Nitrous oxide (N2O) or 'laughing gas' can be used as an anesthetic or pain-relieving drug when inhaled. N2O is
12C and 14C are isotopes of carbon. The atomic number for C is 6.
12C and 14C have the same valence or bonding capacity
The most common isotope of Phosphorus is 31P. The atomic number for P is 15. An atom of 31P would have
15 electrons and 15 protons
How many electrons are present in the valence shell of an element with atomic number 8?
What is the valence of an element with atomic number 8?
Which of the following is an example of a hydrogen bond?
the bond between the H of one water molecule and the N of neighboring ammonia molecule
The bond that joins two oxygen atoms together in a O2 molecule is a
nonpolar double covalent bond
Consider two elements, element X and element Y. The electronegativity of element X is significantly greater than the electronegativity of element Y. Which of the following statements would describe a covalent bond that is formed between these two compounds?
the end of the molecule containing the X atom will be slightly negative relative to the Y end of the molecule
A mole of KCl has a mass of 74.6 grams. In order to prepare a 0.5 M solution, how many grams of postassium chloride must be added to 500 ml (0.5 L) of water?
Which of the following statements correctly describes the bonds that maintain the alpha helix structure of proteins?
hydrogen bonds that occur between H and O atoms of adjacent or adjoining amino acids in the backbone of the polypeptide chain
Results in the loss of water molecules
Synthesis of cellulose from glucose
Digestion of food we eat in our digestive tract
Formation of a ring structure by glucose in aqueous solution
Which of the amino acids shown above has a basic side chain?
Arginine (has NH2 ends)
Which of the amino acids shown above has a non-polar side chain?
Isoleucine (has CH3 ends)
Which of the amino acids shown above has polar side chain
Threonine (has OH end)
Which of the amino acids could participate in hydrophobic interactions within the tertiary structure of proteins
Isoleucine (remember CH3 hates water)
Which of the monosaccharides is glucose?
The six ringed structure (has CH2OH on 6th carbon end, alpha has H on top of 1st carbon end, OH on top when beta)
Which of the monosaccharides is fructose?
Has two CH2OH ends, 5 ringed structure.
Which of the monosaccharides is ribose?
5 ringed structure (one CH2OH end)
Which of the monosaccharides shown are structural isomers of each other?
Glucose and Fructose
Which one of the molecules is a triglyceride containing one unsaturated fatty acid?
Has two non-kinked tails. One with a "kink" is unsaturated.
Which of the molecules is a triglyceride with all saturated fatty acids?
Has 3 non-kinked tails.
Which of the above molecules is a monoglyceride?
None. They all have three saturated tails.
What is the atomic number of the cation formed in the reaction illustrated in the above figure? (shows Na + Cl forming NaCl)
11 (NOT 10, look at reactants side)
Assume that acid rain has lowered the pH of a particular lake to pH 4.0. What is the hydroxide ion concentration of this lake?
1 x 10^-10 mol of hydroxide ion per liter of lake water (14 - pH 4.0 = 1 x 10^-10 [OH] = 1 x 10^10^-4 [H]`)
The enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are the α form. Which of the following could amylase break down?
Which of the following paired items is LEAST correct?
hydrophobic molecules : water soluble
Fatty acids are considered acids because they can donate hydrogen ions to a solution. What functional group is responsible for this property?
Carboxyl group (COOH, with C double bonded to O, single bonded to OH)
How many electrons are shared by two atoms that are joined with a double covalent bond?
This functional group forms the N terminus of a protein
This functional group forms the C terminus of a protein
Compounds with this functional group are called alcohols
An acidic functional group
provides for the hydrophilic properties for phospholipids
A scientist is given two samples of fatty acids. She determines that the ratio of hydrogen to carbon is greater for the fatty acids within solution A compared to the fatty acids within solution B. Which solution would contain a higher concentration of unsaturated fatty acids?
In an aqueous solution, phospholipids often form membranes that consist of two layers of phospholipids. Which statement below correctly describes the orientation of the phospholipid molecules within this membrane?
the phosphate end of the phospholipid is oriented toward the outer surface of the membrane
Identify the asymmetric carbon in the molecule above.
Carbon B. Bonded to carbon, H, OH, and another carbon (look for differences in the bonds to carbon).
Which carbon atom is part of the carbonyl group within this molecule?
Carbon A. Double bonded to oxygen (C=O)
This molecule is an
ALDEHYDE - carbon double bonded to O, single bonded to H, single bonded to R. Ketone - C=O plus single bonded to two separate R's (r1,r2)
When comparing the properties of phospholipids and triglycerides, which of the following statements are true?
both molecules contain fatty acids
Denaturation of a protein
alters the normal conformation of a protein
The hydrocarbon portion of the lipid molecule consists of
hydrogen and carbon atoms joined with nonpolar covalent bonds
Lipids that contain a high concentration of unsaturated fatty acids are typically liquids at room temperature because
the lipid molecules that contain unsaturated fatty acids have kinks and are unable to pack together as tightly as lipids containing saturated fatty acids
Which of the following compounds is contained in BOTH DNA and RNA?
Which of the following compounds would NOT be present in the nucleotides that comprise RNA?
Which of the following bonds or interactions are responsible for maintaining the tertiary structure of proteins?
Hydrogen and ionic bonds, hydrophobic and van der Waals interactions.
Compare a mole of glucose (C6H12O6) versus a mole of sodium chloride (NaCl). Which of the following statements is true?
A mole of glucose would contain the same number of molecules as a mole of sodium chloride. If a mole of each substance is added to 2 L of water, the molarity of each solution would be the same.
What's an alpha carbon?
First carbon that attaches to a functional group.
Which of the steps take place in both mitosis and meiosis
Separation of sister chromatids
The DNA sequence is identical for
The DNA sequence is identical for
is the exchange of genetic material during meiosis between two non-sister chromatids within a tetrad
is an enzyme that catalyzes the conversion of ATP into cyclic AMP
Which of the following alters the activity of other enzymes by phosphorylating the enzyme
Which of the following compounds are outputs from the Calvin cycle?
ADP, NADP+, glyceraldehyde-3-phosphate
Within photosynthesis, oxygen is produced. The source of oxygen is
Which of the following are outputs from the light dependent reactions?
The nuclear envelope
contains openings or pores that allow movement of materials from the nucleus to the cytoplasm
Which of the following compounds is a molecule that is produced within the glycolytic pathway
Which of the following pairs of terms or phrases is mismatched
smooth endoplasmic reticulum - ribosomes
During cellular respiration, CO2 is produced within
the junction between glycolysis and the beginning of the Krebs cycle, and the Krebs cycle
Of the list provided below, which sequence is the most common route for the synthesis and trafficking of proteins that are secreted from a cell
Order the events numbered 1 through 4 below in a sequence that accurately describes the order of events leading to synthesis of ATP within oxidative phosphorylation.
Donations of electrons by NADH, movement of electrons from one carrier complex to next, generation of a proton gradient, synthesis of ATP via enzymatic action of ATP synthase.
The prefix 'glyco' within the term glycoprotein refers to the
carbohydrate portion of the molecule
Which of the following compounds are products of oxidative phosphorylation within the electron transport chain of mitochondria
ATP, NAD+, and H2O
The active site of an enzyme is defined as
a specific region on the enzyme where the substrate or reactant binds
The molecule shown above is
a triglyceride with one unsaturated fatty acid and two saturated fatty acids
The side chain of this amino acid that is labeled as C is an example of a
non-polar side chain (has CH3 endings)
The dashed circle that is labeled as B is what functional group for this amino acid
The structural diagram above is
glucose (6 ringed, 6th carbon has a CH2OH)
Which of the following is an example of a hydrogen bond
the bond between the H of one water molecule and the O of neighboring water molecule
What is the valence or bonding capacity of carbon
How many electrons are present in the valence shell of carbon atoms?
Calcium has an atomic number of 20. In an aqueous solution, calcium is often present as a divalent cation, i.e, a cation with two positive charges. Ca++ has
18 electrons, 20 protons
Aminoacyl - tRNA - synthetase
The two ends of one of the parent strands of DNA are labeled as A and B. Which end is the 5' end of the strand?
It's opposite of the other DNA strand. 5 end is not the direction DNA synthesis goes towards. It is 3.
Which of the two growing strands of DNA, labeled as C and D, is the lagging strand in the replication of DNA?
DNA replication goes from the 5' end to 3' end direction. From the 3' to 5' replication goes backwards.
Bonds between the nucleotides
The 4 nucletides
Purines - two rings, adenine, guanine (answer) Pyrimidines - one ring, cytosine, thymine, uricil
Which of the above arrows points to the 5' end of the sugar - phosphate backbone of this DNA molecule?
Look for PO4 groups.
Which of the above arrows points to the 3' end of the sugar - phosphate backbone of this DNA molecule?
In between the nucleotides and phosphates.
The TATA box is identified by a TATA base sequence
within the template strand of DNA that is upstream from the transcription unit and assists with the binding of RNA polymerase. within the non-template strand of DNA that is upstream from the transcription start point and assists with the binding of RNA polymerase to DNA
With regards to base nucleotide composition of DNA, which of the following statements is true?
A + C = T + G (T+ G = T + G)
In DNA replication,
an RNA primer is required to initiate synthesis of both the leading strand and Oksaki fragments of the lagging strand
The anticodon UCU can pair with more that one codon. Based on your understanding of wobble, which codon would be most likely to pair with anticodon UCU in additon to the standard codon AGA?
A release factor
binds to the A site of the ribosome during the termination of translation
The term wobble refers to a relaxation of base pairing rules for
the binding of anticodons to codons
Which of the following is NOT related to ribosomal activity
tRNA shifts position within the ribosome during translation. Which of the following sequence of events is correct
bonding of the tRNA anticodon to the codon of mRNA -->attachment of growing polypeptide to the single amino acid on tRNA --> shift of tRNA from A to P site
Which of the following events is NOT considered part of RNA processing in eukaryotic cells
addition of a poly-A tail to the 3' end of the pre-mRNA molecule addition of a 5' cap to the 5' end of the of the pre-mRNA molecule removal of introns from the pre-mRNA molecule removal of a primer from the pre-mRNA molecule (answer)
A mutation that results in a base substitution within a gene of eukaryotic cells
may or may not lead to a change in the protein expressed by that DNA
Prior to protein synthesis in the cytoplasm of eukaryotic cells, the large and small ribosomal subunits
are floating freely separated from one another in the cytoplasm
Peptide bonds are
formed when an amino acid is added to the growing polypeptide during the elongation stage of translation
The large and small subunits of the ribosome
join during the initiation stage of translation
are present in the pre-mRNA of eukaryotic cells
Which of the following enzymes removes the RNA primer and substitutes DNA nucleotides in the new strand of DNA?
DNA polymerase I
Transcription factors are
proteins that aid in the initiation of transcription
Initiation of transcription in eukaryotic cells requires all of the following EXCEPT
transcription factors binding to the promoter RNA polymerase binding to the promoter a start codon in the template strand of DNA (answer) the TATA box upstream from the transcription unit
If a polypeptide contains 50 amino acids, what is the minimum length of the mRNA strand that coded for this protein?
150 base pairs
Which one of the following statements best defines the antiparallel nature of DNA structure?
the orientation of the pentose sugars is reversed in one strand compared to the other