Alex - BIO - Flashcards
Select all of the following that constitute differences between prok and euk translation
Initiator tRNA is bound to Met in euk and “formyl-met” in prok
He accidentally adds a lysine-rich protein to the pH-gradient gel instead of his desired sample, which was largely composed of hydrophobic residues. How would this impact the findings?
Adding Lysine will make it more + and move closer to cathode (which is negative in electrophoresis)
Where are fatty acids broken down and how many membranes must they diffuse through to get there?
Fatty acids are broken down in the mitochondria and must diffuse through by the cell membrane and mitochondrial membrane
What is a phospholipid?
A phospholipid is covalently bound to two fatty acids and a phosphate group
What is the difference between LDL and HDL?
LDL is the major transporter of cholesterol to body tissues. HDL brings cholesterol to the liver, chylomicrons and VLDL primarily transport tryglycerides.
What is the function of chaperone proteins?
Lipids, sugars, and phosphates are all regularly added to proteins. Chaperone proteins help guide, NOT ADDED
What is the function of the nucleolus?
Nucleolus assembles ribosomes
What is the function of the large intestine?
Large intestine reabsorbs water using ion transport
If a person is laying supine (lying face upward), is their blood pressure the same as standing or sitting up?
If the body is in a supine position, blood pools in the veins and results in a higher blood pressure
Where is calcitonin made? What is its function?
Calcitonin is released from the hypothalamus. It reduces blood Ca+ levels by inhibiting osteoclast activity.
Do muscles use Ca+ for mechanical responses?
Muscle activation requires the release of calcium from the sarcoplasmic reticulum to cause a mechanical response in muscles.
Passage analysis. Read passage more carefully if it is complex.
Passage analysis. Read passage more carefully if it is complex.
What happens to human cells if of ocean water is consumed?
Got the question right. Ocean water is very concentrated and makes human cells in a surrounding hypertonic solution, so water flows out of cells.
What kind of bonds are peptide bonds?
Peptide bonds are amide bonds, between an amine group and carboxylic group. They exhibit resonance stabilization.
Be careful with true statements.
Make sure the answer answers the question. The answer I picked was just a true statement.
What is DNA hybridization?
Hybridization describes the bonding of complimentary nucleotides
What is the most likely decision for using this compound in the experiment?
For these questions pick the answer choice that HAS to be true and proves why the compound has to be there
If this amino acid is similar to the one described in the passage (S156E) and is often phosphorylated, which of these is likely to be that phosphorylated protein?
Serine, Threonine, and Tyrosine are the amino acids most prone to phosphorylation.
Make sure to read each answer choice before choosing
Did not read the answer I picked fully. Went too fast.
What is the most effective method of sterilization?
An autoclave is the most effective sterilizing technique used in the lab. It heats to 120 C and puts it under 2 atm. Kills almost anything.
Which of the following describe the difference between single and double crossover events?
A double crossover event is when chromosomal arms of homologous chromosomes cross over in 2 different places along the arm and can involve segments in the middle of the chromosome arms. A single crossover event only affects the ends of the chromosome arms.
Which of the following muscle types uses the troponin complex?
Troponin is used in muscle contraction in skeletal and cardiac muscle. It is NOT used in smooth muscle.
At physiological pH, what is the charge of a peptide bond?
Peptide bonds are not ionized at physiological pH. They do possess double bond character.
Injection of insulin into the bloodstream it LEAST likely to result in which of the following?
Insulin functions to promote the buildup of large molecules for energy storage in the body and to stop the body from breaking down molecules for energy.
Which of the following is most likely NOT a result of a fatty acid catabolizing enzyme deficiency?
Dysfunction of an enzyme that catabolizes fatty acids will unlikely NOT cause hyperglycemia, because the body is relying more heavily on glucose for energy so blood glucose levels would be low
Which of the following samples has to be single stranded DNA and can not be double stranded?
A DNA strand with X% A, X% T and Y% C, Y% G could be single stranded, but it is also possible to be double stranded.
Those species that are capable of both sexual and asexual reproduction will typically prefer sexual reproduction because?
Sexual reproduction increases the variation in the next generation. We cannot say it increases the likelihood of survival for each individual
PET scans follow the movement of a radiolabeled compound as it travels throughout the body. Which compound can be labeled to detect metabolic activity in cancer cells?
Radiolabeled glucose is better because it travels throughout the entire body. Not passage analysis, look at the big picture.
Which aspect of this compound presents the biggest obstacle to its use as a cancer drug?
A nonpolar compound with multiple hydrocarbon groups, electron delocalization through rings, and no charge means it is poorly soluble in water. So it has low solubility in a hydrophilic media
Compare the answer with the question before moving on.
Compare the answer with the question before moving on.
What is the effect of cholesterol?
Cholesterol increases membrane rigidty by attracting adjacent phospholipid tails.
Which of the following do not have proteins with a nuclear localization signal?
E Coli and archaea do not have nuclei and do not need a nuclear localization signal. Fungi are eukaryotic and use nuclear localization signals.
Which of these describe a pair of analogous and homologous structures?
Analogous structures are those that evolved independently to carry out same functions ( wing of bee, wing of bird). Homologous structures are those that have a similar evolutionary history and arise from the same source, with different functions.
Where do protons flow in the ETC, in protein complexes and at the end?
Protein complexes in ETC push protons from the matrix into the IM space. This establishes the proton gradient. During ATP regeneration, H+ ions flow from IM space back to the matrix via ATP synthase.
What substrates can undergo gluconeogenesis?
Gluconeogenesis can use oxaloacetate, pyruvate, and alanine. It cannot use acetyl Co-A
What are lacteals?
The lacteals are in the intestines and are associated with absorbing fat into the lymphatic system
Read the question carefully before finding numbers for calculations
Read the question carefully before finding numbers for calculations
Passagea analysis
Passagea analysis
If stuck, go back to the beginning of the passage and eliminate answer choices that do not agree with the main argument
If stuck, go back to the beginning of the passage and eliminate answer choices that do not agree with the main argument
If a researcher wants to halt cell growth before replicaiton, which phase should they be frozen in?
To halt cells before replicaiton, stop division in Interphase, which occurs between rounds of divisions.
Researchers noted that when a Lysine residue on a histone is acetylated, its side chain becomes more neutral. Which of the following conclusions would reasearchers most likely reach?
DNA is negatively charged, and Lysine residues n histone allow for tight histone-DNA interactions. Acetylation of Lysine makes it positive, and therefore looser interactions with DNA. This creates looser chromatin called euchromatin. Deacetylation results in restored positive charge which promotes euchromatin. Heterochromatin is tight, denser chromatin.
Based on the passage, compared to T11, residue T3 is likely:
A residue called “T3) means a threonine group at position 3. The N-Terminus is the beginning of the polypeptide chain, so position 3 is closer to the N-terminus than position 4. The N-terminus is likely to be positively charged in vivo. The C-terminus is likely negatively charged in vivo.
Where are post transcriptional mods made?
Post-transcriptional modifications are made entirely within the nucleus. They involve addition/removal of the substrate and are catalyzed by enzymes
What charge are amino acids at in physiological pH?
At physiological pH, all free amino acids will have at least one negative and positive charge, due to the N-terminus and C-terminus.
Arachidonic acid is not a precursor for which class of molecules?
The compound from the study is degraded into arachidonic acid and ethanolamine. Ethanolamine can be used in phospholipids, thromboxanes, and prostaglandins. Catecholamines are derived from Tyrosine and would not be derived from arachidonic acid.
What happens to a mixture if two competitive inhibitors are mixed together and added? (one inhibitor is a strong base, the other is a strong acid)
If one competitive inhibitor is a strong acid and another is a strong base, if they are mixed before being exposed to the reaction mixture then they will neutralize each other and nothing happens.
Count the elements present in the answer choice and make sure it matches with the calculation
Count the elements present in the answer choice and make sure it matches with the calculation
What happens in mitosis and meiosis? Which stages are haploid and which are diploid?
During Mitosis and Meiosis II, sister chromatids are separated to form 2 diploid daughter cells. Meiosis I separates homologous chromosomes to create haploid daughter cells. These divide again by separating sister chromatids in Meiosis II to form 2 haploid cells.
Phylogenetic trees
Phylogenetic trees
Be careful with true statements
Be careful with true statements
What is the function of gap junctions?
Gap junctions connect cytoskeletons
Are synaptic neurons faster than reflex neurons?
Chemical synapses and neurons that use them are slower than reflex neurons that use electrical synapses
What is hyperglycemia and its effects on the body?
In severe hyperglycemia, insulin cannot effectively uptake glucose. This leads to glucose and ketone bodies found in the urine. In extended hyperglycemia, the body relies on fat metabolism for energy, which produces ketone bodies.
What is the ploidy of mitosis and meiosis daughter cells?
Meiosis I results in 2 haploid cells with 23 chromosomes, each consisting of 2 sister chromatids. Mitosis results in diploid daughter cells, meiosis results in haploid daughter cells.
What is the difference between northern, southern, and western blots?
Western blots give info about proteins, Northern blots give info about RNA, Southern blots give info about DNA.
What is the effect of a competitive inhibitor on a lineweaver-burk plot?
In a Lineweaver-Burk plot, x intercept = -1/Km while the y intercept = 1/Vmax. In competitive inhibitors, Km increases. So the x intercept should move closer to the x axis since -1/Km increases as the x intercept approaches the x axis.
What kind of molecules does the blood brain barrier block?
The blood brain barrier protects the brain against “large and polar agents”, according to the passage. CO2 is small and nonpolar, so it can freely pass the barrier.
What effect does replacing OH groups with acetyl groups have on a molecule?
Replacing OH groups with acetly groups (O=RC-CH3) makes it more lipophilic.
What does the ectoderm give rise to? What does the mesoderm give rise to? What does the endoderm give rise to?
The nervous system is derived from the ectoderm. The ectoderm gives rise to the nervous system, epidermis, and lining of mouth anus and nostrils. The mesoderm gives rise to structures inside the body like musculature, connective tissue, gonads, and kidneys. The endoderm gives rise to interior linings of the body like the GI, lungs, liver, and bladder.
What is the function of the golgi apparatus?
The golgi apparatus packages proteins in vesicles for transport to other parts of the cell. It targets proteins for excretion. It produces Lysosomes.
What makes up eukaryotic flagella?
Microtubules are observed in eukaryotic flagella.
What are lipid rafts and what composes them?
Lipid rafts surround transmembrane proteins and serve signaling purposes. They are composed of long, saturated lipids that strongly adhere to each other and their associated protein.
Where are phospholipids and lipids synthesized?
Phospholipids and lipds are synthesized at the surface of the smooth ER before being packaged into vesicles and delivered to the plasma membrane or stored in the cell for future use
What effect do unsaturated and saturated fats have on the cell membrane?
Unsaturated fats are more flexible due to the “kinks” in their chain from the double bonds. They add fluidity to the membrane. Saturated fats add rigidity to the membrane. Cholesterol stabilizes membranes: it makes the membrane more fluid at low temperatures and less fluid at high temperatures.
What is the difference between cis/trans and E/Z notations?
Cis/Trans notation is for simple alkenes. E/Z is for more complicated molecules. Z means the highest priority substituents are on the same side (“zee zame side”).
Make sure to take the time to understand the graphs and what they represent.
Make sure to take the time to understand the graphs and what they represent.
If a downstream protein is abnormally delayed, at what point does the experiment show you the defect?
The initiation of differentiation refers to when the downstream first becomes active. So once that one protein’s levels increase, you can start to detect abnormalities in the process.
A disease is X-linked. What is the probability that the daughter of an unaffected father and carrier mother is affected by the disease?
A daughter with an unaffected father and carrier mother has a 0% chance of being affected. Since the mom only has one copy and the father has zero copies, she cannot be affected.
Glucagon is released by the pancreas as a response to low blood glucose levels. It increases glycogenolysis to increase blood glucose. Glycogen is stored in the liver, so most of glucagon’s action occurs in the liver.
Glucagon is released by the pancreas as a response to low blood glucose levels. It increases glycogenolysis to increase blood glucose. Glycogen is stored in the liver, so most of glucagon’s action occurs in the liver.
What are the effects of hyperventilation? Make sure to know the blood O2 and CO2 levels
Hyperventilation results in net exhalation of CO2, increased blood pH, and increased hemoglobin affinity for O2. During hyperventilation, there is an increase in blood O2 and decrease in CO2. Hypoxia would not occur, because the body is not oxygen deprived
What is an organic acid?
Organic acids must have both carbon and hydrogen. They must have at least one hydrogen group bound to a carbon.
Hyperaldosteronism causes what?
Aldosterone increases H2O and Na reabsorption in the kidney, while exchanging K for Na ions. Aldosterone is released when blood K rises or blood Na falls. Aldosterone’s effects include increased K secretion and Na reabsorption. It will also inhibit renin production via feedback inhibition.
What is the difference between lytic and lysogenic?
Lysogenic viruses use mitosis to pass viral DNA to daughter cells. Lytic viruses produce a large number of viruses within a cell that escape it and go infect other cells. A virus can be both lytic and lysogenic.
Trap question. Looked at the wrong graph. Make sure to compare the compounds in question and refer to the correct graph.
Trap question. Looked at the wrong graph. Make sure to compare the compounds in question and refer to the correct graph.
In a question that asks about the effects of manipulating a variable in an equation, make sure to get the answer choice picked, go back to the equation, and plug in the answer choice value to see if it yields the correct result/answer
In a question that asks about the effects of manipulating a variable in an equation, make sure to get the answer choice picked, go back to the equation, and plug in the answer choice value to see if it yields the correct result/answer
What is the order of the michaelis-mentin reaction at low substrate and high substrate concentrations?
At very low initial substrate concentrations, the michaelis-mentin reaction is approximately first order (the initial rise in the graph). As it flattens out, it becomes zero order.
Why are viruses unique?
Viruses are unique because they are in a gray area between living and non-living organisms.
Make sure to use the correct numbers from charts for any calculations
Make sure to use the correct numbers from charts for any calculations
Thiokinase converts fatty acids into their CoA derivatives. Next, the CoA derivatives are transported through the mitochondrial membrane bu carnitine. Where is thiokinase likely located?
If an enzyme acts on a fatty acid after it enters the cell but before it is transported into the mitochondria, it must be located on the face of the outer mitochondrial membrane.
If stuck on a question, compare complete guess to the passage before moving on
If stuck on a question, compare complete guess to the passage before moving on
Compare Thymine and Uracil’s molecular structures.
Thymine is identical to Uracil but has an extra methyl group
What type of solvent would favor an SN2 reaction?
Polar aprotic solvents favor SN2
Compare guesses to the graph before moving on
Compare guesses to the graph before moving on
An immunoglobin would most directly involve which eukaryotic strucure?
Ribosomes regulate the translation and production of gene products. The nucleolus is the nuclear subdomain that assembles ribosomal subunits.
What types of amino acids would compose a transmembrane protein?
A transmembrane protein domain would be in contact with the nonpolar tails of the phospholipid molecules in the membrane, so nonpolar amino acids would likely make up parts of this domain
Make sure to read questions about graphs carefully
Make sure to read questions about graphs carefully
A DNA viral vector was most likely which kind of virus?
DNA viral vectors must come from DNA viruses. Retroviruses use positive-sense RNA genomes, not DNA genomes.
What is cell differentiation mediated by?
Cell differentiation occus primarily through different gene expression levels
What is involved in cell movement?
Flagella and cilia are involved in simple prokaryotic and eukaryotic cell propulsion. Actin polymerization near the edge of the cell membrane is responsible for cellular motility. Microtubule depolymerization is involved in mitosis, not movement
Which stages of mitosis and/or meiosis involve separation of homologous chromosomes?
Anaphase of meiosis I
What is genetic drift?
Genetic drift is the change in allele frequencies due to random processes. It can cause some alleles to not be passed down at all or cause others to be fixed as the only alleles present at that locus. It does not introduce new alleles or increase diversity
What is the difference between disruptive and directional selection?
Disruptive selection involves the extreme phenotypes being evolutionarily favored. Directional selection favors either of the extremes, but not both.
What is the difference between convergent and parallel evolution?
Convergent evolution is when entirely separate separate lineages gradually appear more similar over time. Example: birds, bats, and butterflies all developed wings to utilize the advantages of flying. Parallel evolution occurs when closely related species evolve in a similar way over time (and they were not similar beforehand).
What type of people are more likely to have X-linked recessive diseases?
Males because they only need to inherit one recessive copy of the gene to have the disease
How many distinct codons will code for amino acids within a protein?
There are 4 possible RNA bases, so there are 4^3 possibilities. This is a total of 64 possibilities, but subtracting for the 3 stop codons makes 61.
What type of bonds form secondary structures?
Hydrogen bonds between the backbone amide and carbonyl groups.
1% of a population has a recessive phenotype. What is the allele frequency for this recessive allele?
r^2 = 0.01. So the frequency is sqrt(0.01) which is 0.10, which is 10%.
What would happen to NADH levels and O2 consumption of cancer cells that are exposed to an inhibitor that inhibits respiration?
O2 consumption decreases with decreased ETC activity. NADH increases because the mitochondria are not oxidizing NADH in the ETC, which causes a buildup of NADH.
On a hemoglobin saturation curve, a right sided shift signifies what?
A right sided shift signifies decreased affinity for oxygen. 2,3-BPG also shifts the graph right. Low pH also decreases the O2 affinity and shifts the graph right.
Make sure the conclusion of the study is not too extreme or out of scope
Make sure the conclusion of the study is not too extreme or out of scope
What is the difference between cadherin protein and integrin protein?
Cadherin proteins are transmembrane proteins that play a role in cell-cell adhesion. Integrins are transmembrane receptors that modulate cell-extracellular matrix interactions. They often attach the cell to collagen and fibronectin fibers. Cadherin proteins do NOT form interactions with the extracellular matrix proteins.
Make sure to identify which axis contains the different experimental groups/conditions and interpret the data based on that.
Make sure to identify which axis contains the different experimental groups/conditions and interpret the data based on that.
What effects would a drug have that mimics the antagonist of Calcitonin?
The antagonist of Calcitonin is PTH. This increases blood Ca2+ concentration by increasing osteoclast activity and decreasing osteoblast activity.
What is the difference between the relative and absolute refractory periods?
The absolute refractory period lasts nearly the entire duration of the action potential, during which a second action potential cannot be started. V-gated Na channels are “inactivated” and the gate is closed. The relative refractory period is during the hyperpolarization phase. This is when Na channels are “de-inactivated”: the inactivation gate is open but the activation gate is closed. A stimulus could theoretically produce another AP but the stimulus must be larger than usual. At this point, Na channels are de-inactivated and K channels are still activated (because K is still flowing out of the cell to finish the AP).
Where is sperm produced?
Sperm is produced in the Sertoli cells of the seminiferous tubules.
Do Bacteria have any protection outside of their cell envelope?
Bacteria have capsules that can protect it from foreign objects.
What is commensalism?
Commensalism is when one species benefits from the relationship but the other species is neither helped nor harmed from it.
If a drug was administered that irreversibly locked up calcium channels to be open, what would happen?
High calcium concentrations allow muscle contraction to take place. Tropomyosin would stop blocking the myosin binding site and the muscle would be unable to stop contracting, or be in constant tetanus.
What is ETC complex 2 and when is it activated?
Succinate dehydrogenase, which participates in both the citric acid cycle and the ETC. It takes electrons from FADH2 to reduce ubiquinone and in the ETC it metabolizes succinate to fumurate. It is active before complex 1.
What are the stages of zygote development?
Morula, Blastula, Gas, Neurulation. (“More Blasting Gas, I’m Nervous”)
If the concentration of a protein in the blood is increased, is there more pre or post transcriptional control being done?
Post transcriptional control because the amount of translated protein is increased (assuming the amount of pre-mRNA is constant)
In isoelectric focusing, a protein moves closer to the cathode than the control protein. Extra amounts of what types of residues would cause this?
In isoelectric focusing, the cathode is negatively charged. Proteins that migrated farther have more positively charged residues.
An agar plate of growing bacteria becomes contaminated. The next morning, the contaminated area was clear. The contaminant was a? Virus in the lytic phase, Virus in the lysogenic phase, Distilled water, or a nutrient broth lacking the essential nutrients it needs to grow
Virus in the lytic phase, because the bacteria are prevented from growing.
If only one primer is added to a PCR mixture, what is the outcome?
The primer binds to one strand and replication is initiated in this strand. Only this one strand is replicated and replication is linearly amplified.
What does mature mRNA consist of?
Mature mRNA consists of a 5’ cap (1 base), the Untranslated regions, and the 3’ Poly A tail.
Rank the following structures from least to most compact: Euchromatin, Heterochromatin, DNA helix
DNA helix < Heterochromatin < Euchromatin
Where are intermediate filaments used?
Intermediate filaments primarily compose structural elements of skin. Keratin is made from intermediate filaments.
The frequency of an allele on the X chromosome is 8%. What is the frequency of the allele in men and women?
Males only need 1 copy of the allele, so their frequency is 8%. Females need 2 copes, so their frequency is 0.08^2 = 0.0064 or 0.64%.
