Bio 256 Exam 1 (2025/2026 Latest Update) Questions and Answers (100% Guaranteed Pass).

Bio 256 Exam 1 (2025 Latest Update) Questions and Answers (100% Guaranteed Pass). Which is NOT an individual's survival need? Reproduction The purpose of negative feedback is to prevent sudden and severe changes within the body. Which would be a normal measure of protein in venous blood? 6.9g/100mL Homeostasis is best conceived as a state of dynamic constancy Why does your brain require constant blood flow, even during stress, and with intense exercise? to maintain consciousness. Which is NOT a major element of the human body? iron. Which is an inorganic molecule? Oxygen Which would form an electrolytic solution when dissolved in water? sodium chloride Which release OH- in water? bases Which pH would be considered alkaline? pH 9.6 A solution resisting changes in H+ concentration and tending to maintain a stable pH is called a ____ solution. buffer A molecule that is a mirror image of another, having a key functional group orientated in a different direction, is called ____ of the other. a stereoisomer Which is composed of gylcerol and fatty acids? triglycerides which of the following is a polysaccharide? starch the components of phospholipids include: glycerol, fatty acids, and phosphate groups. Saturated fatty acids have ___ double bonds. no One of structural subunits of an amino acid is the -NH2 functional group, called: an amino group. Which is NOT a function of proteins? Provides genetic code Which contains your genetic inheritance from your parents? DNA RNA is made by ____, protein in made by ____ transcription, translation The RNA type that moves through nuclear pores to direct synthesis of new protein molecules at the ribosomes in the cytoplasm, is mRNA Transfer RNA anticodons pair complimentary to the ___ of mRNA. codons If you see polyribosomes when you observe a cell using an electron microscope, the cell is making a lot of a certain protein. Which is NOT a reason why you and your cells age? genes shorten until they no longer function. Which best describes the membranes of your cells? phospholipid bilayers with embedded proteins and cholesterol. The rate of an enzymatic reaction increases as the temperature rises up to a point. Above 40 degrees C or so, however, the reaction rate begins to decline because enzymes change shapes at higher temperatures How can defects in the same metabolic pathway result in different symptoms in different individuals? Different enzymes may be defective in the same metabolic pathway, resulting in different diseases. An oxidation reaction must be coupled to a reduction reaction. When glucose is catabolized under ____ conditions, pyruvates will lose a carbon. Then the acetate made will cross the mitochondrial wall and enter Krebs cycle. aerobic. To obtain metabolic energy from glycogen, you must first break the molecule into glucose units When cells move substances in vesicles into extracellular space, it is called exocytosis red blood cells placed in hypotonic solution will exhibit hemolysis Your blood sugar is glucose what happens during the S phase of the cell cycle? The synthesis of DNA, as well as normal cell activities. During RNA processing, certain regions of the pre-RNA are spliced together to create the mature RNA strand. These are called: exons. Transcribe the following DNA antisense sequence: 3'-ATG-GAG-CAT-TTA-5' 5'-UAC-CUC-GUA-AAU-3' Most often, the integrating center in a feedback loop will be located within the central nervous system Which is a major element of the human body? oxygen which is an inorganic molecule? NaCl the universal solvent of life is water Anions have a ___ charge and are formed when they have ____ an electron to/from a cation. negative, gained if you add a small amount of vinegar (a weak acid) to a buffer, the buffer's pH will stay the same. When molecules have the same chemical formula, arranged in the same sequence, but differing only in their spatial orientation of key functional groups, producing D-isomers and L-isomers, they are called: stereoisomers ATP is a nucleotide Milk sugar, lactose, is composed of glucose and galactose. which of the following characteristics do all lipid molecules have in common? They are all nonpolar, at least in part. Polyunsaturated fatty acids have ____ double bond(s). 2 or more. Which is the part differing in the various amino acids? side chain (-R) The coiling of the protein chain backbone into an alpha helix is referred to as the: secondary structure. Enzymes are ____ proteins. Globular The nitrogenous base in DNA NOT found in RNA is thymine Translation is best defined as the synthesis of specific proteins using the mRNA base sequence code. Anticodons would be found in tRNA The plasma membrane is composed primarily of protein molecules embedded in a double layer of ____ molecules. phospholipid. The main exergonic reaction that drives most of the body's endergonic reactions is the hydrolysis of ATP Phenylketonuria (PKU) occurs when there is a hereditary defect in an enzyme. Which of the following processes does NOT occur as an acetyl unit (acetate) enters the mitochondrion, promoting one complete circuit of the Krebs Cycle? One molecule of oxygen, is combined with carbon to form carbon dioxide. Most of the carbons from CO2 metabolic waste travel through the circulatory system to the body's exterior as: part of the bicarbonate buffer system. Where does glycolysis occur? in the cell's cytoplasm. Which organs can obtain metabolic energy from lactic acid? liver and heart which of the following processes involve the extension of pseudopods to enclose a bacterium causing an infection? phagocytosis. If you put your blood cells in a hypotonic solution, they would swell and lyse. Which contains the code for the primary structure of a protein? mRNA what type of bond is most commonly found in polysaccharides? glycosidic In response to a decreasing blood pH, which molecule would be the most effective buffer? HCO3 Which is the integrating center in the homeostatic control mechanism for regulating blood glucose levels? beta cells of the pancreas. Which statement is NOT true regarding necessary life functions? each organ system is isolated from all other body systems. In a negative feedback loop used to maintain homeostasis, which of the following terms is NOT likely to be used? hypothesis Any water NOT contained within the cells is said to be part of the body's ____ compartment. extracellular Why does your heart require a constant blood flow, even during stress. such as with intense exercise? to provide for blood pumping to all tissues. Which is toxic in high concentration in your body, but essential in less amounts? iron Which is an organic molecule? C6H12O6 Which releases H+ in water? acids If solution A has 100 times the hydrogen ions as solution B and solution B has a pH of 6.0. then solution A will have a pH equal to 4.0 Which is the unit molecule of starch? glucose Which is a molecule with one carbon atom of its glycerol backbone attached to a phosphate group and an alcohol while the two other glycerol carbon atoms are attached to fatty acids? phospholipids there are 20 amino acids in proteins and they differ by their side chain (-R) The sequence of different amino acids in a protein is referred to as the primary structure. Contractile proteins of muscle consist mostly of fibrous protein During translation, the growing peptide is directly attached to tRNA What causes two different cells in one individual to display different characteristics? different genes are expressed If the products of a chemical reaction contain more total energy than the reactants, the reaction must be endergonic Substrate concentration increases the rate of an enzymatic reaction up to a certain point, but then has no further effect and the reaction rate levels off. This is because: all enzyme active sites are saturated with substrate molecules. Nicotinamide adenine dinucleotide (NAD) is a coenzyme in addition to energy (ATP), what are the final products of aerobic respiration Carbon dioxide and oxygen the chemiosmotic theory describes how the electron-transport system produces ATP using active pumps located within the mitochondrial inner membrane. Which of the following energy storage nutrient molecules provides the greatest amount of energy in calories (kilocalories) per gram? fat The favored fuel of resting skeletal muscle is fatty acids Extracellular fluid contains up to 10,000 times more calcium than intracellular fluid, and yet all cells continue to pump out even more calcium. They could do this only by means of active transport The movement of water through a semi-permeable membrane from an area of higher water concentration to an area of lower concentration is called ____ a form of _____ osmosis, diffusion DNA nucleotide bases include ____, but RNA bases include ____ Thymine, uracil Which chemical description best represents what happens to the "egg white" when you fry an egg? The high temp during cooking causes hydrogen bonds in the proteins to denature, resulting in the clear portion of the uncooked egg turning white. What is the correct protein translation of the mRNA sequence 5' GGG-CUC-AGG-AUU-UGU 3'? GLY-LEU-ARG-ILE-CYS Blood pH must remain within a narrow range of values for all the following EXCEPT: a normal blood pH prevents blood coagulation. Which of the following would NOT be a necessary life function decay which is a less common element of the human body? iodine which is NOT a property of water in your body? nonpolar solvent a base is defined as any molecule that can remove protons from a solution as they react with OH- being released. The normal pH inside your stomach is acidic, and thus lower than 7. the molecule central to all metabolism is glucose In the structure of a protein or its subunits, the symbol N stands for nitrogen and the symbol R stands for residue or rest of the molecule, any functional group of an amino acid we have a much greater variety of proteins than polysaccharides in the body, mainly because there are 20 different amino acid building blocks from which protein molecules are made. which nitrogenous base is not found in DNA? uracil within mammalian cells, the "universal energy carrier" is adenosine triphosphate Which of the following represents the reduced form of a coenzyme? FADH2 Oxygen is used as the final electron acceptor in (the) electron transport chain cellular respiration produces ATP Which fuels the brain use for its metabolism? glucose and ketone bodies if cells are placed in a hypertonic solution containing a solute to which the membrane is impermeable, what could happen? the cells will lose water and shrink. We have an expert-written solution to this problem! Which is NOT an input to to Krebs Cycle? oxygen enzymatic reactions in the body are important because they speed up the rate of reactions that would occur too slowly to sustain life. Which is the correct protein translation of the mRNA sequence 5' GUA-AUG-CUU-UGG-AAG 3'? VAL-MET-LEU-TRP-LYS A good example of a positive feedback mechanism would be ovaries produce estrogen with LH stimulation, estrogen stimulates more pituitary LH secretion. Which would be a normal measure of calcium in blood? 5 meq/L when an organ regulates its activity by mechanisms entirely within the organ itself, this is called intrinsic regulation which organ would get the least blood flow during the running of a marathon? small intestine Which is a less common element of the human body calcium water does NOT dissolve triglycerides a salt such as NaCl becomes forms _____ when dissolved in water electrolytes glycogen is a carbohydrate glycogen is composed of chains and branches of glucose units monounsaturated fatty acids have ___ double bond(s) 1 which is NOT a part of an amino acid glucose ionic bonds, hydrogen bonds, and Van der Waals forces stabilize the tertiary structure of proteins which is made using the energy in food molecules and used to do work ATP the RNA type characterized by folding on itself to form a twisted cloverleaf structure with an attached amino acid is called tRNA an exergonic reaction is one in which the reactants have more free energy than the products which is NOT a function of membranes containment of interstital fluids when carbonic anhydrase, an enzyme, and carbonic acid, the enzyme's substrate, are temporarily joined together, they form an enzyme-substrate complex which disease will result form the following faulty metabolic pathway albinism in glycolysis 2 molecules of pyruvate are made when one NADH enters oxidative phosporylation, how many ATP are produced in the mitochondrion 3 crenation of blood cells occurs when they are placed in a(n) hypertonic solution which is NOT a product of glycolysis? carbon dioxide proteins manufactured in the cytosol have a destination in the cytosol, which is narrowed down by information in the protein leader sequence the sequence thr-gly-pro-leu-met best represents which level of protein structure primary which would be a normal measure of fasting glucose in venous blood? 98 mg/100mL which is the fluid found between cells in your blood plasma when stress limits resources for organs, which organ receives top priority for receiving blood brain which best describes water high heat capacity and high heat of vaporization which is NOT part of an amino acid ribose Transfer RNA molecules come to the ribosomes in the order directly dictated by mRNA exergonic reactions drive endegonic reactions because all energy transfers lose some free energy as unusable heat Carbonic anhydrase, an enzyme, catalyzes a reversible reaction converting carbons from CO2 into carbonic acid. The specific area of the enzyme where carbonic acid attaches to it is known as the active site which of these is NOT a final product of aerobic cell respiration oxygen reactions releasing energy are usually called catabolic reactions fatty acid hydrocarbon tails are used for energy are first broken into glucose units movement of ions through protein channels is facilitated diffusion intracellular and extracellular fluids are separated by plasma membranes typical energetic barriers to biological chemical reactions in the human body include reactions that are endergonic or have a high activation energy which statement about stereoisomers is incorrect enantiomers have the same chemical formula and properties which effector primarily responds in the homeostatic control mechanism for coping with excessive body fat eccrine sweat glands Which of the following statements is most correct in reference to homeostatic imbalance it is considered the cause of most health issues which of the following is a typical blood gas oxygen which is the fluid found between cells in your tissues, but not in your blood interstitial fluid cations have a ____ charge positive buffers keep ____ constants in our bodies pH you can store glucose units as ____ but plants store them as ___- which you can eat to obtain energy glycogen, starch which of the following contains the bulk of all cell membranes phospholipids which of the following protein is composed of 4 polypeptides and has quaternary structure hemoglobin the first amino acid of any protein translated is the same-methionine true formation of a cancerous tumor by cells doing uncontrolled mitosis is an example of abnormal hyperplasia according to the _____ whenever energy is transferred from one molecule to another, some of it is lost as heat and is no longer available to do useful work law of thermodynamics the rate of an enzymatic reaction can be affected by all of the following except osmotic pressure which process does not require ATP diffusion water passes from the tissue fluids into the blood capillaries mainly because the blood has a higher concentration than the tissue fluids in a resting cell Na+ and Ca++ are lower in cytosolic concentration than in the activated site a red blood cell is placed in a solution with more solutes than plasma. The solution is called ___ and the RBC will undergo ____. Hypertonic, crenation cell A and cell B are located side by side within the same tissue but are not in direct contact with each other. Cell A releases a chemical messenger . In order for cell B to respond to this chemical messenger cell B must have receptors specific for the paracrine regulator. which would be a normal measure of asking glucose in venous blood 101 mg/ 100mL this fluid compartment is subdivided into blood plasma and interstitial fluid extracellular compartment water absorbs and releases large amounts of heat before changing temp. This is important in maintenance of body temperature steroid hormones are lipids table sugar, sucrose, is composed of glucose and fructose after amino acids are assembled into a polypeptide chain, the chain often coils into a spring like structure called the alpha helix. this coiling is due to hydrogen bonds when complimentary base pairing occurs in DNA adenine pairs with thymine translation is best described as the synthesis of specific proteins from the mRNA base sequence code messenger RNA carries genetic info from chromosomes to the ribosomes which of the following organic molecules is not commonly found in the cell membrane nucleic acids an atom or molecule has been oxidized when it has lost some electrons where does the krebs cycle occur in the mitochondrial matrix the conversion of noncarbohydrate molecules into glucose, in an example of gluconeogenesis which of the following statements is most correct regarding diffusion? the greater the concentration gradient, the faster the rate of diffusion membrane receptors use ____ to transduce a signal to the intracellular compartment g-proteins a protein that works as a biological catalyst is known as an enzyme when you obtain energy from glucose, you break it down into H2O and CO2, this is catabolism