Midterm Flashcards
How are radioisotopes useful in treatment of cancer patients?
A) When they decay they absorb radioactive energy and destroy the cancer cells
B) When they decay they release radioactive energy and destroy cancer cells
C) When they are created they absorb radioactive energy and destroy cancer cells
D) When they are created they absorb radioactive energy and destroy cancer cells
E) Radioisotopes are harmful so they are not useful in the treatment of cancer
B
Each element is unique and different from other elements because of the number of protons in the nuclei of
its atoms. Which of the following indicates the number of protons in an atom’s nucleus?
A) atomic mass
B) atomic weight
C) atomic number
D) mass weight
E) mass number
C
Which of the following molecules contain polar covalent bonds?
A) H2O
B) O2
C) H2
D) CH4
A
The _____ bonds between the carbon atoms in unsaturated fatty acids of phospholipids helps to ______
fluidity of membranes.
A) single; increase
B) single; decrease
C) double; increase
D) double; decrease
E) triple; buffer
C
Phospholipids are amphipathic which means that they __________.
A) contain no hydrogens
B) contain hydrophobic and hydrophilic parts.
C) are hydrophilic only.
D) are hydrophobic only.
E) contain no carbon.
B
Research indicates that Ibuprofen, a drug used to relieve inflammation and pain, is a mixture of two
enantiomers meaning that these_________________.
A) have identical three-dimensional shapes.
B) are mirror images of one another.
C) lack an asymmetric carbon.
D) differ in the location of their double bonds.
E) differ in their electrical charge.
B
Which of the following is a nonpolar amino acid and why?
A) Arginine because the nitrogen and carbon in the backbone have the same electronegativities
B) Lysine because of the polar covalent bonds in the R groups
C) Valine because the hydrogen and carbon in the R groups have the same electronegativities
D) Tyrosine because the oxygen has more electronegativity than the carbon in the R groups
C
Which of the following best summarizes the relationship between dehydration reactions and hydrolysis in the
synthesis and breakdown of polymers?
A) Dehydration reactions occur during polymer synthesis, and hydrolysis reactions occur during the break
down polymers.
B) Polymer synthesis occurs through the hydrolysis and addition of water.
C) Dehydration reactions can occur only after hydrolysis.
D) Hydrolysis reactions creates monomers, and dehydration reactions break down polymers.
E) A and B are correct.
A
Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one
galactose molecule. How is lactose classified?
A) as a pentose
B) as a hexose
C) as a monosaccharide
D) as a disaccharide
E) as a polysaccharide
D
What bonds maintains the secondary structure of a protein?
A) peptide bonds
B) hydrogen bonds
C) disulfide bonds
D) ionic bonds
E) phosphodiester bonds
B
What is the main function of ribosomes?
A) transmit genetic information to offspring.
B) synthesize protein.
C) catalyze reactions
D) act as a pattern or blueprint to form DNA.
E) form the genes of higher organisms.
B
The difference between the sugar in DNA and the sugar in RNA is that the sugar in DNA _____.
A) is a six-carbon sugar.
B) can form a double-stranded molecule.
C) has a six-membered ring of carbon and nitrogen atoms.
D) can attach to a phosphate.
E) contains one less oxygen atom.
E
Which of the following is not part of the prokaryotic cell?
A) DNA.
B) a cell wall.
C) mitochondria
D) a plasma membrane.
E) ribosomes.
C
In animal cells, hydrolytic enzymes are packaged to prevent general destruction of cellular components.
Which of the following organelles functions in this compartmentalization?
A) chloroplast
B) lysosome
C) central vacuole
D) peroxisome
E) glyoxysome
B
Where are proteins that will be secreted chemically modified?
A) lysosome
B) vacuole
C) mitochondrion
D) Golgi complex
D
Which of the following contain the 9 + 2 arrangement of microtubules?
A) cilia
B) actin
C) flagella
D) A and C only
E) A, B, and C
D
Plasmodesmata in plant cells are most similar in function to which of the following structures in animal
cells?
A) peroxisomes
B) desmosomes
C) gap junctions
D) extracellular matrix
E) tight junctions
C
What mechanism do cells use to secrete extracellular matrix proteins?
A) endocytosis
B) phagocytosis
C) autophagy
D) osmosis
E) exocytosis
E
Exothermic reactions will result in a(n) __________ in enthalpy and a(n) _________ entropy, therefore
indicating that these reactions will be ___________.
A) increase; increase; nonspontaneous
B) increase; decrease; nonspontaneous
C) increase; decrease; spontaneous
D) decrease; increase; spontaneous
E) decrease; decrease; spontaneous
D
Which of the following is true for all endergonic reactions?
A) The products have more free energy than the reactants.
B) The reaction proceeds with a net release of free energy.
C) Products will be converted to reactants.
D) The reactions are always spontaneous.
A
In the transfer of free energy from catabolic pathways to anabolic pathways, what is the role of ATP?
A) feedback regulator
B) competitive inhibitor
C) energy coupling agent
D) allosteric activator
E) reversible inhibitor
C
How can one increase the rate of a chemical reaction?
A) Increase the activation energy needed.
B) Cool the reactants.
C) Decrease the concentration of the reactants.
D) Add a catalyst.
E) Increase the stability of the reactants.
D
The active site of an enzyme is the region that ______.
A) binds allosteric regulators of the enzyme.
B) is involved in the catalytic reaction of the enzyme.
C) binds the products of the catalytic reaction.
D) is inhibited by the presence of a coenzyme or a cofactor.
B
Cells do not follow the second law of thermodynamics because they create order, not disorder.
A) True
B) False
B
