Biology Questions

I 4 A solution has a pH of 7 What is the concentration to protons in the solution If you decrease the concentration of protons by 1000 fold hat is the new pH of the solution PROTEINS 5 a Draw the molecular sinnu this molecula the water will move up

21 If you encounter an aggressive driver you should

May not pass that vehicle Should go around the vehicle if it seems safe

25 Motorcycle operators do Are easy to see and determine what they will Must share a traffic lane with another vehicle

6 After 15 min pour the contents from above step into a 50 mL centrifuge tube The tubes from all the groups have to be balanced by the TA before putting them in the centrifuge There is going to be addition removal of solutions All tubes will need to be sealed by the TA after balancing Centrifuge for 15 min at 9 000xg at 4 C to sediment the proteins quosdi A lu Tod anmuloo sii 7 After centrifugation you will see a pellet at the bottom of the tube and the liquid is called the supernatant a SUPERNATANT Pour off the supernatant into a beaker Transfer 1 mL into an Eppendorf tube label as S1 and put aside for protein electrophoresis Estimate the volume remaining in the beaker calculate the amount of ammonium sulfate you ll need to add to reach 50 saturation 85 g L of solution Add Ammonium sulfate slowly while stirring S1 on a stir plate Once the ammonium sulfate has been added continue to stir for 15 min dew IG ni blol 001 slamasz b PELLET Re suspend the pellet in 4 7 mL depending on the pellet size distilled water Gather dialysis tubing and clips from your TA Transfer the resuspended pellet into a dialysis bag and dialyze against Buffer A see recipe below Label this sample as P1 8 After S1 50 saturation supernatant has stirred for 15 min centrifuge S1 at 9 000xg 4 C for 15 min 13 9 Following centrifugation transfer 3 5 mL of the supernatant into a 15 mL conical tube label as S2 and put aside for protein electrophoresis Dissolve the pellet in 4 7 mL of distilled water use more water only if necessary Label this sample as P2 10 Gather dialysis tubing and clips from your TA Place the second pellet suspension into a separate dialysis bag and dialyze against Buffer A After dialysis P1 and P2 will be further purified based on differences in formal negative charge by ion exchange chromatography 11 At the next class transfer your dialyzed samples to falcon tubes

Subcellular fractionation is a biotechnological procedure that separates subcellular components by a series of increasing centrifugation speeds The procedure begins by centrifuging cell lysate broken cells at a low centrifugation speed At lower centrifugation speeds only the densest cellular components will sediment form a pellet while lighter components remain in the supernatant non pellet soluble phase The supernatant can then be separated from the pellet and centrifuged at a higher speed to sediment the lighter cellular components still in solution This incremental increase in centrifugation speeds is known as differential centrifugation Differential centrifugation is a means by which subcellular components can be separated on the basis of their different densities Thus subcellular fractionation uses differential centrifugation to separate different subcellular components on the basis of their varying densities In this lab we will seek to separate nuclei from mitochondria found in plant tissues Since nuclei are more dense than mitochondria we will be able to separate these structures using centrifugation on the basis of their differing densities Centrifugation at a lower speed will sediment the dense nuclei which will form the pellet while the less dense mitochondria remains in the supernatant Centrifuging the filtrate filtered cell lysate separates the filtrate into two fractions supernatant and pellet Each fraction is then tested for the presence of nuclei and mitochondria The presence of nuclei will be assessed via microscopy whereas the presence of mitochondria will be tested for by assaying for the SDH succinate dehydrogenase enzyme which is an enzyme that is specific to mitochondria Subcellular Fractionation of Cauliflower is a 1 week long experiment First you will grind cauliflower to break open cells and then perform differential centrifugation of the cauliflower tissue You will then complete microscopy on various fractions and perform an SDH assay and analyze the results

Fractionation Isolation of Mitochondrial Fraction Tissue Preparation and Fractionation 1 Collect the mortar pestle and a styrofoam tray from your TA Fill the tray with ice and place the mortar and pestle in the ice 2 Use a razor blade to dice 20 g of cauliflower Each group will need 20 g of tissue 3 Place the tissue in a chilled mortar with 40 mL of ice cold Mannitol Grinding Buffer Grind the tissue vigorously with a chilled pestle for 4 min 4 Filter the suspension through four layers of cheesecloth into a chilled 50 mL centrifuge tube Wring out the liquid into the tube This liquid is known as the Filtrate F fraction Save 4 mL of Filtrate into a separate 15 mL falcon tube for later use Place on ice It is essential that all samples and materials be kept on ice at all times 5 Centrifuge the remaining filtrate F at 1000x gravity for 10 min at 0 4 C Make sure the centrifuge tubes are balanced and placed opposite one another in the centrifuge 6 Separate the pellet P1 from the supernatant S1 by pouring the supernatant into a clean chilled centrifuge tube 7 Set aside 4 mL of S1 into a 15 mL Falcon tube for later use Store on ice 8 Use a Pasteur pipette to resuspend P1 and scrape the mitochondrial pellet from the wall of the centrifuge tube and then with a Pasteur pipette thoroughly re suspend the sediment in 8 mL of ice cold Mannitol Assay Buffer Completely disrupt all of the chunks of cell debris Keep the fraction on ice 9 Centrifuge the remaining S1 at 12 000x gravity for 30 min at 4 C 10 During the centrifugation begin microscopy on F S1 and P1 You will create a wet mount for each sample F S1 and P1 using a slide and cover slip Use the instructions guide provided to complete the microscopy using the Zeiss Microscopes Axiocam and Axio Vision software Use the microscope to observe a drop from each of the first three fractions Filtrate S1 and P1 WHAT DO YOU SEE Are there whole cells present that were not disrupted during homogenization Use Azure C dye to stain nuclei by adding a drop of the dye to each slide from above Do you see any nuclei Describe the results in your notebook These images will be used in your report 11 After the centrifugation of S1 separate the supernatant S2 from the pellet P2 by pourin pernatant into a 50 mL falcon tube Save 4 mL of S2 for later use keep on ice

EcoRI 3 Determine the sizes of all DNA fragments generated by digesting pBiol133 with EcoR1 and Kpnl 4 Determine the sizes of all DNA fragments generated by digesting pBiol133 with EcoR1 and Smal 5 Determine the sizes of all DNA fragments generated by digesting pBiol133 with EcoR1 Smal and Nhel Kpnl 3158 6 Determine the sizes of all DNA fragments generated by digesting pBiol133 with EcoR1 Smal Nhel and KpnI 1 352 pBiol133 4321 base pairs 2016 Show calculation EcoRI 1622 Show calculatio Smal Show calculatio Show calculatic

A On low speed city streets If they make several rest stops

When you come within about a one block distance of an oncoming vehicle When you are following another vehicle or in heavy traffic

wa 2n 6 cell going through all of the phases of Meiosis 5 points

A Moving to another question will save this response Question 1 Phosphorus shortages in garden soil would make it difficult for plants to produce which of the following O DNA O Starch

Draw a 2n 4 going through all of the phases of Mitos

estion 5 You label cells with a radioactive isotope of sulfur 35S The only molecules that would be radioactively labeled in these cells are O Proteins O Lipids O Nucleic acids O Carbohydrates

estion 5 molecules removes a unit of water from a system and joins two molecules together 2 points is when water is forced into a bond breaking it and forming two smaller Save Ansva

estion 2 1 points Benedict s reagent is a chemical that is used as a test for the presence of a free aldehyde functional group on glucose The aldehyde is used when glucose and fructose bind together to form sucros and the Benedict s test is negative Starch contains a great deal of glucose but gives a negative Benedict s test because O starch is not soluble in water and cannot react with Benedict s reagent all of the aldehyde groups on the starch are oxidized and cannot react with the Benedict s reagent only the glucose at the end of a chain of starch will have an exposed aldehyde functional group to react with Benedict s reagent Save

Moving to another question will save this response estion 3 Sudan IV a dye that binds to nonpolar molecules is used to detect the presence of macromolecules in food Sudan IV would test positive in the presence of what macromolecule O Starch

estion 4 How many water molecules are produced during the formation of a triglyceride from fatty acids and glycerol 01

application anatomical Perhaps the oldest method of producing images of internal structures of the human body is sketching dissected specimens More recent technology has produced a number of advanced techniques of producing images of human structures One such technique first produced by Wilhelm Roentgen around the turn of the previous century is radiography This technique which is also called x ray photography uses radiation waves that pass through the specimen and onto photographic film Because the waves pass more easily through soft tissue than through dense tissue such as bone shadows of some structures are visible when the film is R A BRA B FIGURE 13 17 A Standard radiograph of the lumbar region notice the images developed Figure 13 17 A shows a radiograph or x ray photograph of the lumbar region Can you identify the structures indicated A more recent variation of this technique is computed tomogra phy CT A CT scanner emits a beam of x rays in a circular path around the subject After passing through the body the beams are processed by a computer that is able to reconstruct a three dimen sional image of internal structures The operator can view differen sections of the body on a video monitor Figure 13 17 B shows a CT image of a horizontal section of the upper abdomen A vertebr is clearly shown can you identify its parts 10 2 5 que perpective B CT image of the abdomen Label the structures

estion 7 If a pair of monosaccharides are bonded together during dehydration synthesis a molecule of glycerol is formed O True O False

Question 6 Most phospholipids are found where in a cell O Inside the nucleus O As enzymes O They make up ribosomes O Cell membranes

Question 3 Match the molecule to it s major biological classification Fructose DNA Keratin Diglyceride A Protein dd B Nucleic acid C Lipid D Carbohydrate

Question 4 What form of RNA is a carrier of information from the nucleus that serves as a blueprint for specifying amino acid sequence for a protein OfRNA O mRNA O SIRNA O tRNA

Question 2 Which of the following would be ways to denature a protein Extreme heat Exposure to acidic basic conditions O Exposure to extremely saline conditions Freezing

deas 6 messed up a couple of times in front of the class It turns out that the next day we managed to find out who won the election and it was my other friend who won the election She wasn t my friend at the time since it was the beginning of 6th grade When I found out she won I tried acting happy for her but at the same time I was jealous But now that I look back at it when she and I started talking more we became good friends I started to stop getting jealous of her getting the set And I would start to help her get elected for a position called secretary and I would help color in her poster and give feedback She ended up doing a good job Sometimes she looks back at the situation and says she doesn t know about it to this day but it was a tiny incident And because both of us tried to run for student council we became really good friends over time Exemplary The narrative tructure 6 13 19 25 skillfully describes an incident and a choice made and thoroughly reflects on the lesson learned shows clear evidence of skillful revision to improve meaning clarity and adherence to the narrative style includes thoughtful reflection with explanations for changes Comments 13 19 Exemplary The narrative Exemplary The narrative 25 Files 1 has an engaging beginning that hooks the reader and reveals all aspects of the incident has a middle that vividly describes the series of events leading to the incident as well as the narrator s feelings thoughts and actions has a reflective ending that examines the consequences of the choice Use of Language 6 13 19 25 effectively uses sensory details and figurative language to vividly show the incident contains few or no errors in spelling punctuation or capitalization Drafts Revisions and Timliness Rubric

the cell would eventually swell up and burst lyse True False Question 21 0 5 points Listen Both phagocytosis and pinocytosis are forms of endocytosis True False Question 22 0 5 points Listen Plant cells will usually burst if in a hypotonic solution

Osmosis Pinocytosis Active Transport Endocytosis Question 24 0 75 points Listen Water always moves from a hypertonic solution into a hypotonic on

usually by forming a channel in the membrane True False Question 17 0 5 points 4 Listen The process by which a white blood cell or an amoeba engulfs bacteria is called phagocytosis True

Which of these processes can move a solute against its concentration gradient diffusion osmosis active transport passive transport facilitated diffusion Question 15 0 5 points Listen A hypertonic solution has a water concentration greater than that that is found inside the cell True

Oxygen and carbon dioxide gas can pass easily through the cell membrane by simple diffusion True False Question 13 0 5 points Listen Crenation of red blood cells results when the red blood cells lose water into a fluid environment that contains more solutes than the cell True

Each of the following is typical characteristics of an integral membrane prote transmembrane segment except 20 30 amino acids long composed primarily of hydrophobic amino acids All are characteristics of a typical transmembrane segment x helical structure Question 8 0 75 points 1 Listen The presence of trans fats in membranes membrane fluidity increases decreases increases or decreases

nost prominent lipids in animal cell membranes are glycolipids phytosterol phospholipids cholesterol Question 4 0 75 points Listen Most cells have a negative plasma membrane potential Vm because they have an excess of positively charged solute molecules inside the cell an excess of negatively charged solute molecules inside the cell equal concentrations of ions on both sides of the membrane an excess of negatively charged solute molecules outside the cell an excess of water molecules inside the cell

Water moves across the plasma membrane into or out of a cell by osmosis when O water diffuses through a semipermeable membrane toward a higher solute concentration water diffuses through a semipermeable membrane toward a lower solute concentration there is an equal solute concentration on both sides of the membrane a high solute concentration opens an aquaporin channel ATP hydrolysis drives aquaporin transport uestion 6 0 75 points Listen One way in which ions are specifically transported into the cell is via simple diffusion ABC transporters gated channels

Which molecule undergoes simple diffusion Na Glucose Amino acid Carbon dioxide Question 2 0 75 points Listen Saturated fats contain more double bond than unsaturated fats contain more hydrogen atoms than unsaturated fats contain more carbon atoms than unsaturated fats contain less hydrogen atoms than unsaturated fats

2 You are car A When merging with traffic flow you should try to enter At speeds lower than the traffic flow A At the same speed as the traffic flow At speeds higher than the traffic flow

Most antimicrobial compounds are going to be most effective when organisms are in O lag phase O exponential phase O stationary phase death phase

In which phase or phases of the growth curve is there very little change in total viable living cell numbers SELECT ALL THAT APPLY meaning multiple answers may be correct Lag Exponential Stationary

The piece of equipment that allows us to quantify turbidity of a microbial culture is called a ar O hemocytometer O spectrophotometer O gas chromatographer thermometer

The phosphotransferase system is called that because O a phosphate is lost when ATP is hydrolyzed to provide energy to get glucose across the membrane O a phosphate group is coupled to the transport of glucose using a symporter O a phosphate group is coupled to the transport of glucose using an antiporter a phosphate group is transfered onto glucose as it enters the cell converting it to glucose 6 phosphate

The shortest lag period would most likely be observed in the transfer of a microbial culture O from a complex medium to a fresh complex medium O from a complex medium to fresh minimal medium O from a complex medium where the culture was growing at a high temperature to fresh complex media where the culture will be growing a lower temperature from a complex medium at a pH 7 0 to a fresh complex medium at a pH of 5 0

Consider the definition of energy and how energy and mass interact in the biosphere Determine which of the following scenarios would violate the first law of thermodynamics People who exercise must consume more calories to maintain the same body weight A pregnant female must consume more food to support the development of the fetus O The molecular motor myosin hydrolyzes ATP to move along a microtubule in a cell A cell accumulates 10 kcal worth of energy in order to generate 15 kcal worth of bioluminescent work

From the graph below the reaction that has the highest rate of product formed is the one catalyzed by Activation Energy Cat BHD Uncatalyzed Erayma A Erazyme B Reaction Progress Question 36 1 point 4 Listen AG AH TAS ZC H0 Enzyme A Enzyme B Uncatalyzed O both enzyme A and uncatalyzed reactions What can be said about an endothermic reaction with a negative entropy change O spontaneous at all temperatures Ospontaneous at high temperatures spontaneous in the reverse direction at all temperatures

Many enzymes cannot recognize a stereoisomer of their substrate Some enzymes accept any of a whole group of substrates Carboxypeptidase recognizes any of the amino acids from the carboxyl end of a polypeptide Cells are often able to carry out metabolic activity with only a handful of enzymes because many are nonspecific Question 30 1 point 4 Listen Which of the following statements is false concerning the value AH OAH is the change in heat content A reaction with a positive AH value is exothermic OAH AE A PV In biology AH is basically the same as AE

as are placed in an aqueous solution The entropy of the phospholipids decreases and the entropy of the entire system also decreases The entropy of the phospholipids increases and the entropy of the entire system decreases O The entropy of the phospholipids decreases and the entropy of the entire system increases Question 38 1 point 4 Listen Under the conditions of a given reaction a positive AG means O the reaction is spontaneous Ono energy needs to be added the reaction is at equilibrium

When the AG of a chemical reaction is positive Keq 1 0 under standard conditions O reactants and products are at equilibrium products predominate over reactants reactants predominate over products None of the above

Which of the following is likely characteristic of pyruvate dehydrogenase ty of allosteric effectors both inhibitors and activators he complex that binds to Pyruvate dehydrogenase has at least two conformations an active form and an inactive form Pyruvate dehydrogenase is a large multisubunit protein The active conformation of pyruvate dehydrogenase likely has a higher affinity for substrates than does the inactive conformation All of the above Question 44 1 point 40 Listen Muscle contraction is an example of which of the following types of work O Heat Mechanical Electrical Concentration

S Km S Km both S Km and S Km Question 32 1 point 4 Listen The image shows a hypothetical enzymatic pathway with four enzymes labeled E1 E2 E3 and E4 The enzymes make products labeled PO P1 P2 P3 and P4 Which of the following statements is most likely to be true in the case of the feedback regulated enzymatic pathway shown OPO binds E4 and activates it OP2 binds E2 and activates it OP4 binds E1 and deactivates it

ving classes of enzymes Transferases Ligases Hydrolases Oxidoreductases Question 28 1 point 4 Listen A classical noncompetitive inhibitor will affect the Km Vmax of an enzymatic reaction

an endergonic system equilibrium an exergonic system the biochemical standard state for cellular reactions mosphere and a Question 42 1 point 4 Listen Succinylcholine is structurally similar to acetylcholine If succinylcholine combines with the enzyme that normally hydrolyzes acetylcholine the enzyme is no longer able to hydrolyze acetylcholine This suggests that Osuccinylcholine must be a noncompetitive inhibitor succinylcholine must be a competitive inhibitor with acetylcholine succinylcholine must be an allosteric regulator for this enzyme the activation energy barrier for succinylcholine hydrolysis is higher than that for

bind to the active site of an enzyme through noncovalent bonds are often toxic to cells have only a temporary effect on enzyme activity are not active against ribozymes Question 24 1 point Listen An enzyme is active in the stomach of an animal but quickly loses its activity when it leaves the stomach This example illustrates that enzymes are Odigested in the small intestine O consumed by the quantities of substrate in the small intestine inactivated by movement