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228 terms

biology

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atom
The smallest unit of an element
energy level
The area surrounding the nucleus of an atom in which electrons are normally located
atomic number
The number of protons in the nucleus of the atom
compound
Atoms of two or more elements chemically bonded to one another
nucleus
The positively charged center of an atom
electron
Exists in energy levels around the nucleus of an atom and carries a negative charge
molecule
Two or more atoms held together by chemical bonds
matter
Anything which occupies space and has mass
mixture
Two or more substances mixed together but not chemically combined
atomic mass
The mass of an element
neutron
A subatomic particle that carries no charge
diatomic
Containing two atoms
proton
A subatomic particle with a positive charge
matter
What has mass and occupies space?
four
Matter can exist in how many phases
92
there are____ elements that can be found to occur in nature.
carbon. oxygen, nitrogen, hydrogen
four of the most abundant elements found in plants and animals.
--A compound consists of two or more distinct bonded atoms
--a molecule is the smallest chemical subunit of a compound
--a molecule may consist of two similar elements chemically bonded
statements regarding a compound and a molecule:
true
Each element consists of only one type of atom. TRUE or FALSE
protons
Each unique element is determined by the number of_______ occurring in the atom.
number of protons
Any particular element can always be identified by its:
electrons
The subatomic particles/ units which govern potential chemical reactions among elements are:
A. electrons of a neutral atom always equals the number of protons
Which statement is correct?
A. electrons of a neutral atom always equals the number of protons
B. neutrons always equal the number of protons
C. neutrons always equal the number of electrons
D. atomic weight is identical to atomic mass
electrons
The common subatomic particles that make up an atom consist of protons, neutrons, and
atom
The smallest unit which retains the properties of an element is a(n)
neutrons
Atomic mass is determined by the number of protons plus
11
12
11
11
23
Element: sodium
Symbol: Na
# Protons
# Neutrons
# Electrons
Atomic Number:
17
18
17
17
35
Element: Chlorine
Symbol: Cl
# Protons
# Neutrons
# Electrons
Atomic Number:
two
Many elements exist naturally as a diatomic molecule. This means that the element is found in nature as ______chemically bonded atoms.
minerals
Naturally occurring compounds in the earth are called
a molecule of two Nitrogen atoms
Nitrogen gas consists of:
molecule
The smallest unit of a compound is a(n
CO2
A molecule of one atom of carbon and two atoms of oxygen would be written:
compound, molecule
HCl is an example of a(n):
ion
Electrically charged atom or group of atoms formed by the loss or gain of electrons
chemical bond
The union between atoms by the interaction of their electrons in the outermost energy level
chemical reaction
Atoms of elements or compounds interact to form at least one new compound
valence
The number of electrons lost or gained to complete an element's outer energy level
ionic bond
A bond formed by the electrical attraction between two oppositely charged ions
two atoms exchange electrons and become ions
An ionic bond occurs when:
+1, -1, +2, -2, +3, -3
Which valences have the greatest tendency to form ions?
anion
A negatively charged ion is called a(n)
cation
A positively charged ion is called a(n)
complete
alence is the number of electrons an atom must gain or lose in order to ______ its outer energy level or have a stable octet.
False
All the subatomic particles participate in chemical reactions. TRUE or FALSE
energy
An electron in the second energy level has more____than an electron in the first energy level.
1.an electron may change to an excited state
2.an electron may move to a higher energy level
If an atom is supplied with excess energy:
to rearrange its configuration to result in a complete outer energy level
Chemical reactions are the result of an atom attempting:
True
Atoms which possess completed outer energy level or have a stable octet are inert. TRUE or FALSE
when less than half of the outer energy level is filled
When will an atom give up electrons?
Na+
How is a sodium ion symbol
written?
-is the attraction of two oppositely charged ions
-involves actual transfer of electrons
An ionic bond:
8, 18
The first (n=1) energy level of an atom contains a maximum of 2 electrons, the second (n=2) energy level contains a maximum of ___, and the third (n=3) energy level contains a maximum of ___
0, 2, -2
Element:Oxygen
Electrons Can Donate:
Electrons Can Receive:
Valence (incl. + or -):
-1, 0, 1
Element:Chlorine
Electrons Can Donate:
Electrons Can Receive:
Valence (incl. + or -):
acid
Donates a hydrogen atom during disassociation.
base
Capable of combining with hydrogen; it normally donates a hydroxyl (OH-)
covalent bond
A chemical bond formed between two atoms by the sharing of electrons
hydrogen bond
An intermolecular force occuring between a hydrogen atom and fluorine, oxygen, and nitrogen atoms
covalent bond
A water molecule is held together by a
hydrogen bonds
Water molecules are attracted to each other by
False
A hydrogen bond is completed by the transfer of its sole electron to another element. TRUE or FALSE
the sharing of electrons by two or more atoms
A covalent bond is:
--an attraction between polar molecules
--inter-molecular force between hydrogen and oxygen, fluorine, or nitrogen
characteristics of a hydrogen bond:
covalent
A bond of the following elements would be of what type? C + 4H
covalent
A bond of the following elements would be of what type? 2H + O
ionic
A bond of the following elements would be of what type? Na + Cl
ionic
A bond of the following elements would be of what type? Ca + 2Cl
organic
Any chemical compound which contains carbon.
solvent
A liquid which acts to dissolve or suspend solutes
cation
A positively charged ion; an atom which has lost an electron.
anion
A negatively charged ion; an atom which has gained an electron.
inorganic
A chemical compound not containing carbon.
salt
The compound formed by the ionic bonding of a cation and anion.
solute
A substance which is dissolved in a liquid.
pH
A measure of the hydrogen ion concentration in a solution
carbon
An organic molecule will always contain:
ionic bonds
Inorganic compounds are usually held together by
put together
The word "synthesize" means:
False
Water can only dissolve inorganic compounds.TRUE or FALSE
separate into ions
When salts are dissolved in water they:
not
Organic lipids will___dissolve in water.
base
A substance which yields a cation plus the hydroxyl ion in water is a(n):
acid
A substance which yields an anion plus a hydrogen ion is a(n):
7
The pH of water is___because it contains an equal amount of H+ and OH- ions.
cation
a positive ion
ion
an atom which has gained or lost electrons
anion
a negative ion
base
produces OH-ions when added to water
acid
produces H+ions when added to water
molecule
Identify this symbol.
H2O
cation
Identify this symbol.
anion
Identify this symbol.
Cl -
atom
Identify this symbol.
Ne
anion
Identify this symbol.
OH -
0 and 14
The pH scale ranges between__and__
strong acid
A pH of 2 indicates a(n):
strong base
A pH of 12 indicates a(n):
True
Salts help to maintain the natural ionic concentration of an organism. TRUE or FALSE
synthesis reaction
Salts help to maintain the natural ionic concentration of an organism.
catalyst
Accelerates a chemical reaction without being used up in the reaction
chemical equilibrium
When a reversible reaction is occurring in both directions at the same rate
metabolism
All of the chemical reactions in the organism for maintenance of the processes of life
buffer
A substance which will resist changes in pH within reasonable limits
enzyme
A protein molecule which speeds up a specific chemical reaction in biological systems
reversible reaction
The reactants used to form the products can also be synthesized from those products
product
That which is produced as a result of a chemical reaction
activation energy
The energy required to start a chemical reaction
exchange reaction
A chemical reaction where the substrates trade constituent parts
Law of Mass Action
The concentration of reactant product influences the rate and net direction of a reversible reaction
decomposition
The compound is broken into its constituent parts
reversible
The products and reactants of a(n) _____ will form at the same rate when equilibrium is attained.
energy input
What is required for reactants to form bonds?
a compound partitions into its components
What occurs during a decomposition reaction?
exchange reaction
molecules rearrange and form new molecules
synthesis reaction
bonds broken and elements released
reversible reaction
molecules formed from components
exchange reaction
simultaneous decomposition and synthesis
synthesis
A(n)_______reaction occurs when a molecule is formed from the bonding of atoms, ions or simpler molecules.
reversible
a_____reaction occurs when the reactants are reproduced by reaction of the products.
exchange
a______reaction occurs when the bonds of the reacting compounds are broken and new combinations are formed.
decomposition
an_____reaction occurs when ionic or covalent bonds are broken and elements, ions, or simpler molecules are formed.
True
When fats decompose in an organism, energy is released. TRUE or FALSE
synthesis, growth, repair,decomposition, energy release,reversible reactions, equilibrium,synthesis and decomposition,exchange reactions, control of pH
Which processes are involved in metabolism?
reversible
Which type of reaction is dependent on the concentration of the products and reactants?
Law of Mass action or molecular concentration because they relate to the same principle
The rate and direction of reactions are greatly influenced by the:
metabolism
The process by which organisms decompose food and synthesize energy and tissue is
reactant
A substance which enters into a chemical reaction is called a
product
A substance which results from a one-way chemical reaction is called a
forward reaction rate equals reverse reaction rate
Chemical equilibrium results if:
False
Chemical reactions will occur independently of the reactant's temperature. TRUE or FALSE
friction
In the chemical reaction that takes place in the lighting of a match, activation energy is supplied by _____.
nucleic acid
A sequence of sugars, phosphates and nitrogenous organic bases
protein
Large number of amino acids linked together by peptide bonds
nucleic acid
A sugar or polymer of sugar
polymer
Two or more simpler molecules strung together
polymerization
Two or more similar molecules unite, forming a larger complex molecule
lipid
A group of organic compounds including fats and steroids
amino acid
basic units of proteins
polymerization
synthesis of repeating molecules
RNA
an acid located in the cell nucleus
carbohydrate
a polymer of sugar
hydrolysis
decomposition using water
four
How many electrons does carbon lack in its outer shell?
False
Carbon is ideally suited to form ionic bonds. TRUE or FALSE
False
Many elements bond to carbon by exchanging electrons. TRUE or FALSE
because it is capable of forming multiple covalent bonds
Why can carbon bond to many elements simultaneously?
hydrogen, nitrogen, oxygen
most common elements which bond to carbon.
energy is released
What happens when organic molecules decompose?
are usually ions of the original elements
When compounds which are formed from ionic bonds decompose, the products:
carbohydrates,polymers,proteins,nucleic acids
Large organic molecules which are synthesized from multiple identical subunits are:
proteins, fats, nucleic acids, carbohydrates
The four organic molecules common to organisms are _____.
polysaccharide
A polymer of simple sugars
glucose
A simple sugar (C6H12O6) occurring in plant and animal tissues
disaccharide
A two-sugar polymer
starch
A polymer of glucose units
monosaccharide
The building block unit of carbohydrates; a simple sugar
dehydration synthesis
A bonding of subunits to form a polymer with the loss of water
carbohydrate
A sugar or polymer of sugar
carbohydrates
Organic compounds consisting of various compounds of sugar are generally called
units of C 6 H 12 O 6
Starch is made up of:
plants
Carbohydrates are produced readily by
carbohydrate polymers formed
Which statement represents dehydration synthesis?
False
Starch is a monosaccharide. TRUE or FALSE
True
A polysaccharide is a polymer of simple sugar. TRUE or FALSE
hydrogen, oxygen
The two elements besides carbon found in carbohydrates are _____.
monosaccharides
The simplest sugars are generally called
polysaccharides
The complex sugars are generally called
photosynthesis
Carbohydrates are manufactured in plants by the process of
green plants
The most abundant sources of carbohydrates are _____.
energy
Carbohydrates are the most readily available source of _____.
lipid
A group of organic compounds including fats, steroids, and phospholipids
antibody
A protein specialized to defend the body against disease
hormone
Aids in the control of a specific function in the organism
protein
A large complex organic molecule consisting of a large number of amino acids
amino acid
The basic building block of proteins
hydrolysis
The breakdown of large molecules into smaller molecules with water being a reactant
True
Lipids are composed of the same basic elements as carbohydrates. TRUE or FALSE
--they are formed from different basic elements
--the H/O ratio is different
How do lipids differ from carbohydrates?
lipids
Steroids are:
hydrolysis
The breakdown of molecules by the addition of water:
phospholipids
The organic chemicals which help cell walls to conserve internal fluids are _____.
steroids, phospholipids, fats
Choose from the following list the three groups of lipids.
organic solvents
Lipids are soluble in solvents called
fats
The most highly concentrated source of energy in the body is
steroids
Cholesterol belongs to the group of lipids called _____.
hormone
A natural chemical which controls a specific body function is called a(n)
antibodies, enzymes, hormones
Which of the following chemicals are proteins?
protein
The physical properties of a _______are highly sensitive to the sequence in which the amino acids are linked.
amino acids
Sickle-cell anemia is caused by incorrect sequencing of _____.
proteins
The building blocks of _____ are amino acids.
nitrogen
In addition to the elements found in carbohydrates and lipids, proteins contain the element
5,000
A protein may consist of as many as _____amino acid molecules.
eggs, black beans, fish, poultry, cheese, milk
sources of protein in our diet.
peptide bonds
Bonds between amino acids are called
hemoglobin
The oxygen-transporting protein in the blood is called
antibody
A protein specialized to protect the body from disease is a(n)
"If even one amino acid in a sequence of several hundred amino acids of a protein is changed, the whole nature of that protein will be changed.An example of the critical nature of a specific sequence is the hemoglobin (the oxygen-transporting molecule in the blood) of a person with sickle-cell disease. Only a single amino acid is different, but that mutation results in insufficient oxygen transport (sickle-cell anemia)."
Describe the effect on a protein if one or more amino acids are changed.
nucleic acid
A sequence of sugars, phosphates and nitrogenous organic bases
DNA
A complex molecule containing the genetic code
RNA
A nucleic acid which participates in the synthesis of proteins
nucleic acids
The largest and most sophisticated molecules in a cell are _____.
hereditary
Nucleic acids carry the____codes of life.
complex information, detailed instructions
Genetic codes contain:
cannot arise by random undirected processes
Many scientists have concluded that coded information:
4
The sugar-phosphate backbones of DNA are connected to one another by sequences of___different bases.
True
Two bases connect the double chain of DNA like a step on a ladder. TRUE or FALSE
paired
The connecting bases of DNA are always made of ___sets.
RNA reads and translates the DNA code
Which statement correctly relates to DNA and RNA:
the sequence of bases making up the "rungs" of the ladder
What determines the coded information contained within DNA?
DNA
Carrying the genetic code and determining an organism's structure and function are the functions of:
double helix
The DNA molecule has a structure similar to a
cytosine, thymine
Adenine pairs with _____, and guanine pairs with_____in DNA.
cofactor
plays an important role in activating that enzyme
active site
The region where the substrate molecule binds andreacts with the enzyme
substrate
Involved in a chemical reaction and is chemically changed by the reaction
protein
An enzyme is a large____molecule
True
An enzyme may react with several substrate chemicals simultaneously. TRUE or FALSE
A or B
In the figure illustrating the typical enzyme reaction, which is a substrate reactant?
False
An organism can live without enzymes. TRUE or FALSE
to act as a catalyst in chemical reactions.
Why are enzymes necessary?
catalyst
A substance which accelerates any chemical reaction but is not consumed by the reaction is called a
a biological catalyst
An enzyme is:
they may not be able to react
If the reactants found in a cell are removed from the cell how will they behave chemically?
are formed from accelerated decomposition of lipids
Enzymes:
True
Numerous different enzymes are produced by the cells. TRUE or FALSE
cofactor
Often enzymes require a______ in order for them to function as a catalyst.
substrate chemical.
The substance on which the enzyme acts is called the