, which provide energy to produce G3P in the Calvin Cycle
Which of the following statements is true for all exergonic reactions?
b. The reaction proceeds with a net release of free energy.
Which of the following solutions would PURE water move toward the most
b. Water potential of -2.8
A student is looking through his light microscope (~450 X) at a squashed and stained onion root tip. Some, but not all, of the cells have clearly visible chromosome strands. When a cell is in anaphase of mitosis, which of the following will he see?
b. a clear area in the center of the cell
Unequal sharing of electrons between atoms will result in which of the following interactions?
b. a polar covalent bond
A protein that spans the phospholipid bilayer one or more times is
b. a transmembrane protein.
One difference between a cancer cell and a normal cell is that
b. cancer cells can divide in the absence of growth factors.
Zinc, an essential trace element for most organisms, is present in theactive site of the enzyme carboxypeptidase. The zinc most likely functionsas a(n)
b. cofactor necessary for enzyme activity.
Which of the following occur in the cytosol of a eukaryotic cell?
b. glycolysis and fermentation
The rough ER is the portion of the ER that
b. has ribosomes attached to it.
Besides the ability of some cancer cells to divide uncontrollably, what else could logically result in a tumor?
b. lack of appropriate cell death
Chloroplasts are the sites of photosynthesis in plants. They are mainly found in the cells of the __________, the tissue in the interior of the leaf.
b. mesophyll
Which of the following best supports the statement that mitochondria are descendants of endosymbiotic bacteria-like cells?
b. mitochondria and bacteria possess similar ribosomes and DNA
The value for water potential in root tissue was found to be -4.5 bars. If you place the root tissue in a 0.3 M solution of sucrose at 20°C in an open beaker, in which direction would the net flow of water be?
b. outside the cell
Proteins that normally stimulate the cell cycle are encoded by
b. proto-oncogenes
Which of the following is the main electrogenic pump of plants, fungi, and bacteria which actively transports hydrogen ions (H+) out of the cell. This creates a voltage across membranes and helps store energy that can be used to drive other processes such as the uptake of nutrients
b. proton pump
In general, the hydrolysis of ATP drives cellular work by __________.
b. releasing free energy that can be coupled to other reactions
When a neuron responds to a particular neurotransmitter by opening gated ion channels, the neurotransmitter is serving as which part of the signal pathway?
b. signal molecule
Which of the following reactions produces the oxygen released by photosynthesis?
b. splitting of water molecules
The existence of a concentration gradient of glucose across a membrane means that
b. the glucose molecules are more crowded on one side of the membrane than on the other.
an ionic bond is formed by
b. transfer of an electron from one atom to another
Which of the following is the simplified and balanced equation for the generation of sugar from sunlight, water, and CO2?
c. 6 CO2 + 6 H2O--> C6H12O6 + 6 O2
Thinking about the environments where plant and animal cells typically exist, which of the following statements is correct?
c. Animal cells are generally in an isotonic solution, and plant cells are generally in a hypotonic solution.
Which step below would be the final step in a signal transduction pathway
c. Change in gene expression.
Which of the following best describes an advantage that eukaryote organisms have over prokaryote organisms?
c. Eukaryotes have organelles that allow for compartmentalization of cellular processes, which increases the efficiency of those processes.
A given organism has 46 chromosomes in its karyotype. Which of the following statements is correct regarding this organism?
c. Its gametes must have 23 chromosomes.
If a cell is making a protein that is then going to be modified and packaged for export out of the cell, what is the order of structures it will most likely pass through?
c. Rough ER; Golgi apparatus; vesicle
Which of the following is true for all exergonic reactions?
c. The reaction proceeds with a net release of free energy.
Which of the following is (are) true for anabolic pathways?
c. They consume energy to build up polymers from monomers.
Mammalian blood contains the equivalent of 0.15 M NaCl. Seawater contains the equivalent of 0.45 M NaCl. What will happen if red blood cells are transferred to seawater?
c. Water will leave the cells, causing them to shrivel and collapse.
Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. This cell is most likely
c. a plant cell in the process of cytokinesis.
Reactants capable of interacting to form products in a chemical reaction must first overcome a thermodynamic barrier known as the reaction's
c. activation energy.
An integral membrane protein would have to be
c. amphipathic, with at least one hydrophobic and one hydrophilic region.
Which of the following groups of cellular components are found in eukaryotic cells but NOT prokaryotic cells?
c. an endoplasmic reticulum, mitochondria, and a nucleus
Which phase of meiosis is represented in the figure above?
c. anaphase I
If the cell whose nuclear material is shown in Figure 12.2 continues toward completion of mitosis, which of the following events would occur next?
c. formation of telophase nuclei
The portion of a (biological) system's energy that is available to do work is called
c. free energy
The extracellular matrix of animal cells
c. helps orient cell movements during embryonic development.
Which of the following is represented by letter A
c. ligand
Hydrophobic substances such as vegetable oil are
c. nonpolar substances that repel water molecules.
The difference between pinocytosis and receptor-mediated endocytosis is that
c. pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis is highly selective.
If chiasmata can be seen in a cell under a microscope, which of the following meiotic processes must have occurred?
c. prophase I
Prokaryotic and eukaryotic cells generally have which of the following features in common?
c. ribosomes
Movement of the chromosomes during anaphase would be most affected by a drug that prevents
c. shortening of microtubules.
What is the primary function of the Calvin cycle?
c. synthesize simple sugars from carbon dioxide
Which of the following transport mechanisms will be affected most directly by a temporary shortage of ATP molecules inside the cell?
c. the transport of glucose molecules against a concentration gradient
Which of the following statements describes a primary function of both alcohol fermentation and lactic acid fermentation?
c. to oxidize NADH to NAD+
how would you categorize the molecule in the picture above
carbohydrate and disaccharide only
short term energy storage
carbohydrates
makes up the cell walls of plants
carbohydrates (cellulose)
all organic compounds contain
carbon
C=O
carbonyl
what is the name of the highlighted functional group in the examples above
carbonyl
-COOH
carboxyl
Which two functional groups are always found in amino acids?
carboxyl and amino
A rigid outer layer that maintains the shape of plant cells.
cell wall
Which of the following is depicted in the picture?
cholesterol
Found in some animal cells; Hair-like projections that can "beat" to cause an organism to move through a fluid
cilia
a carbon atom is most likely to form which of the following bonds with other atoms
covalent bonds
Proteins that are involved in the regulation of the cell cycle, and that show fluctuations in concentration during the cell cycle, are called
cyclins
If there are 20 sister chromatids in a cell, how many centromeres are there
d. 10
The light reactions of photosynthesis provide the Calvin cycle with
d. ATP and NADPH.
Which is the correct order of the stages depicted in the diagrams above?
d. B, C, A, D
You have isolated DNA from three different cell types of an organism, determined the relative DNA content for each type, and plotted the results on the graph shown in the figure above. Which sample(s) of DNA might be from a germ cell arrested in prophase I of meiosis?
d. II
For a chemotherapeutic drug to be useful for treating cancer cells, which of the following is most desirable?
d. It targets only rapidly dividing cells.
A _________________ is a membrane receptor with a region that can act as a gate for ions, opening or closing the channel when the receptor assumes alternative shapes.
d. Ligand-gated ion channel
In addition to ATP, what are the products of glycolysis?
d. NADH and pyruvate
If a plant cell with a water potential of -1.5 bars is placed in a beaker of sugar water with a water potential of -4.0 bars. In which direction will the net flow of water be?
d. Outside the cell
The following questions refer to an experiment in which a dialysis- tubing bag is filled with a mixture of 3% starch and 3% glucose and placed in a beaker of distilled water, as shown below. After 3 hours, glucose can be detected in the water outside the dialysis-tubing bag, but starch cannot. Which of the following best describes the condition expected after 24 hours?
d. The bag will contain more water than it did in the original condition
Which of the following best explains how the phospholipid bilayer of a transport vesicle contributes to cellular functions?
d. The phospholipid bilayer allows the vesicle to fuse with the Golgi apparatus and the plasma membrane, allowing the exocytosis of proteins
Which of the following is (are) true for anabolic pathways?
d. They consume energy to build up polymers from monomers.
If a hospital patient is mistakenly given an IV of pure water instead of a saline solution (isotonic to blood) the patient's red blood cells will
d. absorb water and eventually burst.
At the end of G1 phase of the cell cycle, a cell can "exit" the cell cycle
d. all of the above
At the end of G1 phase of the cell cycle, a cell can "exit" the cell cycle and enter G0
d. all of the above
Which term most precisely describes the cellular process of breaking down large molecules into smaller ones?
d. catabolism
During which process does independent assortment of chromosomes occur?
d. during meiosis I only
The data were obtained from a study of the length of time spent in each phase of the cell cycle by cells of three eukaryotic organisms designated beta, delta, and gamma. Of the following, the best conclusion concerning the difference between the S phases for beta and gamma is that
d. gamma contains more DNA than beta.
Which process in eukaryotic cells will proceed normally whether oxygen (O2). is present or absent?
d. glycolysis
conversion of liquid water to water vapor requires which of the following types of bonds between the molecules
d. hydrogen bonds
The !rst pathway/stage of photosynthesis, in which light energy is converted into chemical energy in the form of ATP and NADPH, is referred to as the
d. light-dependent reactions
What term best describes the name of the stage shown in part C of the diagram above?
d. metaphase
In Figure 5.5, the dots in the space between the two structures represent which of the following types of molecules?
d. neurotransmitters
The secretion of a signal molecule by a cell into the local environment, followed by a response by a number of cells in the immediate vicinity, is an example of
d. paracrine signaling.
What kinds of molecules pass through a cell membrane most easily?
d. small hydrophobic
Where do the light-reactions take place?
d. thylakoid membrane
Which of the following reactions tend to require an input of energy?
dehydration
what is a common chemical reaction mechanism by which cells make polymers from monomers
dehydration reactions
which of the following best summarized the relationship between dehydration reactions and hydrolysis
dehydration reactions assemble polymers, and hydrolysis reactions break down polymers
what structural feature makes the 20 common amino acids different from one another
different side chains (R groups) attached to an alpha carbon
which of the following chemical equation describes a hydrolysis reaction
disaccharide + H2O = monosaccharide + monosaccharide
Most cells are small because
e. a larger surface area-to-volume ratio increases the efficiency of processes within the cell.
Chemiosmosis in chloroplasts involves which of the following processes?
establishment of a proton gradient across the thylakoid membrane
Which of the following is depicted in the picture?
glycoprotein
After telophase I of meiosis, the chromosomal makeup of each daughter cell is
haploid, and the chromosomes are each composed of two sister chromatids.
which of the following is a characteristic of hydrophilic substances
have charges or partial charges to which water molecules adhere and are attracted to
in an aqueous solution, water molecules associate with one another through which of the following
hydrogen bonds
-OH
hydroxyl
what is the name of the functional group highlighted in the molecule above
hydroxyl
which of the following allows for life to exist under a frozen lake
ice floats
Retinoblastoma protein (Rb) and p53 are both examples of __________ proteins because they suppress or prevent the the development of tumors by keeping cell division in check.
inhibitory
which of the following statements is true regarding cellulose
it is a primary structural component of plant cell walls
Which of the following enzymes adds a phosphate group to target proteins in signal transduction pathways that involve a phosphylation cascade?
kinase
involved in the formation of cell membranes
lipids
long term energy storage
lipids
Digestive organelle where macromolecules are broken down.
lysosome
Which phase of meiosis is represented in the figure above?
metaphase II
-CH3
methyl
what is the name of the functional group in the picture above
methyl
which of the following common functional (chemical) groups is hydrophobic and non-reactive due to its non-polar nature
methyl
Cell division occurs during
mitosis
scientist examined the folded structure of a purified protein resuspended in water and found that amino acids with nonpolar R groups were primarily buried in the middle of the protein, whereas amino acids with polar R groups were primarily on the surface of the protein. Which of the following best explains the location the amino acids in the folded protein
nonpolar R group that cannot form hydrogen bonds with water are pushed into the middle of the protein
what type of molecules are pictured below
nonpolar amino acids
A chemical reaction that has a positive ΔG (ΔG>0) is correctly described as
nonspontaneous
carries the genetic code for making proteins
nucleic acid
identify the types of biomolecules pictured below
nucleic acid
stores genetic information
nucleic acid
Surrounded by and envelope and stores DNA in the eukaryotic cell.
nucleus
a covalent bond is likely to be polar when
one of the atoms sharing electrons is much more electronegative than the other atom
the tertiary structure of a polypeptide is the
overall three-dimensional shape of a fully folded polypeptide
-OPO32-
phosphate group
DNA and RNA differ on many qualities, which of the following is not a difference
phosphate group
describe the orientation of the phospholipids in the membrane
phospholipids orient in bilayer with hydrophilic heads on exterior
in a single molecule of water, two hydrogen atoms are bonded to a single atom by
polar covalent bonds
Based on your knowledge of the polarity of water molecules, the solute molecule depicted in Figure 2.7 is most likely
positively charged
which level of protein structure involves the peptide bonds between amino acids
primary
biological catalysts; selective acceleration of chemical reactions
proteins
responsible for growth, maintenance, and regulation of cells
proteins
Located outside rough ER; functions in protein synthesis
ribosome
What diagnostic procedures can a karyotype be used for?
screening for defective or abnormal numbers of chromosomes in an individual
a covalent bond is formed by
sharing of a pair of electrons between two atoms
the two molecules shown in Figure 3.1 are best described as
structural isomers
-SH
sulfhydryl
Which of the following types of signaling is represented in the figure?
synaptic
Adhesion is best described as
the clinging of one substance to another
Carrot slices placed in a 0.2 M salt solution for several hours become flaccid (limp). Carrot slices placed in fresh water for several hours become turgid (stiff). From this we can deduce that
the fresh water is hypotonic and the salt solution is hypertonic to the cells of the carrot slices.
which statement best helps explain the formation of the hydrogen bond represented in the figure
the nitrogen has a partial negative charge, and the hydrogen attached to the oxygen has a partial positive charge
the chemical behavior of an atom depends primarily upon which of the following
the number of electrons in the valence shell
Independent assortment of chromosomes during meiosis is a result of
the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I.
which of the following statements is true of both starch and cellulose
they are both polymers of glucose
which of the following statements concerning saturated fats is true
they are generally solid at room temperature
Where are ATP synthase complexes located in a plant cell?
thylakoid membranes and inner mitochondrial membranes
The primary function of G proteins in signal transduction is
transmitting the signal from an activated receptor to the next protein in the pathway.
A large percentage of patients that develop colon cancer do so because of a mutation in the APC gene of the stem cells.
true
A research team began a study of a cultured cell line. Their preliminary observations showed them that the cell line did not exhibit either density-dependent inhibition or anchorage dependence. What could they conclude right away?
tumor/cancer
the molecule shown in Figure 3.9 is an
unsaturated fatty acid
An enzyme-catalyzed reaction was studied at 25°C and values for ΔG energy of activation, and turnover number measured as shown. If this reaction were carried out under the same conditions in the absence of the enzyme, how would these values di!er from those of the catalyzed reaction? *In enzymology, turnover number (also termed kcat) is de"ned as the maximum number of chemical conversions of substrate molecules per second that a single catalytic site will execute for a given enzyme concentration .
ΔG would be unchanged, energy of activation would be higher, and turnover number would be lower for the uncatalyzed reaction.
