Biology - Review - Unit 2
A substance which yields an anion plus a hydrogen ion is a(n):
Acid
Because enzymes have high specificity, fewer than fifteen are required by any organism. True False
F
Carbon is ideally suited to form ionic bonds. True False
F
Chemical reactions will occur independently of the reactant's temperature. True False
F
Enzyme molecules react with reactants to produce substrate molecules. True False
F
Why can carbon bond to many elements simultaneously? because its +4 valence forms ionic bonds because it has a natural ionic charge of "+4" because it is capable of forming multiple covalent bonds
because it is capable of forming multiple covalent bonds
Which statement is correct? electrons of a neutral atom always equals the number of protons neutrons always equal the number of protons neutrons always equal the number of electrons atomic weight is identical to atomic mas s
electrons of a neutral atom always equals the number of protons
Lavoisier proposed that all matter is composed from the same
element
Carbohydrates are the most readily available source of _____. protein fats nucleic acids energy
engergy
A catalyst for chemical reactions in biological systems is called a(n)
enzyes
Protein catalysts which cause reactions to occur at temperatures and pH values which are common to living cells are called
enzyms
All proteins carry the genetic codes which determine the structure and function of an organism. True False
f
An organism can live without enzymes. True False
f
The most highly concentrated source of energy in the body is
fats
Chemical equilibrium results if:
forward reaction rate equals reverse reaction rate
In the chemical reaction that takes place in the lighting of a match, activation energy is supplied by _____. chemicals in the match friction
friction
The most abundant sources of carbohydrates are _____. simple sugars green plants humans and animals
greent plan
The oxygen-transporting protein in the blood is called
hemoglobin
Nucleic acids carry .......the codes of life.
heriady
A natural chemical which controls a specific body function is called a(n
homornee
The two elements besides carbon found in carbohydrates are _____. hydrogen sodium magnesium oxygen nitrogen
hydro õygen
the characteristics of a hydrogen bond:
intermolecular force between hydrogen and oxygen, fluorine, or nitrogen, an attraction between polar molecules
An enzyme may react with several substrate chemicals simultaneously. True False
t
Atoms which possess completed outer energy level or have a stable octet are inert.
t
Carbohydrates are converted to energy by the process of hydrolysis. True False
t
Numerous different enzymes are produced by the cells. True False
t
The DNA bases are attached to the phosphate part of the structure. True False
t
Two bases connect the double chain of DNA like a step on a ladder. True False
t
When fats decompose in an organism, energy is released. True
t
Adenine pairs with .... , and guanine pairs with .....in DNA.
thymines cytosine
All the subatomic particles participate in chemical reactions
F
A polysaccharide is a polymer of simple sugar. True False
T
Why are enzymes necessary? to retard the rate of decomposition to act as a catalyst in chemical reactions. to conserve the stored energy of a cell
b
The complex sugars are generally called
polysaccherides
Enzyme, antibody, hormone, and muscle are roles played by: carbohydrates proteins
2
Which statement represents dehydration synthesis? decomposition by hydrolysis carbohydrate polymers formed water removed producing decomposition
b
Atomic mass is determined by the number of neutrons plus
proton
A covalent bond is:
the sharing of electrons by two or more atoms
1. the smallest complete unit of a compound or diatomic gas compound 2. a new substance formed by the combination of two or more different atoms energy level 3. area that electrons are found around an atomic nucleus molecule 4. a substance consisting of only one type of atom element
2 3 1 4
1. plays an important role in activating that enzyme substrate 2. The region where the substrate molecule binds andreacts with the enzyme cofactor 3. Involved in a chemical reaction and is chemically changed by the reaction active site
3 12
Organic catalysts are called polysaccharides. True False
P
Chemical reactions in cells are faster than the same reactions outside cells. True False
T
Lipids are composed of the same basic elements as carbohydrates. True False
T
A substance which accelerates any chemical reaction but is not consumed by the reaction is called a .
catalysis
Lipids are water-soluble. True False
f
The process by which organisms decompose food and synthesize energy and tissue is
metabolism
he simplest sugars are generally calle
monossaccharides
A solution that contains equal numbers of hydrogen and hydroxide ions would be called
neutral
Atoms are electrically .........because they have the same number of protons and electrons.
neutral
A substance which results from a one-way chemical reaction is called a
product
Enzymes: are produced at the direction and translation of DNA and RNA respectively must be introduced from appropriate foods, vitamins, minerals, etc. are formed from accelerated decomposition of lipids \
a
Which of the following chemicals are proteins? antibodies starch polysaccharides enzymes amino acids hormones steroids
a d f
What happens when organic molecules decompose? energy is absorbed from the environment energy is released the products quickly form new ionic bonds
energy is released
Steroids are: complex carbohydrates lipids a subclass of fats a type of phospholipids
lipid
Carbohydrates are produced readily by
plants
Amino acids are the building blocks of
protein
An enzyme is a large .....molecule.
protein
The physical properties of a are highly sensitive to the sequence in which the amino acids are linked.
protein
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
Check the correct statements regarding a compound and a molecule:
A substance which enters into a chemical reaction is called a
reacten
Which type of reaction is dependent on the concentration of the products and reactants? decomposition exchange reversible synthesis
riversible
The substance on which the enzyme acts is called the chemical.
substrace
The substance on which the enzyme acts is called the
subtance
A plant must supply energy through photosynthesis in order for its complex starch molecules to breakdown to a simple sugar. True False
F
A substance that releases hydrogen ions in water is a base.
F
Starch is a monosaccharide. True False
F
The number of protons within an atom of an element is equal to its atomic mass. True False
F
1. basic units of proteins hydrolysis 2. synthesis of repeating molecules carbohydrate 3. an acid located in the cell nucleus RNA 4. a polymer of sugar amino acid 5. decomposition using water polymerization
5 4 3 1 2
Enzymes: are produced at the direction and translation of DNA and RNA respectively
ADN and ẢN
A substance which yields a cation plus the hydroxyl ion in water is a(n):
Base
Starch is made up of: polymer for nucleic acids simple proteins units of C6H12O6 amino acid polymers
C6H5
The weak type of bonding which attracts molecules to molecules is: ionic hydrogen
hydro
The breakdown of molecules by the addition of wate
hydrorate
Atoms which transfer electrons can combine to form a(n) bond.
inonic
Carbohydrates are manufactured in plants by the process o
photosynthesis
Two or more units are added together to form a new compound enzyme 2. Accelerates a chemical reaction without being used up in the reaction catalyst 3. When a reversible reaction is occurring in both directions at the same rate exchange reaction 4. All of the chemical reactions in the organism for maintenance of the processes of life Law of Mass Action 5. A substance which will resist changes in pH within reasonable limits activation energy 6. A protein molecule which speeds up a specific chemical reaction in biological systems product 7. The reactants used to form the products can also be synthesized from those products buffer 8. That which is produced as a result of a chemical reaction synthesis reaction 9. The energy required to start a chemical reaction metabolism 10. A chemical reaction where the substrates trade constituent parts decomposition 11. The concentration of reactant product influences the rate and net direction of a reversible reaction chemical equilibrium 12. The compound is broken into its constituent parts reversible reaction
6 2 10 11 9 8 5 1 4 12 3 7
1. A polymer of simple sugars dehydration synthesis 2. A simple sugar (C6H12O6) occurring in plant and animal tissues monosaccharide 3. A two-sugar polymer starch 4. A polymer of glucose units carbohydrate 5. The building block unit of carbohydrates; a simple sugar polysaccharide 6. A bonding of subunits to form a polymer with the loss of water glucose 7. A sugar or polymer of sugar disaccharide
6 5 4 7 1 2 3
If the reactants found in a cell are removed from the cell how will they behave chemically? they will yield the same chemical products they may not be able to react
B
Many elements bond to carbon by exchanging electrons. True False
F
Of the known elements only about ten are needed by living things. True False
F
Score: 100Correct Water can dissolve only inorganic compounds.
F
Sodium and chlorine atoms combine readily because they both tend to lose electrons.
F
A salt is produced when an acid reacts with a base.
T
Chemical reactions are the result of an atom attempting: to reduce the number of electrons to become electrically neutral to rearrange its configuration to result in a complete outer energy level add electrons to have a stable octet in its outer energy level
c
y.) The four classes of organic molecules are
cacbon, lipid, nucle, protein
Organic compounds consisting of various compounds of sugar are generally calle
cacbonhydrat
A substance that helps a reaction to take place, but does not participate in the reaction is called a(n)
catalyst
Nonprotein substances (such as vitamins and some metal ions) which need to be present for enzymes to function are calle
coàcter
Often enzymes require a .... in order for them to function as a catalyst.
coàctor
If the outer energy level of the atom is full, it ________ react readily with other atoms. does does not
dóe not
Chemical reactions are the result of an atom attemptin
o rearrange its configuration to result in a stable octet
The connecting bases of DNA are always made of .....sets.
paired
Lipids are chemically most similar to: carbohydrates
1
Bonds between amino acids are what type bonds? covalent peptide
2
The largest organic molecules are
nuc
Cholesterol belongs to the group of lipids called _____. fatty acids phospholipids steroids amino acids
sterios
Electrically charged atom or group of atoms formed by the loss or gain of electrons ion 2. The union between atoms by the interaction of their electrons in the outermost energy level chemical bond 3. Atoms of elements or compounds interact to form at least one new compound chemical reaction 4. The number of electrons lost or gained to complete an element's outer energy level ionic bond 5. A bond formed by the electrical attraction between two oppositely charged ions va lence
1 2 5 4 3
1. A sequence of sugars, phosphates and nitrogenous organic bases DNA 2. A complex molecule containing the genetic code nucleic acid 3. A nucleic acid which participates in the synthesis of proteins RNA
2 1 3
The smallest unit of an element atomic number 2. The area surrounding the nucleus of an atom in which electrons are normally located electron 3. The number of protons in the nucleus of the atom diatomic 4. Atoms of two or more elements chemically bonded to one another matter 5. The positively charged center of an atom energy level 6. Exists in energy levels around the nucleus of an atom and carries a negative charge compound 7. Two or more atoms held together by chemical bonds atom 8. Anything which occupies space and has mass atomic mass 9. Two or more substances mixed together but not chemically combined proton 10. The mass of an element nucleus 11. A subatomic particle that carries no charge molecule 12. Containing two atoms mixture 13. A subatomic particle with a positive charge neutron
3 6 12 8 2 4 1 10 13 5 7 9 11
1. simple sugars fats 2. complex sugars paired set 3. most highly concentrated energy source DNA 4. polymerization sugar and phosphate 5. decomposition synthesis 6. DNA "upright" electron sharing 7. DNA "rung" monosaccharides 8. nucleic acids polysaccharides 9. double-stranded hydrolysis 10. ionic bonding electron exchange 11. covalent bonding "b lueprint" molecules
3 7 9 6 4 11 1 2 5 10 8
1. A group of organic compounds including fats, steroids, and phospholipids protein 2. A protein specialized to defend the body against disease lipid 3. Aids in the control of a specific function in the organism antibody 4. A large complex organic molecule consisting of a large number of amino acids amino acid 5. The basic building block of proteins hormone 6. The breakdown of large molecules into smaller molecules with water being a reactant hydrolysis
4 1 2 5 3 6
1. Donates a hydrogen atom during disassociation. hydrogen bond 2. Capable of combining with hydrogen; it normally donates a hydroxyl (OH-) base 3. A chemical bond formed between two atoms by the sharing of electrons covalent bond 4. An intermolecular force occuring between a hydrogen atom and fluorine, oxygen, and nitrogen atoms acid
4 2 3 1
1. molecules rearrange and form new molecules synthesis 2. simultaneous decomposition and synthesis decomposition 3. bonds broken and elements released reversible 4. molecules formed from exchange
4 3 2 1
1. a positive ion acid 2. an atom which has gained or lost electrons base 3. a negative ion anion 4. produces OH - ions when added to water ion 5. produces H+ ions when added to water cation
5 4 3 2 1
1. A sequence of sugars, phosphates and nitrogenous organic bases lipid 2. Large number of amino acids linked together by peptide bonds protein 3. A sugar or polymer of sugar polymer 4. Two or more simpler molecules strung together carbohydrate 5. Two or more similar molecules unite, forming a larger complex molecule polymerization 6. A group of organic compounds including fats and steroids nucleic acid
6 2 4 3 5 1
Numerous different enzymes are produced by the cells. True False
T
The effect of a catalyst is the reduction of activation energy required to initiate a chemical reaction. True False
T
Water is an example of a compound.
T
Carrying the genetic code and determining an organism's structure and function are the functions of: DNA RNA
a
Many scientists have concluded that coded information: cannot arise by random undirected processes can be accumulated by chance, if given enough time
a
The organic chemicals which help cell walls to conserve internal fluids are _____. phospholipids
a
A substance which yields an anion plus a proton is a(n): salt acid
acid
The heat needed for chemical reaction to take place is called
activation energy
(Select all that apply.) Choose enzyme cofactors mentioned in the lesson. vitamins iron copper cobalt zinc calcium
alll
Sickle-cell anemia is caused by incorrect sequencing of _____. amino acids hemoglobin fatty acids antibodies
amino acid
A protein specialized to protect the body from disease is a(n
antybody
When compounds which are formed from ionic bonds decompose, the products: are usually atoms of the original reactants are usually simple molecules are usually ions of the original elements are usually of no further chemical value
are usually ions of the original elements
If the reactants found in a cell are removed from the cell how will they behave chemically? they will yield the same chemical products they may not be able to react they will all react but at a slower rate no reaction will take place
b
The building blocks of _____ are amino acids. carbohydrates proteins fats nucleic acids
b
The common name for C6H12O6 is _____. complex sugar glucose polysaccharide carbohydrate
b
Which statement correctly relates to DNA and RNA: RNA contains the genetic code RNA reads and translates the DNA code DNA reads and translates the RNA code DNA synthesizes protein
b
(Select all that apply.) Choose from the following list the three groups of lipids. fatty acids steroids phospholipids amino acids proteins fats
b c f
How do lipids differ from carbohydrates? they are formed from different basic elements they are not soluble in water they release less energy the H/O ratio is different
b d
An enzyme is: a biological reactant a biological product a biological catalyst a biological co-factor
c
What determines the coded information contained within DNA? the sequence of sugar polymers on the "rails" of the ladder the arrangement of amino acids the sequence of bases making up the "rungs" of the ladder the arrangement of genes
c
Genetic codes contain: random data nonfunctional chance information complex information detailed instructions accidental complexity
c d
Score: 100Correct All organic molecules contain the element
cacbon
Often enzymes require a...... in order for them to function as a catalyst.
cofactor
Valence is the number of electrons an atom must gain or lose in order to ......... its outer energy level or have a stable octet.
complete
Atoms that form compounds are held together by chemical bonds. The bond that includes sharing electrons with another atom is called
covalent
Carbon form,,,,,s bonds.
covalent
When electrons are shared, the type of bonding is called:
covalent
The largest and most sophisticated molecules in a cell are _____. carbohydrates proteins fats nucleic acids
d
Many gases exist as ............molecules of an element.
diatomic
The DNA molecule has a structure similar to a
double helix
When atoms combine, interactions occur between their:
electrons
In addition to the elements found in carbohydrates and lipids, proteins contain the element
nitrogent
Lipids are soluble in solvents called
ogranic sovenlt
Bonds between amino acids are called bonds.
peptide
(Select all that apply.) The four organic molecules common to organisms are _____. proteins sugars fats amino acids methane nucleic acids carbohydrates
protein fat nuc cacbon
