Chapter 2 (Pearson)

How would you describe the polarity of the enzyme glucose-6-phosphatase, knowing it is a transmembrane protein?

Amphipathic

Which of the following is (are) organic? To be marked correct, you'll need to select all true statements, as there may be more than one correct answer. CO2 CH4 C6H12O6 HCl

CH4 C6H12O6

How are DNA and RNA different? To be marked correct, you'll need to select all true statements, as there may be more than one correct answer. View Available Hint(s) DNA is made from nucleotides, while RNA is made from nucleic acids. DNA is usually double-stranded, while RNA is usually single-stranded. Deoxyribonucleotides make up DNA, while ribonuclotides make up RNA. Sugar phosphate bonds are in RNA, while DNA contains deoxyribose bonds.

DNA is usually double-stranded, while RNA is usually single-stranded. Deoxyribonucleotides make up DNA, while ribonuclotides make up RNA.

What type of reaction does the figure show?

Decomposition and Hydrolysis

What kind of bond is broken in order to digest cornstarch?

Glycosidic, covalent bond

_____________ are atoms with the same number of protons but a different number of neutrons.

Isotopes

In the figure shown, which atom(s) will have a partial negative charge?

Nitrogen and Oxygen

Is glycogen an organic or inorganic compound?

Organic Compound

Which particle is described incorrectly?

Proton: Found in shells orbiting the nucleus

Which of the following is incorrectly matched?

Salt: Formed by the combination of hydrogen ions (H+) and hydroxide ions (OH-)

Cations:

Sodium Potassium Magnesium Calcium Iron

In cornstarch therapy, what is the solvent and what is the solute?

Solute: Cornstarch Solvent: Water

How would oysters tainted with Vibrio vulnificus taste?

There is no change in the flavor of tainted oysters.

Which of the following lipids tends to be liquid at room temperature?

Unsaturated lipids

Pure water is defined by

a neutral pH of 7 and an equal number of H+ and OH- ions.

Microorganisms that thrive in acidic environments are called _____.

acidophiles

In the figure shown, what does the dotted line represent?

an electrostatic interaction between the partially-positive hydrogen and the partially-negative nitrogen

Which of the following is not one of the four main groups of biomolecules?

electrolytes

Electrolytes

include acids, bases, and salts, are ionic compounds dissolved in solution and are involved in regulating the nervous system, heartbeat, blood volume and water balance in the body.

The primary structure of a protein

is the linear sequence of amino acids which are held together by peptide bonds and is dictated by genetic sequence and is unique to that protein and lays the foundation for all higher order structure of that protein.

Compared to a solution with a pH value of 4, a solution with a pH value of 2 has ________ H+ ions.

one hundred times as many

What is an emerging disease?

one that appears in a population for the first time

Which level of protein structure can involve hydrogen bonds?

secondary and tertiary

Choose the true statement(s) about activation energy. To be marked correct, you'll need to select all true statements, as there may be more than one correct answer. Synthesis reactions have an activation energy, but decomposition reactions do not. Activation energy is the minimum amount of energy needed to start a reaction. Exergonic reactions do not have an activation energy. Enzymes lower the activation energy of a reaction.

Activation energy is the minimum amount of energy needed to start a reaction. Enzymes lower the activation energy of a reaction.

Select the true statement(s) about ionic bonds. To be marked correct, you'll need to select all true statements, as there may be more than one correct answer. Ionic bonds are required to form polar molecules. An ionic bond requires the transfer of electrons from one atom to another. The atoms of ionic compounds only exist as ions in a solution. An ionic bond is an electrostatic force that exists between cations and anions.

An ionic bond requires the transfer of electrons from one atom to another. An ionic bond is an electrostatic force that exists between cations and anions.

What effect do antacids have on stomach contents?

Antacids raise the pH of stomach contents.

Hydrogen bonds

are responsible for the unique properties of water and are involved in stabilizing the structure of proteins and nucleic acids.

Choose the true statement(s) regarding the pH scale. To be marked correct, you'll need to select all true statements, as there may be more than one correct answer. A solution's pH decreases as H+ concentration increases. Acidosis is a pathological situation in which the body has a lower than normal blood pH. Most pH values fall between 0 and 14, with 14 being very acidic and 0 being basic. A solution with a pH of 6 has an H+ concentration that is tenfold higher than that of a solution with a pH of 7.

A solution's pH decreases as H+ concentration increases. Acidosis is a pathological situation in which the body has a lower than normal blood pH. A solution with a pH of 6 has an H+ concentration that is tenfold higher than that of a solution with a pH of 7.

Choose the true statement(s) about polar covalent bonds. To be marked correct, you'll need to select all true statements, as there may be more than one correct answer. Atoms within a molecule may take on a charge due to the unequal sharing of electrons. These types of bonds commonly involve highly electronegative atoms, like hydrogen. These types of bonds generate dipoles. The presence of dipoles in polar molecules lay the foundation for ionic bonds.

Atoms within a molecule may take on a charge due to the unequal sharing of electrons. These types of bonds generate dipoles.

Select all of the true statements regarding biomolecules and their building block monomers. To be marked correct, you'll need to select all true statements, as there may be more than one correct answer. Nucleotides are built from nucleic acids. Fatty acids are built from glycerol. Carbohydrates are built from monosaccharides. Proteins are built from amino acids.

Carbohydrates are built from monosaccharides. Proteins are built from amino acids.

Choose the true statement(s) about equilibrium. To be marked correct, you'll need to select all true statements, as there may be more than one correct answer. By definition, equilibrium is a term that mainly applies to reversible reactions. Reactions at equilibrium have the forward and reverse reactions occurring at the same rate. In reactions that are at equilibrium, the amount of product(s) and the amount of reactant(s) present are equal. Equilibrium is not a static situation where the reaction just stops.

By definition, equilibrium is a term that mainly applies to reversible reactions. Reactions at equilibrium have the forward and reverse reactions occurring at the same rate. Equilibrium is not a static situation where the reaction just stops.

Which of the biomolecules is incorrectly matched with its building block? Nucleic acid: Nucleotide Protein: Amino acid Carbohydrate: Polysaccharide Lipid: Fatty acid Lipid: Glycerol

Carbohydrate: Polysaccharide

Which of the following elements make up the reactants in the chemical equation catalyzed by glucose-6-phosphatase?

Carbon Hydrogen Oxygen

Select the TRUE statements. Carbon's atomic number is 6. A carbon atom has 12 electrons One carbon atom contains 6 protons and 6 neutrons. Carbon's atomic mass is 16.

Carbon's atomic number is 6. One carbon atom contains 6 protons and 6 neutrons.

____________ are organic or inorganic substances that increase the rate of a reaction but are not used up in the reaction.

Catalysts

Hundreds of mutations in the enzyme glucose-6-phospahatase have been discovered; most result in small errors in amino acid sequence. Based on your introductory exposure to protein structure, explain why this would impact the enzyme's function.

Changes in amino acid sequence affect the structure of the protein, and may promote protein misfolding, potentially decreasing enzyme function.

Anions:

Chloride Carbon dioxide (measured as bicarbonate, HCO3) Phosphate

Assume you are a pediatric patient suffering from a severe form of infectious diarrhea. Which of the following condition(s) is/are they most likely to develop as a direct result of diarrhea? To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.

Electrolyte imbalance Dehydration

Choose the false statement(s) about carbohydrates. To be marked correct, you'll need to select all false statements, as there may be more than one correct answer. Glucose is stored in the liver as starch. Carbohydrates serve as the chief energy source for a cell. Monosaccharides are linked together by glycosidic bonds. Sucrose is an example of a monosaccharide.

Glucose is stored in the liver as starch Sucrose is an example of a monosaccharide.

How would you describe Henry's blood pH in comparison with normal ranges? In relation to his observed blood pH, what would he be described as manifesting?

Henry's blood pH is lower than normal, producing acidosis.

Plasma membranes, the key boundary layer of cells, are composed of amphipathic molecules called phospholipids. Why would neither purely hydrophilic nor purely hydrophobic molecules be a suitable molecule for plasma membranes?

Hydrophilic molecules would dissolve in the aqueous environment in which cells live, disrupting the structural integrity of the cell, and hydrophobic molecules would be unable to interact with the aqueous environment in which cells live.

This kind of bacterial pneumonia can be difficult to diagnose. Often, patients (especially elderly adults) may not produce enough sputum for specimen sampling. Gram stains and culture of organisms are the mainstays of diagnostic tests, but they are often inconclusive within the time frame necessary to manage the patient's disease. As such, more rapid testing is needed to make efficient decisions on the etiology of the infection. For this reason, many hospital labs are turning to serology, the use of specific antibody binding, to hasten diagnosis. The immune system produces molecules known as antibodies during an infection. The antibodies float through the body and are attracted to the foreign molecule, known as an antigen. Each antibody interacts with a single specific antigen, so the bonding of an antibody to an antigen is based in molecular interactions. Serology testing involves mixing a patient sample with antibodies and observing a binding event based on chemical bonding principles. Based on the information given, which of the following would you interpret to be the best description of this interaction?

Ionic Bonding

Why do patients with GSD exhibit hepatomegaly?

Patients with GSD I cannot release free glucose from glycogen stored in the liver, leading to an accumulation of glycogen within the liver.

Which type of bond links amino acids together to form a protein's primary structure?

Peptide bonds

One of the most common causes of pneumonia is Streptococcus pneumoniae, a gram-positive bacterium. Surrounding the bacterium is a thick structural component layer known as a capsule. This capsule is made up of repeating molecular units and serves as a sticky, protective macromolecule. There are over 84 known different molecular configurations of capsule, and it is the primary component of vaccines against this organism. The capsule is the antigen that we commonly detect in the serology testing referred to in the previous question. Based on the information given about capsules, which of the following types of molecules would you suspect comprises an S. pneumoniae capsule?

Polysaccharide Carbohydrate

The final tests ordered for the patient are a BUN (blood-urea-nitrogen) test, a procalcitonin test, and a CRP test. The BUN test measures kidney function and catabolism (an increased BUN signifies impairment, which is common in pneumonia). Calcitonin is a molecule derived from the splitting of a larger precursor molecule called procalcitonin. In healthy adults, the procalcitonin is converted to calcitonin, which then participates in calcium and phosphorus metabolism. The conversion of procalcitonin to calcitonin is inhibited by bacterial infection and immune responses; so, levels of procalcitonin are often elevated in patients with pneumonia. The other is test for CRP, which is synthesized by the liver and binds to phosphocholine on dead or damaged cells in order to mark those cells for immune responses. Measuring CRP level (normal levels are < 10 mg/ml) is a screen for infection and inflammation, because CRP levels can increase rapidly and markedly when processes go awry (in bacterial infection, CRP levels can range from 40 to 200 mg/ml). Various structural views of urea (for the BUN), procalcitonin, and CRP are shown below. Based on the functional groups and levels of structure you see, all these molecules are related to which macromolecule family?

Proteins

Choose the true statement(s) about atoms. To be marked correct, you'll need to select all true statements, as there may be more than one correct answer. The nucleus of an atom contains neutrons. An atom is the smallest unit of an element. The nucleus of an atom contains electrons. Atoms can vary their number of protons.

The nucleus of an atom contains neutrons. An atom is the smallest unit of an element.

While the lab is working on the diagnosis for the patient, the critical care team is assessing his basic functions. Since any living organism carries out chemical reactions, an infection skews the body's "normal" laboratory test values as the microbes compromise the body's functions. Another test ordered for the patient is an arterial blood gas (ABG) test. ABGs are performed to measure the pH, and amount of oxygen and carbon dioxide in the blood. The body carefully regulates and maintains blood pH within a very narrow range of 7.35 to 7.45. Abnormal pH values might signify that a patient is not regulating the level of carbon dioxide (CO2). Our patient with pneumonia has a blood pH of 7.52, and the partial pressure of CO2 in his blood is decreasing, likely because he is hyperventilating. Which of the following would be the best description of this situation?

The patient is in respiratory alkalosis (overly alkaline).

Plasma membranes must be in a fluid (liquid) state in order to function properly. Fluidity is temperature-dependent. Bacteria can regulate the specific lipid composition of their plasma membranes. Which of the following statements is true?

The proportion of unsaturated lipids in the plasma membrane will increase with cooler growth temperatures.

Choose the false statement(s) about van der Waals interactions. To be marked correct, you'll need to select all false statements, as there may be more than one correct answer. Van der Waals interactions are weaker than hydrogen and ionic bonds. They involve temporary dipoles that are the results of hydrogen bonding. These are significant stabilizers of molecular structures when added up. They do not bind atoms into molecules, but instead are electrostatic interactions between molecules.

They involve temporary dipoles that are the results of hydrogen bonding.

Choose the false statement(s) about dehydration synthesis. To be marked correct, you'll need to select all false statements, as there may be more than one correct answer. Water is released when a covalent bond is formed. Cells use dehydration synthesis to build macromolecules. Water is added to break covalent bonds. The following reaction depicts dehydration synthesis.A+B→ AB + H2O

Water is added to break covalent bonds.

Which type of lipid is incorrectly matched to its description? Glycolipid: A lipid linked to a carbohydrate Phospholipid: An amphipathic lipid found in the plasma membrane of cells Wax: Refers to any lipid which is solid at room temperature Steroid: Made of four fused hydrocarbon rings Mono-, di-, or triglyceride: One, two, or three fatty acids linked to a glycerol molecule

Wax: Refers to any lipid which is solid at room temperature

Activation Energy

is the minimum amount of energy needed to get a reaction started and is due to the necessity of collisions between reactants which have enough energy and with the reactants properly oriented and can be lowered by catalysts such as enzymes in biochemical reactions.

In the human genetic disease sickle cell anemia, a single change in the genetic sequence of the hemoglobin-beta gene results in the amino acid valine being substituted for the amino acid glutamic acid in the beta chain of the hemoglobin protein. Which level(s) of the protein structure will be affected?

primary, secondary, tertiary, and quaternary structures

The figure shown is an exergonic reaction because

the products have a lower final energy than the reactants.

An atom is best described as

the smallest unit of an element.