General Biology 1005 - Exam 1
Chap 4 - The number of ATPs produced directly as a result of one turn of the citric acid cycle is
1 Extra info: Each turn of the citric acid cycle produces one ATP. Per glucose molecule, two ATPs are formed.
Chap 2 - Potassium, a metal with one electron in the outermost shell, will react with how many chlorine atoms? (Chlorine is a nonmetal with seven electrons in the outermost shell.)
1 Extra info: Potassium will attain stability by transferring the one electron in its outermost shell to chlorine, which needs only one more electron in its outermost shell to become stable. The result will be a potassium ion (K+) and a chloride ion (Cl-). The two oppositely charged ions will be attracted to one another, thus forming an ionic compound.
Chap 3 - If 0.9% NaCl were isotonic to a cell, then
1.0% would be hypertonic. Extra info: Since the 1.0% solution contains more NaCl than the 0.9% solution, it is hypertonic. Hypertonic solutions contain a higher concentration of solute than the cell.
Chap 5 - How many total carbons are involved in carbon dioxide fixation with 3 molecules of carbon dioxide and 3 molecules of RuBP?
18 Extra info: Carbon dioxide contains 1 carbon each while RuBP contains 5 carbons each, for a total of 18 carbons.
Chap 2 - If an element has an atomic number of 12, how many electrons are in its outermost shell?
2 Extra info: Two electrons fill the innermost shell and eight fill the next, leaving two for the outermost shell.
Chap 4 - How many molecules are formed from the cleavage of glucose during the first step of glycolysis? How many carbons are found in the resulting molecules?
2 molecules, each with 3 carbons Extra info: Glucose is a 6-carbon molecule. It is broken into two molecules of glyceraldehyde 3-phosphate, each with three carbons.
Chap 4 - Overall, the final products of glycolysis are
2 pyruvate, 2 ATP, and 2 NADH. Extra info: Glycolysis results in 2 ATP, 2 NADH + H+, and 2 pyruvate.
Chap 5 - In the Calvin cycle, the three-carbon molecule that will be immediately formed after carbon dioxide fixation occurs is
3-PGA Extra info: The first three-carbon molecule formed is 3PG (3-phosphoglycerate).
Chap 2 - One carbon atom can form covalent bonds with up to ________ other atoms to form an organic molecule.
4 Extra info: Carbon, with an atomic number of 6, has 4 electrons in its outermost shell. Thus, carbon can form 4 single covalent bonds with other atoms.
? Which of the following organisms do not have a dependence on photosynthesis for their energy?
? All of the answer choices will have a dependency on photosynthesis.
? Enzymes maintain their same shape when they bind to a substrate.
? False
? The nucleus of an atom contains
? Protons and neutrons
? Determine what would happen to an individual's proteins if they developed a fever of 103∘ F for several days.
? The proteins would denature due to the increase in body temperature and would become unable to function correctly.
? The body temperature in humans is maintained around 37°C. Which characteristic of life does this information represent?
? homeostatic
? The water strider is an insect that skates across the water without sinking. The tips of its feet must be coated with molecules that are
? hydrophobic
? The "powerhouse" of the cell is the
? mitochondria.
? A piece of petrified wood was once part of a living organism that has had its tissues replaced by minerals. Which property of life will still be present in the wood?
? organization
? Enzymes are organic compounds classified as
? proteins
?When a plant cell is placed in a hypotonic solution, the cell wall prevents
? the cell from bursting.
Which statement regarding the scientific method is false?
A control group is always exposed to the factor being tested. Extra info: An experimental group, not a control group, is always exposed to the factor being tested. All the other answer choices are accurate statements.
Chap 3 - Which of the following events would increase the cell's ability to exchange materials across the membrane?
A, B, and C would increase the cell's ability to exchange materials across the membrane. Extra info: All of these events would increase the cell's ability to exchange materials across the membrane.
Chap 4 - ATP can be broken down into
ADP plus phosphate plus energy. Extra info: ATP is broken down into ADP plus phosphate plus energy.
Chap 4 - The "energy currency" of the cell is ___.
ATP
Chap 5 - Some herbicides inhibit the electron transport chain in the thylakoid membrane. Without the movement of electrons, hydrogen ions would not be pumped from the stroma to the thylakoid space and the hydrogen ion gradient would not be established. How would this affect the Calvin cycle reactions?
ATP would not be produced and, as a result, the Calvin cycle reactions would not occur. Extra info: The electron transport chain produces ATP. Without ATP the Calvin cycle reactions would not run.
Chap 2 - Which statement regarding acids and bases is correct?
Acids increase the proportion of hydrogen ions (H+), and bases reduce the proportion of H+. Extra info: Acids raise the hydrogen ion (H+) content of a solution, while bases reduce the proportion of H+. The lower the pH, the more acidic the solution, and the higher the pH, the more basic the solution. Strong acids and bases are both harmful. When acids combine with bases, salts result.
Chap 4 - Which is true about energy of activation?
Adding the correct enzyme can lower the energy of activation. Extra info: The energy of activation is the energy that must be overcome for a reaction to proceed. Enzymes lower this energy of activation. Free energy is the difference between the energy of the reactant and the energy of the product.
Chap 4 - Which of the following is NOT an example of an energy transformation?
All of these are examples of energy transformations. Extra info:
A fox belongs to the kingdom ___.
Animalia
Which statement regarding applied science (= technology) is false?
Applied science is a basis for all ethical or moral decisions. Extra info: Science technology is morally and ethically neutral, and can be used for benefit (as in understanding cancer, producing better food sources, and developing antibiotic drugs), or for harm (such as damage to the environment). Thus, science technology cannot serve as a basis for all ethical and moral decisions. Such decisions must be made by all people, not just scientists. Scientific experimentation may be guided by morals and ethics, as in using a cell culture or animal as a model for a new drug or procedure before testing it on humans.
Which domains contain organisms that lack a membrane-bound nucleus?
Archaea and Bacteria Extra info: The domains Archaea and Bacteria both contain organisms that lack a membrane-bound nucleus. Domain Eukarya contains organisms that have a membrane-bound nucleus. Animalia is not a domain.
Chap 4 - While eating a container of yogurt, you have to leave, so you store the yogurt in the refrigerator. A day later you return and find the surface of the yogurt is no longer smooth but has broken into several liquified products. You correctly guess that enzymes from your saliva, via the spoon, have continued digesting the yogurt in your absence. What will happen over time?
As long as the enzyme is not denatured by environmental conditions, the reaction will continue until all of the substrate is used up. Extra info: Enzymes continue to function until all of the substrate is converted into product. The enzymes you introduced in your saliva would continue to digest the sugars in the yogurt until all the sugars were gone.
Chap 5 - Which of the following is NOT a characteristic shared by cellular respiration and photosynthesis?
Both processes produce oxygen. Extra info: Photosynthesis produces oxygen, while cellular respiration produces carbon dioxide.
Chap 5 - Which of the following statements comparing the ATP synthase complex in cellular respiration and photosynthesis is not true?
Both require the movement of H+ from inside a compartment to outside of the compartment. Extra info: In photosynthesis, the H+ move from inside the thylakoid space to outside while in cellular respiration, the H+ move from outside the matrix inside.
Chap 5 - In what ways are photosynthesis and cellular respiration not alike?
Both will use the electron carrier NADH. Extra info: Cellular respiration requires the electron carrier NADH, while photosynthesis requires NADPH.
Chap 5 - Which of the following is a substrate in the photosynthesis equation?
CO2 Extra info: The substrates of photosynthesis include CO2 and H2O. C6H12O6 and O2 are the end products of the reaction.
Chap 5 - Which part of photosynthesis does not occur inside the thylakoid membrane?
Calvin cycle reactions Extra info: The Calvin cycle reactions occur within the stroma of the chloroplast. All of the others occur in the thylakoid membrane.
Chap 5 - NADPH and ATP are used in the
Calvin cycle reactions. Extra info: The NADPH and ATP generated in the light reactions are used by the Calvin cycle reactions to produce carbohydrates.
Chap 2 - ________ is a polysaccharide that is found in plant cell walls and accounts for their strength.
Cellulose Extra info: Cellulose is a structural polysaccharide found in plant cell walls. Starch and glycogen are storage forms of glucose found in plants and animals, respectively. Chitin is a polysaccharide found in the cell walls of fungi and the exoskeletons of arthropods. DNA is a nucleic acid, not a polysaccharide, and is found in cell nuclei.
Which statement is false regarding science?
Correct scientific conclusions are permanent and never subject to change or refinement. Extra info: Scientific conclusions are always subject to change and refinement. All of the other statements are accurate.
Which of the following domains contains organisms that are adapted to life in harsh environments?
Domain Archaea Extra info: The domain Archaea contains organisms that can survive in harsh environments. Domain Bacteria contains organisms that can be found everywhere but tend not to be in harsh environments. Domain Eukarya contains the plants, animals, fungi, and protists which are not adapted to harsh environments either. Animalia and Plantae are not domains.
Chap 5 - Which of the following statements is false?
During photosynthesis, oxygen is used. Extra info: During photosynthesis, oxygen is produced
Chap 4 - In cellular respiration, what is the relationship between the energy content of the reactants (glucose and O2) and products (CO2 and H2O)?
Each turn of the citric acid cycle produces one ATP. Per glucose molecule, two ATPs are formed. Extra info: Glucose is a high-energy molecule while carbon dioxide is low energy. The energy content of the reactants is greater than that of the products because ATP is formed.
Chap 4 - Which of the following statements most accurately describes the first law of thermodynamics?
Energy can be neither created nor destroyed but it can be changed from one form to another. Extra info: The first law is the law of conservation of energy. It states that energy cannot be created or destroyed, but it can be changed from one form to another.
Which of the following is one of the domains of life?
Eukarya Extra info: Eukarya is a domain of life. Animalia, Protista, and Fungi are all kingdoms of life. Molds is not a level of scientific classification.
Chap 4 - Which of the following is consistent with the laws of physics governing energy?
Eventually, sunlight that is absorbed on the earth returns to the atmosphere as dispersed heat. Extra info: Energy does not cycle through the environment. All of the energy that is absorbed on Earth will eventually be lost as heat back into the atmosphere. No conversion of energy is 100% efficient so none of the other answers are possible.
Which of these is an example of inductive reasoning used to form a hypothesis?
Every fungus that has ever been studied absorbs its food; therefore, food absorption is characteristic of fungi.
Chap 4 - The final product of glycolysis is oxygen.
Fales Extra info: The final product of glycolysis is pyruvate.
Chap 4 - Because the inside of a cell is more organized than the outside, the inside of the cell has increased entropy.
Fales Extra info: Increased organization means decreased entropy.
Chap 4 - A reactant will always produce the same type of product, regardless of the enzymes present.
False Extra info: A particular reactant can be a substrate for various enzymes, each resulting in a different product.
Chap 4 - The only end product of alcoholic fermentation is the alcohol.
False Extra info: Carbon dioxide is produced along with the alcohol.
Chap 5 - Only organisms with chloroplasts are capable of photosynthesis.
False Extra info: Cyanobacteria do not have organelles, yet they carry on photosynthesis. They do have thylakoids.
Chap 4 - Since enzymes are not used up during a reaction, they do not play any role in the reaction.
False Extra info: Enzymes are not used up in the reaction. Instead, they play an active role in increasing the rate at which the reaction occurs. They are also reusable.
Chap 3 - Exocytosis is carried out by proteins in the cell membrane.
False Extra info: Exocytosis and endocytosis involve a vesicle fusing with or being released from the plasma membrane, so phospholipids are also involved in these two processes.
Chap 4 - There is a net gain of four ATPs as a result of glycolysis.
False Extra info: Four ATPs are formed from glycolysis, however two ATPs are used to activate the glucose, resulting in a net gain of only two ATP.
Chap 4 - Heat is not a form of energy.
False Extra info: Heat is not a usable form of energy once it dissipates into the environment, but it is a form of energy.
Chap 3 - Because mitochondria were once independently living prokaryotic cells, if removed from a eukaryotic cell they can survive independently.
False Extra info: Mitochondria have now evolved to be totally dependent on the nucleus of the eukaryotic cell for many of the proteins and genes necessary for mitochondrial structure and function.
Chap 5 - At night, plants cannot run metabolic pathways because there is no sunlight.
False Extra info: Plants carry out cellular respiration at night. They cannot carry out the light reactions of photosynthesis without sunlight, but they carry out other chemical reactions.
Chap 3 - According to the endosymbiotic theory, eukaryotes became the mitochondria and chloroplasts found in prokaryotic cells.
False Extra info: Prokaryotic cells do not contain mitochondria and chloroplasts. The endosymbiotic theory proposes that prokaryotic cells became the mitochondria and chloroplasts found in eukaryotic cells.
Chap 5 - In the process of photosynthesis, the light reactions follow the Calvin cycle reactions.
False Extra info: The light reactions occur first. This provides the energy for the Calvin cycle reactions.
Chap 3 - The primary plant cell wall and the bacterial cell wall are both composed of peptidoglycan.
False Extra info: The primary plant cell wall is not composed of peptidoglycan.
Chap 4 - Heat is not a form of energy.
False Extra info: Heat is not a usable form of energy once it dissipates into the environment, but it is a form of energy.
Chap 4- All of the energy that a plant stores in the bonds of glucose are available to an animal to power its muscles.
False Extra info: No, some of the energy is lost as heat, so not all of the energy is available.
Chap 4 - All of the ATP molecules formed by the complete oxidation of glucose result from the electron transfer chain.
False Extra info: Some of the ATP come from glycolysis and the citric acid cycle.
Chap 5 - Photosynthesis and cellular respiration utilize the same chemical pathways but in reverse of each other.
False Extra info: The chemical equation for photosynthesis and cellular respiration are the reverse of each other, but the pathways are not the same.
Chap 5 - Photosystem I comes before photosystem II in the electron transport chain of photosynthesis.
False Extra info: The photosystems were named for the order in which they were discovered, not the order in which they participate in photosynthesis. Photosystem II comes before photosystem I.
Chap 4 - Which of the following statements about fermentation is not true?
Fermentation involves the citric acid cycle. Extra info: Fermentation does not use the citric acid cycle.
Chap 5 - What is the molecule that leaves the Calvic cycle to be converted into glucose?
G3P
Which of these classification categories contains the closest related group of organisms?
Genus. Extra info: Members of closely related species are grouped into the same genus. The categories listed, from the greatest to least degree of relatedness of organisms, are: genus, family, phylum, kingdom, and domain.
Chap 3 - Which cellular structure is responsible for packaging materials with the cell?
Golgi apparatus Extra info: The Golgi apparatus collects, sorts, packages, and distributes materials such as proteins and lipids. The other organelles are involved in different functions.
Chap 5 - We set up an experiment where the same species of plant is grown in boxes covered with plastic that only allows a single color of light through. In which box would we expect the least plant growth and even perhaps the death of the plant to occur?
Green Extra info: White light is a combination of all the colors so it would allow the plants to grow. Chlorophyll absorbs light in the indigo, blue, violet, and red region so those colors would allow the plant to grow. Chlorophyll does not absorb green light so that plant would not be able to photosynthesize and might die.
Chap 2 - Which functional groups are associated with a dehydration reaction?
H and OH Extra info: H and OH are associated with the dehydration reactions.
Chap 2 - Which of the following molecules is NOT a compound?
H2 Extra info: A compound consists of atoms of two or more different elements bound together; H2 is two molecules of the same element (hydrogen) bound together.
When you are overheated, you perspire, and when you are too cold, you shiver to generate heat. Which property of life is best represented by this example?
Homeostasis is the body's physical and physiological responses to changing conditions over a short period of time.
Chap 2 - Which of the following statements about hydrogen bonding is incorrect?
Hydrogen bonding occurs only between water molecules. Extra info: Hydrogen bonding is not limited to bonding between adjacent water molecules. For example, hydrogen bonds can form between hydrogen in water and nitrogen in ammonia, or between the two strands of a DNA molecule. Hydrogen bonds are important in determining the shape of large, complex molecules such as proteins. Even so, hydrogen bonds are relatively weak when compared to ionic or covalent bonds, and are easily broken.
Which statement regarding the scientific method is false?
Hypotheses are finally proven as absolutely true or false. Extra info: Hypotheses are always subject to repeated testing because they are not absolutely provable. This is because, in experiments to test a hypothesis, there is always the possibility of inaccuracy. All the other answer choices are true statements.
Of the following, which is the testable answer to a question? (It is sometimes called an "educated guess.")
Hypothesis
Chap 2 - Which of the following is not a property of water that results from hydrogen bonding?
Ice melts at -100°C. Extra info: Due to its hydrogen bonding, water melts at 0°C instead of -100°C. All the other answer choices are accurate statements.
The type of logical thinking that uses related observations to arrive at a general conclusion is called ___.
Inductive reasoning
Chap 5 - What is the function of ribulose bisphosphate (RuBP) during photosynthesis?
It combines with CO2 to produce a 6-carbon compound. Extra info: RuBP joins with carbon dioxide during the first step of the Calvin cycle, carbon dioxide fixation, to form three 6-carbon molecules.
Chap 4- What role does NAD+ play in cellular respiration?
It is an electron carrier. Extra info: NAD+ is a coenzyme which functions as an electron carrier.
Chap 3 - Which of the following is not a function of the cell membrane?
It serves as a site for protein synthesis. Extra info: The endoplasmic reticulum is the site for protein synthesis.
Chap 5 - What is the value of photosynthesis to humans?
It will reduce the amount of carbon dioxide in the atmosphere. Extra info: Photosynthesis will reduce the amount of carbon dioxide in the atmosphere and form sugars and oxygen. The reduction of carbon dioxide in the atmosphere will help reduce climate change.
Chap 3 - Which of the following is not true concerning the cell theory?
Leeuwenhoek first used the term "cells." Extra info: All of the statements are true except Hooke, not Leeuwenhoek, was the first to use the term "cells" because the tiny chambers he observed in cork reminded him of the rooms, or cells, in a monastery.
Chap 3 - Which statement is false concerning movement of molecules across the cell membrane?
Lipid molecules do not pass through easily. Extra info: The membrane is differentially permeable. Lipids, small uncharged molecules, water, and gases have no difficulty passing through the membrane. Charged molecules do not pass through easily.
Which statement about living organisms is not correct?
Living organisms create energy. Extra info: Living organisms cannot create energy. Instead, they convert it from one form to another. It will then be used to maintain homeostasis, reproduce, and adapt, as well as grow and develop.
Nutrient molecules are used to build cellular structures or for energy. This best represents which characteristic of life?
Living things acquire materials and energy from the environment. Extra info: The ability to acquire materials and energy from the environment is crucial to all the other activities of living organisms, including homeostasis, adaptation, growth and development, and responses to stimuli.
Chap 5 - Which cofactor is involved in the Calvin cycle reactions?
NADP+ Extra info: NADP+ is the cofactor involved in the Calvin cycle reactions.
Which of the following statements is based on scientific observation and reasoning?
Objects fall downward anywhere on the earth's surface, regardless of the observer. Extra info: Science seeks to formulate laws that objectively explain natural phenomena, as when objects fall due to gravity. Natural phenomena operate on a cause-and-effect basis and have consistency of outcome that is not influenced by human cultures or the presence of human observers. Scientists must be conscientious in recording all data, not just those which are easiest to interpret.
Which statement regarding the scientific method is false?
Original hypotheses are formed after an experiment. Extra info: Original hypotheses are formed prior to an experiment, through inductive reasoning based on observations. Inductive reasoning is the process of taking individual observations and weaving them into a cohesive explanation. In a controlled experiment, the control and experimental groups should be the same except for a single factor, called a variable. Experiments should be repeatable, even by different individuals in different places.
Chap 4 - Pyruvate can be converted to lactate instead of going to the formation of acetyl CoA. Why does this occur?
Oxygen is not available. Extra info: Pyruvate is converted into lactate during fermentation, which occurs when oxygen is not available.
Chap 5 - Which statement about photosynthesis and cellular respiration is true?
Photosynthesis produces oxygen, while cellular respiration uses oxygen. Extra info: It is true that photosynthesis produces oxygen, while cellular respiration uses oxygen. Photosynthesis does not produce water, does not occur in the mitochondria, does not break down carbohydrates, and does not require oxygen.
All the banded sunfish (Enneacanthus obesus) in a pond would comprise a(n)
Population. Extra info: A species is a category of organisms within the same genus that share very similar characteristics. Banded sunfish (Enneacanthusobesus) are a species. A population is all the members of a given species within a particular area, as in the example of all the banded sunfish in one pond. All the different populations in the same area make up a community. A community together with its physical environment makes up an ecosystem. The biosphere is the zone of air, land, and water on the earth where living organisms are found.
Chap 5 - Which statement about producers (= autotrophs) and/or consumers (= heterotrophs) is true?
Producers produce more food than they use. Extra info: Producers produce more food than they use, which then provides foods for the consumers.
Chap 4 - Why is cellular respiration organized into four phases?
So that the energy within the glucose molecule can be released in a stepwise fashion. Extra info: The four phases of cellular respiration allow the energy of the glucose molecule to be released in a stepwise fashion and converted into ATP. If the breakdown occurred all at once, most of the energy would be released as heat. The body can make ATP from different substrates but that is not the reason for the phases.
Chap 2 - Which of the following statements is NOT true of chemical bonds?
Table salt (NaCl) is covalently bonded. Extra info: Salts, such as sodium chloride (NaCl), are ionic compounds. All the other answer choices are accurate statements.
Chap 4 - During an enzymatic reaction, what happens to the enzyme?
The enzyme and the substrate form a temporary complex. Extra info: The enzyme and the substrate form a temporary enzyme-substrate complex, which is broken down to release the enzyme unchanged and the product. The enzyme is not used up by the reaction.
Which statement concerning reproduction is false?
The offspring of multicellular organisms tend to be identical to the parent. Extra Info: Multicellular organisms generally use sexual reproduction, in which each parent contributes to the genetic makeup of the offspring; thus, the offspring is not genetically identical to either parent.
Chap 2 - Rain falling in the northeastern U.S. has a pH between 5.0 and 4.0. Normally, rainwater has a pH of about 5.6. Which of the following statements is not correct?
The pH of the rainwater has changed from neutral to acidic. Extra info: The pH of rainwater is normally acidic (5.6) not neutral (7). All the other answer choices are accurate statements.
Chap 4 - While eating some yogurt, you have to leave and accidentally leave it sitting on the table. A day later you return and find the surface of the yogurt is no longer smooth but has broken into several liquefied products. You correctly guess that enzymes from your saliva, via the spoon, has continued digesting the yogurt in your absence (since enzymes are not used up during the digesting process). What will happen over time?
The reaction will continue until all the substrate is used and the enzyme will still remain.
Which statement regarding the scientific method is false?
Theories formed in everyday life carry the same validity as a scientific theory. Extra info: In everyday life, the word theory is used as a synonym for speculation. But in science, a theory grows from a hypothesis that has withstood repeated testing and consistently explains many observations. Hypotheses can be testing in various ways, but one of the most common is controlled experiments, in which only one variable is studied. Scientists know about one another's studies through publication; this enables them to test hypotheses by repeating experiments.
Which of the following is a potential consequence if people stop using applied science in the agriculture industry?
There could be a significant decrease in the amount of food produced. Extra info: If the agriculture industry stops using technology the most likely consequence will be a significant decrease in the amount of food produced. Ecosystems will flourish with a decrease in technology which will then make it easier for the top level species to survive. Unfortunately, the amount of food produced would decrease.
Which of the following might plausibly be said by a scientist?
There is always a possibility that a more advanced experiment might falsify any hypothesis. Extra info: Hypotheses are always subject to additional testing; they are only conditionally accepted or rejected. If two individuals performing the same experiment obtain different results, this would fail to support the hypothesis. Test methods are important because they may influence the results obtained. Scientific endeavors do not end with obtaining results and a conclusion; researchers share their results via publications and meetings.
Chap 4 - Which of the following is not true about enzymes?
They are consumed by the reactions they catalyze.
Chap 4 - Which of the following statements is true about enzymes?
They catalyze only one specific type of reaction. Extra info: Enzymes are specific for their substrate and only perform one type of reaction. They are affected by temperature and pH. An enzyme with an altered 3D shape will not bind its substrate.
Chap 3 - What property of phospholipids makes them suitable for the formation of the double layer found in membranes?
They have both a hydrophobic and a hydrophilic end. Extra info: Because phospholipids have both a hydrophobic and a hydrophilic end, the hydrophobic ends interact to form a bilayer with the hydrophilic ends facing the exterior. Phospholipids are charged. The remaining statements are true but do not explain why phospholipids can form a bilayer.
Chap 5 - Why are plant leaves green?
They reflect green wavelengths of light. Extra info:Leaves reflect green light so they appear green to us.
Chap 3 - What will happen to dye crystals if placed in the bottom of a beaker of water over a long period of time?
They will diffuse equally throughout the beaker. Extra info: Since diffusion is the movement of molecules from an area of higher to lower concentration, the dye molecules will move around the beaker until they are evenly distributed. Active transport and osmosis both require a membrane.
Chap 5 - How many membranes does a chloroplast have?
Three Extra info: A chloroplast has three membranes: an outer and inner membrane and a thylakoid membrane.
Chap 3 - Since cyanobacteria do not contain chloroplasts and yet they photosynthesize, chloroplasts are not required for photosynthesis.
True Extra info: Although they do not have chloroplasts, cyanobacteria do have thylakoids. Therefore, thylakoids are required for photosynthesis.
Chap 3 - One way to determine whether something is being actively transported across a membrane is to compare its rate of transport with and without a chemical that blocks ATP production.
True Extra info: Because active transport requires energy, blocking ATP production would stop active transport. If the rate of transport did not change, then active transport is not involved.
Chap 4 - Pyruvate contains less chemical energy than glucose.
True Extra info: Glucose is broken down, releasing energy, during glycolysis. Therefore pyruvate does contain less energy than glucose.
Chap 4 - Fermentation follows glycolysis in some cells if oxygen is not available.
True Extra info: Glycolysis converts glucose to pyruvate. Pyruvate can either be fermented if oxygen is not available or enter the preparatory reaction if oxygen is available.
Chap 5 - There is an inverse relationship between wavelength of light and amount of energy.
True Extra info: The greater the wavelength, the less the energy. This is an inverse relationship.
Chap 3 - If a molecule crosses a plasma membrane faster than it diffuses in water, then the process is likely to involve active transport.
True Extra info: The only way a molecule can cross a membrane faster than diffusion is if it is actively being transported into the cell.
Chap 5 - Visible light has more energy than radio waves
True Extra info: Visible light is in the middle of the spectrum and contains more energy than radio waves.
Chap 4 - Less energy is needed to bring about a reaction when an enzyme is present.
True Extra info: An enzyme reduces the energy of activation for a reaction.
Chap 5 - At the base of most food chains are autotrophs.
True Extra info: Autotrophs produce their own food and are able to sustain themselves and all other living things on Earth.
Chap 4 - NADH and FADH2 bring electrons to the electron transport chain during cellular respiration.
True Extra info: Both NADH and FADH2 are electron carriers that bring electrons to the electron transport chain during cellular respiration .
Chap 3 - Since plant cells do not have centrioles, they are not required for all organisms to conductcell division.
True Extra info: Centrioles may be involved in microtubule assembly and disassembly in animal cells, but they are not required for cell division (mitosis and meiosis) in plant cells.
Chap 4 - When heat dissipates into the environment, it is no longer usable by the individual who produced it.
True Extra info: Once heat dissipates it is not available to do work for the individual who produced it.
Chap 3 - Which is a correct example of tonicity?
Turgor pressure is created when a plant cell swells in a hypotonic solution. Extra info: The definition of turgor pressure is correct. Water is hypotonic to red blood cells. Plasmolysis results from plant cells in hypertonic solutions. Crenated red blood cells result when placed in a hypertonic solution. If cells are placed in a hypertonic solution, water leaves the cell.
In the late 1800s, Louis Pasteur was searching for a vaccine for anthrax in livestock. One French veterinarian had a local reputation for being able to cure anthrax by applying oils and wrapping the animal in cloth to induce a fever. Pasteur also knew that some animals got well on their own when left untreated. Pasteur tested the effectiveness of the local veterinarian's methods by injecting four cattle with anthrax bacteria. He then directed the veterinarian to perform his procedures on two cattle. The other two cattle were left alone. What is the rationale for Pasteur's experimental design?
Two cattle represent a test of the treatment; two serve as a control to determine the likelihood of survival without treatment. Extra info: The two cattle left alone constitute a control group, since they were injected with anthrax but not subjected to the veterinarian's treatment; they are not intended to represent all the cattle in France. The other two cattle represent the test group, since they received both the anthrax injection and the veterinarian's treatment. The entire experimental design is based on deductive reasoning: If the veterinarian's treatment is more effective than lack of treatment, then the treated cattle should recover and the untreated ones should not.
? Which of the following is not a function of ATP within the cell?
WRONG - Energy currency of the cell
? Calcium chloride, CaCl2, is an ionic compound in which
WRONG - calcium has gained two electrons.
? The cholesterol synthesized by cells uses which component of the glycolytic pathway as a starting point?
WRONG - glucose
Chap 5 - At the base of most food chains are autotrophs.
Water Extra info: Water contains oxygen which is broken down during photosynthesis to produce oxygen gas.
Chap 2 - Hydrogen bonding produces which of the following properties of water?
Water is less dense as ice than as liquid water. Extra info: Due to the increased stability of hydrogen bonding at lower temperatures, water is less dense as ice than as liquid water. Water can absorb and release heat, but with a relatively small change in temperature. Due to hydrogen bonding, water boils at 100°C; without hydrogen bonding, it would boil at -91°C.
Chap 4 - We often say that we need food for energy. In a biological sense, is this correct?
Yes, because the food we eat has potential energy in its structure and this chemical energy can be converted into mechanical energy. Extra info: Food contains energy in the form of chemical bonds that is being stored. Our bodies break these bonds and utilize the energy.
Chap 3 - The term hypertonic means
a higher solute concentration. Extra info: Hyper- means "more than" and refers to a solution with a higher percentage of solute (lower concentration of water) than the cell.
Chap 3 - When you cut into most active plant tissue, water appears almost immediately because plant cells contain
a hypotonic solution that produces turgor pressure. Extra info: Plant cells are normally in a hypotonic solution and turgor pressure is the swelling of a plant cell in a hypotonic solution. When the cell is cut open, the pressure forces the water out.
Chap. 2 - If an element has an atomic number of 15, then
a neutral atom has 15 electrons. Extra Info: Feedback In an electrically neutral atom, the number of protons (the atomic number) is the same as the number of electrons. The atom would need three orbitals to accommodate 15 electrons, and there would be 5 electrons in its outermost shell. The atomic mass includes the protons and the neutrons; the number of neutrons is not specified in this question.
Chap 5 - Which of these is most closely associated with the process of electron transport?
a sequence of molecules in the membranes of the thylakoids Extra info: The electron transport chain consists of a series of electron carriers in the thylakoid membrane.
Chap 2 - A covalent bond is
a sharing of electrons between two atoms. Extra info: A covalent bond results when two atoms share electrons in such a way that each atom has eight electrons in its outermost shell. In contrast, ionic compounds result from the complete transfer of electrons between bonded atoms.
Chap 5 - To what does the term granum (plural = grana) refer?
a stack of thylakoid membrane structures Extra info: Grana are stacks of thylakoid membranes within the chloroplast.
Chap 2 - When two glucose molecules combine they form a disaccharide molecule and
a water molecule. Extra info: Glucose is a monosaccharide (a carbohydrate monomer); two glucose molecules combine to form a disaccharide, not a dipeptide or a lipid. In the process, a water molecule is released, which is why this is called a dehydration reaction.
Chap 4 - The location in which the enzyme and substrate complexes is called the
active site. Extra info: The enzyme and substrate will complex at the active site.
Chap 3 - The number of mitochondria in a cell would be a general indicator of the extent of
active transport. Extra info: Of the choices, only active transport requires energy. A high number of energy-producing mitochondria would suggest a cell that requires a lot of energy.
Chap 2 - Aspirin is acetyl salicylic acid and can therefore pose a problem to people who have ulcers. Bufferin is an alternative to aspirin that uses a buffer to neutralize this effect by
adding chemicals that take up excess hydrogen (H+) ions. Extra info: Bufferin contains a buffering system to bind the excess H+ from the aspirin (acetyl salicylic acid). This would not be a salt; salts form when acids and bases react.
Chap 3 - The cell theory states
all cells come only from other cells. Extra info: Cell theory states that all organisms are made up of basic living units called cells, and that all cells come only from previously existing cells. Many living organisms are multicellular and cells, not organelles, are the basic living unit. Whereas all multicellular organisms may begin as a unicellular organism at some point in their life cycle, this is not part of cell theory.
Chap 3 - One part of the cell theory states ___.
all living things are made of one or more cells
Chap 5 - The main function of stomata is to
allow passage of CO2 and O2 into the leaf. Extra info: The stomata are small openings in the leaf that allow the exchange of carbon dioxide and oxygen.
Chap 2 - The backbone of a nucleic acid strand is composed of
alternating pentose sugars and phosphate groups. Extra info: The backbone of a nucleic acid such as DNA is composed of alternating pentose sugars and phosphate groups. Glycerol is the backbone of a triglyceride. Although nitrogenous bases such as adenine and thymine are part of DNA, they do not make up the backbone. R groups are part of amino acids, not nucleotides.
Chap 2 - Organic molecules
always contain carbon (and usually hydrogen) Extra info:
You are conducting an experiment to determine which brand of fertilizer results in the greatest amount of fruit production by tomato plants. In this example, the response variable would be the
amount of fruit produced by the tomato plants. Extra info: The response (dependent) variable would be the amount of fruit produced, because this is the response to the different fertilizer varieties used. The fertilizer varieties would constitute the experimental (independent) variable, because this is the factor that the researcher is manipulating. It would be a good experimental design to have two groups of plants: a test group (fertilized plants) and a control group (unfertilized plants). To minimize the number of variables in the experiment, only one variety of plant should be used.
Chap 4 - ATP contains
an adenine base, a ribose sugar, and three phosphate groups. Extra info: ATP is adenosine (an adenine base plus a ribose sugar) plus three phosphates (triphosphate).
Chap 2 - Since pure water is neutral in pH, it contains
an equal number of hydrogen ions (H+) and hydroxide ions (OH-) Extra info: Pure water is neutral, with a pH of 7 (midway between 0 and 14 on the pH scale), meaning that it has equal concentrations of hydrogen ions (H+) and hydroxide ions (OH-).
Chap 4 - If there are 12 different intermediate products produced during production of a molecule in a cell, we can expect that there
are about 12 enzymes, at least one responsible for each step in the metabolic pathway. Extra info: Each step of a metabolic pathway must be carried out by a different enzyme. Therefore, if there are 12 intermediates, there must be 12 enzymes.
Heterotrophs
are ultimately dependent upon preformed organic molecules made by autotrophs. Extra info: Heterotrophs are also known as consumers. They must take in preformed organic molecules in order to survive.
Chap 4 - If an enzymatic reaction was controlled by feedback inhibition, we would expect it to stop
as soon as a critical level of end product builds up. Extra info: Feedback inhibition involves the binding of the end product of an active pathway to a site on the enzyme causing it to change shape.
Chap 3 - Which of the following cells were most likely the first type of cells on Earth?
bacteria Extra info: Bacteria were the first cell types to appear on Earth. Archaea are more closely related to eukaryotes, so it would indicate that they evolved after the bacteria. The rest of the groups are eukaryotic types of cells.
Chap 3 - Which of the following is a prokaryotic cell?
bacterium Extra info: Only a bacterium is a prokaryotic cell. Plants, animals (liver and muscle), and paramecia are all eukaryotes.
Chap 2 - Which of these combinations would be found in a nucleotide?
base-sugar-phosphate Extra info: A nucleotide is composed of a nitrogenous base, a pentose sugar, and a phosphate group. Adenine, thymine, and uracil are bases. Combining an acid and a base yields a salt. Sugars, proteins, and fats are all biological organic molecules. DNA and RNA are nucleic acids composed of nucleotides. Both are made in the nucleus of a cell.
Chap 4 - The various uses of ATP include all of the following except
being a structural component of the cell membrane. Extra info: ATP can do chemical, mechanical, and transport work. Moving substances into a cell is a type of transport work. ATP is not a structural component of the cell membrane.
The layer where organisms can exist on the surface of the earth is the
biosphere. Extra Info: The biosphere is the zone of air, land, and water on the earth where living organisms are found. An ecosystem is a community of organisms plus the non-living components of their environment. A community is a collection of populations of different species living in the same area. A population is a collection of members of the same species living in the same area. Homeostasis is the maintenance of a steady internal environment.
Chap 4 - Which stage(s) will produce carbon dioxide in cellular respiration?
both the formation of acetyl CoA and the citric acid cycle Extra info: Both the preparation reaction and the citric acid cycle produce carbon dioxide.
Chap 4 - Cellular respiration involves all of the following EXCEPT ___.
breathing in and out Extra info: Cellular respiration is the release of energy from molecules such as glucose accompanied by the use of this energy to synthesize ATP molecules. It is an aerobic process that uses oxygen and releases carbon dioxide. Do not confuse cellular respiration with the respiratory system.
Chap 2 - Calcium chloride, CaCl2, is an ionic compound in which
calcium has lost two electrons. Extra info: In the ionic compound CaCl2, calcium has transferred two electrons from its outermost shell, becoming a calcium ion (Ca2+). One of the electrons has been accepted by each chlorine atom, so they become chloride ions (Cl-).
Chap 2 - Maltose is classified as a
carbohydrate. Extra info: Maltose is classified as a carbohydrate due to its carbon and hydrogen backbone.
Chap 5 - The raw materials (or reactants) of the photosynthetic process include
carbon dioxide and water. Extra info: The chloroplast requires carbon dioxide and water for photosynthesis. Glucose and oxygen are the end products.
Chap 5 - The Calvin cycle reactions are dependent upon a supply of
carbon dioxide, NADPH, and ATP. Extra info: The Calvin cycle fixes carbon dioxide using NADPH and ATP so it needs all three molecules.
Chap 3 - Which is NOT a correct association of cell organelles and function?
cell wall - regulate molecule passage in and out of animal cells Extra info: The cell membrane, not the cell wall, regulates the passage of molecules in and out of animal cells.
The smallest unit that has all of the characteristics of life is the
cell. Extra info: The cell is the basic unit of life. Some organisms are single-celled; however, others are comprised of cells arranged into tissues, organs, and organ systems.
Which sequence correctly lists the different levels of biological organization, from the smallest and simplest to the largest and most complex?
cells-tissues-organs-organ systems-organisms
Chap 4 - The production of ATP as a result of an electrochemical gradient is called
chemiosmosis Extra info: Chemiosmosis is when ATP production is tied to an electrochemical gradient, as in mitochondria.
Chap 5 - The substance that initially traps solar energy in photosynthesis is
chlorophyll Extra info: Pigments, such as chlorophyll, capture solar energy.
Chap 3 - Which organelle will give off oxygen and use up carbon dioxide in plants?
chloroplasts Extra info: Chloroplasts give off oxygen and use up carbon dioxide during photosynthesis. Mitochondria will give off carbon dioxide and use up oxygen during respiration. The other organelles have different functions.
Chap 3 - Which of these is present in plant, but not animal, cells?
chloroplasts Extra info: Plants have chloroplasts but animal cells do not. Both plant and animal cells have a cell membrane, Golgi apparatus, and nucleus. Only animal cells have centrioles.
Chap 5 - Which two organelles are most directly involved in the flow of energy from the sun through all living things?
chloroplasts and mitochondria Extra info: Chloroplasts are involved in the capture of solar energy to form carbohydrates. Mitochondria are involved in the breakdown of carbohydrates to form ATP.
Chap 3 - Thylakoids and cristae are, respectively, structures of
chloroplasts and mitochondria. Extra info: Thylakoids are found in chloroplasts, while cristae are found in mitochondria.
Chap 3 - Which nuclear structure(s) contain(s) the hereditary material?
chromatin Extra info: Chromatin, housed within the nucleus, is composed of DNA and proteins and thus contains the hereditary structure. While the nuclear envelope and nucleoplasm are part of the nucleus, they do not contain DNA. The chloroplasts and mitochondria are not located within the nucleus.
Chap 3 - Which of the following structures are NOT found in the cytoplasm?
chromosomes Extra info: Chromosomes are found within the nucleus. Each of the others is found within the cytoplasm.
Chap 3 - In a certain group of people, males are more subject to respiratory infections and are sterile. The most likely explanation for this disease is malfunctioning
cilia and flagella. Extra info: The respiratory system uses cilia to keep the passageways clear while sperm use flagella to swim. There is most likely a problem with microtubule formation.
Chap 4 - Which pathway in cellular respiration will produce ATP, NADH2, and carbon dioxide?
citric acid cycle Extra info: Only the citric acid cycle produces all three products.
Chap 2 - You notice that rain water forms "beads" on your car. This is an example of what property of water?
cohesion Extra info: The formation of water beads on the surface of a car is due to the cohesiveness of water molecules for one another, thanks to hydrogen bonding. Adhesion is attraction of water molecules for a surface—a property that is not demonstrated here, since the surface of the car (especially a freshly waxed car) repels the water. The high heat of vaporization and solvent capabilities of water are not apparent in this example. Water does dissociate into ions, but this does not manifest in the formation of beads.
All the organisms of various species living within a given area constitute a(n)
community.
Chap 3 - The nucleolus
contains RNA and is found in the nucleus
Chap 4 - The main reason that ATP is considered the energy currency in cells is because it
contains accessible energy in phosphate bonds. Extra info: While ATP is small and does contain an adenine base and a sugar ring, these are not responsible for its energy-carrying capacity. That is a result of the energy within the phosphate bonds. ATP carries a negative charge.
Chap 4 - The ATP synthase complex is located in the
cristae of the mitochondria. Extra info: The ATP synthase complex is in the cristae of the mitochondria.
Chap 4 - Where does glycolysis take place within the cell?
cytoplasm Extra info: Glycolysis takes place within the cytoplasm.
Chap 3 - If cells were moved to a low-gravity environment, such as in space exploration, a change would most likely be expected in the
cytoskeleton. Extra info: Since the cytoskeleton is responsible for cellular movement, it would be most affected by a low-gravity environment.
Chap 2 - Two molecules of glucose combine to form a disaccharide molecule during a(n) ________ reaction.
dehydration Extra info: The glucose molecules are monomers; forming a covalent bond between them requires a dehydration reaction. A hydrolysis reaction could be used to break the disaccharide apart into individual glucose monomers. An inert material would not react at all.
Chap 2 - The final shape of a protein is very important to its function. When proteins undergo an irreversible change in shape called ________ they ________ perform their usual functions.
denaturation/cannot Extra info: Denaturation is when a protein loses its shape and cannot function. Although dehydration reactions do join amino acids together, this represents only the most basic (primary) level of protein structure.
Chap 3 - Which membrane transport process can continue whether the cell is alive or dead?
diffusion Extra info: Diffusion is the only process that does not require energy, so it would continue in a non-living cell.
Chap 3 - A student sitting on the back row opened a bottle of foul-smelling perfume and dabbed it on her wrists. One by one (beginning from the back of the room) the students began to cough due to the foul smell. This phenomena was due to
diffusion Extra info: Diffusion is the movement of molecules from a higher concentration (the back of the room) to a lower concentration (the other parts of the room). Osmosis and active transport require a membrane. Smelling something is not the same as an allergic reaction.
Chap 3 - The definition of osmosis is the
diffusion of water across a selectively permeable membrane. Extra info: Osmosis is the diffusion of water across a selectively permeable membrane. Diffusion is the movement of solute molecules from a higher to a lower concentration.
A community of organisms along with their physical environment constitutes a(n)
ecosystem.
Chap 4 - The largest number of ATP molecules is produced in which phase of cellular respiration?
electron transport chain Extra info: The electron transport chain produces the most ATP: 32-34 ATP.
Chap 4 - Chemical reactions that require the input of energy are
endergonic reactions. Extra info: Endergonic reactions require energy. Exergonic reactions release energy. Catabolic reactions break down molecules. Coupled reactions combine an endergonic with an exergonic reaction. Kinetic reactions involve motion.
Chap 3 - Which is NOT a correct association of cell organelles and their structure?
endoplasmic reticulum - concentrated chromatin, RNA, and nucleoli Extra info: The endoplasmic reticulum synthesizes and processes proteins. Concentrated chromatin, RNA, and nucleoli are associated with the nucleus.
Chap 5 - What is the energy of a photon first used to do in photosynthesis?
energize an electron
Chap 3 - Which of the following refers to a process that only moves materials out of a cell (never into the cell)?
exocytosis
You are conducting an experiment to determine what concentration of disinfectant is most effective in killing bacteria. In this example, the concentration of disinfectant would represent the
experimental variable.
Chap 2 - A long chain of carbon atoms with hydrogen atoms attached, ending in the acidic carboxyl group would be a(n)
fatty acid. Extra info: A fatty acid is a hydrocarbon chain ending with a -COOH group, which is acidic; a triglyceride is composed of three fatty acids bound to glycerol. Amino acids are the monomers of proteins, and monosaccharides are carbohydrates. Nucleic acids are polymers of nucleotides such as DNA and RNA.
Chap 3 - A cell placed in a hypotonic solution will
gain water. Extra info: A cell in a hypotonic solution will gain water because there is a lower concentration of solution (higher concentration of water) outside than inside the cell.
Chap 3 - Which intercellular junction allows for the rapid movement of small molecules or ions to flow from one animal cell to the next?
gap junctions Extra info: Gap junctions allow for the rapid movement of small molecules or ions to flow from one animal cell to the next. Tight junctions form a solid barrier. Adhesion junctions form a porous membrane that filters substances. Desmosomes are a type of adhesion junctions. Plasmodesmatas are found in plant cells.
Chap 2 - Which nutrient source is the easiest one for humans to break down and form ATP?
glucose Extra info Glucose is the easiest substance to break down into ATP. Proteins, cellulose, phospholipids, and chitin are not easily broken down into ATP.
Chap 4 - What phase(s) of cellular respiration produce(s) NADH?
glycolysis, formation of acetyl CoA, and citric acid cycle Extra info: All three phases of these reactions produce NADH + H+.
Chap 4 - What is the correct order of phases in the release of energy from glucose?
glycolysis, formation of acetyl CoA, citric acid cycle, electron transport chain
Chap 5 - Which color(s) of light does chlorophyll a reflect?
green
Chap 2 - An ion is an atom that
has a net charge. Extra info: An ion has more or less electrons than a neutral atom of the same element, so it has a net positive or negative charge.
Chap 4 - Enzymes are specific. This means that they
have a particular substrate. Extra info: Although enzymes do have preferred temperatures and pHs, require ATP and cofactors, and are present only in certain cells, the term "specific" refers to their particular substrate. An enzyme is specific because it has only one substrate.
Chap 4 - Each enzyme has a particular substrate because enzymes
have active sites complementary in shape to their substrates. Extra info: The specificity of an enzyme is due to the complementarity of the active site and the shape of the substrate. Although enzymes are named for their substrates, this does not account for their specificity.
Chap 3 - Microtubules
help distribute chromosomes in an orderly manner during cell division. Extra info: The function of microtubules is to form a spindle that distributes chromosomes in an orderly manner. They are composed of the protein tubulin and are found throughout the cytoplasm.
About 12 to 24 hours after the last meal, a person's blood sugar level normally varies from 60 to 90 milligrams per 100 milliliters of blood, although it may rise to 130 mg per 100 ml after meals high in carbohydrates. That the blood sugar level is maintained within a fairly narrow range, despite uneven intake of sugar, is due to the body's ability to carry out ___.
homeostasis.
Chap 4 - Which of the following is not an example of fermentation used by organisms to produce ATP?
human cells producing alcohol Extra info: Humans do not produce alcohol from fermentation.
Chap 2 - Which type of bond formation is responsible for the properties of water?
hydrogen Extra info: Hydrogen bonds are the attraction between the hydrogen of one water molecule and the oxygen of a second water molecule. This attraction sets up the properties of water. A polar covalent bond forms between the hydrogen and oxygen of a particular water molecule. Water doesn't form ionic or nonpolar covalent bonds.
Chap 2 - Water is a liquid at room temperature. This is due to
hydrogen bonding between water molecules. Extra info: Hydrogen bonding between water molecules keeps water in a liquid state at temperatures typically found on the Earth's surface, including room temperature. Water molecules do not covalently bond to one another, and the water molecule is too small to permit intramolecular hydrogen bonds to form. Water molecules do ionize, but this does not influence the fluid nature of water.
A suggested and testable explanation for an event is called a ___.
hypothesis
A possible explanation for a natural event, based on observations and past knowledge, is a
hypothesis Extra info: A hypothesis is defined as a possible explanation for a natural event (phenomenon) based on observations and past knowledge. When a hypothesis has withstood repeated testing over time, it may be elevated to a theory. In a controlled experiment, the control is the subject or group not subjected to the factor, or variable, being tested.
Chap 3 - If you have a 10% sugar solution and a 35% sugar solution, how does the 10% solution compare to the 35% solution?
hypotonic Extra info: The 10% solution has less solute than the 35% solution, so it would be considered hypotonic to the 35% solution. It would not be sweeter than the 35% solution because it contains less sugar.
Why do organisms without oxygen need to convert pyruvate to lactate?
in order to regenerate NAD+ Extra info: Pyruvate is reduced to lactate when oxygen is unavailable in order to regenerate NAD+ to be used during glycolysis.
Chap 4 - The function of an enzyme is to
increase the rate of a metabolic reaction. Extra info: An enzyme lowers the energy of activation for a reaction and allows it to proceed faster.
Chap 3 - When a lysosome fuses with a vesicle or vacuole,
its contents are digested. Extra info: Lysosomes are the "garbage disposals" of the cell which digest the contents of the vacuole.
Chap 2 - Buffers
keep the pH within normal limits. Extra info: Buffers are the chemicals or combinations of chemicals that keep pH within normal limits. Weak acids and bases may be used as buffers, not strong ones, which would greatly influence the H+ concentration of the solution and thereby raise or lower the pH.
Chap 3 - Compared with a eukaryotic cell, a prokaryotic cell
lacks membrane-bound organelles. Extra info: A prokaryotic cell lacks membrane bounded organelles. It does have ribosomes. Prokaryotic cells are smaller than eukaryotic cells and do require energy. Prokaryotic cells are living and many have methods of movement.
Chap 5 - In which plant structure does photosynthesis primarily occur?
leaf Extra info: The leaves of a plant are specialized to carry out photosynthesis.
Chap 3 - During photosynthesis, solar energy is converted to chemical energy by the chloroplasts. The process is represented by
light energy + carbon dioxide + water → glucose + oxygen Extra info: The formula for photosysnthesis is solar energy + carbon dioxide + water goes to carbohydrate + oxygen. This occurs in the chloroplast.
Chap 5 - What are the two sets of reactions for photosynthesis?
light reactions, Calvin cycle reactions Extra info: The two sets of reactions in photosynthesis are the light reactions and the Calvin cycle reactions.
Chap 3 - The plasma membrane is composed of
lipids and proteins. Extra info: The plasma membrane is a phospholipid bilayer in which protein molecules are embedded. Actin filaments and microtubules make up the cytoskeleton.
Chap 2 - If neutral atoms become positive ions, they
lose electrons. Extra info: The electron transfer is what will determine if an atom becomes a positive or negative ion. To become a positive ion an atom will need to lose electrons so there are more protons than electrons.
Chap 4 - Where within the cell is ATP built up?
mitochondria Extra info: Mitochondria are the powerhouses of the cell where ATP is produced.
Chap 3 - Which of these is mismatched?
mitochondria - stroma Extra info: Mitochondria contain a matrix, not a stroma. A stroma is found within chloroplasts.
Chap 3 - When viewed through a microscope, one characteristic of living cells is that their internal structures move. What organelles are most directly responsible for this motion we see?
mitochondria and cytoskeleton Extra info: Mitochondria provide the energy for organelle movement, while the cytoskeleton provides the structures needed for movement. The other organelles are involved in different functions.
Chap 3 - Which of the following is not a component of the endomembrane system?
mitochondrion
Chap 3 - Cellular respiration is best associated with the
mitochondrion. Extra info: Cellular respiration occurs within mitochondria. The other organelles have different functions.
Chap 3 - A selectively permeable membrane separates a molasses solution from distilled water. Over time, the
molasses will become more dilute. Extra info: The molasses cannot cross the membrane, but the water will enter the membrane, diluting the molasses solution.
Chap 5 - The H+ (protons) accumulate in the thylakoid space during electron transport between photosystems I and II. The excess of protons in the thylakoid space
moves from the thylakoid space to the stroma through the ATP synthase complex. Extra info: These excess H+ move through the ATP synthase complex and synthesize ATP from ADP + P. This is chemiosmosis.
Chap 3 - In a person with a mitochondrial disease in which the mitochondria do not produce enough energy for the cell, which organs would most likely be affected?
muscles Extra info: High energy demand tissues include muscles, the central nervous system, and the eye. Although the other organs would be affected, the high energy demand tissues would be most noticeably affected earlier.
Ever since the antibiotic drug penicillin was discovered in 1928, the incidence of resistant bacteria has steadily increased as a direct result of
natural selection Extra info: In natural selection, members of a species that are best adapted to survive and reproduce in their environment have more offspring than those that are not. Thus, more members of the population will come to have the successful adaptation. In this example, when people started using penicillin to fight bacterial infections, only susceptible bacteria were killed; resistant ones were able to survive and reproduce. Now there are many more resistant bacteria. Biodiversity is the total number of species, the variability of their genes, and the ecosystems they inhabit. Although genetic variability is the raw material for natural selection, it is not equivalent. Homeostasis is an organism's ability to maintain a stable internal environment. Development is the series of changes that occur throughout the lifespan of an organism. Reproduction is the ability of an organism to make more like itself; it is related to natural selection in that more successful organisms can pass their adaptations on to their offspring, but the terms are not equivalent.
Chap 3 - Both plant and animal cells have mitochondria because they both
need ATP for energy. Extra info: Mitochondria provide ATP for energy from glucose; therefore, both plant and animal cells need them. Mitochondria do not carry out the other functions listed.
Chap 3 - According to cell theory
new cells arise only from preexisting cells. Extra info: Cell theory states that all organisms are made up of basic living units called cells, and that all cells come only from previously existing cells. While multicellular organisms are composed of many cells, this is not part of cell theory. Some organisms are single celled, the smallest unit of life is a cell, and both animals and plants are composed of cells.
Chap 4 - Muscles undergo fermentation when
no oxygen is available. Extra info: Fermentation occurs when oxygen is not available.
Chap 3 - Ribosomal RNA is produced in the
nucleolus. Extra info: Ribosomal RNA is made within the nucleolus. Ribosomes contain rRNA and the rough endoplasmic reticulum contains ribosomes but the rRNA is made in those structures, not in the Golgi apparatus or the smooth ER.
Chap 2 - Nucleic acids are polymers of
nucleotides Extra info: Nucleic acids such as DNA and RNA are polymers of nucleotides. Polysaccharides are polymers of monosaccharides, triglycerides are made up of fatty acids bound to glycerol, and proteins are composed of amino acids.
Which answer choice lists the steps of the scientific method in the correct order?
observation, hypothesis, experiment, data collection, conclusion
Which level of biological organization is composed of several tissues?
organ Extra Info: Organs are composed of tissues working together in a common set of functions. Tissues are collections of cells, and cells are made up of various molecules. Organs make up organ systems, which comprise the organism.
A physician specializes in surgery involving the following group of organs: mouth, esophagus, stomach, and intestines. Overall, what is the highest level of organization that this physician is specialized in?
organ system Extra info: The mouth, esophagus, stomach, and intestines are all organs belonging to the digestive system. An organism is made up of multiple organ systems. The individual organs are made up of tissues, which are collections of cells.
An unmanned spacecraft has been sent to another planet to detect other life forms that might be quite different from those on Earth. If the probe could only send back one still picture, which property or properties of life would be observable in a picture?
organization Extra info: A still image would not be likely to show dynamic processes such as homeostasis, metabolism, evolution, growth, or reproduction. However, organization would be evident.
Chap 4 - Which of the following is a by-product of photosynthesis?
oxygen Extra info: Although all of these are involved in photosynthesis, oxygen is the by-product of the production of glucose from carbon dioxide and water.
Chap 4 - The final acceptor for hydrogen ions in aerobic cellular respiration is
oxygen Extra info: Oxygen takes the hydrogen ions and becomes water.
Chap 5 - What are the products of photosynthesis?
oxygen and carbohydrate Extra info: The end products of photosynthesis are a carbohydrate (glucose) and oxygen. Carbon dioxide and water are the substrates of the reaction.
Chap 4 - Which molecules are the reactants or substrates for aerobic respiration?
oxygen and glucose Extra info: Glucose and oxygen are the substrates for aerobic respiration. Carbon dioxide and water are the products.
Chap 2 - What type of bond will connect the amino acids in a protein?
peptide Extra info: A peptide bond will connect the amino acids together to form a protein. The atoms associate with a peptide bond unevenly because the oxygen is more electronegative than nitrogen.
Chap 3 - Which organelle primarily functions to package or regulate the production of H2O2?
peroxisome Extra info: The peroxisome contains enzymes that break down hydrogen peroxide, a toxic molecule. The other organelles are not involved in this process.
Chap 3 - Neutrophils, a type of white blood cell, are able to remove bacteria from our bloodstream and tissues by
phagocytosis Extra info: Phagocytosis is the process whereby a large substance, such as another cell, is taken into a cell by endocytosis. None of the other processes can move such a large substance.
Chap 2 - Which of the following types of lipids is the most abundant constituent of cell membranes?
phospholipid Extra info: Phospholipids are the most abundant type of lipids in cell membranes. Animal cells also have cholesterol in their membranes, but it is less abundant than phospholipids. Triglycerides, also known as neutral fats or simply fats, are energy-storage molecules, not structural molecules.
Chap 5 - Which of the following allows photosynthetic organisms to capture solar energy?
pigments Extra info: Pigments, such as chlorophyll, allow organisms to capture solar energy.
CHap 2 - Which of these do ALL prokaryotes and eukaryotes share?
plasma membrane
Chap 3 - Which structure regulates passage of molecules into and out of the bacterial cell?
plasma membrane Extra info: The plasma membrane is the boundary that separates the living contents of the cell from the nonliving surrounding environment. Nuclei, mitochondria, and chloroplasts are organelles within the eukaryotic cell. While flagella are on the surface of the cell, they do not regulate the passage of molecules into and out of the cell.
Chap 2 - Glycogen is a
polysaccharide used to store glucose/energy. Extra info: Glycogen (a polysaccharide) is the storage form of glucose (a monosaccharide). It is rich in chemical bond energy, found in animal tissues such as liver and skeletal muscle. DNA would be a nucleic acid found in the nucleus of a cell, and trans fats are found in margarine.
Chap 2 - A genetic mutation can cause a change in the sequence of the 20 amino acids used to build proteins. Such a change is a change to the protein's
primary structure, but this will likely alter higher levels of structure as well. Extra info: A mutation (a change in a DNA sequence) may directly alter the primary structure of a protein, since this is the sequence of amino acids in the chain. However, the primary level of structure dictates the higher levels of structure—secondary, tertiary, and even quaternary—so these may be indirectly affected as a result of the mutation.
In the search to discover the agents that cause mad cow disease, scrapie in sheep, and CJD and kuru in humans, diseased brain tissues were passed through a fine filter to remove bacteria. The filtrate was still infectious, indicating that something smaller than bacteria, either viruses or organic molecules, must be the causative agent. If a virus was responsible for these brain diseases, then the infectious agent would contain either RNA or DNA. Other possibilities were that the agent was a carbohydrate, fat, or protein. Tissue filtrates were treated with agents that destroyed just one of these chemicals and then injected into a healthy animal, with the results as follows. What is the infectious agent? •Amylase digests carbohydrates; tissue filtrate still infects healthy test animal. •Lipase digests fats; tissue filtrate still infects healthy test animal. •Formaldehyde and/or heat denatures DNA and RNA; tissue filtrate still infects healthy test animal. •Trypsin digests protein; tissue filtrate does not infect healthy test animal.
protein Extra info: CJD, kuru, mad cow disease, and scrapie are caused by prions—infectious proteins. This was supported by the finding that only trypsin, which digests proteins, was able to deactivate the infectious agent.
Chap 4 - Most enzymes are
protein molecules. Extra info: Enzymes are proteins, although some RNA molecules can speed chemical reactions.
Chap 3 - According to the fluid-mosaic model of membrane structure,
proteins float inside or within the phospholipid bilayer. Extra info: The fluid mosaic model states that proteins form a mosaic pattern just outside or within the phospholipid layer of the membrane. Cholesterol is found in membranes but it is not the main constituent. Glycolipids are on the outside of the cell.
Chap 2 - Which of the following subatomic particles will be found within the nucleus of the atom?
protons and neutrons Extra info: The nucleus of an atom will contain the protons and neutrons. Electrons are found in the electron orbitals that circle the nucleus.
Chap 3 - Which function does the lipid bilayer component of the plasma membrane NOT provide for the cell?
provides an impermeable, self-sealing membrane that keeps all internal living processes sealed inside Extra info: The membrane is not impermeable. Many things cross the membrane in both directions.
Chap 4 - The glucose that enters glycolysis is split into two molecules of ___.
pyruvate
Chap 2 - Hemoglobin is a protein composed of two pairs of polypeptide chains. What is the highest level of protein structure represented by hemoglobin?
quaternary Extra info: Amino acids joined together by peptide bonds constitute the primary level of protein structure. In secondary structure, hydrogen bonding between amino acids causes the polypeptide to form an alpha helix or a beta pleated sheet. In tertiary structure, interactions such as covalent bonds between R groups cause the polypeptide to fold and twist. When two or more polypeptides join together, this represents a quaternary level of structure. There is no level of protein structure termed the molecular level.
Chap 2 - The primary function of carbohydrates is
quick fuel and short-term energy storage. Extra info: Carbohydrates are primarily fuel and short-term energy storage molecules, although some polysaccharides do reinforce cell walls in certain organisms. DNA, a nucleic acid, encodes hereditary information. Proteins can function as enzymes to speed chemical reactions, or as transporters to move molecules across cell membranes.
Chap 4 - Cellular respiration is an aerobic process. This means that it
requires oxygen. Extra info: An aerobic process is one that requires oxygen.
Chap 3 - If an active cell produces an important protein for secretion (export from the cell), what is the correct sequence of organelles that are involved in the production of the protein?
ribosomes- to - endoplasmic reticulum - to - Golgi apparatus Extra info: The protein must be made on ribosomes, processed in the endoplasmic reticulum, and then packaged into vesicles sent to the Golgi apparatus.
Chap 2 - The proposed cause of CJD and kuru in humans, mad cow disease, and scrapie in sheep is a change in a brain protein. Disease victims appear to have a protein that should normally contain alpha helices but instead they have changed into a protein made of beta pleated sheets. The disease appears to spread when the abnormal protein comes into contact with the normal protein, causing it to become deformed. Which level of protein structure is associated with these diseases?
secondary Extra info: Amino acids joined together by peptide bonds constitute the primary level of protein structure. In secondary structure, hydrogen bonding between amino acids causes the polypeptide to form an alpha helix or a beta pleated sheet—this is the level affected in CJD and similar brain diseases. In tertiary structure, interactions such as covalent bonds between R groups cause the polypeptide to fold and twist. When two or more polypeptides join together, this represents a quaternary level of structure. There is no level of protein structure termed the "molecular level."
Chap 3 - Which is NOT a function of the cytoskeleton?
secretes the calcium for bone tissue Extra info: All of the above are functions of the cytoskeleton except that it does not secrete the calcium for bone tissue.
Chap 3 - Osmosis can occur when a membrane is
selectively permeable. Extra info: Osmosis is the diffusion of water across a semi- or differentially permeable membrane. Water can pass through the membrane but other things cannot.
Chap 3 - If a cell lacks ATP, which of the following processes would cease to operate immediately?
sodium/potassium pump Extra info: The sodium/potassium pump is a form of active transport which requires energy. Without ATP, it would cease to function. All of the other processes do not require energy.
Chap 3 - When you add sugar to your coffee or tea, the sugar is the
solute Extra info: The substance dissolved in a solution is the solute.
Chap 3 - When viewing a specimen through a light microscope, scientists use ___ to distinguish the individual components of cells.
special stains
Chap 5 - Plants produce oxygen when they photosynthesize. Where does the oxygen come from?
splitting water molecules
Chap 2 - Which type of lipid molecule is characterized by a backbone of four fused rings?
steroid Extra info: Only steroids are characterized by their backbone of four fused rings. Phospholipids and triglycerides are lipids, but they do not share the same structure as steroids. Amino acids and DNA are not lipids.
Chap 2 - Cholesterol is a component of cell membranes and is an example of which type of lipid?
steroids Extra info: Due to the structure of cholesterol it is classified as a steroid within the body.
Chap 5 - Where in plant cells does the Calvin cycle take place?
stroma
Chap 5 - The formation of carbohydrate occurs within the
stroma. Extra info: The Calvin cycle, which produces carbohydrate operates within the stroma.
Chap 2 - Potassium hydroxide (KOH) almost completely dissociates in aqueous solution into K+ and OH-, which means it is a
strong base. Extra info: Because potassium hydroxide dissociates completely and adds hydroxide ions (OH-) to an aqueous solution, it is a strong base. A weak base would not dissociate so completely. An acid would contribute hydrogen ions (H+) to an aqueous solution. Potassium hydroxide is an ionic compound; a nonpolar covalent molecule would not dissociate or dissolve in an aqueous solution.
Chap 3 - If a cell lacked ribosomes, it would NOT be able to
synthesize proteins. Extra info: Ribosomes are responsible for the synthesis of proteins using messenger RNA as a template. Other organelles are associated with the remaining functions listed.
CHap 3 - In moving from the outside environment to the inside of a bacterium, the first layer encountered would be
the capsule. Extra info: Bacteria are often surrounded by a capsule or slime layer. This covers the cell wall which is outside of the cell membrane. The DNA is internal to the cell. Prokaryotes do not have a nucleus.
Chap 5 - What does the term stroma refer to?
the central fluid-filled space of the chloroplast Extra info: The stroma is the fluid-filled interior of the chloroplast.
Chap 5 - At the cellular level, photosynthesis occurs within
the chloroplast. Extra info: Photosynthesis occurs within chloroplasts.
Chap 5 - Which statement correctly describes carbon fixation?
the conversion of CO2 to an organic compound
Chap 3 - Permeability refers to
the extent to which a membrane allows a substance to pass through. Extra info: The ability of a membrane to allow substances to pass through is permeability. The movement of molecules from greater to lesser concentration is diffusion. The amount of solute in a solution is concentration. The state of being permanent is permanence. It is not possible to establish a permanent solute level in a solution.
Chap 3 - The body of a slime mold that flows over a rotten log appears to lack any partitioning into distinct cells; however it does become cellular when it changes form and produces spores. The surfaces of parasitic flatworms and some insect tissues are "syncytial" layers of living material that developed from a single cell but now contains many nuclei but lack partitioning by cell membranes. These tissues actively consume food and produce wastes. Considering that the cell theory states that "all living things are composed of cells," then
the general concept of life-is-cellular still holds since sometime in their life these organisms still utilize cells, but this shows cell membranes can be abandoned. Extra info: These organisms are living and were once composed of cells, even if the internal membranes between cells have been done away with. Since these organisms exhibit other characteristics of living cells, they are not nonliving, nor do they do not form a bridge between nonliving and living. Since they were once cells, no other vital force needs to be implicated. Since these cells do not have complete cell membranes, cell membranes are not a necessity to be classified as living.
Chap 4 - The specificity of an enzyme to a substrate is currently best explained by
the induced-fit model. Extra info: The active site of the enzyme undergoes a slight change in shape in order to accommodate the substrate(s). This is called the induced-fit model.
Chap 3 - If the chloroplast is the result of endosymbiosis, what membrane of the chloroplast represents the plasma membrane of the original prokaryote?
the inner chloroplast membrane Extra info: The outer chloroplast membrane would represent the membrane of the engulfing vesicle. The inner chloroplast membrane would represent the membrane of the original prokaryotic cell. The thylakoid membrane and grana are interior to the chloroplast. Cristae are found in mitochondria.
Chap 5 - Water is split and oxygen is released in
the light-dependent reactions. Extra info: In the noncyclic electron pathway, water is split in order to replace the electrons that are lost by photosystem II.
Chap 2 - The lower the pH
the more acidic the solution. Extra info: The pH scale is based on hydrogen ion (H+) concentration. The higher the concentration of H+ (and the lower the concentration of OH-, hydroxide), the lower the pH, and the more acidic the solution.
Chap 2 - How elements interact with each other is dependent on
the number of openings for electrons in the outermost shell. Extra info: It is the outermost shell of an atom that can potentially react with electrons in the outermost shells of other atoms. The protons and neutrons remain in the nucleus and do not engage in chemical reactions.
Chap 3 - If the mitochondrion is the result of endosymbiosis, what membrane of the mitochondrion represents the engulfing vesicle?
the outer mitochondrial membrane Extra info: The outer mitochondrial membrane would come from the engulfing vesicle. The crista is the inner mitochondrial membrane and would have represented the original prokaryotic membrane. The thylakoid membrane and grana are part of chloroplasts. A vacuole membrane is not found in mitochondria.
Chap 5 - The "antenna" system of a plant that gathers the solar energy consists of
the pigment complex, or photosystem. Extra info: The pigment complex gathers the solar energy.
Chap 2 - Isotopes of a given element have
the same number of protons but differ in atomic mass. Extra info: Isotopes are atoms of the same element that differ in the number of neutrons only; thus, they have the same atomic number but different atomic masses.
Chap 4 - Occasionally someone claims to have built a machine that can run forever, producing as much energy as it consumes. This has always been disproved because it violates
the second law of thermodynamics. Extra info: This violates the second law which states that energy cannot be changed from one form to another without a loss of usable energy.
Chap 3 - The Golgi apparatus directs its protein products to the correct location in the cell based on
the specific molecule that is added and the molecule determines the destination in or out of the cell. Extra info: Proteins made in the rough ER have specific molecular tags that serve as "zip codes" to tell the Golgi apparatus where to send them. DNA does not leave the nucleus. Vesicles do not make the determination, either by picking up particular proteins, or by how long they take to travel from the ER to the Golgi. Proteins are specifically carried by vesicles to their destination.
Chap 4 - Lactose is milk sugar that is broken down by the enzyme lactase. The reason that some people are "lactose intolerant" could be because
they are missing the enzyme lactase in their digestive system. Extra info: Most people that are lactose intolerant are missing the enzyme lactase in their digestive system.
Chap 5 - The reservoir for hydrogen ions for chemiosmotic ATP synthesis during photosynthesis is the
thylakoid space. Extra info: The H+ accumulate in the thylakoid space
Chap 5 - The flattened sacs within the stroma of a chloroplast, which are connected to form a single inner compartment, are called
thylakoids Extra info: The thylakoids are the flattened sacs within the chloroplast.
Chap 4 - The energy difference between the reactant glucose and oxygen molecules and the product water and carbon dioxide is 686 kilocalories, yet the 36 ATP molecules produced are only storing 263 kilocalories in their outermost phosphate bond. The rest of the energy went
to provide heat that is soon lost from the organism. Extra info: The remainder of the energy is lost as heat. Energy cannot be created or destroyed.
Chap 4 - Why does chemiosmosis require a membrane?
to separate two compartments of the cell to allow for gradient formation Extra info: Chemiosmosis requires two separate compartments to allow for the formation of a gradient. The membrane is similar to using a dam to hold back water in order to generate electricity.
Chap 4 - In feedback inhibition of a metabolic pathway, where does the inhibitor bind?
to the enzyme of the first reaction Extra info: In feedback inhibition, the final product binds to the enzyme, either at the active site or at another site.
Chap 2 - When an ionic bond forms, electrons are
transferred from one atom to another. Extra info: Ionic compounds form when one atom gives up an electron, which is accepted by the other member of the pair. Now that one atom is a positively charged ion and the other is a negatively charged ion, the two atoms are attracted to one another.
Chap 4 - For the complete respiration of one molecule of glucose, the citric acid cycle must turn a total of
two times Extra info: Because two pyruvate are formed from one glucose molecule, the citric acid cycle must turn two times per glucose molecule.
Chap 2 - Polar covalent bonds result from
unequal sharing of electrons in a covalent bond. Extra info: Covalent bonds result from the sharing of electrons between bound atoms; when the sharing is unequal, it is a polar bond, and when the sharing is equal, it is a nonpolar bond. Ionic bonds are a different type of chemical bond from covalent bonds; in an ionic bond, one or more electrons are completely transferred from one member of the compound to the other(s). Hydrogen bonding is a relatively weak attraction between hydrogen in one molecule and a highly electronegative atom (such as O or N) in an adjacent molecule.
Chap 3 - The ________ functions in storage and transport.
vacuole Extra info: Vacuoles store water, sugars, salts, pigments, and toxic molecules. Both lysosomes and peroxisomes enclose enzymes. Mitochondria and chloroplasts are involved in energy production.
Chap 3 - Which of the following would be a way of finishing this hypothesis about the function of the Golgi apparatus? If the Golgi apparatus is involved in packaging products for secretion (export from the cell), then
vesicles must travel from the Golgi to the cell surface. Extra info: In order to be secretory, vesicles must travel from the Golgi to the cell surface. Although vesicles do travel from the rough ER and smooth ER to the Golgi apparatus, this does not apply to secretion, only to intracellular transport. The Golgi apparatus is part of the endomembrane system, does consist of 3-20 slightly curved sacs, and does contain proteins, but none of these apply to a secretory function.
Chap 5 - Which molecule would you need to radioactively label in order to produce radioactive oxygen during photosynthesis?
water
Chap 5 - Which of the following is not an autotroph?
yeast Extra info: All of the organisms are capable of photosynthesizing except the yeast.