Chapter 2 Practice Questions

Urine has a pH of 6, therefore its H+ concentration is __________ times greater than a solution with a pH of 9

1,000

Phospholipids

1. Arrange themselves as a bilayer in the plasma membrane 2. Have hydrophilic heads and hydrophobic, non polar tails

Hydrogen bonds

1. Bonds between charged molecules or portions of a molecule 2. Weak attraction between slightly charged parts of molecules, which are readily broken and re-formed

Amino acids are built around a central _______ atom bonded to a(n) __________ atom and three other groups of atoms

1. Carbon 2. Hydrogen

DNA

1. Deoxyribose 2. Double-stranded with base pairing 3. Helical structure

DNA

1. Double stranded 2. Housed within the nucleus of an animal cell 3. Nitrogenous bases A, T, G, C

3 examples of covalent bond

1. H2 2. O2 3. N2

Steroids

1. Have backbone of four fused carbon rings 2. Attached groups will vary the ultimate function of the chemical

Hydrophilic

1. Ions 2. Proteins 3. K+ 4. Enzymes 5. Water 6. Polar compounds 7. Carbohydrates 8. Glucose 9. Starch

Hydrophobic

1. Lipids 2. Triglycerides 3. Cholesterol 4. Oil

2 examples of Ioic bond

1. NaCl 2. MgCl2

Fats and oils

1. Neutral (non polar), three-part fat 2. Composed of three fatty-acids and one glycerol

The four most common elements of the human body

1. Oxygen 2. Hydrogen 3. Carbon 4. Nitrogen

The reason water behaves in this manner is because the _________ charge on the hydrogen end of the water molecule is attracted to the negative charge of a polar molecule, while the _________ charge of the oxygen end of the water molecule is attracted to the positive side of a polar molecule

1. Positive 2. Negative

RNA

1. Ribose 2. Single stranded 3. Uracil

RNA

1. Single stranded 2. Nitrogenous bases A, U, G, C 3. Ribose sugar within backbone

As a result of the electron configuration of a water molecule, water is a great ________ because water can break up and surround a __________, as long as it is not ____________, dissolving it into solution

1. Solvent 2. Solute 3. Nonpolar

Covalent bonds

1. Strong chemical bond due to sharing of electrons 2. Bonds between hydrogen and oxygen atoms within a water molecule

Decreasing acidity

1. adding 1M (-OH) to a solution 2. removing H+ 3. adding base 4. removing acid 5. adding 1M H+ to a solution while simultaneously adding 2M (-OH)

Increasing acidity

1. adding 1M H+ to a solution 2. decreasing pH 3. decreasing proton acceptor concentration

One of the additional three groups is a(n) __________ group, another is a carboxyl group, or a(n) ___________, hence the name of this submit of proteins

1. amino 2. acid

_____ are the building blocks of proteins. They are made up of a center carbon atom bound to a positively charged ________ group and a negatively charged _________ group and a side chain

1. amino acids 2. amino 3. carboxyl

Polysaccharide

1. cellulose 2. starch 3. glycogen

Nonpolar molecules

1. consists of bonds formed between the same elements 2. C--C 3. O--O 4. Triglycerides

Polar Molecules

1. contains different elements that are bonded together 2. water 3. glucose

Monosaccharide

1. glucose 2. fructose 3. C6H12O6

When water breaks apart, it releases positively charged _______ ions and negatively charged ______ ions

1. hydrogen 2. oxygen

Sodium ion

1. most common extracellular cation 2. most important in osmotic movement of water

Potassium ion

1. most common intracellular cation 2. function in pH balance

_______ formed by ________ reactions link amino acids together, forming a linear chain

1. polypeptides 2. dehydration

The _________ of a protein is the sequence of amino acids that are attached together by ______ bonds

1. primary structure 2. peptide

Isotopes of the same element have the same number of ________ but differ in the number of _________

1. protons and electrons 2. neutrons

In the _________ of a protein the polypeptide is folded through the mechanism of amino acids rotating around bonds and folding into an alpha helix or beta pleated sheet structure and stabilized by _________ bonds

1. secondary structure 2. hydrogen

Disaccharide

1. sucrose 2. maltose 3. lactose 4. C12H22O11

In the _______ of a protein the amino acid side chains of the folded peptide interact, forming a complex _____________

1. tertiary 2. 3-dimensional shape

The ________ structure of a protein determines its function, and can be ___________ by heat, acids, or bases

1. tertiary 2. denatured

Non polar molecules consist of bonds formed between ________ elements or by ________ bonds

1. the same 2. C--H

Glucose and galactose are examples of molecules that have ________ molecular formulas but _______ structural formulas

1. the same 2. different

A solution of pH 2.0 is _________ more acidic than a solution of pH 3.0

10 times

Household ammonia has a pH of 11, therefore its H+ concentration is ___________ times less than a solution with a pH of 7

10,000

Beer has a pH of 3, therefore its H+ concentration is ________ times greater than a solution with a pH of 5

100

Black coffee has a pH of 5, therefore its H+ concentration is ____________ times greater than a solution with a pH of 10

100,000

The atomic mass of carbon 13 is

13

Sulfur has an atomic mass of 32 and an atomic number of 16. With this information, the total number of electrons for this element is _________

16

Hydrogen can form ________ covalent bonds and oxygen can form _________

1; 2

Carbon atoms are unique in that their outer shell needs _______ additional electrons to be complete

4

Covalent bonds occur when the participating atoms that form the bond have ___________ electrons in the outer shell

4, 5, 6, or 7

The atomic number of carbon 13 is

6

If the atomic number of nitrogen (N) is 7, then the total number of electrons is equal to ____________

7

In humans, the most healthy pH is ________ or slightly basic

7.4

Likely to become an anion

Na Mg Al K Ca

An example of a structural formula is ___________

O=C=O

Likely to become a cation

P S Cl

All atoms of the same element have the same number of positive subatomic particles, _________, also known as the atomic number. Neutrons have a _________ charge when combined with protons, determine the atomic mass

Protons Neutral

The third group, which comprises the rest of the molecules, is a(n) _________ group, which varies depending on the specific amino acid

R

The nucleic acid that is single stranded and is located within the nucleus of the cell and the cytoplasm is __________________

Ribonucleic acid (RNA)

If an atom has seven electrons in the outer shell, it will tend to _________ electron

accept one

A solution with a pH below 7.0 is considered a(n) __________

acid

A(n) ________ acts to increase hydrogen ion concentration of a solution

acid

Substances that release hydrogen ions when dissociated in water are ____________

acids

The nucleotide that is the central molecule in the transfer of chemical energy within cells is __________

adenosine triphosphate (ATP)

Carbonic acid will dissociate and realize hydrogen ions in a(n) __________ environment

alkaline

A life threatening condition in which blood pH rises to about 7.8 is _________

alkalosis

Intramolecular bonding of polypeptide chains produce numerous _______ and beta sheets

alpha helices

The building blocks of proteins are called ___________, of which there are 20 different types

amino acids

When forming an ionic compound of NaCl, each chlorine atom becomes a(n) _______ because it receives an electron

anion

Lipids ________ polymers

are not

The smallest part of an element that maintains the properties of the element is defied as a(n) ______________

atom

A(n) ______ acts to decrease the hydrogen ion concentration of a solution

base

Human blood always contains some combination of carbonic acid and some ___________ ions as part of the buffer system

bicarbonate

HCO3- is also called the

bicarbonate ion

The amount of time it takes for 50% of radioactive material to leave the body is refereed to as the __________ half-life

biological

A(n) ______ acts to maintain a relatively stable concentration of hydrogen ions in a solution

buffer

They have two electron shells

carbon and nitrogen

When forming an ionic compound of NaCl, each sodium atom (Na) becomes a(n) ______ because it donates an electron

cation

Ionic bonds are formed between a _________________

cation and an anion

Each atom can have a slight ________

charge

When diagramming an atom, the electron shells __________ the nucleus must be filled first

closest to

Chloride ion

component of stomach acid

Non polar molecules contain non polar ______ bonds

covalent

The bond that is formed when atoms share electrons is a(n) ______________ bond

covalent

As the hydrogen ion concentration of a solution increases, the pH ___________

decreases

When the pH of a solution increases, the amount of hydrogen ions in the resolution is __________

decreasing

The double stranded nucleic acid that is found within the nucleus is ____________

deoxyribonucleic acid (DNA)

Isotopes of the same element have _________ atomic masses

different

Polar molecules contain _______ elements that are bonded together

different

Elements _________ become ions to satisfy the octet rule

do

The bond between two oxygen atoms would be a _________ covalent bond

double

If two carbon atoms share two pairs of electrons, they have a ______________ bond

double covalent

The second electron shell can hold up to _______ electrons

eight

An ion is formed when an atom gains or loses a(n) ____________

electron or electrons

The larger oxygen atom, with more protons, is more _________ than the hydrogen atom and attracts the electron pair closer

electronegative

Of the three basic components of an atom, _________ have a negative charge and are NOT located in the nucleus of the atom

electrons

The orbitals of an atom contain negatively charged particles called

electrons

These charges dictate how each atom will share the _________

electrons

Substances composed of atoms that all have the same number of protons are called

elements

A buffere resists pH changes by taking up ________ hydrogen or hydroxide ions

excess

A hydrogen atom of one water molecular binds via a hydrogen bond to a hydrogen atom of another water molecule

false

Bonds between water molecules are stronger than the bonds between the atoms within a water molecule

false

Ice is denser than liquid water at all temperatures True or false

false

It is ______ that most molecules formed with non polar bonds dissolve easily in water

false

It is _______ that most molecules formed with non polar bonds dissolve easily in water

false

The bonds between water molecules are stable True or false

false

Calcium ion

functions to create hardness of bone and teeth

Nucleic acids are macromolecules that store and transfer ________ information in cells

genetic

Examples of polar molecules are water and ________

glucose

Proteins with a carbohydrate attached are called _________

glycoproteins

Their outermost electron shell is full

helium and argon

The more hydroxide ions released by a base, the _______ the pH value of the solution becomes

higher

In a carbon skeleton, if a carbon atom does not have its required four bonds shown in the structural formula, the additional atoms are assumed to be _________ atoms

hydrogen

Milk of magnesia is commonly used as an antacid because it can also take up acidic _________ ions

hydrogen

Organic molecules always contain carbon and _______ atoms

hydrogen

They have oen electron shell

hydrogen and helium

Due to the electronegative nature of water, __________ in one molecule are attracted to oxygen atoms in the water molecules

hydrogen atoms

Sodium chloride (NaCl) is an example of a _________ molecule because, as the figure illustrates, it is soluble in water

hydrophilic

Molecules that are _______ are insoluble in water

hydrophobic

Molecules that are __________ are insoluble in water

hydrophobic

As the pH of a solution increases, the concentration of __________ ions increases

hydroxide

Bases are substances that release _______ ions

hydroxide

Isotopes of the same element have essentially __________ chemical characteristics

identical

As the hydrogen ion concentration of a solution decreases, the pH _________

increases

Lipids are _________ in water

insoluble

Na+ and Cl- are held together by _______ bonds to form NaCl

ionic

The bond that is formed when one ion donates an electron and another ion accepts the electron is called a(n) ___________ bond

ionic

The ionic bonds that hold together the sodium and chloride ions in a lattice crystal structure compose a(n) ____________

ionic compounds

Atoms that have gained or lost electrons and are no longer electrically neutral are called

ions

Molecules composed same number elements but arranged differently in space are called

isomers

Molecules that are composed of the same number and kinds of elements but arranged differently are called ____________

isomers

If different atoms have the same numbers of neutrons they are called

isotopes

When a sodium atom donates one outer shell electron to a chlorine atoms, the sodium becomes an ion with a __________ charge

positive

Ions have a _____________ charge

positive or negative

Amino acids link together end-to-end forming the __________ structure of proteins

primary

Macromolecules made of one or more linear strands of amino acid monomers are _________

proteins

Nucleic acids determine the types of _________ synthesized within cells

proteins

The nucleus of an atom always contains one or more _______

protons

The atomic nucleus is made up of ______________

protons and neutrons

More than one globular or fibrous protein subunit now interact to produce _______ structures which results from ionic and hydrophilic and hydrophobic interactions

quaternary

The _________ of a protein exists if multiple polypeptides bind together to form a functional protein

quaternary structure

Magnesium ion

required for ATP production

With the exception of hydrogen, the elements that form covalent bonds with each other are on the _________ side of the periodic table

right

atoms on the _______ side of the periodic table tend to become anions in order to satisfy the octet rule

right

Ionic bonds form structures called _________

salts

Chemical properties of amino acid groups within a sequence interact with one another in _________ protein structure resulting in hydrogen bonding and chain folding

secondary

Polarity deals with the _______ of electrons between the atoms

sharing

The bond between two hydrogen atoms would be a __________ covalent bond

single

If two carbon atoms share a pair of electrons, it is called a ____________ bond

single covalent bond

They have three electron shells

sodium and chlorine

O=C=O is an example of ________ formula

structural

The ________ formula of a molecule exhibits the numbers and types of atoms as well as their arrangements within the molecule

structural

Nucleotides are composed of a ___________ (ribose or deoxyribose), a _____________ functional group, and a _____________ base

sugar phosphate nitrogenous

Globular and fibrous shapes are created with ________ structure of proteins caused by further folding due to disulfide bridges, hydrophobicity, and Van der Waals forces

tertiary

Examples of non polar molecules are __________

triglycerides

The most common form of lipids are ____________

triglycerides

The bond between two nitrogen atoms would be a _______ covalent bond

triple

As temperature drops the bonds between water molecules are less likely to break True or false

true

It is _____ that the nature of water molecules allows them to "pull apart" ionic bonds such as NaCl, due to the positive and negative charges attracting each other.

true

It is ______ that the nature of water molecules allows them to "pull apart" ionic bonds such as NaCl, due to the positive and negative charges attracting each other

true

The polar covalent bonds between hydrogen and oxygen atoms within a water molecule creates slightly positively and negatively charged ends to the molecule True or false

true

The innermost electron shell can hold _______ electrons

two

Non polar bonds means there is equal sharing of electrons; polar bonds have ________ sharing

unequal

The attraction between the hydrogen and oxygen atoms i a water compound is ________

unequal

Van der Waals forces occur when electrons orbiting the nucleus of an atom are briefly distributed _______________

unequally

A molecule of _______ is comprised of one oxygen atom and two hydrogen atoms

water

The bonding of water molecules to each other with _______ bonds is called hydrogen bonding

weak

Individual van der Waals forces are _________ than covalent bonds

weaker

The unequal sharing of electrons in a covalent bond creates a(n) ____________ bond

polar covalent

Cation that determines pH of blood

H+

________ is a strong acid because it almost fully dissociates into hydrogen ions and chlorine ions in water

HCl

The more hydrogen ions related by an acid, the ________ the pH value of the solution becomes

lower

Radioisotopes lose nuclear energy as they decay or break down, thus becoming __________ stable

more

When an element becomes an ion, it becomes __________ stable

more

Atoms in group VA periodic table form ions with a ________ charge

negative 3

The pH of a solution is defined as the _________ of the hydrogen ion concentration

negative logarithm

Water dissociates into an equal number of hydrogen and hydroxide ions, which creates a ________ pH value

neutral

Radioisotopes are unstable forms of isotopes because they contain an excess number of _____________

neutrons

They have the same number of electrons in their outermost shells

nitrogen and phosphorous

In a covalent bond, the bond can be either polar or ________

nonpolar

Molecules that are ________ share electrons equally

nonpolar

Van der Waals forces involve ________ molecules

nonpolar

DNA and RNA are ___________

nucleic acids

Lipids function as stored ___________

nutrients

The NaCl chemical formula indicates that there is/are _______ sodium ion(s) for each chloride ion

one

Electrons are located in regions of the atom called

orbitals

The electrons donated or accepted in order to form an ionic bond are in the atom's ___________ shell

outer

The covalent linkage between nucleotide monomers is called a ________________

phosphodiester bond

An example of an amphipathic molecule is a ___________ molecule

phospholipid

The _________ half-life is the amount of time it takes for 50% of the radioisotopes to become stable

physical

The ________ region of an amphipathic molecule is attracted to water

polar

The unequal sharing of electrons between the oxygen and hydrogen atoms within a water molecule makes water a ________ molecule

polar

Water molecules are ______ because the hydrogen atoms are positively charged on one end and the oxygen atoms are negatively charged on one end

polar

Water molecules are _________ because the hydrogen atoms are positively charged on one end and the oxygen atoms are negatively charged on one end

polar

Amphipathic molecules contain ___________ components

polar and nonpolar