Exam Flashcards
Write a good definition of a gene.
• They code for different proteins which do work for the cell/they are information passed down from a parent.
Name THREE types of mRNA processing after transcription.
• Poly (A)
• 5’ cap
• Alternative Splicing
What are the TWO conditions within a region of the cell that could lead to catastrophic microtubule collapse?
• Low Tubulin
• Low GTP
Describe TWO molecular mechanisms that control gene expression.
• HETEROCHROMATIN - turns off gene expression/suppress/methylation
• EUCHROMATIN - turns on gene expression/not suppress/phosphorylation & acetylation
The genomes of any two cells in your body are identical. Given this fact, how can you have cells with radically different cell function, such as muscle cells and neurons?
• Genes are expressed differently depending on the location in the body. It can turn on/off a gene to code different proteins.
- Topiomerase - ?
- Helicase - ?
- Ligase - ?
- Polymerase - ?
- Topiomerase - Release TENSION
- Helicase - UNWINDS DNA at the middle
- Ligase - SEAL gaps
- Polymerase - COPIES DNA
_____ releases tension
• Topiomerase
_____ unwinds at the middle
• Helicase
_____ Seals gaps
• Ligase
______ Copies DNA
• Polymerase
In order for a neuron to secrete neurotransmitters, what process need to take place?
A) movement of vesicles from golgi to membrane
B) translation in the rough ER
C) transcription
D) all of these
E) exocytosis
D) ALL OF THESE
For Na+ transport, you find 150mM outside of the cell and 50mM inside the cell. You also measure a Vm of -20mV. Which way will the ion move and why?
A) out of the cell because of both concentration and charge
B) into the cell because of both concentration and charge
C) out of the cell due to charge
D) into the cell due to charge
E) into the cell due to concentration
B) INTO THE CELL BECAUSE OF BOTH CONCENTRATION AND CHARGE
For Cl- transport, you find 40mM outside of the cell and 150mM inside the cell. You also measure a Vm of -15mV. Which way will the ion move and why?
A) out of the cell because of both concentration and charge
B) into the cell because of both concentration and charge
C) out of the cell due to charge
D) into the cell due to charge
E) into the cell due to concentration
A) OUT OF THE CELL BECAUSE OF BOTH CONCENTRATION AND CHARGE
Which junction + cytoskeleton association is correct?
A) gap junctions and actin
B) desmosomes and intermediate filaments
C) hemidesmosomes and microtubules
D) adherens junction and intermediate filaments
E) tight junctions and actin
B) DESMOSOMES AND INTERMEDIATE FILAMENTS
Which junction is required for cell polarity?
A) gap junctions
B) desmosomes
C) hemidesmosomes
D) adherens junctions
E) tight junctions
E) TIGHT JUNCTIONS
(polariTy = Tight)
Which type of DNA element controls gene-specific transcription?
A) core promoter
B) upstream promoter
C) terminator
D) transcription factor
E) repressor
B) UPSTREAM PROMOTER
Which motor protein is required for vesicle movement around the cell?
A) dynein
B) myosin
C) non-muscle myosin
D) clatherin
E) helicase
A) DYNEIN
(D = Drive)
You are studying a eukaryotic gene whose initial transcript is 1500 nucleotides in length. The mature mRNA derived from the gene is 1200 nucleotides in length. What is the most probable reason for the discrepancy?
A) a mutation that results in a shorter product
B) removal of introns
C) removal of exons
D) mRNA breakage
E) a mutation that result in a shorter product of mRNA breakage could have occurred
B) REMOVAL OF INTRONS
The 5’ cap of an mRNA regulates:
A) mRNA translation
B) mRNA length
C) mRNA splicing
D) mRNA location
E) all of the above
A) mRNA TRANSLATION
The nuclear envelope functions as a:
A) means of separating nuclear and cytoplasmic proteins
B) means of localizing of the chromosomes within the cell
C) selective barrier, allowing certain proteins in or out
D) means of sequestering many of the mRNA processing activities from the cytosol
E) all of the above
E) ALL OF THE ABOVE
Moving material against a charge or concentration gradient requires?
A) a channel protein
B) passive transport
C) active transport
D) all of these
E) cell junctions
C) ACTIVE TRANSPORT
(Active = against/energy)
Heterochromatin differs from euchromatin in that it:
A) is modified with methylation sites
B) contains genes whose expression is suppressed
C) is tightly packed and condensed chromatin
D) contains low levels of histone acetylation
E) all of these statements are true
C) IS TIGHTLY PACKED AND CONDENSED CHROMATIN
Telomeres are thought to play a role in preventing rapid aging because:
A) telomeres play a role in cell division
B) telomeres protect against chromosome degradation during DNA replication
C) telomeres suppress metabolism
D) telomeres are highly repetitive and do not contain genes
E) telomeres attach to microtubule ends and ensure high fidelity chromosome segregation
B) TELOMERES PROTECT AGAINST CHROMOSOME DEGRADATION DURING DNA REPLICATION
A gene is:
A) a chromosome
B) RNA
C) a codon
D) a monomer
E) DNA that codes for some functional unit in the cell
E) DNA THAT CODES FOR SOME FUNCTIONAL UNIT IN THE CELL
Which of the following junctions is abundant in tissues such as skin and is required to resist significant mechanical stress?
A) gap junctions
B) gap junctions
C) focal adhesions
D) tight junction
E) desmosomes
E) DESMOSOMES
Kinesin motor proteins move vesicles along which type of cytoskeletal filament?
A) actin
B) septins
C) microtubules
D) intermediate filaments
E) gap junctions
C) MICROTUBULES
The cytoskeletal motor protein is a major component of muscle fibers.
A) actin
B) tubulin
C) integrin
D) intermediate filaments
E) myosin
E) MYOSIN
(Muscle = Myosin)
What type of pyruvate metabolism take place in the mitochondria:
A) synthetic
B) anaerobic
C) fermentation
D) anabolic
E) aerobic
E) AEROBIC
A temporary oxygen deficit during strenuous exercise cause a muscle to:
A) synthesize muscle proteins in response to steroid hormone stimulation
B) synthesis glycogen
C) ferment pyruvate to lactate
D) switch to aerobic glycolysis
E) synthesize more NAD+
C) FERMENT PYRUVATE TO LACTATE
(No O2 = Fermentation)
Glycolysis cleavage to pyruvate takes place in the:
A) cytoplasm
B) mitochondria
C) endoplasmic reticulum
D) nucleus
E) all of the above
A) CYTOPLASM
Transmembrane proteins called channels allow for:
A) active transport
B) facilitated transport
C) endomembrane transport
D) protein folding
E) ER trafficking
B) FACILITATED TRANSPORT
Water moves across the plasma membrane into or out of a cell by osmosis when:
A) water can not move across the plasma membrane
B) water diffuses through a semipermeable membrane toward a lower solute concentration
C) ATP hydrolysis drives aquaporin transport
D) water diffuses through a semipermeable membrane toward a higher solute concentration
E) there is an equal solute concentration on both sides of the membrane
D) WATER DIFFUSES THROUGH A SEMIPERMEABLE MEMBRANE TOWARD A HIGHER SOLUTE CONCENTRATION
(Water follows solute)
A positive membrane potential (Vm) could describe:
A) an excess of negatively charged solute molecules outside the cell
B) an excess of water outside the cell
C) the inability of a cell to change shape
D) the ability of a cell to migrate
E) an excess of positive charged solute molecules outside the cell
A) AN EXCESS OF NEGATIVELY CHRGED SOLUTE MOLECULES OUTSIDE THE CELL
Match GTPases with its major biological function
A) tubulin
B) ran
C) rho
D) rab
E) rac
1) nuclear transport
2) lamellipodia
3) actin stress fibers
4) vesicle fusion
5) microtubule stability
A) TUBULIN —— microtubule stability
B) RAN —— nuclear transport
C) RHO —— actin stress fibers
D) RAB —— vesicle fusion
E) RAC —— lamellipodia
Match the cell junction with its major protein constituent.
A) tight junction
B) adherens junction
C) desmosomes
D) gap junction
E) hemidesmosomes
1) cadherin
2) connexin
3) integrin
4) claudin
5) desmosomal cadherin
A) TIGHT JUNCTION —— claudin
B) ADHERENS JUNCTION —— cadherin
C) DESMOSOMES —— desmosomal cadherin
D) GAP JUNCTION —— connexin
E) HEMIDESMOSOMES —— integrin
