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