Biology review chapters 5-8 Flash Cards

 
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*Protein kinases are enzymes that catalyze phosphorylation of target proteins at specific sites, whereas protein phosphatases catalyze removal of phosphate(s) from phosphorylated proteins. Phosphorylation and dephosphorylation can function as an on-off switch for a protein's activity, most likely through

a. the excision of one or more peptides.
b. the change in a protein's charge leading to a conformational change.
c. the change in a protein's charge leading to cleavage.
d. a change in the optimal temperature at which a reaction will occur.
e. a change in the optimal pH at which a reaction will occur.
? 0 Jennymarie790 Tue, 04 Oct 2011 19:03:47 GMT view revision history
When you have a severe fever, what grave consequence may occur if the fever is not controlled?

a. removal of amine groups from your proteins
b. change in the tertiary structure of your enzymes
c. binding of your enzymes to inappropriate substrates
d. destruction of your enzymes' primary structure
e. removal of the amino acids in active sites of your enzymes
b. change in the tertiary structure of your enzymes 0 Jennymarie790 Tue, 04 Oct 2011 18:31:15 GMT view revision history
For living organisms, which of the following is an important consequence of the first law of thermodynamics?

a. Organisms grow by converting energy into organic matter.
b. Life does not obey the first law of thermodynamics.
c. The energy content of an organism is constant.
d. The organism ultimately must obtain all of the necessary energy for life from its environment.
e. The entropy of an organism decreases with time as the organism grows in complexity.
d. The organism ultimately must obtain all of the necessary energy for life from its environment. 0 Jennymarie790 Tue, 04 Oct 2011 18:31:15 GMT view revision history
What is the difference (if any) between the structure of ATP and the structure of the precursor of the A nucleotide in RNA?

a. There is no difference.
b. The number of phosphates is three instead of two.
c. The sugar molecule is different.
d. The nitrogen-containing base is different.
e. The number of phosphates is three instead of one.
there is no difference 1 Jennymarie790 Wed, 05 Oct 2011 01:07:55 GMT view revision history
*How might an amino acid change at a site distant from the active site of the enzyme alter the enzyme's substrate specificity?

a. by changing the enzyme's location in the cell
b. an amino acid change away from the active site cannot alter the enzyme's substrate specificity
c. by changing the enzyme's stability
d. by changing the shape of the protein
e. by changing the enzyme's pH optimum
? 0 Jennymarie790 Tue, 04 Oct 2011 18:31:15 GMT view revision history
Choose the pair of terms that correctly completes this sentence: Catabolism is to anabolism as ________ is to ________.

a. entropy; enthalpy
b. free energy; entropy
c. work; energy
d. exergonic; spontaneous
e. exergonic; endergonic
e. exergonic; endergonic 0 Jennymarie790 Tue, 04 Oct 2011 18:29:45 GMT view revision history
If an enzyme is added to a solution where its substrate and product are in equilibrium, what will occur?

a. Nothing; the reaction will stay at equilibrium.
b. The free energy of the system will change.
c. Additional product will be formed.
d. The reaction will change from endergonic to exergonic.
e. Additional substrate will be formed.
a. Nothing; the reaction will stay at equilibrium. 0 Jennymarie790 Tue, 04 Oct 2011 18:29:45 GMT view revision history
A series of enzymes catalyze the reaction X → Y → Z → A. Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of the enzyme.


With respect to the enzyme that converts X to Y, substance A functions as

a. the substrate.
b. a competitive inhibitor.
c. an intermediate.
d. an allosteric inhibitor.
e. a coenzyme.
a. the substrate. 0 Jennymarie790 Tue, 04 Oct 2011 18:29:45 GMT view revision history
Why is ATP an important molecule in metabolism?

a. Its terminal phosphate group contains a strong covalent bond that, when hydrolyzed, releases free energy.
b. Its terminal phosphate bond has higher energy than the other two.
c. Its hydrolysis provides an input of free energy for exergonic reactions.
d. It is one of the four building blocks for DNA synthesis.
e. It provides energy coupling between exergonic and endergonic reactions.
e. It provides energy coupling between exergonic and endergonic reactions. 0 Jennymarie790 Tue, 04 Oct 2011 18:29:45 GMT view revision history
Which of these are not embedded in the hydrophobic portion of the lipid bilayer at all?

a. integral proteins
b. peripheral proteins
c. transmembrane proteins
d. glycoproteins
e. integrins
b. peripheral proteins 0 Jennymarie790 Tue, 04 Oct 2011 18:25:34 GMT view revision history
*Which of the following would increase the electrochemical potential across a membrane?

a. a proton pump
b. a potassium channel
c. both a proton pump and a potassium channel
d. a sucrose-proton cotransporter
e. a chloride channel
? 0 Jennymarie790 Tue, 04 Oct 2011 18:25:34 GMT view revision history
When biological membranes are frozen and then fractured, they tend to break along the middle of the bilayer. The best explanation for this is that

a. water that is present in the middle of the bilayer freezes and is easily fractured.
b. the integral membrane proteins are not strong enough to hold the bilayer together.
c. the carbon-carbon bonds of the phospholipid tails are easily broken.
d. the hydrophobic interactions that hold the membrane together are weakest at this point.
e. hydrophilic interactions between the opposite membrane surfaces are destroyed on freezing.
d. the hydrophobic interactions that hold the membrane together are weakest at this point. 0 Jennymarie790 Tue, 04 Oct 2011 18:25:34 GMT view revision history
*Nitrous oxide gas molecules diffusing across a cell's plasma membrane is an example of

a. facilitated diffusion.
b. cotransport.
c. diffusion across the lipid bilayer.
d. osmosis.
e. active transport.
? 0 Jennymarie790 Tue, 04 Oct 2011 18:25:34 GMT view revision history
Which of the following factors would tend to increase membrane fluidity?

a. a greater proportion of relatively large glycolipids compared with lipids having smaller molecular masses
b. a greater proportion of saturated phospholipids
c. a relatively high protein content in the membrane
d. a greater proportion of unsaturated phospholipids
e. a lower temperature
d. a greater proportion of unsaturated phospholipids 0 Jennymarie790 Tue, 04 Oct 2011 18:23:50 GMT view revision history
The sodium-potassium pump in animal cells requires cytoplasmic ATP to pump ions across the plasma membrane. When the proteins of the pump are first synthesized in the rough ER, what side of the ER membrane will the ATP binding site be on?

a. It will be on the side facing the interior of the ER.
b. It will be on the cytoplasmic side of the ER.
c. It could be facing in either direction because proteins are properly reoriented in the Golgi apparatus.
d. It doesn't matter, because the pump is not active in the ER.
b. It will be on the cytoplasmic side of the ER. 0 Jennymarie790 Tue, 04 Oct 2011 18:23:50 GMT view revision history
Singer and Nicolson's fluid mosaic model of the membrane proposed that

a. membranes are a single layer of phospholipids and proteins.
b. membranes are a phospholipid bilayer.
c. membranes consist of protein molecules embedded in a fluid bilayer of phospholipids.
d. membranes are a phospholipid bilayer between two layers of hydrophilic proteins.
e. membranes consist of a mosaic of polysaccharides and proteins.
c. membranes consist of protein molecules embedded in a fluid bilayer of phospholipids. 2 Jennymarie790 Wed, 05 Oct 2011 01:08:30 GMT view revision history
ECM proteins are made by ribosomes in which part of a eukaryotic cell?

a. nuclear envelope
b. cytoplasm
c. rough ER
d. mitochondria
e. Golgi apparatus
c. rough ER 0 Jennymarie790 Tue, 04 Oct 2011 18:23:50 GMT view revision history
Cyanide binds with at least one molecule involved in producing ATP. If a cell is exposed to cyanide, most of the cyanide will be found within the

a. lysosomes.
b. peroxisomes.
c. ribosomes.
d. mitochondria.
e. endoplasmic reticulum.
d. mitochondria. 0 Jennymarie790 Tue, 04 Oct 2011 18:21:16 GMT view revision history
Which animal cell organelle contains enzymes that transfer hydrogen from various substrates to oxygen?

a. lysosome
b. Golgi apparatus
c. mitochondrion
d. peroxisome
e. vacuole
d. peroxisome 0 Jennymarie790 Tue, 04 Oct 2011 18:21:16 GMT view revision history
In a liver cell detoxifying alcohol and some other poisons, the enzymes of the peroxisome remove hydrogen from these molecules and

a. transfer the hydrogen to the mitochondria.
b. use the hydrogen to break down hydrogen peroxide.
c. combine the hydrogen with water molecules to generate hydrogen peroxide.
d. transfer the hydrogen to oxygen molecules to generate hydrogen peroxide.
d. transfer the hydrogen to oxygen molecules to generate hydrogen peroxide. 0 Jennymarie790 Tue, 04 Oct 2011 18:21:16 GMT view revision history
Which organelle or structure is absent in plant cells?

a. peroxisomes
b. Golgi vesicles
c. centrosomes
d. microtubules
e. mitochondria
c. centrosomes 0 Jennymarie790 Tue, 04 Oct 2011 18:21:16 GMT view revision history
Which of the following statements correctly describes some aspect of protein secretion from prokaryotic cells?

a. Prokaryotes are unlikely to be able to secrete proteins because they lack an endomembrane system.
b. In prokaryotes, the ribosomes that are used for the synthesis of secreted proteins are located outside of the cell.
c. Prokaryotes contain large pores in their plasma membrane that permit the movement of proteins out of the cell.
d. Proteins that are secreted by prokaryotes are synthesized on ribosomes that are bound to the cytoplasmic surface of the plasma membrane.
e. The mechanism of protein secretion in prokaryotes is probably the same as that in eukaryotes.
d. Proteins that are secreted by prokaryotes are synthesized on ribosomes that are bound to the cytoplasmic surface of the plasma membrane. 0 Jennymarie790 Tue, 04 Oct 2011 18:19:21 GMT view revision history
All of the following serve an important role in determining or maintaining the structure of plant cells. Which of the following are distinct from the others in their composition?

a. intermediate filaments
b. microtubules
c. plant cell walls
d. microfilaments
e. nuclear lamina
c. plant cell walls 0 Jennymarie790 Tue, 04 Oct 2011 18:19:21 GMT view revision history
The nuclear lamina is an array of filaments on the inner side of the nuclear membrane. If a method were found that could cause the lamina to fall into disarray, what would you expect to be the most likely consequence?

a. the loss of all nuclear function
b. failure of chromosomes to carry genetic information
c. inability of the nucleus to keep out destructive chemicals
d. the inability of the nucleus to divide during cell division
e. a change in the shape of the nucleus
e. a change in the shape of the nucleus 0 Jennymarie790 Tue, 04 Oct 2011 18:19:21 GMT view revision history
Hydrolytic enzymes must be segregated and packaged to prevent general destruction of cellular components. Which of the following organelles contains these hydrolytic enzymes in animal cells?

a. glyoxysome
b. peroxisome
c. central vacuole
d. chloroplast
e. lysosome
e. lysosome 0 Jennymarie790 Tue, 04 Oct 2011 18:19:21 GMT view revision history
Which plant cell organelle contains its own DNA and ribosomes?

a. mitochondrion
b. Golgi apparatus
c. glyoxysome
d. vacuole
e. peroxisome
a. mitochondrion 0 Jennymarie790 Tue, 04 Oct 2011 18:17:15 GMT view revision history
DNAase is an enzyme that catalyzes the hydrolysis of the covalent bonds that join nucleotides together. What would first happen to DNA molecules treated with DNAase?

a. The two strands of the double helix would separate.
b. The phosphodiester bonds between deoxyribose sugars would be broken.
c. The pyrimidines would be separated from the deoxyribose sugars.
d. All bases would be separated from the deoxyribose sugars.
e. The purines would be separated from the deoxyribose sugars.
b. The phosphodiester bonds between deoxyribose sugars would be broken. 0 Jennymarie790 Tue, 04 Oct 2011 18:17:15 GMT view revision history
*If cells are grown in a medium containing radioactive 15N, which of these molecules will be labeled?

a. proteins only
b. nucleic acids only
c. both proteins and nucleic acids
d. fatty acids only
e. amylase only
? 1 Jennymarie790 Tue, 04 Oct 2011 18:26:51 GMT view revision history
*A molecule with the chemical formula C6H12O6 is probably a

a. lipid.
b. monosaccharide
c. carbohydrate and monosaccharide only.
d. carbohydrate.
e. carbohydrate and lipid only.
? 1 Jennymarie790 Tue, 04 Oct 2011 18:26:41 GMT view revision history
The structural level of a protein least affected by a disruption in hydrogen bonding is the

a. primary level.
b. quaternary level.
c. All structural levels are equally affected.
d. secondary level.
e. tertiary level.
a. primary level. 0 Jennymarie790 Tue, 04 Oct 2011 18:15:42 GMT view revision history
What aspects of protein structure are stabilized or assisted by hydrogen bonds?
secondary structure
b. primary structure
c. secondary, tertiary, and quaternary structures, but not primary structure
d. tertiary structure
e. quaternary structure
c. secondary, tertiary, and quaternary structures, but not primary structure 0 Jennymarie790 Tue, 04 Oct 2011 18:15:42 GMT view revision history
What is the structural feature that allows DNA to replicate?
a. disulfide bonding (bridging) of the two helixes
b. twisting of the molecule to form an α helix
c. three-component structure of the nucleotides
d. sugar-phosphate backbone
e. complementary pairing of the nitrogenous bases
e. complementary pairing of the nitrogenous bases 0 Jennymarie790 Tue, 04 Oct 2011 18:15:42 GMT view revision history
What is the chemical reaction mechanism by which cells make polymers from monomers?
a. the formation of disulfide bridges between monomers
b. phosphodiester linkages
c. dehydration reactions
d. ionic bonding of monomers
e. hydrolysis
c. dehydration reactions 0 Jennymarie790 Tue, 04 Oct 2011 18:15:42 GMT view revision history
A chemical reaction that has a positive G is correctly described as
A. exothermic.
B. spontaneous.
C. enthalpic.
D. endergonic.
E. endothermic.
D. endergonic. 0 Jennymarie790 Tue, 04 Oct 2011 18:11:40 GMT view revision history
Which of the following is true for all exergonic reactions?
A. The reactions are nonspontaneous.
B. The reaction proceeds with a net release of free energy.
C. The products have more total energy than the reactants.
D. A net input of energy from the surroundings is required for the reactions to proceed.
E. Some reactants will be converted to products.
B. The reaction proceeds with a net release of free energy. 0 Jennymarie790 Tue, 04 Oct 2011 18:11:40 GMT view revision history
The mathematical expression for the change in free energy of a system is G =H-TS. Which of the following is (are) correct?
A. G is the change in free energy.
B. T is the temperature in degrees Celsius.
C. H is the change in entropy, the energy available to do work.
D. S is the change in enthalpy, a measure of randomness.
A. G is the change in free energy. 0 Jennymarie790 Tue, 04 Oct 2011 18:11:40 GMT view revision history
Which of the following statements is representative of the second law of thermodynamics?
A. Without an input of energy, organisms would tend toward decreasing entropy.
B. Every energy transformation by a cell decreases the entropy of the universe.
C. Heat represents a form of energy that can be used by most organisms to do work.
D. Cells require a constant input of energy to maintain their high level of organization.
E. Conversion of energy from one form to another is always accompanied by some gain of free energy.
D. Cells require a constant input of energy to maintain their high level of organization. 0 Jennymarie790 Tue, 04 Oct 2011 18:11:40 GMT view revision history
Whenever energy is transformed, there is always an increase in the
A. free energy of the system.
B. enthalpy of the universe.
C. entropy of the universe.
D. entropy of the system.
E. free energy of the universe.
C. entropy of the universe. 0 Jennymarie790 Tue, 04 Oct 2011 18:08:14 GMT view revision history
Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics?
A. Life obeys the second law of thermodynamics because the decrease in entropy as the organism grows is balanced by an increase in the entropy of the universe.
B. Living organisms do not follow the laws of thermodynamics.
C. Living organisms do not obey the second law of thermodynamics, which states that entropy must increase with time.
D. As a consequence of growing, organisms create more disorder in their environment than the decrease in entropy associated with their growth.
E. Living organisms are able to transform energy into entropy.
Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics?
A. Life obeys the second law of thermodynamics because the decrease in entropy as the organism grows is balanced by an increase in the entropy of the universe.
B. Living organisms do not follow the laws of thermodynamics.
C. Living organisms do not obey the second law of thermodynamics, which states that entropy must increase with time.
D. As a consequence of growing, organisms create more disorder in their environment than the decrease in entropy associated with their growth.
0 Jennymarie790 Tue, 04 Oct 2011 18:08:14 GMT view revision history
Which of the following is (are) true for anabolic pathways?
A. They do not depend on enzymes.
B. They are usually highly spontaneous chemical reactions.
C. They release energy as they degrade polymers to monomers.
D. They consume energy to build up polymers from monomers.
D. They consume energy to build up polymers from monomers. 0 Jennymarie790 Tue, 04 Oct 2011 18:08:14 GMT view revision history
Which term most precisely describes the cellular process of breaking down large molecules into smaller ones?
A. anabolism
B. catabolism
C. dehydration
D. catalysis
E. metabolism
B. catabolism 0 Jennymarie790 Tue, 04 Oct 2011 18:08:14 GMT view revision history
Of the following functions, which is most important for the glycoproteins and glycolipids of animal cell membranes?

A. maintaining membrane fluidity at low temperatures
B. a cell's ability to distinguish one type of neighboring cell from another
C. maintaining the integrity of a fluid mosaic membrane
D. active transport of molecules against their concentration gradients
E. facilitated diffusion of molecules down their concentration gradients
B. a cell's ability to distinguish one type of neighboring cell from another 0 Jennymarie790 Tue, 04 Oct 2011 18:04:11 GMT view revision history
Which of the following is true of integral membrane proteins?A. They serve only a structural role in membranes.
B. They are loosely bound to the surface of the bilayer.
C. They lack tertiary structure.
D. They are not mobile within the bilayer.
E. They are usually transmembrane proteins.
E. They are usually transmembrane proteins. 0 Jennymarie790 Tue, 04 Oct 2011 18:04:11 GMT view revision history
In order for a protein to be an integral membrane protein it would have to be which of the following?
A. hydrophilic
B. completely covered with phospholipids
C. exposed on only one surface of the membrane
D. amphipathic
E. hydrophobic
D. amphipathic 0 Jennymarie790 Tue, 04 Oct 2011 18:04:11 GMT view revision history
According to the fluid mosaic model of cell membranes, which of the following is a true statement about membrane phospholipids?
A. They have hydrophilic tails in the interior of the membrane.
B. They frequently flip-flop from one side of the membrane to the other.
C. They are free to depart from the membrane and dissolve in the surrounding solution.
D. They can move laterally along the plane of the membrane.
E. They occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane.
D. They can move laterally along the plane of the membrane. 0 Jennymarie790 Tue, 04 Oct 2011 18:04:11 GMT view revision history
The presence of cholesterol in the plasma membranes of some animals
A. enables the animal to add hydrogen atoms to unsaturated phospholipids.
B. enables the membrane to stay fluid more easily when cell temperature drops.
C. enables the animal to remove hydrogen atoms from saturated phospholipids.
D. makes the animal more susceptible to circulatory disorders.
E. makes the membrane less flexible, allowing it to sustain greater pressure from within the cell.
B. enables the membrane to stay fluid more easily when cell temperature drops. 0 Jennymarie790 Tue, 04 Oct 2011 18:00:31 GMT view revision history
Which of the following types of molecules are the major structural components of the cell membrane?
A. glycoproteins and cholesterol
B. proteins and cellulose
C. nucleic acids and proteins
D. phospholipids and cellulose
E. phospholipids and proteins
E. phospholipids and proteins 0 Jennymarie790 Tue, 04 Oct 2011 18:00:31 GMT view revision history
Enzymes are
A. carbohydrates.
B. proteins.
C. nucleic acids.
D. lipids.
B. proteins. 0 Jennymarie790 Tue, 04 Oct 2011 18:00:31 GMT view revision history
In the double helix structure of nucleic acids, cytosine hydrogen bonds to
A. adenine.
B. thymine.
C. ribose.
D. guanine.
E. deoxyribose.
D. guanine. 0 Jennymarie790 Tue, 04 Oct 2011 18:00:31 GMT view revision history
Which of the following is an example of hydrolysis?
A. the reaction of a fat, forming glycerol and fatty acids with the utilization of water
B. the reaction of a fat, forming glycerol and fatty acids with the release of water
C. the synthesis of two amino acids, forming a peptide with the release of water
D. the reaction of two monosaccharides, forming a disaccharide with the release of water
E. the synthesis of a nucleotide from a phosphate, a pentose sugar, and a nitrogenous base with the production of a molecule of water
A. the reaction of a fat, forming glycerol and fatty acids with the utilization of water 0 Jennymarie790 Tue, 04 Oct 2011 17:56:08 GMT view revision history
If a DNA sample were composed of 10% thymine, what would be the percentage of guanine?

A. impossible to tell from the information given
B. 20
C. 40
D. 10
E. 80
C. 40 0 Jennymarie790 Tue, 04 Oct 2011 17:56:08 GMT view revision history
Which of the following are nitrogenous bases of the pyrimidine type?
A. ribose and deoxyribose
B. adenine and thymine
C. thymine and guanine
D. cytosine and uracil
E. guanine and adenine
D. cytosine and uracil 0 Jennymarie790 Tue, 04 Oct 2011 17:56:08 GMT view revision history
Which of the following best describes the flow of information in eukaryotic cells?
A. RNA → proteins → DNA
B. DNA → RNA → proteins C. RNA → DNA → proteins
D. proteins → DNA → RNA
E. DNA → proteins → RNA
B. DNA → RNA → proteins 0 Jennymarie790 Tue, 04 Oct 2011 17:56:08 GMT view revision history
What is the term used for a protein molecule that assists in the proper folding of other proteins?
A. enzyme protein
B. denaturing protein
C. renaturing protein
D. tertiary protein
E. chaperonin
E. chaperonin 0 Jennymarie790 Tue, 04 Oct 2011 17:53:12 GMT view revision history
Misfolding of polypeptides is a serious problem in cells. Which of the following diseases are associated with an accumulation of misfolded proteins?
A. Parkinson's
B. diabetes
C. Alzheimer's
D. A and B only
E. A, B, and C
D. A and B only 0 Jennymarie790 Tue, 04 Oct 2011 17:53:12 GMT view revision history
The tertiary structure of a protein is the
A. overall protein structure resulting from the aggregation of two or more polypeptide subunits.
B. bonding together of several polypeptide chains by weak bonds.
C. unique three-dimensional shape of the fully folded polypeptide.
D. order in which amino acids are joined in a polypeptide chain.
E. organization of a polypeptide chain into an α helix or β pleated sheet.
C. unique three-dimensional shape of the fully folded polypeptide 0 Jennymarie790 Tue, 04 Oct 2011 17:53:12 GMT view revision history
The α helix and the β pleated sheet are both common polypeptide forms found in which level of protein structure?
A. secondary
B. primary
C. quaternary
D. tertiary
E. all of the above
A. secondary 0 Jennymarie790 Tue, 04 Oct 2011 17:53:12 GMT view revision history
What maintains the secondary structure of a protein?
A. phosphodiester bonds
B. hydrogen bonds
C. disulfide bonds
D. peptide bonds
E. ionic bonds
B. hydrogen bonds 0 Jennymarie790 Tue, 04 Oct 2011 17:48:55 GMT view revision history
How many different kinds of polypeptides, each composed of 12 amino acids, could be synthesized using the 20 common amino acids?
A. 20
B. 12^5
C. 4^12
D. 12^20
E. 20^12
E. 20^12 0 Jennymarie790 Tue, 04 Oct 2011 17:48:55 GMT view revision history
Dehydration reactions are used in forming which of the following compounds?
A. proteins
B. triacylglycerides
C. polysaccharides
D. A and C only
E. A, B, and C
E. A, B, and C 0 Jennymarie790 Tue, 04 Oct 2011 17:48:55 GMT view revision history
There are 20 different amino acids. What makes one amino acid different from another
A. different side chains (R groups) attached to an alpha (α) carbon
B. different asymmetric carbons
C. different carboxyl groups attached to an alpha (α) carbon
D. different alpha (α) carbons
E. different amino groups attached to an alpha (α) carbon
A. different side chains (R groups) attached to an alpha (α) carbon 0 Jennymarie790 Tue, 04 Oct 2011 17:48:55 GMT view revision history
The bonding of two amino acid molecules to form a larger molecule requires
A. the release of a water molecule.
B. the release of a carbon dioxide molecule.
C. the addition of a water molecule.
D. the addition of a nitrogen atom.
E. both B and C
A. the release of a water molecule. 0 Jennymarie790 Tue, 04 Oct 2011 17:45:06 GMT view revision history
All of the following contain amino acids except
A. hemoglobin.
B. cholesterol.
C. antibodies.
D. enzymes.
E. insulin.
B. cholesterol. 0 Jennymarie790 Tue, 04 Oct 2011 17:45:06 GMT view revision history
Which of the following statements is false for the class of biological molecules known as lipids?
A. They contain more energy than proteins and carbohydrates.
B. They contain waxes and steroids.
C. They are soluble in water.
D. They are not true polymers.
E. They are an important constituent of cell membranes.
C. They are soluble in water. 0 Jennymarie790 Tue, 04 Oct 2011 17:45:06 GMT view revision history
Which of the following is true of both starch and cellulose?
A. They are geometric isomers of each other.
B. They are both polymers of glucose.
C. They can both be digested by humans.
D. They are both used for energy storage in plants.
E. They are both structural components of the plant cell wall.
B. They are both polymers of glucose 0 Jennymarie790 Tue, 04 Oct 2011 17:45:06 GMT view revision history
The molecular formula for glucose is C6H12O6. What would be the molecular formula for a molecule made by linking three glucose molecules together by dehydration reactions?
A. C18H36O18
B. C3H6O3
C. C18H30O15
D. C6H10O5
E. C18H10O15
C. C18H30O15 0 Jennymarie790 Tue, 04 Oct 2011 17:41:32 GMT view revision history
What is the chemical mechanism by which cells make polymers from monomers?
A. dehydration reactions
B. the formation of disulfide bridges between monomers
C. ionic bonding of monomers
D. phosphodiester linkages
E. hydrolysis
A. dehydration reactions 0 Jennymarie790 Tue, 04 Oct 2011 17:41:32 GMT view revision history
Which of the following is a false statement concerning amino groups?They are components of urea.
A.They are components of urea.
B.They are nonpolar.
C.They are found in amino acids.
D.They contain nitrogen.
E.They are basic in pH.
B. They are non ploar 0 Jennymarie790 Tue, 04 Oct 2011 17:41:32 GMT view revision history
Which two functional groups are always found in amino acids?
A. carboxyl and amino
B.carbonyl and carboxyl
C.ketone and aldehyde
D.hydroxyl and aldehyde
E.phosphate and sulfhydryl
A. carboxyl and amino 0 Jennymarie790 Tue, 04 Oct 2011 17:41:32 GMT view revision history

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