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PCC Biochemistry

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PCC Biochemistry
 

True/False
Indicate whether the statement is true or false. Write  + for true and  0 for false.
 1.
Atoms have a positive charge.
 2.
An element is made up of more than one kind of atom.
 3.
Hydrogen and oxygen atoms have an equal number of electrons.
 4.
A molecule is an atom that has gained or lost an electron.
 5.
An atom that gains or loses one or more electrons is called an ion.
 6.
An atom with more electrons than protons has a positive charge.
 7.
Ionic bonds form between two negatively charged particles.
 8.
A covalent bond forms between two atoms that share electrons to form a molecule.
 9.
Adhesion is an attraction between different substances.
 10.
The ability of water to retain heat helps cells maintain homeostasis.
 11.
Nonpolar molecules dissolve well in water.
 12.
Water molecules attract nonpolar molecules such as oil.
 13.
Organic compounds contain carbon atoms that are covalently bonded to other elements—typically hydrogen, oxygen, and other carbon atoms.
 14.
A nucleotide has four parts.
 15.
RNA is made up of a double strand of nucleotides.
 16.
DNA stores hereditary information that can be used to make proteins.
 17.
When cells break down food, the energy from the food is temporarily stored as ATP.
 18.
The amount of energy needed to cause a chemical reaction to start is called activation energy.
 19.
Without enzymes, chemical reactions necessary for life would not occur at a rate sufficient to sustain life.
 20.
Enzymes speed up a chemical reaction by increasing the activation energy of the reaction.
 21.
When an enzyme binds with its substrate, the activation energy needed for the chemical reaction to occur is increased.
 22.
Chemical reactions that occur in cells are called biochemical reactions.
 

Multiple Choice
Identify the choice that best completes the statement or answers the question.
 23.
Atoms are composed of
a.
 protons.
c.
 electrons.
b.
 neutrons.
d.
 All of the above
 24.
The electrons of an atom
a.
 are found in the nucleus along with the protons.
b.
 occupy the space surrounding the nucleus.
c.
 have a positive charge.
d.
 are attached to the positive charge of neutrons.
 25.
The smallest particle of matter that can retain the chemical properties of carbon is a(n)
a.
 carbon molecule.
c.
 carbon atom.
b.
 carbon macromolecule.
d.
 element.
 26.
A substance that is composed of only one type of atom is called a(n)
a.
 nucleus.
c.
 element.
b.
 cell.
d.
 molecule.
 27.
All matter is composed of
a.
 cells.
c.
 atoms.
b.
 molecules.
d.
 carbon.
 28.
A molecule that has a partial positive charge on one side and a partial negative charge on the other side is called a
a.
 nonpolar molecule.
c.
 charged molecule.
b.
 polar molecule.
d.
 bipolar molecule.
 29.
A chemical formula shows the
a.
 kinds of bonds found in the molecule.
b.
 kinds of bonds found in the compound.
c.
 kinds of elements found in the compound.
d.
 arrangement of the elements found in the compound.
 30.
Ionic bonds form between molecules that have
a.
 opposite charges.
c.
 no charges.
b.
 the same charge.
d.
 neutral charges.
 31.
The bond formed when two atoms share a pair of electrons is called a(n)
a.
 hydrogen bond.
c.
 covalent bond.
b.
 ionic bond.
d.
 water bond.
 32.
Sharing of electrons in the outer energy levels of two atoms
a.
 results in ion formation.
b.
 occurs in covalent bonds.
c.
 only occurs if both are atoms of the same element.
d.
 is found only among carbon atoms.
 33.
Water is important to life because it
a.
 surrounds all cells.
b.
 is found inside cells.
c.
 influences the shape of the cell membrane.
d.
 All of the above
 34.
Nonpolar molecules have
a.
 no negative or positive poles.
c.
 only a negative pole.
b.
 both negative and positive poles.
d.
 only a positive pole.
 35.
When placed in the same container, oil and water do not mix because
a.
 they are both polar.
c.
 they are both nonpolar.
b.
 water is polar and oil is nonpolar.
d.
 water is nonpolar and oil is polar.
 36.
Due to the polarity of water, compounds that dissolve best in water contain
a.
 nonpolar bonds.
c.
 polar bonds.
b.
 ionic bonds.
d.
 Both (b) and (c)
 37.
Water is a polar molecule because
a.
 it contains two hydrogen atoms for each oxygen atom.
b.
 it has a charge.
c.
 different parts of the molecule have slightly different charges.
d.
 it does not have a charge.
 38.
Acidic solutions have a pH that is
a.
 less than 7.
c.
 a negative number.
b.
 between 7 and 14.
d.
 more than 7.
 39.
Hydrogen ions, H+, react with hydroxide ions, OH-, to form
a.
 water.
c.
 a base.
b.
 an acid.
d.
 None of the above
 40.
Which of the following is not an organic macromolecule?
a.
 carbohydrate
c.
 lipid
b.
 ice
d.
 nucleic acid
 41.
All organic compounds contain the element
a.
 carbon.
c.
 calcium.
b.
 nitrogen.
d.
 sodium.
 42.
Which of the following organic molecules are classified as carbohydrates?
a.
 amino acids
c.
 nucleotides
b.
 fatty acids
d.
 sugars
 43.
Polysaccharides are
a.
 carbohydrates.
c.
 proteins.
b.
 lipids.
d.
 unsaturated fats.
 44.
Lipids are
a.
 polar molecules.
c.
 water soluble.
b.
 similar to water molecules.
d.
 nonpolar molecules.
 45.
Which of the following organic molecules are most closely related to proteins?
a.
 amino acids
c.
 nucleotides
b.
 fatty acids
d.
 sugars
 46.
Long chains of amino acids are found in
a.
 carbohydrates.
c.
 proteins.
b.
 lipids.
d.
 sugars.
 47.
All of the following are examples of lipids except
a.
 saturated fats.
c.
 cholesterol.
b.
 starch.
d.
 earwax.
 48.
Lipids are soluble in
a.
 water.
c.
 oil.
b.
 salt water.
d.
 All of the above
 49.
Which organic molecules below are most closely related to lipids?
a.
 amino acids
c.
 nucleotides
b.
 fatty acids
d.
 sugars
 50.
Which of the following organic molecules are most closely related to nucleic acids?
a.
 amino acids
c.
 nucleotides
b.
 fatty acids
d.
 sugars
 51.
Which of the following is a carbohydrate?
a.
 DNA
c.
 wax
b.
 insulin
d.
 sucrose
 52.
Carbohydrates and lipids have many carbon-hydrogen bonds; therefore, they both
a.
 store energy in these bonds.
c.
 dissolve only in vinegar.
b.
 are easily dissolved in water.
d.
 exist only in cells of plants.
nar001-1.jpg
nar001-2.jpg
Molecule A
Molecule B
 53.
Refer to the illustration above. Molecules like Molecule B are found in
a.
 carbohydrates.
c.
 nucleic acids.
b.
 lipids.
d.
 proteins.
 54.
Liquid fats called oils contain
a.
 mostly unsaturated fatty acids.
c.
 many glucose molecules.
b.
 mostly saturated fatty acids.
d.
 amino acids.
 55.
Animals store glucose in the form of
a.
 cellulose.
c.
 wax.
b.
 glycogen.
d.
 lipids.
 56.
The shape of a protein is primarily determined by
a.
 the type and sequence of its amino acids.
b.
 its size.
c.
 its cell location.
d.
 None of the above
 57.
The two types of nucleic acids are
a.
 chlorophyll and retinal.
c.
 lipids and sugars.
b.
 DNA and RNA.
d.
 glucose and glycogen.
 58.
DNA stores
a.
 fat.
c.
 protein.
b.
 carbohydrates.
d.
 heredity information.
 59.
The two strands of a DNA molecule are held together by
a.
 ionic bonds.
c.
 hydrogen bonds.
b.
 covalent bonds.
d.
 None of the above
 60.
A molecule shaped like a spiral staircase (double helix) is typical of
a.
 deoxyribonucleic acid.
c.
 lipids.
b.
 ribonucleic acid.
d.
 carbohydrates.
 61.
ATP (adenosine triphosphate) stores energy for cells to use in the bonds between its
a.
 amino acids.
c.
 nucleotides.
b.
 carbon atoms.
d.
 phosphates.
nar002-1.jpg
 62.
Refer to the illustration above. Which graph illustrates what happens during an energy-releasing reaction?
a.
 Graph A
b.
 Graph B
c.
 both graphs because they each show a different stage of an energy releasing reaction
d.
 None of the above
 63.
Refer to the illustration above. Which graph illustrates a reaction during which energy is released?
a.
 Graph A
b.
 Graph B
c.
 both graphs because all chemical reactions release energy
d.
 None of the above
nar003-1.jpg
 64.
Refer to the illustration above. Which of the following statements regarding the graph is true?
a.
 Reaction 2 occurs faster than Reaction 3 because Reaction 2 requires more energy than Reaction 3.
b.
 The difference between the graphs shown for Reaction 2 and Reaction 3 is because of a difference in the activation energy of these reactions.
c.
 Reactant A contains more energy at the beginning of the reaction than product C has after the reaction.
d.
 All of the above
 65.
Refer to the illustration above. Reaction 3 in the graph
a.
 probably occurred in the presence of a catalyst.
b.
 requires more activation energy than Reaction 2.
c.
 is the same as Reaction 1, but faster.
d.
 is slower than Reaction 2.
 66.
The molecule on which an enzyme acts is called a(n)
a.
 active site.
c.
 organic molecule.
b.
 inactive site.
d.
 substrate.
 67.
An enzyme
a.
 is not used up when catalyzing a reaction.
b.
 lowers the activation energy of a reaction.
c.
 bonds with a substrate molecule at the enzyme’s active site.
d.
 All of the above
 68.
Which of the following conditions affects the function of enzymes?
a.
 pH
c.
 enzyme concentration
b.
 heat
d.
 All of the above
 69.
Reducing activation energy
a.
 is a violation of the laws of nature.
b.
 requires higher temperatures than those found within cells.
c.
 occurs only when reactants are quickly added to the reaction mixture.
d.
 is accomplished by the action of catalysts on reactants.
 70.
Enzymes
a.
 are able to heat up molecules so that they can react.
b.
 always provide carbon dioxide for chemical reactions.
c.
 are biological catalysts.
d.
 absorb excess heat so that reactions occur at low temperatures.
 71.
A cell contains
a.
 thousands of different kinds of enzymes, each promoting a different chemical reaction.
b.
 one kind of enzyme that promotes thousands of different chemical reactions.
c.
 approximately 100 kinds of enzymes, each promoting a different chemical reaction.
d.
 one enzyme that promotes photosynthesis and one enzyme that promotes cellular respiration.
 72.
Amylase is a digestive enzyme that breaks down starch into
a.
 amino acids.
c.
 glycogen.
b.
 glucose.
d.
 cellulose.
 73.
The digestive enzyme pepsin works with hydrochloric acid to break down proteins in the stomach. Pepsin probably works best at a pH of
a.
 11.
c.
 3.
b.
 7.
d.
 Both (b) and (c).

 
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Quiz DNA

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Quiz DNA

 

 

True/False
Indicate whether the sentence or statement is true or false.
1.
Despite years of research, the actual structure of the DNA molecule is still unknown.
2.
Franklin’s X-ray diffraction images suggested that the DNA molecule resembled a tightly coiled spring, a shape called a helix.
3.
In all living things, DNA replication must occur after cell division.
4.
Multiple DNA polymerases may become attached to more than one portion of a DNA molecule at once, speeding up the rate of replication.
5.
Before a DNA molecule can replicate itself, it must make itself more compact. This is accomplished by the double helix coiling up on itself.
 

Completion
Complete each sentence or statement.
6.
A DNA subunit composed of a phosphate group, a five-carbon sugar, and a nitrogen-containing base is called a(n) ____________________.
7.
The name of the five-carbon sugar that makes up a part of the backbone of molecules of DNA is ____________________.
8.
Watson and Crick determined that DNA molecules have the shape of a(n) ____________________.
9.
Due to the strict pairing of nitrogen base pairs in DNA molecules, the two strands are said to be ____________________ to each other.
10.
According to base-pairing rules, adenine pairs with ____________________ and guanine pairs with ____________________.
11.
The enzyme that is responsible for replicating molecules of DNA by attaching complementary bases in the correct sequence is ____________________.
12.
Enzymes called ____________________ are responsible for unwinding the DNA double helix by breaking the hydrogen bonds that hold the complementary strands together.
13.
The process by which DNA copies itself is called ____________________.
14.
Molecules of ____________________ carry instructions for protein synthesis from the nucleus to the cytoplasm.
15.
The nitrogen-containing base that is found only in RNA is ____________________.
16.
The enzyme responsible for making RNA is called ____________________.
17.
The form of ribonucleic acid that carries genetic information from the DNA to the ribosomes is ____________________.

 
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Quiz Genetics

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Genetics

 

 

True/False
Indicate whether the sentence or statement is true or false.
1.
Genetics is the branch of biology that involves the study of how different traits are transmitted from one generation to the next.
2.
Mendel discovered predictable patterns in the inheritance of traits.
3.
The scientific study of heredity is called genetics.
4.
In Mendel’s experiments with the flower color of pea plants, only the parental generation produced white flowers.
5.
Mendel concluded that the patterns of inheritance are determined entirely by the environment.
6.
The law of independent assortment was proposed by Mendel to explain his observations of inheritance patterns.
7.
Genes on chromosomes are the units of inheritance.
8.
The allele for a recessive trait is usually represented by a capital letter.
9.
Heterozygous individuals have two of the same alleles for a particular gene.
10.
A probability of 1/4 is equal to a probability of 75 percent.
11.
The dominant allele for tallness in pea plants is represented by the letter t.
12.
In codominance, two alleles are expressed at the same time.
13.
All genes have only two alleles.
14.
A dihybrid cross involves two pairs of contrasting traits.
15.
Crosses involving a study of one gene are called monohybrid crosses.
 

Completion
Complete each sentence or statement.
16.
A reproductive process in which fertilization occurs within a single plant is ____________________.
17.
Mendel produced strains of pea plants through the process of ____________________.
18.
____________________ refers to the transmission of traits from parent to offspring in sexually reproducing organisms.
19.
In heterozygous individuals, only the ____________________ allele achieves expression.
20.
A trait that is not expressed in the F1 generation resulting from the crossbreeding of two genetically different, true-breeding organisms is called ____________________.
21.
The principle that states that one factor may mask the effect of another factor is the principle of ____________________.
22.
In Mendel’s experiments, a trait that disappeared in the F1 generation but reappeared in the F2 generation was always a ____________________.
23.
The cellular process that results in the segregation of Mendel’s factors is ____________________.
24.
Mendel formulated two principles known as the laws of ____________________.
25.
An organism that has two identical alleles for a trait is called ____________________.
26.
An organism’s ____________________ refers to the set of alleles it has inherited.
27.
The likelihood that a specific event will occur is called ____________________.
In pea plants, tallness (T) is dominant to shortness (t). Crosses between plants with these traits can be analyzed using a Punnett square similar to the one shown below.
T
t
T
1
2
t
3
4
28.
Refer to the illustration above. The parents shown in the Punnett square could have offspring with a genotype ratio of ____________________.
29.
Refer to the illustration above. The phenotype of the plant that would be represented in box “4” of the Punnett square would be ____________________.
30.
A cross involving two pairs of contrasting traits is a(n) ____________________ cross.

 
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Quiz Protein Synthesis

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Protein Synthesis

 

 

Completion
Complete each sentence or statement.
1.
In eukaryotes, gene expression is related to the coiling and uncoiling of ____________________.
2.
A DNA subunit composed of a phosphate group, a five-carbon sugar, and a nitrogen-containing base is called a(n) ____________________.
3.
The name of the five-carbon sugar that makes up a part of the backbone of molecules of DNA is ____________________.
4.
Knowing the order of the bases in a gene permits scientists to determine the exact order of the amino acids in the expressed ____________________.
5.
Due to the strict pairing of nitrogen base pairs in DNA molecules, the two strands are said to be ____________________ to each other.
6.
According to base-pairing rules, adenine pairs with ____________________ and guanine pairs with ____________________.
7.
The enzyme that is responsible for replicating molecules of DNA by attaching complementary bases in the correct sequence is ____________________.
8.
Enzymes called ____________________ are responsible for unwinding the DNA double helix by breaking the hydrogen bonds that hold the complementary strands together.
9.
The process by which DNA copies itself is called ____________________.
10.
Molecules of ____________________ carry instructions for protein synthesis from the nucleus to the cytoplasm.
11.
The nitrogen-containing base that is found only in RNA is ____________________.
12.
The enzyme responsible for making RNA is called ____________________.
13.
The form of ribonucleic acid that carries genetic information from the DNA to the ribosomes is ____________________.
14.
A ____________________ is a sequence of DNA at the beginning of a gene that signals RNA polymerase to begin transcription.
15.
Messenger RNA is produced during the process of ____________________.
16.
Of the 64 codons of mRNA, 61 code for ____________________, 3 are ____________________ signals, and one is a ____________________ signal.
17.
Nucleotide sequences of tRNA that are complementary to codons on mRNA are called ____________________.
18.
The sequence of three nucleotides that code for specific amino acids or stop signals in the synthesis of protein is called a(n) ____________________.
19.
The information contained in a molecule of messenger RNA is used to make protein during the process of ____________________.
20.
During translation, amino acids are brought to the ribosomes by molecules of ____________________.

 
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Safety quiz

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Safety Quiz

 

 Check your knowledge of lab safety! 

1. When you find an unlabeled bottle of chemical in the lab, you should:

Smell it to see what it is
Ask your teacher
Waft the chemical
Pour it down the drain

2. If you break a beaker in the lab, the first thing you should do is:

Tell your teacher
Clean up the glass
Put the broken glass in a separate container labeled broken glass
Carefully use your hands to pick up the largest pieces

3. When you complete your lab work, which of the following should you not do:

Clean & return materials to the lab cart
Try your own experiment
Turn in all lab work to your teacher
Return to your own seat

4. Which of the following procedures is not correct:

Add acid to water
Pipette by mouth
Keep flammables away from open flames
Never used chipped glass

5. What is the most important thing to do before starting a lab:

Put on goggles
Put on your lab apron
Pick up your materials from the lab cart
Read the entire lab

6. When heating liquids in test tubes:

Always tightly cork the test tube
hold the test tube pointing upward
Hold test tubes at a slant pointed away from everyone
None of the above

7. Which of the following is true about heating glass:

Only use glassware marked Kimex
Only use glassware marked Pyrex
Both A & B are correct
Always ask the teacher if the container can be heated

8. Which of the following is correct lab procedure:

Place heated glassware on countertops away from the edge
Hold dissecting specimens tightly with your hand when cutting with a scalpel
Wear gloves when dissecting & dispensing irritating chemicals
Pour excess chemical back into its original container

9. Which of the following statements is correct:

Never use cracked glassware
Wash hands before & after dissecting
Treat all chemicals as poisonous
All of the above

10. When inserting glass tubing into stoppers:

Use glycerin & a twisting motion
Hold the stopper tightly as you push the glass tubing into it
Insert the tubing into the stopper under water
Always ask your teacher to insert the glass tubing for you

 

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