ch 24 :))))) Flashcards
A polypeptide is
an addition polymer of amino acids.
a condensation polymer of amino acids.
a polymer of sugar molecules.
a part of nucleic acids.
a polymer of nucleic acids.
b
Which of the following is not a lipid?
triglycerides
fatty acids
glycerol
steroids
phospholipids
c
How many rings are found in a steroid molecule?
a
When a drop of the fatty acid oleic acid (CH3(CH2)7CH=CH(CH2)7CO2H) is added to water it forms a molecule thick layer on the surface of the water. What is the likely orientation of the acid on the water surface?
?
Which of the following statements concerning enzyme chemistry is/are correct?
1. Enzymes are biological catalysts.
2. A reaction occurs when substrate binds the enzyme active site.
3. Enzymes catalyze multiple types of reactions.
d
Which statement concerning the twenty different α-amino acids widely found in nature is true?
d
What carbohydrate is the form in which plants store glucose for future use as cellular fuel?
a
The amide linkages in a protein are also called _____ bonds.
peptide
The sequence of amino acids linked by peptide bonds is called the _____ structure of a protein.
b
Classification of a compound as a lipid is based on the _____ of the compound.
e
Which of the following concerning protein structure is not correct?
c
Which of the following statements concerning proteins is not correct?
e
What is the most prevalent form of the amino acid glycine (R = H) in an aqueous environment when mixed with an excess of strong acid.
c
Which DNA or RNA base is guanine?
c
How many RNA nucleotides comprise a codon?
c
Saturated fats and oils have ___ melting points than unsaturated fats and oils because of greater ___ forces between molecules.
b
The fully protonated form of the amino-acid glycine (R=H) may be simply written as H2Gly+. Write the balanced acid dissociation equilibria (Ka1 and Ka2) for this acid.
?
The principal compound used to store and transport energy in a cell is called adenosine 5’-triphosphate. Is this statement true or false?
true
In the context of polymerase chain reaction, if you start with a single double-stranded DNA molecule, how many double-strabded DNA molecules will you have after 10 amplification cycles?
1,024
Which of the following is the product of transcription in protein synthesis?
d
The process by which a double stranded of DNA is copied is called ___. In the process, a ___ strand of DNA is produced from each single strand of the original double-stranded DNA.
replication; rna?
Starch and cellulose are polysaccharides made up long chains of glucose linked by glycosidic bonds. Despite the identical composition, why can humans digest starch but not cellulose?
Humans can digest starches because they have an alpha linkage. We can’t digest cellulose because it has a beta linkage.
Which of the following functional groups is not found in naturally occurring proteins or their amino acid building blocks?
not b. or a
Which of the following base forms hydrogen bonds with adenine in double-stranded DNA molecule?
a
Which of the following statements concerning RNA is/are correct?
d
Which of the following statements concerning metabolism is/are correct?
e
A fragment of a DNA molecule has the base sequence GACT. Which of the following is the complementary sequence of the DNA fragment?
d
Which of the following functional groups are not found in carbohydrates?
a
A phospholipid may include all of the following except
d
The oxygen that bridges two sugars in a disaccharide is known as a ___ bond.
glycosidic
Which of the following units is not found in a DNA molecule?
b
Which of the following amino-acids is not chiral?
e
Which of the following statements concerning cell membranes is/are correct?
b
Which of the following represents the linkage connecting amino acids in proteins?
a
Which of the following statements concerning polysaccharides is/are correct?
1. Humans do not have enzymes that will break down cellulose.
2. Amylopectin and glycogen are both branched chains of glucose.
3. Amylose starch is a linear polysaccharide.
e
Which of the following is not a polysaccharide?
b
Given the following reduction potentials,
NAD+ + H+ + 2e− → NADH Ε° = −0.105 V
2H+ + 2e− → H2 Ε° = 0.000 V
calculate the standard reduction potential and identify the reducing agent in the following reaction.
NAD+ + H2 → NADH + 2H+
c
One way our bodies produce ATP is to couple the formation of ATP from ADP with the hydrolysis of phosphoenopyruvate (PEP), as shown below.
b
The melting point of lipids depends on the strength of the intermolecular forces present in the solid. Rank the following fatty acids in order of increasing melting point.
a
An important reaction in the production of energy from sugars (glycolysis) is the reduction of pyruvate to lactate by NADH.
e
Which of the following statements concerning lipids is/are correct?
e
Which of the following pairs of compounds form a nucleoside?
not b
Which of the following is not a component of DNA?
c
Which of the following reactions is responsible for the formation of glycosidic bonds in disaccharides?
not c or a or e
The side chains of nonpolar amino acids contain _____.
a
Which of the following statements concerning protein synthesis is/are correct?
e
A compound which contains both a positive and negative charge is called a ____.
dipolar
Which of the following is not a step in protein synthesis?
c
Aerobic respiration links the oxidation of glucose with the production of ATP form ADP.
d
Which of the following pairs of compounds form a nucleoside?
a
How many unique tripeptides can be made from two molecules of valine (val) and one molecule of alanine (ala)?
c
Which of the following statements concerning carbohydrates is not correct?
d
What is the functional group corresponding to a peptide bond?
c
A triose is a monosaccharide with three carbon atoms. The molecular formula of a triose is _____.
a
A disaccharide is formed when two monosaccharides are linked by the elimination of a molecule of water and the formation of an ether bond. The newly formed C⎯O bond linking the monosaccharides is called the ____ bond.
e
What is the general formula for carbohydrates?
not c or e maybe d
What is the role of tRNA in protein synthesis?
to decode the codons
