Clicker Questions Flashcards
Each element has an atomic number. What does that indicate?
A. Number of neutrons
B. Number of protons
C. Number of electrons
D. Number of orbitals
B. Number of protons
What is the ONE THING we really need to know about each element to understand how molecules are built?
A. # of protons
B. # of valence electrons
C. # of unpaired valence electrons
D. Its symbol on the periodic table
C. # of unpaired valence electrons
So, if hydrogen bonds usually involve O-H or N-H groups in organic molecules, which one of the following is correct?
A. O-H * H-N
B. O-H *** N-H
C. H-O *** N-H
* The dotted line is a hydrogen bond
* The ”-” is a polar covalent bond
A. O-H ***** H-N
Which of the following is true of
hydrophobic molecules?
1. They are non-polar
2. They do not form a hydration shell
3. They dissolve in water
4. All of the above
- They do not form a hydration shell
Which of the following is NOT a
functional side group on the molecule below?
A. Phosphate
B. Carboxyl
C. Methyl
D. Hydroxyl
C. Methyl
Which of the following is true of the
phospholipid molecule shown below?
A. It is a triglyceride
B. It has a hydrophobic head
C. It has one unsaturated fatty acid
D. It looks like it is walking
A. It is a triglyceride
Proteins are polymers of “amino
acids,” which get their name
because they have:
A. An NH3 on their carbon backbone
B. A small ring structure
C. Nine carbons in their backbones
D. An HCl group that drops H+
A. An NH3 on their carbon backbone
Which one of the following best
defines “diffusion”?
A. Movement of solutes from low to high concentration
B. Movement of solutes from high to low concentration
C. Movement of water across a membrane
D. I do not know about diffusion
B. Movement of solutes from high to low concentration
Two solutions are placed in a beaker
separated by a membrane permeable to ions. Initially there is 30 mM NaCl on the left and 30 mM KCl on the right. Which of
the following will happen?
A. Na+ will move to the right
B. Cl- will move towards Na+
C. Nothing, it is at equilibrium
D. Water will move by osmosis
A. Na+ will move to the right
If a cell makes a protein to facilitate
diffusion of K+ out of the cytoplasm, what would we name that protein?
A. Transmembrane protein
B. Transport protein
C. K+ passive transport protein
D. K+ ion channel
D. K+ ion channel
Which functional group adds energy
to molecules?
A. Hydroxyl
B. Carboxyl
C. Amino
D. Phosphate
D. Phosphate
The Sucrose-H+ cotransporter below
is an example active transport. How
do we know?
A. H+ is diffusing
B. Sucrose moving to high concentration
C. It says it is a cotransporter
D. It is a symport protein
B. Sucrose moving to high concentration
Cells transport H+ into the stomach to make it acidic. Will this be passive or active transport?
A. Passive – H+ always diffuses out of cells
B. Passive – H+ is at higher concentration in cells
C. Active – H+ is at higher concentration in stomach
D. Active – H+ cannot “do diffusion”
C. Active – H+ is at higher concentration in stomach
Cells in the gut take up glucose using active transport. Which transport protein from your toolbox can they use?
A. A glucose carrier protein
B. A sodium-glucose cotransporter
C. A proton-sucrose cotransporter
D. A glucose-ATPase pump
B. A sodium-glucose cotransporter
What else do cells need in there membranes to make a sodium-glucose cotransporter work for active transport?
A. A sodium-potassium pump
B. A sodium ion channel
C. A potassium ion channel
D. A sodium-potassium pump AND a Na+ channel
E. A sodium-potassium pump AND a K+ channel
E. A sodium-potassium pump AND a K+ channel
What trick do cells use to be able to
continuously bring in molecules using passive transport, without ever reaching equilibrium?
A. They make sure there are always more outside
B. They pump them back out immediately
C. They hide the molecules in another compartment
D. They use the molecules as they are brought in
D. They use the molecules as they are brought in
Which of the following would clearly
indicate active transport is happening?
A. Solutes moving to high concentration
B. There is co-transport of Na+
C. There is no osmosis
D. A transport protein is involved
A. Solutes moving to high concentration
With proteins, how is quaternary structure different from tertiary structure?
A. Quaternary can’t change shape
B. Formation of helices instead of sheets
C. Number of polypeptides in the protein
D. 3D structure instead of 2D structure
C. Number of polypeptides in the protein
Why are we rarely going to be using
increases in kinetic energy to run
chemical reactions in living cells?
A. There is no kinetic energy in
living cells
B. Molecules don’t run into each
other in living cells
C. That equals heat and would harm
living cells
C. That equals heat and would harm
living cells
Which of the following represents a
situation with HIGH ENTROPY?
A. Hundreds of sugars connected by alpha glycosidic bonds
B. Sodium ions at equilibrium on two sides of a membrane
C. An H+ gradient across a membrane
D. A hot pizza waiting to be eaten
B. Sodium ions at equilibrium on two sides of a membrane
Which of the following represents a
situation with LOW POTENTIAL
ENERGY?
A. Hundreds of sugars connected by alpha glycosidic bonds
B. Sodium ions at equilibrium on two sides of a membrane
C. An H+ gradient across a membrane
D. A hot pizza waiting to be eaten
B. Sodium ions at equilibrium on two sides of a membrane
A negative delta G reaction is
spontaneous, and a cell can make
it proceed using an enzyme. What
do all enzymes do?
A. Reverse delta G
B. Add activation energy
C. Lower activation energy
D. Eliminate activation energy
C. Lower activation energy
Which of the following is true?
A. Malate gets oxidized; NADH gets
reduced
B. Malate gets reduced; it is charged
C. Malate gets oxidized; it lost 2 Hs
C. Malate gets oxidized; it lost 2 Hs
What is the FUNCTION of photolysis?
A. Make oxygen gas
B. Provide H+ for ETC
C. Provide new electrons for PSII
D. Acidify the thylakoid space
A. Make oxygen gas
What is the WORK done by the ETC
(PQ+cytochrome complex+PC)?
A. Move H+ across membrane
B. Oxidize PQH2
C. Make ATP
D. Lower energy of electrons
A. Move H+ across membrane
So… What are the products of the
photosynthetic light reactions?
A. H+ gradient and ATP
B. PQH2, PC, and reduced FD
C. ATP and NADH
D. ATP and NADPH
D. ATP and NADPH
What is the net product of the Calvin
Cycle?
A. ATP
B. NADPH
C. G3P
D. Glucose
C. G3P
Glycolysis breaks down glucose
to harvest energy. Where is the
energy from glucose located at
the end of glycolysis?
A.In ATP
B.In NADH
C.In pyruvate
D.All of the above
D.All of the above
WHY can’t eukaryotes digest
cellulose?
A. Beta glycosidic bonds are indigestible
B. They did not evolve an that enzyme
C. Hydrolysis does not work
D. Sure they can, like cows!
A. Beta glycosidic bonds are indigestible
The catabolism of glucose to carbon
dioxide yields -686 kcal/mol of free
energy. By the end of the citric acid
cycle, how much energy is in ATP?
A. -686 kcal/mol
B. -343 kcal/mol
C. -29.2 kcal/mole
D. Zero
B. -343 kcal/mol
Where is the NADH from glycolysis
typically oxidized back to NAD+?
A. The mitochondrial ETC
B. In the reduction step of the Calvin Cycle
D. During the Kreb’s Cycle
E. At the end of glycolysis
D. During the Kreb’s Cycle
Watson and Crick immediately
recognized the structure of DNA
made it easy to copy, because all you
need to do is…
A. Have the right enzymes
B. Separate the two strands
C. Follow the pairing rules for bases
C. Follow the pairing rules for bases
DNA replication has to occur before
cell division, resulting in two copies
of every chromosome. Why do we get two copies?
A. DNA is a double helix
B. There is strict base pairing
C. Semiconservative replication
D. All of the above
D. All of the above
Which one of the following is NOT an
enzyme?
A. Helicase
B. DNA binding protein
C. Topoisomerase
D. DNA polymerase
B. DNA binding protein
What happens to begin replication?
1. Helicase opens the helix
2. Primase lays down a primer
3. Proteins bind to the origin of
replication
4. Topoisomerase untangles the DNA
- Proteins bind to the origin of
replication
Once the bubble has opened, what
two enzymes are needed (A and B)?
1. Primase is A and helicase is B
2. Helicase is A and topoisomerase is B
3. Topoisomerase is A and primase is B
4. Topoisomerase is A and helicase is B
- Helicase is A and topoisomerase is B
What happens next?
1. DNA polymerase III comes in to start synthesis
2. DNA polymerase I comes in to start synthesis
3. Primase comes in to lay down some primers
- Primase comes in to lay down some primers
What happens next?
1. Helicase unwinds the daughter strands.
2. DNA polymerase I attaches to the end of each C fragment
3. DNA polymerase III attaches to the end of each C fragment
4. Ligase links the two C fragments
- DNA polymerase III attaches to the end of each C fragment
During replication, the bubble continuously gets bigger as replication continues. Look at
the larger bubble above. Which of the following are true?
1. Primase keeps laying down more primers.
2. DNA pol III continuously synthesizes more DNA.
3. Helicase continuously unwinds more DNA.
4. All of the above.
- All of the above.
What enzyme is binding at E?
1. Ligase
2. DNA pol III
3. DNA pol I
4. Primer hydrolase
- DNA pol I
Finally, what happens at F?
1. Ligase adds the missing base then links the two fragments.
2. Ligase makes a covalent bond between the two fragments.
3. The 2 fragments hydrogen bond together.
4. Okasaki glues the fragments together.
- Ligase makes a covalent bond between the two fragments.
On a gene model, if you know that
RNA polymerase is moving to the left
of +1, which of the following is true?
A. Upstream is to the left of +1
B. The promoter is to the right of +1
C. Transcribed region is to the right of +1
D. The transcript is oriented 5’ — 3’
+1
B. The promoter is to the right of +1
Which one of the following is
true for both DNA polymerase
and RNA polymerase enzymes?
A. Need a primer
B. Need helicase to unwind DNA
C. Only add to the 3’-end
D. “Can’t make something out of
nothing”
C. Only add to the 3’-end
The sequence below is part of a gene with one intron that is transcribed and spliced as shown.
3’-TTAGCATACCGATTAGACTTATCGGTGTCACCGAT-5’
5’-AAUCGUAUGGCUUAGCCACAGUGGCUA-3’
Which of the following is the intron?
A. TTAGACTT
B. TCGGT
C. CGGTGT
A. TTAGACTT
What peptide is encoded in the mRNA
sequence 5’-AUG AUA AUU UGA-3’?
1. Lys-Leu-Leu
2. Met-Ile-Ile
3. Met-Gln-Arg
4. Ser-Leu-Ile-Val
- Met-Ile-Ile
What peptide is encoded by this
mRNA sequence?
5’-GCUAAUGUAUGAUGCCUGAU-3’?
1. Met-Ser-Val-Val-Cys
2. Ala-Ile-Val
3. Met-Pro-Asp
4. Met-Tyr-Asp-Ala
- Met-Tyr-Asp-Ala
If a tRNA has a
3’-AAG-5’
anticodon, what
amino acid will be
attached to that
tRNA?
A. Met
B. Phe
C. Lys
D. Leu
B. Phe
What is the first amino acid for every polypeptide?
A. Met
B. Phe
C. Lys
D. Leu
A. Met
Consider our Big Ideas of Structure-
Function Relationships and Evolution. Which of the following statements is most likely true?
A. DNA pol I and DNA pol III evolved from a common ancestral polymerase enzyme.
B. DNA pol I and DNA pol III evolved
independently in different organisms.
C. DNA pol III evolved from RNA
polymerase; DNA pol I evolved from ligase.
A. DNA pol I and DNA pol III evolved from a common ancestral polymerase enzyme.
Which functional group can be added or removed from molecules as a tag to change their identity?
A. Phosphate
B. Hydroxyl
C. Methyl
D. Carbonyl
C. Methyl
Which the following would tell
you if transport of a solute is
active?
A. It is a high energy solute
B. It is moving up it’s gradient
C. Entropy is increasing
D. It is using a co-transport protein
B. It is moving up it’s gradient
Where would you find pyruvate? What process makes pyruvate?
A. A; pyruvate oxidation
B. F; citric acid cycle
C. C; fermentation
D. E; glycolysis
D. E; glycolysis
__________ molecules are soluble in
water, while _______ molecules are
not
A. Polar; non-polar
B. Hydrophilic; hydrophobic
C. Non-polar; polar
D. Hydrophobic; hydrophilic
B. Hydrophilic; hydrophobic
______________ is an emergent
property that is the result of elements
having different electronegativities.
A. Orbital geometry
B. Polar covalent bonds
C. Hydrogen bonding
D. Surface tension
B. Polar covalent bonds
Looking at this cell, compartments E
and G allow separation of what 2
processes?
A. Transcription and
splicing
B. Transcription and
translation
C. Glycolysis and
citric acid cycle
D. DNA synthesis and
mitosis
B. Transcription and
translation
For this ETC, where is the high H+
concentration?
A.Intermembrane space, to the right
B. Cytoplasm, to the left
C. Stroma, to the left
D.Thylakoid lumen, to
the right
A.Intermembrane space, to the right
What happens to electrons as they travel through an electron transport chain?
A. They are oxidized.
B. They are reduced.
C. They lose energy.
D. They pump hydrogens.
C. They lose energy.
What do cohesion of water, secondary structure of peptides, and annealing of polynucleotides have in common?
A.Interaction of polymers
B. Covalent interactions
C.Hydrogen bonding
D.Ionization of hydroxyl groups
C.Hydrogen bonding
Given the starting conditions below,
when the solutes reach equilibrium, if there is no osmosis, what has to be
true?
A. A Ca+/lactose cotransporter pumps water out
B.Water diffused to the same on each side
C.Ca+ channels and lactose carriers are both present
C.Ca+ channels and lactose carriers are both present
Enzymes can only make
spontaneous reactions proceed. What else do all endergonic reactions need to work in living cells?
A.Reaction coupling
B. Coenzymes
C.Activation energy
D.Entropy
A.Reaction coupling
Some bacteria use a type of fermentation that make propanoic acid. What functional group makes the molecule an acid?
A.Methyl
B.Hydroxyl
C. Carboxyl
D.Carbonyl
C. Carboxyl
