Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
149 Cards in this Set
- Front
- Back
|
The atomic number of an atom refers to the number of
|
Protons
|
|
|
What are the elements that make up SPONCH
|
Sulfur
Phosphorus Oxygen Nitrogen Carbon Hydrogen |
|
|
The atomic mass is equal to the number of
|
Protons plus neutrons
|
|
|
Which component of an atom has a positive charge
|
Proton
|
|
|
Which atom consists solely of one proton and one electron in its elemental form
|
hydrogen
|
|
|
An atom has 18 electrons and an atomic number of 17. What is the charge of the atom
|
-1
|
|
|
More then one orbital can be in a particular electron shell
|
true
|
|
|
Carbon has 6 electrons in its outer shell
|
false
|
|
|
An atom is reactive if
|
the valence shell is not full
|
|
|
Most of an atom is
|
empty space
|
|
|
Ions are formed by a change in the number of ___________, while isotopes are formed by a change in the number of ________
|
electrons, neutrons
|
|
|
Isotopes are atoms that have the same number of ____________ but different numbers of __________
|
protons, neutrons
|
|
|
Ionization is caused by the gain or loss of _______
|
electrons
|
|
|
Considering the valence electron configuration of magnesium, which is the most likely charge produced by the ionization of magnesium
|
+2
|
|
|
If an atom gains or loses electrons it becomes
|
An ion
|
|
|
Isotopes of the same atom differ in the number of
|
neutrons.
|
|
|
Which of the following is true about the use of radioisotopes in biological experiments?
|
They are used to trace biological pathways.
|
|
|
Scientists knew the products of photosynthesis in the early 1900s. What are two of the products?
|
oxygen gas and glucose
|
|
|
Which of the following is both a reactant and a product of photosynthesis?
|
water
|
|
|
The electronegativity of an atom is its ability to
|
attract electrons
|
|
|
Electrons are the __________ particles of atoms
|
negatively charged
|
|
|
An atom with a high electronegativity is more likely to become which type of ion?
|
negative
|
|
|
When two oxygen atoms (atomic number 8) interact to form molecular oxygen
|
they share electrons
|
|
|
Covalent bonds are formed when
|
a pair of electrons is shared between atoms of similar electronegativities.
|
|
|
Ionic bonds are formed when
|
two atoms of opposite charge come together to form an uncharged compound.
|
|
|
A polar molecule is able to
|
dissolve in water
|
|
|
Which type of bond has unequally shared electrons?
|
polar covalent
|
|
|
Which of the following chemical bonds is the weakest?
|
van der Waals
|
|
|
The electron pairs on oxygen in an H2O molecule
|
carry a partial negative charge
|
|
|
Atoms with low electronegativities are most likely to form what kind of ions?
|
positively charged ions
|
|
|
Potassium atoms (atomic number 19) have one electron in their valence shell. Talk about their valence shells
|
They will have a full valence shell
|
|
|
The atomic mass of an element is the
|
average mass of its various isotopes
|
|
|
When an atom of fluorine becomes an ion it
|
gains one electron
|
|
|
An electron shell represents
|
A level of potential energy the electron exists in
|
|
|
Fluorine has 7 valence electrons. Therefore, fluorine is likely to
|
gain one electon
|
|
|
Negative ions are attracted to
|
positive ions
|
|
|
If an atom has 15 protons, 16 neutrons, and 12 electrons, the atomic number of the atom is
|
15
|
|
|
An atom has an atomic mass of 131 amu and contains 54 protons. How many neutrons does this atom contain?
|
77
|
|
|
By mass, most of the human body is composed of
|
oxygen
|
|
|
The helium atom has one electron in the first shell and one electron in the second shell.
t or f |
false
|
|
|
Potassium and sodium behave similarly in chemical reactions because
|
They have the same number of valence electrons
|
|
|
43 of 43
Boron has 5 protons. How many electrons are in the second shell of boron? |
3
|
|
|
Which of the following statements regarding hydrogen bonding is true?
|
Hydrogen bonding is possible when hydrogen is in a polar covalent bond.
|
|
|
The intramolecular bonds in water are
|
polar covalent
|
|
|
The intermolecular bonds in water are
|
hydrogen bonds
|
|
|
The bonds broken when water vaporizes to form a gas are
|
hydrogen bonds
|
|
|
Which of the following is an effect of the polarity of the water molecule?
|
The polarity of water molecules allows for the formation of hydrogen bonds.
|
|
|
If a compound has a low specific heat, that means
|
that the amount of heat required to increase the temperature of one gram of the compound is low.
|
|
|
Unlike most liquids which steadily decrease in density as they increase in temperature, water exhibits unusual behavior because of the hydrogen bonds between water molecules. Place the following in order of increasing density: ice, water at 4°C, water at 20°C.
|
ice, water at 20°C, water at 4°C
|
|
|
Some insects are able to walk on water. This is partially a result of the high __________ of water caused by the __________ between water molecules.
|
surface tension, hydrogen bonds
|
|
|
Water at 4°C occupies ________ volume than it does at 0°C, and water is _______ dense at 4° C than it is at 0°C
|
less, more
|
|
|
Ice is less dense than liquid water because
|
the crystal structure is rigid
|
|
|
Water can move through the xylem (circulatory tissue) of plants, apparently in defiance of gravity. What property of water makes it able to do this?
|
cohesion and adhesion
|
|
|
The surface tension of water is caused by
|
the downward net cohesive force on the water molecules at the surface
|
|
|
An acid is a substance that
|
donates protons to a solution
|
|
|
A base is a substance that
|
increases the pH of a substance
|
|
|
A solution with a pH of 9 is more __________ than a solution with a pH of 6.
|
basic
|
|
|
The strongest bases would have a pH of ____.
|
14
|
|
|
When in the presence of a strong acid, water acts like a (an) ________ and becomes a __________.
|
base, hydronium ion
|
|
|
In the presence of a strong base, water acts like a (an) _________ and becomes a ___________.
|
acid, hydroxide ion
|
|
|
A solution has a pH of 10. Another solution has a pH of 7. The first solution is _____ times more basic than the second.
|
1,000
|
|
|
Carbon dioxide in the blood reacts with water to form carbonic acid. Which of the following is not true about this reaction?
dont answer |
Carbonic acid can release -OH
|
|
|
A chemical solution that is capable of donating or accepting hydrogen ions is a(an)
|
buffer
|
|
|
Which of the following is not true regarding buffers?
|
Buffers are only necessary in very few biological processes.
|
|
|
Water molecules separate positive and negative ions from one another by forming ____.
|
hydration shells
|
|
|
What causes the large specific heat of water?
|
hydrogen bonding between water molecules
|
|
|
The bonds between carbon and hydrogen in methane (CH4) are nonpolar covalent bonds. Therefore, methane is not very soluble in water.
t or f |
true
|
|
|
The ability of water molecules to cling to other molecules (which are not water) is called _____.
|
adhesion
|
|
|
The high surface tension of water results from _____ between water molecules
|
cohesion
|
|
|
If a base is added to water, the pH will
|
decrease
|
|
|
Water can dissociate into
|
hydronium and hydroxide ions
|
|
|
If a buffer was not present in blood, CO2 produced by cells would cause the pH of blood to
|
decrease
|
|
|
How many bonds can carbon form?
|
4
|
|
|
What are isomers that have the same molecular formula but a different arrangement of atoms called?
|
structural isomers
|
|
|
Which functional side group is found in aldehydes and ketones?
|
carbonyl
|
|
|
Alcohols contain carboxyl groups.
t or f |
false
|
|
|
How many electrons does carbon have in its valence shell?
|
4
|
|
|
All organic compounds contain
|
carbon
|
|
|
Carbon is well suited to be the backbone of organic compounds because of which of the following characteristics?
|
It can form four covalent bonds with many different types of atoms.
|
|
|
Each carbon atom can share a pair of electrons with as many as __________ other atoms.
|
4
|
|
|
Isomers are
|
molecules with identical formulas but different structures.
|
|
|
Carbon is able to form so many different chemical compounds because
|
its valence shell has 4 electrons
|
|
|
Which side group forms the basis of alcohols?
|
hydroxyl
|
|
|
Which side group has a carbon-oxygen double bond?
|
aldyhide and carboxyl
|
|
|
Which two functional side groups are included in the straight-chain form of all monosaccharides?
|
carbonyl and hydroxyl
|
|
|
What is the name for the simplest carbohydrates?
|
monosaccharides
|
|
|
Maltose is a disaccharide formed from two molecules of _____.
|
glucose
|
|
|
The reverse reaction of dehydration synthesis is called _____.
|
hydrolysis
|
|
|
What is the name of the storage polysaccharide in humans?
|
glycogen
|
|
|
Which of the following is used as “glue” to hold the cellulose together in plant cell walls?
|
pectin
|
|
|
The exoskeletons of arthropods contain _____.
|
chitin
|
|
|
Glucose and fructose are common sugars. What is the relationship between the two?
|
glucose and fructose are structural isomers
|
|
|
The most common structure of sugars in solution is
|
a single ring
|
|
|
Carbohydrates are a class of molecules made up of
|
sugars and polysacharides
|
|
|
Carbohydrates are composed of individual units known as
|
monosaccharides
|
|
|
The ratio of carbon to oxygen in a carbohydrate is
|
1:1
|
|
|
Sucrose is formed from glucose and fructose by __________. In this process, water is __________.
|
dehydration: formed
|
|
|
__________ is a reaction in which two monomers are joined to form a macromolecule and water is released as a byproduct.
|
dehydration synthesis
|
|
|
The formation of a disaccharide from two monosaccharides is considered a hydrolysis because water is split in the process.
t/f |
false
|
|
|
In plant cells, glucose is stored as
|
starch
|
|
|
Which of the following molecules is not a polysaccharide?
|
sucrose
|
|
|
The principal fuel source for living animals i
|
monosaccharides
|
|
|
In animal cells, glucose is stored as
|
glycogen
|
|
|
Which of the following polysaccharides would be found stored within a muscle cell?
|
glycogen
|
|
|
Mammals lack cellulases and cannot digest cellulose without the help of symbiotic bacteria that produce cellulase for them. Why can't amylase, an enzyme that digests starch, effectively digest cellulose?
|
The shape of cellulose
|
|
|
Structural carbohydrates are
|
generally unbranched
|
|
|
Carbohydrates serve two major purposes. These purposes are
|
energy and structure
|
|
|
Which type of carbohydrate is found in plant cell walls and is responsible in part for the strength of these walls?
|
cellulose
|
|
|
After germination, the ____________ of the embryo will give rise to the leaves.
|
epicotyl
|
|
|
Germination begins when
|
the seed swells and starts the uptake of water
|
|
|
When glycerol combines with three fatty acid chains, a __________ results.
|
triglyceride
|
|
|
A lipid is defined as a biomolecule that is
|
insoluble in water
|
|
|
At room temperature, fats are __________ and oils are __________.
|
solid, liquid
|
|
|
A major role of lipids is as
|
fuel molecules
|
|
|
To form a triglyceride, three fatty acids are covalently joined to
|
glycerol
|
|
|
The region of a triglyceride that has three chains containing only carbon and hydrogen is the_____________ portion of the molecule.
|
hydrophobic
|
|
|
Which portion of the fatty acid molecules are bonded to glycerol to form a triglyceride?
|
the carboxyl group
|
|
|
Saturated fats are solid at room temperature because
|
the absence of carbon-carbon double bonds in the fatty acid tails allows the tails to fit more compactly together.
|
|
|
What makes a fatty acid an acid?
|
the -COOH group
|
|
|
Saturated fats are saturated with
|
hydrogen
|
|
|
Choose the correct answer for the following description: a molecule that contains double bonds between C atoms.
|
unsaturated fatty acids
|
|
|
Phosphorus is an important component of lipids that are involved in
|
cell membranes
|
|
|
Which membrane lipid has a structure that consists of a backbone formed by four fused carbon rings?
|
cholesterol
|
|
|
Which of the following is the most abundant membrane lipid?
|
phopholipids
|
|
|
Which are the most abundant lipids in the body?
|
phospholipids
|
|
|
Fats, phospholipids, and steroids have which of the following characteristics in common?
|
they are not solulable in water
|
|
|
All nucleic acids are
|
polymers of nucleotides
|
|
|
In RNA, the base __________ is substituted for the base __________ found in DNA.
|
uracil, thymene
|
|
|
DNA and RNA
|
carry genetic information
|
|
|
Cytosine, thymine, and uracil are
|
, they have one ring each pyramidies
|
|
|
DNA is not composed of
|
ribose
|
|
|
Amino acids are composed of protein
t/f |
false
|
|
|
Proteins consist of many amino acids linked to each other by
|
peptide bonds
|
|
|
A string of 100-1000 amino acids joined by peptide bonds is a
|
polypeptide
|
|
|
The R group of amino acids
|
is different for each amino acid
|
|
|
R groups
|
can be acidic, basic, or neutral.
|
|
|
The formation of a peptide bond requires
|
the release of a water molecule
|
|
|
Which statement about the primary structure of a protein is not true?
|
The primary structure of a protein is influenced by hydrogen bonding.
|
|
|
The structural level of the protein least affected by a disruption in hydrogen bonding is the
|
primary structure
|
|
|
The linear sequence of amino acids joined by peptide bonds is the __________ structure of a protein.
|
primary
|
|
|
Two major types of secondary structure found in proteins are
|
α- helices and β- pleated sheet
|
|
|
Primary structure describes
|
The order of amino acids in a protein
|
|
|
Which statement regarding the secondary structure of a protein is correct?
|
It may be in either the alpha-helix or the beta-pleated sheet configuration.
|
|
|
The __________ structure refers to the way a protein folds upon itself.
|
tertiary
|
|
|
Which of the following types of covalent bonds contributes to the tertiary structure of a protein?
|
disulfide bonds
|
|
|
The quaternary structure of a protein
|
consists of multiple subunits
|
|
|
All proteins are
|
polymers of amino acids
|
|
|
Protein shape is the same as protein conformation, and protein conformation dictates
|
protein function
|
|
|
Proteins differ from one another because
|
The exact formation of each protein is different
|
