College Bio Mindtaps chapters 2 & 3

Which of the following are true of molecules? Select all that apply. -A molecule is held together by a chemical bond. -All molecules contain only one element. -All molecules contain more than one element. -A molecule contains two or more atoms.

-A molecule is held together by a chemical bond. -A molecule contains two or more atoms.

Adjacent amino acids are linked together by the formation of a peptide bond between which of the following? -Two R groups -An R group and a carboxyl group -An amine group and a carboxyl group -Two amine groups

-An amine group and a carboxyl group

Which of the following best describes the difference between an atom and an element? -An element is a single unit of an atom. -An element is two or more of the same atom joined together by a chemical bond. -An atom is two or more elements joined together by a chemical bond. -An atom is a single unit of an element.

-An atom is a single unit of an element.

The number of particles in one mole of a substance is equal to what? Select all that apply. -Avogadro's number -Atomic mass -6.02×1023 -Molecular mass

-Avogadro's number -6.02×1023 -Molecular mass

Which of the following represent the experimental conditions of this experiment? Check all that apply. -No crowding agents -BSA -Ficoll 70

-BSA -Ficoll 70

What is the molecular formula of glucose? -C6H12O6 -C3H6O3 -C12H22O11 -C12H24O12

-C6H12O6

Is a key component of ketones. -Amino -Phosphate -Hydroxyl -Carboxyl -Carbonyl -Sulfhydryl

-Carbonyl

Participates in chemical reactions. Check all that apply. -Carbonyl -Amino -Hydroxyl -Phosphate -Carboxyl -Sulfhydryl

-Carbonyl -Amino -Hydroxyl -Phosphate -Carboxyl -Sulfhydryl

Which functional groups are polar? Select all that apply. -Methyl -Carbonyl -Hydroxyl

-Carbonyl -Hydroxyl

What types of functional groups do all amino acids contain? Select all that apply. -Methyl -Polar -Carboxyl -Amino -Basic

-Carboxyl -Amino

Is or includes at least one -OH or -O- group. Check all that apply. -Carboxyl -Sulfhydryl -Carbonyl -Phosphate -Amino -Hydroxyl

-Carboxyl -Phosphate -Hydroxyl

Phospholipids are the main components of which of the following? Select all that apply. -Phospholipid bilayers -Aqueous solutions -Cell membranes

-Cell membranes

Which type of bond is the strongest? -Ionic bond -Van der Waals interaction -Covalent bonds -Hydrogen bond

-Covalent bonds

Which types of bonds involve atoms sharing electrons? Select all that apply. -Covalent bonds -Ionic bonds -Nonpolar covalent bonds -Polar covalent bonds

-Covalent bonds -Nonpolar covalent bonds -Polar covalent bonds

What is the name of the chemical reaction, represented by the letter B in the preceding image, in which covalent bonds are made? -Hydrolysis -Hydrogen bonding -Dehydration synthesis

-Dehydration synthesis

What properties of carbon make it the central component of organic compounds? Select all that apply. -Ionic bonding -Formation of four covalent bonds -Covalent bonding with many different elements -Strong carbon-to-carbon bonds

-Formation of four covalent bonds -Covalent bonding with many different elements -Strong carbon-to-carbon bonds

Which of the following make up a protein's secondary structure? Select all that apply. -Helices -Sheets -Amino acid sequences -Loops

-Helices -Sheets -Loops

Which of the following might cause the denaturation of a protein? Select all that apply. -High concentrations of salt -Highly basic conditions -High heat -Highly acidic conditions

-High concentrations of salt -Highly basic conditions -High heat -Highly acidic conditions

Which types of functional groups are hydrophilic? Select all that apply. -Hydrocarbon -Polar -Ionic

-Hydrocarbon

What is the main component of lipids? -Oxygen -Hydrocarbons -Polar functional groups -Ionic functional groups

-Hydrocarbons

Which of the following bonds is not a chemical bond? -Polar covalent bond -Nonpolar covalent bond -Ionic bond -Hydrogen bond

-Hydrogen bond

Which type of bond is responsible for water molecules sticking to other water molecules? -Nonpolar covalent bond -Polar covalent bond -Ionic bond -Hydrogen bond

-Hydrogen bond

Which of the following are molecules? Select all that apply. -Hydrogen gas (H2) -Oxygen gas (O2) -Water (H2O) -Oxygen (O)

-Hydrogen gas (H2) -Oxygen gas (O2) -Water (H2O)

Protein denaturation usually refers to the disruption of which of the following types of molecular interactions? Select all that apply. -Hydrophobic interactions -Van der Waals attraction -Covalent bonds -Hydrogen bonds

-Hydrophobic interactions -Van der Waals attraction -Hydrogen bonds

Which of the following can impact the structure of a protein? Select all that apply. -Ion concentration -Salt concertation -pH -Temperature

-Ion concentration -Salt concertation -pH -Temperature

What type of bond would you expect might be formed between a potassium (K+) cation and a chloride (Cl-) anion? -Nonpolar covalent bond -Hydrogen bond -Ionic bond -Polar covalent bond

-Ionic bond

What type of chemical bond forms between two atoms bearing opposite charges? -Nonpolar covalent bond -Polar covalent bond -Hydrogen bond -Ionic bond

-Ionic bond

Which of the following are carbohydrates? Select all that apply. -Monosaccharides -Polysaccharides -Polypeptides -Starch

-Monosaccharides -Polysaccharides -Starch

Which molecules function in a cell's energy metabolism? Select all that apply. -NAD+ -Nucleotides without phosphate groups -ATP

-NAD+ -ATP

What components do all nucleic acids, both DNA and RNA, contain? Select all that apply. -Nucleotides -Nitrogenous bases -Deoxyribonucleic acid -Phosphate groups -5-carbon sugars

-Nitrogenous bases -Phosphate groups -5-carbon sugars

Which of the following ALWAYS contain the elements C, H, O, N, and P? -Nucleic acids -Proteins -Lipids -Carbohydrates

-Nucleic acids

Two different isotopes of an atom differ in which of the following? -Number of neutrons in the nucleus -Number of neutrons in the outermost energy level -Number of electrons in the outermost energy level -Number of protons in the nucleus

-Number of neutrons in the nucleus

Structure of Hydroxyl

-OH

Structure of Phosphate

-OPO^2- 3

Which of the following are elements? Select all that apply. -Oxygen (O) -Hydrogen gas (H2) -Water (H2O) -Hydrogen (H)

-Oxygen (O) -Hydrogen (H)

Amino acids often have additional functional groups. For example, phosphoserine has an additional functional group, shaded here in blue. What is the name of this group? -Phosphate -Carbonyl -Carboxyl -Amino

-Phosphate

Which type of chemical bond generates polarity within a water molecule? -Polar covalent bond -Nonpolar covalent bond -Ionic bond -Hydrogen bond

-Polar covalent bond

Which of the following best describes table salt? -Negatively charged sodium ions and positively charged chloride ions joined together by ionic bonds. -One oxygen atom covalently bonded to two hydrogen ions. -Positively charged sodium ions and negatively charged chloride ions joined together by covalent bonds. -Positively charged sodium ions and negatively charged chloride ions joined together by ionic bonds.

-Positively charged sodium ions and negatively charged chloride ions joined together by ionic bonds.

What level of protein structure is least likely to be affected if a protein's environment experiences a shift in pH below its optimal range? -Quaternary -Primary -Tertiary -Secondary

-Primary

Structure of a Sulfhydryl

-SH

Which of the following are properties of water molecules? Select all that apply. -Adhesion -Surface tension -Capillary action -Cohesion

-Surface tension -Cohesion

Which level of organization of protein molecules is the overall shape of the polypeptide chains? -Secondary -Quaternary -Primary -Tertiary

-Tertiary

Which of the following best describes the reason water is considered a polar molecule? -Each of the hydrogen atoms have a different, negative charge. -The hydrogen atoms have a slightly positive charge while the oxygen atom has a slightly negative charge. -There is no difference in the charge at any part of the water molecule. -The hydrogen atoms have a slightly negative charge, while the oxygen atom has a slightly positive charge.

-The hydrogen atoms have a slightly positive charge while the oxygen atom has a slightly negative charge.

Rutherford's observations support which of the following statements about atomic structure? Check all that apply. -Alpha particles cannot interact with Au atoms. -The nucleus of an atom contains virtually all of the atom's mass. -The nucleus of an atom takes up very little space.

-The nucleus of an atom contains virtually all of the atom's mass. -The nucleus of an atom takes up very little space.

What can make up a chemical compound? Select all that apply. -Two or more elements -Exactly one element -Molecules -Atoms

-Two or more elements -Molecules -Atoms

Which of the following types of molecular interactions play a role in protein folding? Select all that apply. -Van der Waals attraction -Covalent bonds -Hydrogen bonds -Hydrophobic interactions

-Van der Waals attraction -Covalent bonds -Hydrogen bonds -Hydrophobic interactions

Some less common forms of certain elements will decay and emit a detectable particle signature. For example, ^3H is far less common than its counterpart ^1H. When an atom of ^3H decays, it changes dramatically, as shown by the decay reaction: ^3H → ^3He + e- Which of the following statements regarding ^3H and how it decays are true? Check all that apply. -^3H can be used as a tracer in biological research. -The atom's atomic mass changes. -A neutron decomposes into a proton and an electron.

-^3H can be used as a tracer in biological research. -A neutron decomposes into a proton and an electron.

A salt is made up of which components? Select all that apply. -Acid -Base -Water

-acid -water

Proteins are made up of _______________ joined by ____________________.

-amino acids -peptide bonds

Oleic acid is a monounsaturated fatty acid and the major fatty acid in olive oil (hence its name). Of all the oils, olive oil has the highest percentage of monounsaturated fatty acids, which may confer health benefits. (Incidentally, oleic acid is also released by dead insects and acts as a death recognition signal.) The molecular formula for oleic acid is C18H34O2. Which of the following terms correctly describe oleic acid? Check all that apply. -Isotope -Element -Compound -Matter

-compound -matter

Electrons move in _____________ and _____________ consists of electrons in orbitals at the same principal energy level.

-electron orbitals -an electron shell

Unsaturated fatty acids contain ___________ bonds to __________________ than do saturated fatty acids.

-fewer -hydrogen

The structure of glucose seen here has _______ asymmetric carbon(s). Therefore, ß-Glucose, a sugar ______ have enantiomers.

-five -does

The largest number of amino acids found in proteins are _______________ meaning that they tend to be ___________________ water.

-hydrophobic -repelled from

In the cytosol, most protein folding _______________ spontaneous, meaning that most proteins ____________ refold following denaturation.

-is not -cannot

Organic polymers are made up of ______________ linked through ____________________________.

-monomers -condensation reactions

_______________ DNA is made up of monomers called _______________

-nucleic acid -nucleotides

Water is a ___________ molecule with a __________ specific heat.

-polar -high

In a _______________, two atoms share electrons unequally, while in a _________________, atoms are split equally between two atoms.

-polar covalent bond -nonpolar covalent bond

Which type of isomer differs in the covalent arrangement of atoms? -Structural -Geometric -Enantiomer

-structural

Two atoms of different elements in the same column, such as Li and H , have ______________________ of valence electrons. As a result, they face _______________ challenges in trying to achieve a stable electron configuration.

-the same number -the same

A molecule of amylose requires _____________ linkages between its individual monosaccharide units.

1-4

# of neutrons in Magnesium (atomic number 12, atomic mass 24)

12

# of protons in Magnesium (atomic number 12, atomic mass 24)

12

# of protons in Potassium (atomic number 19, atomic mass 39)

19

How many oxygen (O) atoms are in a single molecule of oleic acid? -15 -10 -2 -0

2

# of neutrons in Potassium (atomic number 19, atomic mass 39)

20

# of protons in Copper (atomic number 29, atomic mass 63)

29

# of neutrons in Copper (atomic number 29, atomic mass 63)

34

Based on the data above, what is the maximum number of disulfide linkages found in a molecule of native (natural) ribonuclease?

4

What is the activity of a ribonuclease molecule that has four sulfhydryl (-SH ) groups?

50%

In an Au atom, how many energy levels contain electrons? -6 -7 -1 -2

6

Hydrogen (H) is an example of which of the following? -An element -A chemical bond -A molecule -A protein

An element

Which type of amino acid would you expect to find in large numbers in a protein found in a deep-sea hydrothermal vent (a very hot environment)? -Cysteines -Nonpolar amino acids -Polar amino acids -Hydrophobic amino acids

Cysteines

Ficoll 70 is an organic molecule with the chemical formula C12H22O11 . BSA is an organic molecule also known as bovine serum albumin. Which of these crowding agents is a carbohydrate?

Ficoll 70

Why are water molecules less dense in ice than in water? -Van der Waals forces -Ice floats -Hydrogen bonding -Specific heat

Hydrogen bonding

Assume that instead of being told the molecular formula of oleic acid, you were given the simplest formula of oleic acid. Based only on its simplest formula, would you still be able to tell how many O atoms are in a single molecule of oleic acid? -Yes -No

No

Most carbohydrates are what type of molecule? -Disaccharides -Glycosidic linkages -Polysaccharides -Monosaccharides

Polysaccharides

What level of protein structure includes polypeptide aggregates? -Tertiary -Primary -Quaternary -Secondary

Quaternary

Water molecules have ___________ attraction for sodium and chloride ions than sodium and chloride ions have to each other.

a greater

Based on this experiment, proteins fold better in __________________ environment.

an uncrowded

Which of the following is defined by its inability to be broken down into simpler substances by ordinary chemical reactions? -Element -Atom -Matter -Subatomic particles

atom

What is the term for the number of protons in an atom? -Atomic mass unit -Atomic mass -Mass number -Atomic number

atomic number

Which element is the backbone of organic molecules? -Oxygen -Nitrogen -Hydrogen -Carbon

carbon

Is Magnesium a trace or common element?

common

Is Potassium a trace or common element?

common

The number of free sulfhydryl groups in ribonuclease increases as the protein undergoes a chemical process called reduction. Therefore, reduction causes ribonuclease to undergo ___________________.

denaturation

A strong acid is a proton __________

donor

Amino acids are so named because every amino acid has the same amino group and the same carboxyl group, shown here shaded in ______________

green

Which of the following biological macromolecules is usually not considered to be a polymer? -DNA -Proteins -Polysaccharides -Lipids

lipids

A buffer maintains a pH that is which of the following? -Acidic -Neutral -Basic -Consistent

neutral

Is the monosaccharide shown here in its linear form? -yes -no

no

In the table, only the atomic mass of the most common form of the element is shown. Other less common forms of the same element will differ in their ______________

number of neutrons

___________________ link together amino acid monomers in proteins.

peptide bonds

Alpha particles are helium (He ) atoms that have lost two electrons. The charge of an alpha particle must be _______________

positive (2+)

A protein's _______________ structure is entirely determined by the sequence of amino acids.

primary

Amino acids are the monomers that make up which of the following polymers? -Proteins -Lipids -DNA -Polysaccharides

proteins

Is Copper a trace or common element?

trace

In contrast, gold foil is a pure, neutrally charged lattice of gold atoms. The atomic number of gold (Au ) is 79. Given the number of electrons it has, a neutral Au atom should contain ________________ in its 1s orbital.

two electrons

Dehydration synthesis always results in the formation of which of the following? -Water -Peptides -Amino acids -Proteins

water