Biology Test 2

what is the name of this process seen in the animation?

dehydration synthesis

Which polymers are composed of amino acids?


Which of the following is not attached to the central carbon atom in an amino acid?

An Oxygen

Which part of an amino acid is always acidic?

Carboxyl functional group

Which monomers make up RNA?


Describe the formation of polypeptides from amino acids

A bond forms between the carboxyl functional group of one amino acid and the amino functional group of the other amino acid.

Enzymes in the digestive tract catalyze hydrolysis reactions.



structure is achieved when a protein folds into a compact, three dimensional shape stabilized by interactions between side chain R groups of amino acids


structure is the result of two or more protein subunits assembling to form a larger, biologically active protein complex


structure is the sequence of amino acids in a protein


structure describes the alpha-helices and the beta-sheets that are formed by hydrogen bonding between backbone atoms located near each other in the polypeptide chain

Proteins are polymers of _____.

amino acids

What type of bond joins the monomers in a protein's primary structure?


The secondary structure of a protein results from _____.

hydrogen bonds

Tertiary structure is NOT directly dependent on _____.

peptide bonds

This animation illustrates the functioning of a ____ protein.


Which of these does NOT contain a structural protein?

Ovalbumin- is a storage protein

Defensive proteins are manufactured by the _____ system.


In general, enzymes are what kinds of molecules?


Enzymes work by___

Reducing EA (energy of activation)

An enzyme _____.

is an organic catalyst

What name is given to the reactants in an enzymatically catalyzed reaction?


As a result of its involvement in a reaction, an enzyme _____.

Is unchanged

Lowest Reaction Rate to Highest Reaction Rate

1. Uncatalyzed Reaction
2. Reaction Catalyzed by Enzyme A
3.Reaction Catalyzed by Enzyme B

An Enzyme is ______ when it loses its native conformation and its biological activity.


An Enzyme is considered a _____ because it speeds up chemical reactions without being used up.


An Enzyme is considered ______ because of its ability to recognize the shape of a particular molecule.


A _____, such as a vitamin, binds to an enzyme and plays a role in catalysis.


When properly aligned, the enzyme and substrate form an enzyme-substrate (ES)______.


A substrate binds to an enzyme at the _______, where the reaction occurs.

Active Site

In a catalyzed reaction a reactant is often called a _______.


A(n) ____ inhibitor has a structure that is so similar to the substrate that it can bond to the enzyme just like the substrate.


A(n) ______ inhibitor binds to a site on the enzyme that is not the active site.


Usually, a(n) _____ inhibitor forms a covalent bond with an amino acid side group within the active site, which prevents the substrate from entering the active site or prevents catalytic activity.


The competitive inhibitor competes with the substrate for the ______ on the enzyme.

Active Site

When the noncompetitive inhibitor is bonded to the enzyme, the shape of the ____ is distorted.


enzyme inhibitors disrupt normal interactions between an enzyme and its ______.


You have added an irreversible inhibitor to a sample of enzyme and substrate. At this point, the reaction has stopped completely.
What can you do to regain the activity of the enzyme?

The enzyme is inactive at this point. New enzyme must be added to regain enzyme activity.

You have an enzymatic reaction proceeding at the optimum pH and optimum temperature. You add a competitive inhibitor to the reaction and notice that the reaction slows down.
What can you do to speed the reaction up again?

Add more substrate; it will outcompete the inhibitor and increase the reaction rate.

Which of these is Not a Lipid?
a. cholesterol
b. RNA
c. steroids
d. phospholipid
e. wax


Which of these is rich in unsaturated fats?
a. olive oil
b. lard
c. butter
d. beef fat
e. a fat that is solid at room temperature

Olive Oil

A function of cholesterol that does not harm health is its role ____.

as a component of animal cell membranes

Which of the following factors does not affect membrane permeability?
a. temperature
b. the amount of cholesterol in the membrane
c. the polarity of membrane phospholipids
d. the saturation of hydrocarbon tails in membrane phospholipids

The polarity of membrane phospholipids

How can a lipid be distinguished from a sugar?
a. a lipid is made up of only hydrocarbons.
b. lipids are mostly nonpolar.
c. lipids are mostly saturated.
d. a lipid dissolves in water.

Lipids are mostly nonpolar.

True or False? Osmosis is a type of diffusion.


What property of dishwashing liquid (detergent) makes it useful to wash grease from pans?
a. solubility in water
b. permeability
c. hydrophobic nature
d. amphipathic nature

Amphipathic Nature

Which of the following particles could diffuse easily through a cell membrane?
a. Oxygen
b. Sodium ion
c. Hydrogen ion
d. Glucose


True or false? The water-soluble portion of a phospholipid is the polar head, which generally consists of a glycerol molecule linked to a phosphate group.


If a red blood cell is placed in a salt solution and bursts, what is the tonicity of the solution relative to the interior of the cell?
a. hypertonic
b. Osmotic
c. hypotonic
d. Isotonic


What distinguishes facilitated diffusion from simple diffusion?
a. Molecules move from a region of lower concentration to a region of higher concentration.
b. Membrane proteins help move molecules across the membrane.
c. No energy is used to move molecule

Membrane proteins help move molecules across the membrane.

Which of the following transporters does not use passive transport to move molecules across a membrane?
a. GLUT-1 glucose transporter
b. Gramicidin ion channel
c. Sodium-potassium pump
d. Valinomycin

Sodium-potassium pump

True or false? Active transport differs from passive transport in that active transport does not require an input of energy.


Which membrane protein would be used to move glucose across a membrane from a region of higher concentration to a region of lower concentration?
a. Ion channel
b. Transporter
c. Pump
d. No protein is necessary.


Which of the following statements is true about the net movement of an ion across a membrane by passive diffusion through a membrane channel?
a. For every ion that diffuses through the membrane, a different ion diffuses in the opposite direction.
b. The c

The charge on the other side of the membrane is generally the opposite of the ion's charge.

True or false? During active transport through the sodium-potassium pump, ATP hydrolysis provides the energy to pump three sodium ions into the cell for every two potassium ions pumped out of the cell.


Lactose transport by membrane proteins occurs under conditions in which the concentration of lactose inside the cell is higher than the concentration outside the cell. What type of transport is used to move lactose into the cell?
a. Simple diffusion
b. Ac

Active transport

Identifying a DNA nucleotide
Identify three possible components of a DNA nucleotide.

Deoxyribose, phosphate group, thymine

If a strand of DNA has the nitrogen base sequence 5'-ATTTGC-3', what will be the sequence of the matching strand?
a. 3'-ATTTGC-5'
b. 3'-GCAAAT-5'
c. 3'-UAAACG-5'
d. 3'-TAAACG-5'
e. 3'-TUUUCG-5'


If a DNA double helix is 100 nucleotide pairs long and contains 25 adenine bases, how many guanine bases does it contain?


The two strands of a DNA double helix are held together by _____ that form between pairs of nitrogenous bases.
a. hydrogen bonds
b. hydrophilic interactions
c. ionic bonds
d. covalent bonds
e. S�S bonds

Hydrogen Bonds

A nucleotide is composed of a(n) _____.
a. glycerol, a nitrogen-containing base, and a five-carbon sugar
b. amino group, a nitrogen-containing base, and a five-carbon sugar
c. phosphate group, a nitrogen-containing base, and a hydrocarbon
d. phosphate gro

phosphate group, a nitrogen-containing base, and a five-carbon sugar

Which structure is not a component of a nucleotide?
a. Phosphate group
b. Sulfhydryl Oxygen group
c. Nitrogen-containing base
d. Pentose

Sulfhydryl Oxygen group

Which of the following statements about nucleotide structure is false?
a. The sugar can be either ribose or deoxyribose.
b. The sugar is bonded to the phosphate group.
c. The nitrogenous base is bonded to the sugar.
d. The phosphate group is bonded to the

The phosphate group is bonded to the nitrogenous base.

True or false? Guanine and uracil
are examples of nitrogenous bases.


Which linkage forms the backbone of a nucleic acid?
a. A sugar-base-phosphate linkage
b. A sugar-base linkage
c. A base-phosphate linkage
d. A sugar-phosphate linkage

A sugar-phosphate linkage

Which of the following statements about DNA structure is true?
a. The nucleic acid strands in a DNA molecule are oriented antiparallel to each other.
b. The arrangement of the sugar-phosphate groups determines the genetic code.
c. Phosphodiester bonds for

The nucleic acid strands in a DNA molecule are oriented antiparallel to each other.

What is the complementary DNA sequence to 5' ATGCATGTCA 3'?


DNA is composed of building blocks called _____.


In eukaryotic cells DNA has the appearance of a _____.

Double Helix

Glycogen is _____.

a polysaccharide found in animals

glucose + glucose �> _____ by _____.

maltose + water ... dehydration synthesis

Which of these is a source of lactose?
a. potatoes
b. milk
c. sugar cane
d. starch
e. sugar beets


Which of these is a polysaccharide?
a. sucrose
b. galactose
c. lactose
d. cellulose
e. glucose


_____ is the most abundant organic compound on Earth.


A _______ cannot be hydrolyzed any further.


A carbohydrate that yields many monosaccharides when hydrolyzed is a _______.


A simple sugar is composed of equal parts carbon and water, which gave rise to the general name of any sugar as a ________.


Lactose, the sugar in milk, is a _______, because it can be split into two monosaccharides.


Which molecule is not a carbohydrate?
a. Lipid
b. Glycogen
c. Starch
d. Cellulose


Which of the following statements about monosaccharide structure is true?
a. A six-carbon sugar is called a pentose.
b. Aldoses and ketoses differ in the position of their hydroxyl groups.
c. All monosaccharides contain carbon, hydrogen, oxygen, and nitro

Monosaccharides can be classified according to the spatial arrangement of their atoms.

True or false? Peptidoglycan is a polysaccharide found only in bacteria.


Which complex carbohydrate contains only a-1,4-glycosidic linkages?
a. Amylopectin
b. Glycogen
c. Cellulose
d. Amylose


Which of the following complex carbohydrates is listed with its correct function?
a. Starch: primary energy-storage molecule in animals
b. Amylose: main component of plant starch
c. Cellulose: structural component of plant cell walls
d. Chitin: constituen

Cellulose: structural component of plant cell walls

Which polysaccharide contains a modified monosaccharide?
a. Starch
b. Cellulose
c. Glycogen
d. Peptidoglycan


In a DNA double helix an adenine of one strand always pairs with a(n) _____ of the complementary strand, and a guanine of one strand always pairs with a(n) _____ of the complementary strand.


Which of these is a difference between a DNA and an RNA molecule?
a. DNA contains uracil, whereas RNA contains thymine.
b. DNA is double-stranded, whereas RNA is single-stranded.
c. DNA contains five-carbon sugars, whereas RNA contains six-carbon sugars.

DNA is double-stranded, whereas RNA is single-stranded.

Nucleotides are composed of a _____, a ______________, and a ____________.

pentose sugar, a nitrogenous base, and a phosphate group.

Which of these nitrogenous bases is found in DNA but not in RNA?
a. cytosine
b. uracil
c. thymine
d. adenine
e. guanine


In a nucleotide, the nitrogenous base is attached to the sugar's _____ carbon and the phosphate group is attached to the sugar's _____ carbon.

1' ... 5'

Nucleic acids are assembled in the _____ direction.

5' to 3'

Who demonstrated that DNA is the genetic material of the T2 phage?

Hershey and Chase

The radioactive isotope 32P labels the T2 phage's _____.


Hershey and Chase used _____ to radioactively label the T2 phage's proteins.

Sulfur 35

After allowing phages grown with bacteria in a medium that contained 32P and 35S, Hershey and Chase used a centrifuge to separate the phage ghosts from the infected cell. They then examined the infected cells and found that they contained _____, which dem

labeled DNA ... DNA

Short segments of newly synthesized DNA are joined into a continuous strand by _____.


After DNA replication is completed, _____.

each new DNA double helix consists of one old DNA strand and one new DNA strand

The action of helicase creates _____.

replication forks and replication bubbles

Why is the new DNA strand complementary to the 5' to 3' strands assembled in short segments?

DNA polymerase can assemble DNA only in the 5' to 3' direction

An old DNA strand is used as a _____ for the assembly of a new DNA strand.


What catalyzes DNA synthesis?

DNA polymerase

Which of the following statements about DNA synthesis is true?

Primers are short sequences that allow the initiation of DNA synthesis.

Which part of a deoxynucleoside triphosphate (dNTP) molecule provides the energy for DNA synthesis?

Phosphate groups

Which of the following enzymes creates a primer for DNA polymerase?


Which of the following statements about Okazaki fragments in E. coli is true?

They are formed on the lagging strand of DNA.

Which of the following enzymes is important for relieving the tension in a helix as it unwinds during DNA synthesis?


True or false? Single-stranded DNA molecules are said to be antiparallel when they are lined up next to each other but oriented in opposite directions.


The first step in the replication of DNA is catalyzed by _____.


The synthesis of a new strand begins with the synthesis of a(n) _____.

RNA primer complementary to a preexisting DNA strand

Short segments of newly synthesized DNA are joined into a continuous strand by