Ch. 2

An acid with a pH of 6 has ________ hydrogen ions than pure water. 10-fold fewer 100-fold fewer 10-fold more 100-fold more

10-fold more

An atom with 3 electrons in its outermost (valence) shell may have a total of ________ electrons altogether. 8 3 13 17

13

An atom with an atomic number of 10 and a mass number of 24 would have ________. 10 neutrons 14 electrons 14 neutrons 24 protons

14 neutrons

The numbers listed represent the number of electrons in the first, second, and third energy levels, respectively. On this basis, which of the following is an unstable or reactive atom? 2, 8 2, 8, 8 2, 8, 1 2

2, 8, 1

What is the ratio of fatty acids to glycerol in triglycerides (neutral fats)? 2:1 4:1 3:1 1:1

3:1

Atom X has 17 protons. How many electrons are in its valence shell (outermost energy level)? 5 3 10 7

7

If atom X has an atomic number of 74 it would have which of the following? 37 protons and 37 neutrons 37 protons and 37 electrons 74 protons 37 electrons

74 protons

Which of the following would be regarded as an organic molecule? H2O CO2 NaOH CH4

CH4

Select the most correct statement regarding nucleic acids. DNA is a long, double-stranded molecule made up of A, T, G, and C bases. tDNA is considered a "molecular slave" of DNA during protein synthesis. RNA is a long, single-stranded molecule made up of the bases A, T, G, and C. Three forms exist: DNA, RNA, and tDNA.

DNA is a long, double-stranded molecule made up of A, T, G, and C bases.

Which statement about enzymes is FALSE? Most enzymes can catalyze millions of reactions per minute. Enzymes require contact with substrate in order to assume their active form. Enzymes may use coenzymes derived from vitamins or cofactors from metallic elements. Enzymes may be damaged by high temperature.

Enzymes require contact with substrate in order to assume their active form.

Which of the following does NOT describe enzymes? Enzymes work by raising the energy of activation. Some enzymes are purely protein. Each enzyme is chemically specific. Some enzymes are protein plus a cofactor.

Enzymes work by raising the energy of activation.

A dipeptide can be broken into two amino acids by dehydration synthesis. True False

False

About 60% to 80% of the volume of most living cells consists of organic compounds. True False

False

Chemical properties are determined primarily by neutrons. True False

False

Triglycerides are a poor source of stored energy. True False

False

A patient is hyperventilating. The "blowing off" of excessive carbon dioxide causes a decrease in blood H+ concentration. How can the carbonic acid-bicarbonate buffer system function to correct this imbalance?CO2 + H2O ↔ H2CO3 ↔ H+ + HCO3- HCO3- binds with H+ to form H2CO3 and lower pH H2CO3 dissociates to form more H+ and lower pH HCO3- binds with H+ to form H2CO3 and raise pH H2CO3 dissociates to form more H+ and raise pH

H2CO3 dissociates to form more H+ and lower pH

Which of the following is a neutralization reaction? NH3 + H+ → NH4+2 NaOH → Na+ + OH- HCl → H+ + Cl- HCl + NaOH → NaCl + H2O

HCl + NaOH → NaCl + H2O

Which of the following statements is FALSE? Chemical reactions proceed more quickly at higher temperatures. Catalysts increase the rate of chemical reactions, sometimes while undergoing reversible changes in shape. Larger particles move faster than smaller ones and thus collide more frequently and more forcefully. Chemical reactions progress at a faster rate when the reacting particles are present in higher numbers.

Larger particles move faster than smaller ones and thus collide more frequently and more forcefully.

Which of the following elements is necessary for proper conduction of nerve impulses? I Na Fe P

Na

Which of the following does NOT describe uses for the ATP molecule? pigment structure mechanical work chemical work transport down their concentration gradient

Pigment structure

Salivary amylase is an enzyme produced by the salivary glands that breaks down carbohydrates. What will happen to this enzyme as it follows the food into the stomach where the pH drops to 2.5? The enzyme will denature but retain its function. The enzyme will continue to function as it remains unchanged in chemical reactions. The enzyme will denature and become inactive. The enzyme will assume an alternate form and catalyze additional reactions.

The enzyme will denature and become inactive.

What does the formula C6H12O6 mean? There are 6 carbon, 12 hydrogen, and 6 oxygen atoms. There are 6 calcium, 12 hydrogen, and 6 oxygen atoms. The substance is a colloid. The molecular weight is 24.

There are 6 carbon, 12 hydrogen, and 6 oxygen atoms.

What does CH4 mean? This is an inorganic molecule. There is one carbon and four hydrogen atoms. There are four carbon and four hydrogen atoms. This was involved in a redox reaction.

There is one carbon and four hydrogen atoms.

Which of the following does NOT characterize proteins? Their function depends on their three-dimensional shape. They appear to be the molecular carriers of coded hereditary information. They have both functional and structural roles in the body. They may be denatured or coagulated by heat or acidity.

They appear to be the molecular carriers of coded hereditary information.

A charged particle is generally called an ion or electrolyte. True False

True

All organic compounds contain carbon except CO2 and CO. True False

True

Buffers resist abrupt and large changes in the pH of body fluids by releasing or binding ions. True False

True

Glucose is an example of a monosaccharide. True False

True

Glycogen, the storage form of glucose, is primarily stored in skeletal muscle and liver cells. True False

True

Hydrogen bonds are too weak to bind atoms together to form molecules, but they do hold different parts of a single large molecule in a specific three-dimensional shape. True False

True

It is the difference in the R group that makes each amino acid chemically unique. True False

True

Omega-3 fatty acids appear to decrease the risk of heart disease. True False

True

The acidity of a solution reflects the concentration of free hydrogen ions in the solution. True False

True

The lower the pH, the higher the hydrogen ion concentration. True False

True

The pH of body fluids must remain fairly constant for the body to maintain homeostasis. True False

True

The sharing of electrons in covalent bonds makes them stronger than ionic and hydrogen bonds. True False

True

________ is fat soluble, produced in the skin on exposure to UV radiation, and necessary for normal bone growth and function. Vitamin A Vitamin D Vitamin K Cortisol

Vitamin D

Which of the following is incorrectly matched? amino acid; protein eicosanoid; triglyceride monosaccharide; carbohydrate nucleotide; nucleic acid

eicosanoid; triglyceride

Which of the following statements is FALSE? The pH of blood is slightly basic. The more hydrogen ions in a solution, the more acidic the solution. When acids and bases are mixed, they react with each other to form water and a salt. When the hydrogen ion concentration decreases, the hydroxyl ion concentration also decreases.

When the hydrogen ion concentration decreases, the hydroxyl ion concentration also decreases. Submit

Choose the answer that best describes HCO3-. a proton donor a weak acid a bicarbonate ion common in the liver

a bicarbonate ion

What is a cation? an atom that shares its valence electrons an atom that gains one or more electrons and acquires a net negative charge a molecule that has both positive and negative charges an atom that loses one or more electrons and acquires a net positive charge

an atom that loses one or more electrons and acquires a net positive charge

Forming glycogen as energy storage in the liver is an example of ________. anabolism exergonic oxidation catabolism

anabolism

Which of the following is an example of a suspension? water blood cytosol rubbing alcohol

blood

What happens in redox reactions? the reaction is uniformly reversible both decomposition and electron exchange occur the electron acceptor is oxidized the organic substance that loses hydrogen is usually reduced

both decomposition and electron exchange occur

The four elements that make up about 96% of body weight are ________. carbon, oxygen, phosphorus, calcium nitrogen, hydrogen, calcium, sodium sodium, potassium, hydrogen, oxygen carbon, oxygen, hydrogen, nitrogen

carbon, oxygen, hydrogen, nitrogen

Tendons are strong, rope-like structures that connect skeletal muscle to bone. Which of the following proteins would provide strength to a tendon? actin collagen molecular chaperone albumin

collagen

The single most abundant protein in the body is ________. DNA collagen glucose hemoglobin

collagen

You notice that you cannot read your book through a test tube of patient fluid held against the print, making it so blurred as to be unreadable. There is no precipitant in the bottom of the beaker, though it has been sitting for several days in a rack. What type of liquid is this? mixture colloid solution suspension

colloid

Which type of proteins can function as chemical messengers or as receptors in the plasma membrane? defensive communication enzyme transport

communication

ATP → ADP + Pi is an example of a(n) ________ reaction. reversible exchange decomposition synthesis

decomposition

Isotopes differ from each other only in the number of electrons the atom contains. True False

false

The atomic number of any atom is equal to the number of electrons in its nucleus and is written as a subscript to the left of its atomic symbol. True False

false

Select which reactions will usually be irreversible regarding chemical equilibrium in human bodies. H2O + CO2 to make H2CO3 ADP + Pi to make ATP glucose molecules joined to make glycogen glucose to CO2 and H2O

glucose to CO2 and H2O

Carbohydrates are stored in the liver and skeletal muscles in the form of ________. triglycerides cholesterol glycogen glucose

glycogen

Starch is the stored carbohydrate in plants, while ________ is the stored carbohydrate in animals. triglyceride cellulose glucose glycogen

glycogen

Which property of water is demonstrated when we sweat? polar solvent properties high heat capacity high heat of vaporization reactivity cushioning

high heat of vaporization

When DNA is replicated, it is necessary for the two strands to "unzip" temporarily. Choose which bonding type is most appropriate for holding the strands together in this way. hydrogen bonding polar covalent bonding non-polar covalent bonding ionic bonding

hydrogen bonding

A high fever causes an enzyme to lose its three-dimensional structure and function. Which bonds are broken when a protein denatures? polar covalent bonds non-polar covalent bonds ionic bonds hydrogen bonds

hydrogen bonds

What type of chemical bond can form between an atom with 11 protons and an atom with 17 protons? hydrogen polar covalent ionic non-polar covalent

ionic

Salts are always ________. single covalent compounds hydrogen bonded ionic compounds double covalent compounds

ionic compounds

If the atomic mass of an element is 14 and the atomic number is 6, which of the following would describe this element? isotope ion compound neutral

isotope

What structural level is represented by the sequence of amino acids in a polypeptide chain? primary structure secondary structure tertiary structure quaternary structure

primary structure

Which of the following is chemically inert (unreactive)? sodium (atomic number 11) neon (atomic number 10) oxygen (atomic number 8) carbon (atomic number 6)

neon (atomic number 10)

With a family history of cardiovascular disease, which toast spread would be considered the most "heart healthy"? lard (pig fat) olive oil butter containing butter fat margarine containing trans fats

olive oil

Lithium has an atomic number of 3. How many electrons are there in the outermost (valence) shell? one two three zero

one

Starch is a ________. triglyceride polysaccharide disaccharide monosaccharide

polysaccharide

When frying an egg, the protein albumin denatures and maintains only its ________ structure. secondary tertiary quaternary primary

primary

What is a chain of more than 50 amino acids called? polysaccharide triglyceride protein nucleic acid

protein

The basic structural material of the body consists of ________. nucleic acids carbohydrates lipids proteins

proteins

Carbohydrates and proteins are built up from their basic building blocks by the ________. removal of a carbon atom between each two units addition of a carbon atom between each two units removal of a water molecule between each two units addition of a water molecule between each two units

removal of a water molecule between each two units

The genetic information is coded in DNA by the ________. regular alteration of sugar and phosphate molecules sequence of the nucleotides arrangement of the histones three-dimensional structure of the double helix

sequence of the nucleotides

Which of the following is the major positive ion outside cells? potassium magnesium hydrogen sodium

sodium

Which of the following is a general function for a fibrous protein? catalysis structural framework transport body defense protein management

structural framework

Amino acids joining together to make a peptide is a good example of a(n) ________ reaction. exchange reversible synthesis decomposition

synthesis

The chemical symbol O=O means ________. the atoms are double bonded both atoms are bonded and have zero electrons in the outer orbit zero equals zero this is an ionic bond with two shared electrons

the atoms are double bonded

A chemical reaction in which bonds are created is usually associated with ________. degradation forming a smaller molecule the release of energy the consumption of energy

the consumption of energy

Which of the following is NOT considered a factor in influencing a reaction rate? particle size concentration of reactants time temperature

time

In a DNA molecule, the phosphate serves ________. to bind the sugars to their bases as nucleotides as a code to hold the molecular backbone together

to hold the molecular backbone together

A chemical bond is an energy relationship between outer electrons and neighboring atoms. True False

true

Mixtures are combinations of elements or compounds that are physically blended together but are not bound by chemical bonds. True False

true

The fact that no chemical bonding occurs between the components of a mixture is the chief difference between mixtures and compounds. True False

true

How many phosphates would ADP have attached to it? none one two three

two

Phospholipids make up most of the lipid part of the cell membrane. Since water exists on both the outside and inside of a cell, which of the following phospholipid arrangements makes the most sense? a single layer of phospholipids with the polar heads facing inside the cell two back-to-back phospholipid layers with the non-polar tails facing out on both sides two back-to-back phospholipid layers with the polar heads facing out on both sides a single layer of phospholipids with the polar heads facing outside the cell

two back-to-back phospholipid layers with the polar heads facing out on both sides

Phospholipids make up most of the lipid part of the cell membrane. Since water exists on both the outside and inside of a cell, which of the following phospholipid arrangements makes the most sense? two back-to-back phospholipid layers with the polar heads facing out on both sides a single layer of phospholipids with the polar heads facing outside the cell a single layer of phospholipids with the polar heads facing inside the cell two back-to-back phospholipid layers with the non-polar tails facing out on both sides

two back-to-back phospholipid layers with the polar heads facing out on both sides

In general, the lipids that we refer to as oils at room temperature have ________. a high water content long fatty acid chains saturated fatty acids unsaturated fatty acids

unsaturated fatty acids