Understanding the Properties and Functions of Water, Carbohydrates, Proteins, and Lipids, Exams of Nursing

Download Understanding the Properties and Functions of Water, Carbohydrates, Proteins, and Lipids and more Exams Nursing in PDF only on Docsity! Biology Questions with Answers 2024 If there is overwhelming evidence supporting a scientific statement a. it can be used to predict future outcomes with a high degree of probability. b. it is considered factual and indisputable. c. it is considered "scientific proof". d. experiments on the topic are no longer performed ✔ A Science is not a good approach to questions that a. are not measurable with tools currently available b. require intuition c. have a limited number of possible objective answers d. have already been answered ✔ A Which of the following is mismatched? a. intuition / knowing something without conscious reasoning b. scientific theory / broad explanation based on a large amount of empirical evidence c. subjective / influenced by a person's mood or temperament d. Math / truth by authority ✔ D "What causes migraine headaches?" is not a good scientific question because a. objective answers do not exist b. we don't have the tools to address this c. it is too broad, and doesn't immediately suggest an experimental approach d. animal models do not exist ✔ C Why is it important for scientists to publish the exact details of the experimental methods used? a. to ensure that they didn't make mistakes. b. to increase the significance of their results. c. so that other scientists in their field of expertise can repeat the experiment. d. to prove that they used sound, well established scientific methods. ✔ C True or false? Science is limited to observable, measurable phenomena ✔ True True or false? Science provides the most reliable answers to our questions ✔ False What is a hypothesis? A) the same thing as an unproven theory B) a tentative explanation that can be tested and is falsifiable C) a verifiable observation sensed directly, or sensed indirectly with the aid of scientific instrumentation D) a fact based on qualitative data that is testable E) a fact based on quantitative data that is falsifiable ✔ B What is the primary reason for including a control group within the design of an experiment? A) To ensure that the results obtained are due to a difference in only one variable B) To ensure that the experimenter can perform a more complete statistical analysis C) To demonstrate in what way the experiment was performed incorrectly D) To accumulate additional facts that can be reported to other scientists E) To test the effect of more than one variable ✔ A The best experimental design _____. A) includes a large sample size for each condition B) includes a control C) alters only one condition between the controls and the experimental condition D) all of the above ✔ D Statistical significance A) indicates a high likelihood that your results are due to your treatment versus due to chance. B) B. is more likely to be reliable if you have a small sample size versus a large sample size. C) is a requirement of the data from a scientific experiment. D) indicates that the hypothesis should be rejected. E) depends on large data sets. ✔ A Why can't science answer questions about the existence of a supernatural being? ✔ Science requires a hypothesis that is testable and falsifiable. There is no way to test the existence of a supernatural being, nor is it possible to prove that something does not exist. Objective answers do not exist. What does it mean to say that a scientific study has undergone "peer review"? Why is this important? ✔ When a study has undergone peer review it means that other scientists have examined the study to make sure the experiment was carried out properly and that the ____5.The combination of cohesion and adhesion causes water molecules to travel up the stem of a tree without expending energy ✔ 1. True 2. True 3. True 4. True 5. True True or False? ____6. Water stabilizes air temperatures by absorbing heat from air that is warmer and releasing the stored heat to air that is cooler. ____7. The specific heat of a substance is defined as the amount of heat that must be absorbed or lost for 1 gram of that substance to change its temperature by 1 degree Celsius. ____8. A calorie of heat causes a relatively small change in the temperature of water because much of the heat energy is used to disrupt hydrogen bonds before the water molecules can begin moving faster. ____9. It takes about twice the amount of energy to vaporize a gram of alcohol than to vaporize the same amount of water. ____10. Sugar crystals dissolve in water because water breaks the covalent bonds between sugar molecules. ✔ 6. True 7. True 8. True 9. False 10. False Many mammals control their body temperature by sweating. Which property of water is most directly responsible for the ability of sweat to lower body temperature? A) water's change in density when it condenses B) water's ability to dissolve molecules in the air C) the release of heat by the formation of hydrogen bonds D) the absorption of heat by the breaking of hydrogen bonds E) water's high surface tension ✔ C Which of the following is NOT a functional trait of a living organism? A) growing and reproducing B) moving from place to place C) responding to their environment D) obtaining and using energy E) maintaining a stable internal environment ✔ B Maintaining a separate and distinct internal environment from the external environment is called A) life. B) cell exclusion. C) metabolism. D) hydrophobicity. E) homeostasis. ✔ E An isotope is the form of an element that has more or fewer neutrons than its most common form. Knowing this, what is the atomic number of an isotope with one extra neutron, if its atomic mass is 15? A) 7 B) 8 C) 14 D) 16 E) 30 ✔ A What is the maximum number of atoms to which a single carbon can bind? A) 1 B) 2 C) 3 D) 4 E) 6 ✔ D In a water molecule, hydrogen atoms are bonded to oxygen by _________ bonds, whereas neighboring water molecules are held together by __________ bonds. A. polar covalent; hydrogen B. hydrogen; polar covalent C. ionic; polar covalent D. polar covalent; ionic E. ionic; hydrogen ✔ A When making sugar water, the sugar is the _____________ whereas the water is the ___________. A) solute; solvent B) solvent; solute C) solute; solution D) solution; solute E) solvent; solution ✔ A The _____ of water molecules explains how some insects can walk on water. A) solubility B) cohesion C) aversion D) adhesion E) movement ✔ B The pH scale goes from ______ to______. A pH of 7 is considered________, a pH <7 is considered ________, and a pH >7 is considered_________. A) 0; 14; neutral; acidic; basic B) 0; 14; neutral; basic; acidic C) 0; 14; basic; neutral; acidic D) 0; 7; neutral; acidic; basic E) 0; 7; neutral; basic; acidic ✔ A Hydrophobic substances such as vegetable oil are A) nonpolar substances that are repelled by water molecules. B) nonpolar substances that have an attraction for water molecules. C) polar substances that repel water molecules. D) polar substances that have an affinity for water. E) charged molecules that hydrogen-bond with water molecules ✔ A Viruses contain genetic material. They can make copies of themselves, but only by using the services of a living host cell. Viruses are assembled in their final form and size by the host cell. Viruses use the host cell's energy mechanisms; they lack any of their own. Is a virus alive? Support your answer. ✔ No, a virus is not considered alive. A living cell must be able to accomplish all of the above-stated tasks by itself. A virus must use another cell to make copies of itself. It uses the other cell's metabolism, and it does not grow and develop on its own. Instead, it is assembled in its final form. Just because they contain genetic material does not make them alive. Viruses seem alive because they can reproduce themselves; however, they are not made of cells. All living things have hereditary material in the form of DNA. What role does DNA play in evolution? ✔ Draw the "electron configuration" of Carbon. ✔ Unlike neon, elemental chlorine (lone chlorine atom) is never found in nature. Why? ✔ Since it combines directly with nearly every element, chlorine is never found free in nature. cells. Thus the phospholipid "bilayer" is perfectly suited to serve as a barrier between the intracellular solution and the extracellular solution. How does a saturated fat differ from an unsaturated one? ✔ Saturated fats lack double bonds so their fatty acid chains do not kink. Consequently, they pack together more easily and must be kept warm to prevent solidification. The major difference between the molecular structure of phospholipids and fats is the presence of the negatively charged phosphate group on phospholipids. How does this structural difference relate to the different roles served by these molecules? ✔ The phosphate group on phospholipids causes these molecules to be amphipathic - meaning one end is hydrophilic and the other end is hydrophobic. It is the amphipathic nature of phospholipids that makes them perfectly suited to form a barrier between two aqueous solutions. Fats on the other hand are entirely hydrophobic and form dense spheres when excluded by water - and therefore store energy without taking up much space. Only plant cells can convert the two monosaccharides, glucose and fructose, into the disaccharide sucrose. Why can't animals synthesize sucrose? ✔ Animals didn't inherit the genetic information encoding the enzyme sucrose synthetase. Or perhaps we did inherit it but it was lost because it wasn't important to survival. Using hemoglobin as an example distinguish between its primary, secondary, tertiary and quaternary structure. Sketches may help here. ✔ The primary structure of a protein is the sequence of its amino acids starting at the N terminus. The amino acids are joined together by peptides bonds. The secondary structure of a protein results from regular and repeated hydrogen bonds between the Oxygen and Hydrogen atoms in the backbone of the polypeptide chain. Alpha-helices and beta-pleated sheets. The tertiary structure of a protein results from interactions between the side groups (or R-groups) and therefore is determined by its primary structure. The tertiary structures are as varied as the primary structures of proteins. Interactions include H-bonds, ionic bonds, Van der waals and disulfide bridgesSome proteins have a fourth level of structure: Quaternary structure. Each polypeptide chain is called a subunit. Subunits interact with each other via weak bonds such as H-bonds, ionic bonds and hydrophobic interactions. Match up macromolecules with their structural units. A. Carbohydrates a. Nucleotides B. Proteins b. Hydrophobic molecules C. Lipids c. Amino acids D. Nucleic Acids d. Monosaccharides ✔ A. Monosaccharides B. Amino Acids C. Hydrophobic molecules D. Nucleotides Label each of the following as either a monomer (M) or a polymer (P). _____ Monosaccharide _____ Protein _____ Lipid _____ Amino acid _____ Nucleic acid _____ Carbohydrate ✔ M P M M P P Which of the following would you expect to be most similar for the two proteins, hemoglobin and insulin? a. primary structure b. secondary structure c. function d. amino acid sequence ✔ B For a protein to have quaternary structure it must, a. have two or more amino acids b. have four polypeptide subunits c. consist of two or more subunits d. have polar and nonpolar regions ✔ C Polymers of polysaccharides, nuclei acids, and proteins are all synthesized from monomers by a. connecting monosaccharides together b. the addition of water to each monomer c. the removal of water (condensation synthesis) d. ionic bonding of monomers e. none of the above ✔ C What type of interaction stabilizes the secondary structure of proteins? a. disulfide bridges b. weak bonds between protein subunits c. regular and repeated hydrogen bonds d. covalent bonds e. hydrophobic interactions ✔ C Which of the following is true both of starch and cellulose? a. They are both polymers of glucose. b. They can both be digested by humans. c. They are both used for energy storage. d. They are both structural components of the plant cell wall. ✔ A Hydrolysis is involved in which of the following? a. synthesis of starch b. peptide bond formation c. hydrophobic interactions d. digestion of maltose to glucose ✔ D All of the following molecules are carbohydrates except a. lactose b. cellulose c. hemoglobin d. glycogen e. starch ✔ C Which of the following would yield the most energy per gram if oxidized? a. starch b. fat c. glycogen d. protein e. glucose ✔ B Which of the following are energy-storing polymers? A) proteins B) carbohydrates C) lipids D) proteins and lipids E) carbohydrates and lipids ✔ E cell and raise the blood glucose level. (There are many other functions as well)the blood glucose level. (There are many other functions as well) List all functions served by the cytoskeleton in animal cells. ✔ Anchor organelles, transport vesicles, cell shape, mitotic spindle formation, cleavage during cell division, endo and exocytosis, cell migration. Outline the pathway of secretory protein synthesis. For example, describe the synthesis and secretion of insulin by pancreatic cells naming each structure and organelle involved. ✔ The insulin gene is turned on, insulin mRNA is synthesized and travels to the cytoplasm, ribosome binds to it and begins to synthesize insulin but pauses after signal sequence is made. Docking protein helps complex attach to RER and insulin synthesis resumes across the RER membrane. Vesicles containing insulin bud off the RER and travel to the cis side of the Golgi. They are modified and then packaged into vesicles that bud off the trans side of the Golgi. The vesicles fuse with the plasma membrane and insulin is released into the extracellular fluids. If a single lysosome in an animal cell bursts the hydrolases released will not be active. Why? ✔ The pH of the cytosol is 7, the hydrolases are inactive at this pH. What structure determines the shape of plant cells? ✔ Assuming a hypotonic environment, the cell wall 1_________ synthesis of ribosomal RNA 2_________ synthesis of membrane 3_________ pH is 5 nucleolus 4_________ synthesis of cytosolic 5________ synthesis of lipids 6_________modification of proteins 7_________determines the shape of animal cells 8________determines the shape of plant cells 9_________produces CO2 10_________detoxifies hydrogen peroxide 11 _________digests macromolecules into building block 12_________fuses with and hydrolyzes defunct organelles 13_________specialized in muscle cells to sequester calcium ions 14 _________appear green under the microscope ✔ 1: nucleolus 2: RER 3: Lysosome 4: free floating ribosome 5: SER 6: Golgi 7: Cytoskeleton 8: cell wall 9: mitochondria 10: peroxisome 11: Lysosome 12: Lysosome 13: SER 14: chloroplast True or False? 29. _______ Continuous alcohol consumption causes the proliferation of peroxisomes in liver cells. 30. _______ A human liver cell recycles half of its macromolecules each week. 31. _______ If a lysosome in a cell bursts the cell will die. 32. _______ The inner-most solution of a mitochondrion has a pH of 2. 33. _______ All eukaryotic cells have mitochondria. 34. _______ The type of endocytosis whereby an entire cell, organelle or large structure is engulfed is called phagocytosis. 35. _______ The central vacuole found in many plant cells allows them to increase in size without a loss of efficiency. 36. _______ Some plant cells don't function until after they die ✔ 29. True 30. True 31. False 32. False 33. True 34. True 35. True 36. True Plasmids a. are circular chromosomes of approximately 1 million base pairs. b. may be passed from one bacterium to another through pili. c. contain genes that are essential for bacterial reproduction. d. all of the above ✔ B Gram negative bacteria a. have a membrane outside of their thin peptidoglycan cell wall b. are perfect targets for penicillin c. use magnetite crystals to orient in a magnetic field d. are not pathogenic ✔ A Which of the following is an example of a symbiotic relationship? a. E.coli that reside in the human intestine b. Yeast that infect the vagina in women taking antibiotics c. Bacteria that cause body odor d. Microorganisms in the gut of cows that digest cellulose e. all of the above ✔ E Which of the following is an advantage of the compartmentalization seen in eukaryotic cells? a. Incompatible reactions can be separated b. The small volume of cytosol reduces the cell-surface-area-to-volume ratio c. Groups of enzymes and their substrates can be clustered within an organelle increasing the speed and efficiency of reactions. d. all of the above e. None of the above ✔ D Which of the following statements about the nucleus is false? a. The nuclear lamina controls what enters and exits the nucleus. b. The genes encoding rRNA are found in a region of the nucleus called the nucleolus. c. Each chromosome occupies a distinct area within the nucleus. d. Chromatin structure affects gene expression. For example the hemoglobin gene in a pancreatic cell would likely be in a highly condensed form of chromatin. e. The nuclear envelope is composed of two membranes. ✔ A Which of the following concerning ribosomes is false? a. They are membrane bound organelles found exclusively in eukaryotic cells. b. They bind to mRNA molecules. c. They catalyze the formation of peptide bonds between amino acids. d. Cells that have high rates of protein synthesis have particularly large numbers of them. ✔ A Tay Sachs disease is associated with a malfunction in which organelle? a. peroxisome b. mitochondrion c. lysosome d. ribosome e. none of the above ✔ C Which cell would be best for studying lysosomes? D. They form provide structural integrity to cell wall ✔ A The proteins we consume are hydrolyzed into individual amino acids which are then taken up into our blood stream and used by cells to build human proteins. The amino acids that are not immediately needed for protein synthesis undergo the reaction illustrated below. What happens to the products of this reaction? A. the ammonia is toxic and must be excreted from the body B. both products are toxic and must be eliminated in the feces - A and C are correct D. the nitrogenous product is a precursor in the synthesis of Niacin C. the carbohydrate can be used for the synthesis of other biological molecules ✔ Which of the following is true of amino acids? A. all are correct B. they all contain an amino group, a carboxyl group and a central carbon attached to an "R" group C. some have non-polar side chains D. they are joined together by dehydration reactions to form peptide bonds E. some are "essential" meaning they must be present in the diet ✔ A Messenger RNA A. all are correct B. contains ribonucleotides rather than deoxyribonucleotides C. interacts with ribosomes to direct the production of polypeptides. D. conveys genetic instructions for building proteins from the nucleus to the cytoplasm ✔ A The "Cell Theory" A. all are correct B. states that all living things are made up of one or more cells C. states that all cells arise from pre-existing cells D. is based on empirical evidence derived from hundreds of researchers E. includes contributions made by Louis Pasteur ✔ A All of the following are true of the bacterial cell wall EXCEPT A. it is made up of polysaccharide fibers that are connected by proteins B. it is unlike any molecules seen in eukaryotes C. it is the outermost layer of Gram positive bacteria D. it prevents the bacterial cell from popping in a hypotonic environment E. it is too dense for solutes to cross through it. ✔ E A new antibiotic puts holes in phospholipid bilayers. Would this antibiotic be useful as an antibacterial therapy? A. No, because we also have membranes made of phospholipid bilayers, so it would be toxic for humans B. No, because bacteria don't have phospholipids C. Yes, but only on gram positive bacteria D. Yes, because all bacteria have cell membranes composed of phospholipid bilayers ✔ A Penicillin A. binds to the bacterial enzyme required to form the cross links between cell wall components B. binds to DNA C. signals the immune system to begin antibody production D. interferes with several eukaryotic metabolic pathways ✔ A Most bacteria on earth are A. beneficial for the planet B. commensalists C. mutualistic symbionts D. pathogenic to humans ✔ A Which of the following statements is FALSE? A. A hydrogen bond is a weak (non-covalent) interaction between the partial positive charge on a H atom of one molecule and the partial negative charge on an electronegative atom of another molecule. B. Hydrophilic molecules are not soluble in water C. Hydrogen bonding makes it possible for almost any charged or polar molecule to dissolve in water D. Water's small size, highly polar covalent bonds, and bent shape make it unique among molecules ✔ B The cohesive properties of water accounts for A. the ability to float a steel pin on the surface of water B. the shape of a water droplet C. all are correct D. the movement of water from the roots to the leaves E. the insolubility of fats ✔ C If it takes 3 minutes in the microwave to bring tea water to a boil (100 oC) how long should you heat a slice of pizza? A. less than 3 minutes B. more than 3 minutes C. 3 minutes ✔ A The synthesis of polysaccharides A. occurs in the lumen of the intestine B. adds one amino acid at a time to a growing chain C. produces water as a product D. is called hydrolysis ✔ C Which of the following is mismatched? A. Glucose / building block of glycogen B. Nucleic Acids / encode proteins C. Hemoglobin / fuel storage in blood plasma D. Collagen / polymer provides structural support between cells ✔ C