Bio Lab Practical I
Match the reagent with its experimental purpose in the procedures you will be doing in lab. 1) Electron Acceptor 2) Carbon source used in measuring CO2 fixation 3) Chloroplast preparation 4) Blocks electron transport 5) Carbon source used in determining the rate of oxygen synthesis 6) pH indicator 7) Uncouples Chemiosmosis Answer choices: A. NH2OH B. Free CO2 C. NaHCO3 D. spinach E. Phenol red F. DPIP G. DCMU
1) - F, 2) - B, 3) - D, 4) - G, 5) - C, 6) - E, 7) - A
Why does catalase bubble?
Catalase bubbles due to the release of oxygen when hydrogen peroxide is split into water and oxygen.
Do free amino acids have peptide bonds?
No
To build sugars requires ______________ from the atmosphere a) CO2 b) Ribulose bisphosphate c) H20 d) NADPH e) O2 f) Chlorophyll
a) CO2 from the atmosphere (taken in in the stroma of the chloroplast in the Calvin cycle)
In human testing controlled experiments can be tricky and can have ethical considerations. In a controlled experiment investigators apply treatments and then observe the effect of the treatment compared to a control group that does not receive the treatment. When this is not possible investigators may rely on observational studies where investigators simply observe effects without applying any treatment, in observational studies there is no human intervention. Consider the following example. In one study on the effect of niacin (vitamin B3) on cholesterol level, 100 subjects who acknowledged being long time niacin takers had their cholesterol levels compared with those of 100 people who had never taken niacin. In a second study, 50 subjects were randomly chosen to receive niacin and 50 were chosen to receive a placebo for 5 years and have their cholesterol levels compared. a) The first study was and observational study while the second group was an experiment. b) Both studies were observational studies. c) The first study was a controlled experiment, while the second group was an observational study. d) Both studies were controlled experiments
a) The first study was an observational study while the second group was an experiment.
In the experiment where O 2 consumption is measured with a respirometer how is a constant volume achieved? a) By adding glass beads b) By adding geminating beans c) By adding dry beans d) By adding KOH e) By using identical respirometers.
a) by adding glass beads
Benedict's solution will be used during the experiment that tests for which macromolecule? a) carbohydrates b) lipids c) proteins d) nucleic acids
a) carbohydrates, specifically tests for reducing sugars (glucose and fructose, for example). Blue is no reaction, green is some reducing sugars, reddish-orange is an abundance of reducing sugars
Which of the enzymes being tested is found in peroxisomes? a) Catalase b) Acid Phosphatase c) Lysozyme d) Pepsin e) Urease f) Amylase
a) catalase, acts on toxic hydrogen peroxide and produces water and oxygen. Identified with heat and bubbles.
A net total of 32 ATPs are produced in this process a) cellular respiration b) Ethanol fermentation c) Lactic acid fermentation d) Both Cellular respiration and Ethanol fermentation e) Both Cellular respiration and Lactic Acid fermentation f) Both Ethanol fermentation and Lactic Acid fermentation g) Common to cellular respiration, and both Lactic acid and Ethanol fermentation.
a) cellular respiration
Process begins in the cytoplasm and ends in the mitochondria a) Cellular respiration b) Ethanol fermentation c) Lactic acid fermentation d) Both Cellular respiration and Ethanol fermentation e) Both Cellular respiration and Lactic Acid fermentation f) Both Ethanol fermentation and Lactic Acid fermentation g) Common to cellular respiration, and both Lactic acid and Ethanol fermentation.
a) cellular respiration (glycolysis in the cytoplasm, ETC in the mitochondria)
Water is produced in this process a) Cellular respiration b) Ethanol fermentation c) Lactic Acid fermentation d) Both Cellular respiration and Ethanol fermentation e) Both Cellular respiration and Lactic Acid fermentation f) Both Ethanol fermentation and Lactic Acid fermentation g) Common to cellular respiration, and both Lactic acid and Ethanol fermentation.
a) cellular respiration, oxygen is the final electron acceptor, forms H2O
In lipids, dehydration forms what type of bond? a) ester b) glycosidic c) phosphodiester d) peptide
a) ester bonds
In carbohydrates, hydrolysis breaks what type of bond? a) glycosidic b) ester c) phosphodiester d) peptide
a) glycosidic bond, ester is in primarily lipids but also nucleotides, phosphodiester is in nucleotides, peptide is in proteins
During which of the following procedures will you need to add methylene blue in order to complete your observations? Select all that apply. a) Human epithelium b) Potato c) Elodea d) Yogurt e) Red Blood Cells f) Onion g) Fungi h) Pond Water
a) human epithelium, d) yogurt, f) onion, g) fungi
According to the ideal gas law PV = nRT. If volume and number of molecules are held constant, when the temperature increases you should expect the pressure to___________. a) increase, since the two are directly proportionally b) decrease, since the two are inversely proportional c) increase, since the two are inversely proportional d) decrease, since the two are directly proportional
a) increase, since the two are directly proportional
Below is a U-tube experiment with a membrane that is selectively permeable to water, but does not allow movement of solute particles. Predict in which direction there will be a net movement of water. (can't upload the image but imagine that the solute is more concentrated on the left side) a) More water will move to the left. b) More water will move to the right. c) There will be no net flow of water molecules.
a) more water will move to the left
Which of these foods would give the highest positive Iodine test? a) potatoes b) beans c) butter d) eggs e) cheese
a) potatoes, they contain the highest starch content
What is the purpose of DPIP in the ETC experiment?
The purpose of DPIP is to function as an artificial electron acceptor in place of NADP+
What would happen if another substance competed for the enzyme active site?
The rate of reaction would decrease, as it would be difficult to pair every substrate with an enzyme in the same amount of time it would normally take.
During cellular respiration how many ATP are produced during the citric acid cycle by substrate-level phosphorylation per glucose molecule? a) 0 b) 1 c) 2 d) 3 e) 4 f) 5 g) 6
c) 2 ATP
In the yeast experiment measuring CO 2 production, your trendline for the tubes in the warm temperature water bath gives the equation: y = 1.74x + 12.8, where time (in minutes) is plotted as the independent variable and distance moved (in mm) is plotted as the dependent variable. How far would the water have moved after 23 minutes? a) 5.9 mm b) 21.3 mm c) 52.8 mm d) 40.0 mm e) 12.8 mm
c) 52.8 mm ((1.74 x 23) + 12.8) = 52.8
Calculate the rate of photosynthesis (mm/hr) for Elodea if when measuring net photosynthesis, the water level moved up 5 mm from the initial level in 5 min and, when measuring cellular respiration it took 20 minutes for the water level to move down 1 mm. a) 67 mm/hr b) 52 mm/hr c) 63 mm/hr d) 61 mm/hr e) 57 mm/hr
c) 63 mm/hr because it's actually the gross rate of photosynthesis
The molecular formula of glucose is C 6H 12O 6. What would be the molecular formula for a polymer made by linking six glucose molecules together by dehydration reactions? a) C36H72O36 b) C36H60O30 c) C36H62O31 d) C36H68O31 e) C36H66O30
c) C36H62O31, multiply C6H12O6 by 6 and subtract (H2O x 5) to account for dehydration synthesis
The molecular formula of glucose is C 6H 12O 6. What would be the molecular formula for a polymer made by linking five glucose molecules together by dehydration reactions? a) C30H60O30 b) C30H50O25 c) C30H52O26 d) C30H56O26 e) C30H55O25
b) C30H50O25
____________ is the substrate for photolysis. a) Chlorophyll b) H20 c) O2 d) Ribulose bisphosphate e) CO2 f) NADPH
b) H2O
Which of the following macromolecules is not a true polymer? a) glycogen b) antibodies c) DNA d) cholesterol
d) cholesterol, because it is a lipid molecule and forms a ring, rather than a chain and requires more than one kind of subunit to build
Formation of a glycosidic bond requires which functional groups? a) Carboxyl group (-COOH) b) amino group (-NH2) c) Carbonyl group (>C=O) d) hydroxyl group (-OH) e) phosphate group (-OPO3^2-)
d) hydroxyl group, dehydration synthesis occurs between hydroxyl groups to form water
At the end of glycolysis the carbons of glucose are converted to (check all that apply)? a) CO2 b) Acetyl CoA c) Oxaloacetate d) Pyruvate e) Lactate
d) pyruvate (two three-carbon molecules)
Protons build up in the _______________ during photosynthesis chemiosmosis. a) Stroma b) Intermembrane space between the outer and inner membrane c) Outer membrane of the chloroplast d) Thylakoid space e) Inner membrane of the chloroplast f) Thylakoid membranes
d) thylakoid space
In the experiment where CO 2 production is measured with a respirometer what is the experimental organism? a) yeast b) Seeds c) Fruit flies d) Bacteria
a) yeast
What is the blue part of the image called?
enzyme
Which of the following line the inside of your mouth? (also couldn't upload more than one image but they look like that)
human epithelial cells
How did methylene blue help improve your visualization of Lactobacillus?
it stained the cell membrane
How did methylene blue help improve your visualization of onion cells?
it stained the nucleus and membrane
Match each of the following cell structures into the appropriate category, Prokaryotic, Eukaryotic, or both No nucleus DNA in cytoplasm DNA in nucleus (membrane bound) organelles plasma membrane cytoplasm
no nucleus - prokaryotic DNA in cytoplasm - prokaryotic DNA in nucleus - eukaryotic (membrane bound) organelles - eukaryotic plasma membrane - both cytoplasm - both
Does anything other than the amyloplasts stain with iodine in the potato cells?
no, only the parts of the potato containing starch (just amyloplasts were visible)
What is the three dimensional shape of lactobacillus?
pairs of spheres
what was the optimum pH for amylase?
the optimum pH for amylase is 6-7 as this is the body's pH
If ethanol fermentation is used in the process of making bread, how come you don't get drunk eating bread?
the ethanol evaporates when the reaction produces CO2 in the bread
Compare tubes 1 (salad oil) and 3 (distilled water) in the second experiment. What is the distribution of dye with respect to the separated water and oil?
the separated oil and water has a concentrated section of dye while the water evenly distributes the dye.
Is cytoplasmic streaming in all of the cells in the same direction?
yes
Correctly match an item that you will be preparing a slide for (column A), with what you plan to observe from that slide preparation (column B). Question: yogurt, potato, fungi, red blood cells, pond water All Answer Choices: A. mycelium composed of hyphae, B. protists, C. amyloplasts, D. hemolysis, E. lactobacillus bacteria
yogurt - lactobacillus bacteria, potato - amyloplasts, fungi - mycelium composed of hyphae, red blood cells - hemolysis, pond water - protists
Which respirometers in the cellular respiration experiment were the negative controls? why?
The distilled water respirometers were the negative controls because they showed what the reaction would look like if no cellular respiration took place.
Did the amylase enzyme activity differ at 4 degrees and 100 degrees Celsius? why?
(our reaction differed) the activity of amylase should be the same for 4 degrees and 100 degrees celsius because hot or cold temperatures cause a slower rate of enzyme reaction.
Match the following test tubes with the scenarios listed: -Based on this observation the student has deduced that the Calvin Cycle is running, and CO2 is being removed from the solution. -Based on this observation the student has deduced that the Calvin Cycle is running poorly, and there is still plenty of CO2 remaining. -Based on this observation the student has deduced that they forgot to add the phenol red solution to the test tube. a) red solution in test tube b) clear solution in test tube c) yellow solution in test tube
-Based on this observation the student has deduced that the Calvin Cycle is running, and CO2 is being removed from the solution. - a) red solution -Based on this observation the student has deduced that the Calvin Cycle is running poorly, and there is still plenty of CO2remaining. - c) yellow solution -Based on this observation the student has deduced that they forgot to add the phenol red solution to the test tube. - b) clear solution in test tube
What size were the lactobacillus when viewed at 40x magnification?
.5 microns
According to the Elodea photosynthetic action spectrum above rank the following wavelengths of light that show the highest photosynthetic rate (1 highest - 6 lowest) a) 425 b) 650 c) 450 d) 700 e) 500 f) 550
1 - a (425), 2 - b (650), 3 - c (450), 4 - e (500), 5 - f (550), 6 - d (700)
A student is given five samples and told they are lysine (an amino acid), lactose (a disaccharide), insulin (a protein hormone), RNA and fat. The samples are in test tubes marked 1-5, but the student doesn't know which compound is in which tube. The student is instructed to identify the contents of each tube. In her first test, she tries to hydrolyze a portion of the contents of each tube. Hydrolysis occurs in all tubes except tube 5. In the next test, she finds that tubes 3, 4, and 5 are positive for nitrogen but only tube 3 gives a positive result for the presence of sulfur. In the next test the student shows that the compound in tube 4 contains a high percentage of phosphate. In the final test the student shows that compound 1 is hydrophobic. Base on these data, identify what is in each tube. Options: fat, insulin, lysine, RNA, lactose
1 - fat (hydrophobic, does not contain nitrogen), 2 - lactose (no nitrogen, sulfur, or high % of phosphate), 3 - insulin (sulfur present - proteins, nitrogen present), 4 - RNA (nitrogen present, high % of phosphate), 5 - lysine (hydrolysis doesn't occur)
what are the size of amyloplasts in potato cells when viewed on 10x magnification?
1.5 microns
How many um is one micron equal to?
10 um = 1 micron
Which three amylase and Benedict's test tubes contain the highest amount of product? 1 - blue 2 - reddish orange 3 - reddish orange 4 - green 5 - blue 6 - blue 7 - reddish orange 8 - green 9 - green
2, 3, and 7, because Benedict's indicates the presence of glucose, meaning that amylase has acted upon starch and produced a large amount of glucose in those test tubes.
What was the size of elodea when viewed with 40x magnification?
20 microns
How long does cellular metabolism persist after death?
4-10 minutes
The temperature optima of three different enzymes is depicted by three lines on a graph, one peaking at 4 degrees celsius - A, one at 25 degrees celsius - B, and one at 100 degrees celsius - C. Which line could have been isolated from an arctic flounder fish?
A - 4 degrees celsius
After death cellular metabolism continues for ______ This leads to an accumulation of ________ in cells. Which in turn leads to a ____________ intercellular pH. This will cause ___________ to rupture and autolysis of tissue. The entire process will __________ if the environmental temperature is warm Answer choices: A. 4-10 minutes B. higher C. H20 D. 20-30 minutes E. Lysosomes F. CO2 G. O2 H. lower I. 30 seconds J. Stop K. 1 hour L. Nuclei M. ribosomes N. Slow down O. speedup
A. 4-10 minutes; F. CO2; H. lower; E. lysosomes; O. speedup
Approx. how many amyloplasts are there in a potato cell?
About 60 amyloplasts
What is the function of amyloplasts?
Amyloplasts store starch within internal membrane compartments
although in this experiment you have used iodine to measure the disappearance of the substrate starch, you could have used Benedict's reagent to measure the appearance of the product glucose. Remember from the macromolecule lab that when there is no glucose Benedict's remains blue, at medium glucose levels the reagent turns green and at high glucose levels the reagent turns a reddish-orange. According to your above results what colors would you have expected at pH 2, 5, 7, 9, and 11?
At 2 and 11 I would have expected a blue color, as amylase hasn't removed any of the starch, at 5 and 9 I would expect a green color because amylase has done some activity, and at 7 I would expect reddish-orange because amylase would have digested all of the starch and produced glucose at optimum pH.
Why did the solution in the tubing move downward when covered with foil?
Because the Calvin cycle doesn't need light to take up CO2 left in the tubing to continue performing photosynthesis
Which seed variety had the highest O2 consumption and which one had the lowest?
Black eyed beans had the highest and red beans had the lowest consumption of O2.
How is the activity of amylase affected by a low pH? by a high pH? Explain.
Both a low and high pH are beyond amylase's optimal pH causing either hydrogen ions or hydroxide ions to alter the active site of the enzyme.
Which of the following images demonstrates animal cells in a hypotonic solution? B - the solution outside the cell has a lower concentration of solute than inside the cell. C - the solution outside the cell has a lower concentration of solute than inside the cell. C - the solution outside the cell has a higher concentration of solute than inside the cell. B - the solution outside the cell has a higher concentration of solute than inside the cell. A - the solution outside the cell has the same concentration of solute as inside the cell.
C - the solution outside the cell has a lower concentration of solute than inside the cell.
What happened when DCMU and ammonia were added and why?
DCMU blocks photosystem II from occurring by blocking transport while ammonia promotes the transport of electrons.
Which contains more peptide bonds, egg albumin or honey? How do you know?
Egg albumin contains more peptide bonds. This is apparent because the solution turned purple and the honey remained blue.
As temperature increases, enzymatic activity increases up to a certain point beyond which enzymatic activity decreases. Explain.
Enzymatic activity increases up to its optimal temperature but decreases once it gets too hot. The enzymes begin to denature at that point.
Why did the solution in the tubing move upward in the volumeter when exposed to light?
It moved upward because photosynthesis light reactions were releasing O2, which pushed the solution up the tube
What would happen if you increase substrate concentration?
If more substrate is added the reaction will remain the same as long as there are enough enzymes to act on the substrates.
What would happen if you increased the enzyme concentration?
If the enzyme concentration were increased, the reaction would be faster up until the enzymes had no more substrates to bind to. At that point the enzymes would be "saturated" and the rate would stay the same.
Which of the three solutions (hypertonic, hypotonic, or isotonic) approximates a red blood cell's solute concentration? How do you know?
Isotonic most closely resembles the concentration inside of the red blood cell. I can tell because the cells appeared normal under the microscope
After the lamp is turned on, what color did the elodea and water solution change to? Why?
It changed to red because photosynthesis could resume and the CO2 would be used in the chloroplasts during the Calvin cycle to make sugars
Why does the elodea and distilled water solution change to a yellow color after you blow on it?
It changes to a yellow color because CO2 is acidic when combined with H2O and phenol red changes to yellow when in contact with acids
What do you conclude about the solubility of lipids in polar solvents such as water compared to non polar solvents such as acetone?
Lipids are more soluble in non polar molecules. Their particles are suspended more evenly in the the nonpolar solution whereas the polar solution separates the polar and non polar elements with one floating on the top.
What did Sudan IV test for?
Lipids, negative for lipids was light pink and positive for lipids was dark pink
What molecule(s) supply the electrons to the electron transport chain?
NADH and FADH2 supply electrons to the ETC
Which contains more reducing sugars, potato juice or onion juice? How do you know?
Onion juice contained more, the color was greenish-yellow rather than bluish like the potato juice
Pepsin hydrolyzes proteins in the stomach. The pH in the stomach is 2, and the optimum pH for pepsin is 2. What do you think would happen to the activity of pepsin when it reaches the small intestine, where the pH is 8? Explain why.
Pepsin would become denatured or at least inactive in a pH of 8 when its optimum is 2.
Which one of the solutions is the positive control, and which is the negative for the buret reaction?
Positive control - 1% protein solution, negative control - distilled water
Which of the solutions was the positive control, and which was the negative control for the Benedict's reaction?
Positive control - 1% reducing sugar solution, negative control - distilled water solution
Which one of the solutions is the positive control, and which is the negative in the iodine reaction?
Positive control - 1% starch solution, negative control - distilled water solution
Which one of the solutions is the positive control and which is the negative control for the Sudan IV reaction?
Positive control - lipid solution, negative control - distilled water
Which of the solutions is the positive control and which is the negative for the dische reaction?
Positive - DNA solution (without RNA), negative - distilled water
Why is temperature equilibration necessary?
Temperature equilibration is necessary because the rate of reactivity is more accurate when the temperature isn't fluctuating or increasing/decreasing.
What did Dische Diphenylamine test for?
Tested for DNA, acidic conditions bind with diphenylamine to form a blue complex. The amount of DNA is proportional to the intensity of the blue color. (+ is dark blue, ++ is dark purple)
In the image of the mitochondria where is ATP synthase located?
The inter membrane space - between the outer and inner mitochondrial membrane
which colors more intensely for the iodine reaction, the potato juice or the onion juice? Why?
The potato juice was a darker color, this is because there are more coiled glucose molecules in potatoes
What happened when the emulsifier was added?
The solution appeared more homogenized and cloudy. The lipids dispersed in the water
Where does the oxygen come from in photosynthesis?
The splitting of water
How does the rate of O2 consumption (in the cellular respiration lab) differ when calculated just using the endpoint data versus using a trend line?
The trend line would make O2 consumption appear lower than it actually was. It's more accurate using the actual data.
Is a fungi more like a plant or an animal?
They are more like an animal because they utilize food from an outside source rather than photosynthesizing it, like plants
Why do Elodea and onion cells have more consistent shapes than human epithelial cells?
They contain a cell wall
Do DNA and RNA react alike? Why or why not?
They react differently because they contain different binding properties to be detected by dische solution.
What size was penicillium when viewed on 40x magnification?
They were .5 microns
Was each enzyme specific for one substrate or was there some overlap? why?
They were specific to each substrate because of enzyme specificity and there wasn't any cross-contamination
How does the size of a Human epithelial cell compare to the bacteria and elodea cells that were examined?
They're larger than the bacteria but smaller than the elodea cells
Where are the chloroplasts located in the Elodea cell? Why?
They're located on the outside of the cell so that cytoplasmic streaming can occur and they can absorb maximum sunlight
How does the color compare between tubes 1 (DNA solution) and 2 (DNA solution and distilled water)
Tube 1 is more intense in reaction (++) because the concentration of DNA is higher than that of the second tube, which has distilled DNA.
Why does the urease reaction change pH?
When urease and urea are combined they produce ammonia, which is basic and increases the pH from about 3 to 7.
The magnification of the eyepiece of a microscope is 10x. A student observes an animal cell under magnification 20x of the objective lens. What is the total magnification? a) 200x b) 2000x c) 10x d) 20x
a) 200x (10 x 20 = 200x)
Do plants have mitochondria?
Y e s
Through which red blood cell tubes could you read the printed page? why?
You could read it through the tubes in hypotonic solutions because too much water came into the cell causing them to lyse. This made the solution more transparent.
What is the three dimensional shape of elodea?
a rectangular prism
What is the size of onion cells when observed with 40x magnification?
about 35 microns
What is the approx. number of chloroplasts per cell?
about 50 chloroplasts appear in each cell
Why did the water levels in the CO2 collection tube move downward?
as more CO2 was introduced into the tube the water was pushed out
Two test tubes, A is a light bluish-green, B is a dark blue. Both test tubes contain a buffer solution, DPIP, and chloroplasts. They were both exposed to light. One of these test tubes had the herbicide DCMU added, the other did not. Which test tube had DCMU? In the tube with DCMU has DPIP been reduced? a) Test tube A had DCMU. No DPIP has not been reduced b) Test tube B had DCMU. No DPIP has not been reduced c) Test tube A had DCMU. Yes DPIP has been reduced. d) Test tube B had DCMU. Yes DPIP has been reduced.
b) Test tube B had DCMU. No DPIP has not been reduced (the lighter color means DPIP has been effective and DCMU blocks DPIP from accepting electrons)
How could changes be applied to increase the rate of enzyme activity beyond the end of the graph? a) Add more water b) Add more enzyme c) Change the pH d) Add more substrate e) Increase the temperature
b) add more enzyme
EDTA can inhibit the amylase reaction by a) Altering hydrophobic conditions. b) Binding up ions. c) Breaking disulfide bonds. d) Blocking the active site.
b) binding up ions, they are needed for enzymatic activity but they are so tightly bound that they can't bind to anything else
Which of the following best describes a positive reaction in the Iodine Test? a) reddish-orange color b) bluish-black color c) violet color d) blue color e) no color change
b) bluish-black color, the reddish-orange or brownish color is an indication that no reaction has taken place, tested for starch
In the experiment where CO 2 production is measured with a respirometer the dependent variable is a) Time b) Distance moved c) Temperature d) Ph e) pressure
b) distance moved (depends on the time)
Which of the following are considered eukaryotic organisms? Select all that apply. a) Bacteria b) Fungi c) Archaea d) Plants
b) fungi, and d) plants
NADPH builds up in the ________________ during electron transport. a) Thylakoid space b) Inter membrane space between the outer and inner membrane c) Thylakoid membranes d) Outer membrane of the chloroplast e) Stroma f) Inner membrane of the chloroplast
b) inter membrane space between inner and outer membrane (all other answer choices are in the chloroplast anyway)
An emulsifier will be used during the experiment that tests for which macromolecule? a) carbohydrates b) lipids c) proteins d) nucleic acids
b) lipids, emulsifiers cause fat molecules to disperse in water
During which of the following procedures will you need to add NaCl in order to complete your observations? Select all that apply. a) Fungi b) Onion c) Potato d) Yogurt e) Pond Water f) Elodea g) Human epithelium h) Red Blood Cells
b) onion, and h) red blood cells
In human testing controlled experiments can be tricky and can have ethical considerations. In a controlled experiment investigators apply treatments and then observe the effect of the treatment compared to a control group that does not receive the treatment. When this is not possible investigators may rely on observational studies where investigators simply observe effects without applying any treatment, in observational studies there is no human intervention. Consider the following example. In one study bodybuilders were given either a placebo or 1,000 milligrams of creatine, and the increase in strength gained in the bench press was noted. In a second study people responded to a questionnaire asking about their use of creatine, the average time they spend in the gym in a day and the amount of weight they can bench press. a) Both studies were observational. b) The first study was a controlled experiment, while the second was an observational study. c) Both studies were controlled experiments d) The first study was an observational study, while the second was a controlled experiment.
b) the first study was a controlled experiment, while the second was an observational study
What was the optimum temperature for amylase activity?
body temperature - 37 degrees C
Process can occur in muscle cells during intense activity. a) Cellular respiration b) Ethanol fermentation c) Lactic Acid fermentation d) Both Cellular respiration and Ethanol fermentation e) Both Cellular respiration and Lactic Acid fermentation f) Both Ethanol fermentation and Lactic Acid fermentation g) Common to cellular respiration, and both Lactic acid and Ethanol fermentation.
c) lactic acid fermentation
Which of the following macromolecules make up antibodies, which provide immunity to an organism? a) carbohydrates b) lipids c) proteins d) nucleic acids
c) proteins make up antibodies
Which of the following best describes a positive reaction in the Biuret Test a) reddish-orange color b) bluish-black color c) violet color d) blue color e) no color change
c) violet color, tests for protein (specifically peptide bonds and not individual amino acids)
How many microns across were the human cheek cells and their nuclei when viewed on 40x magnification?
cheek cells - 10 microns, nuclei - 4 microns
Choose all that are correct.Identify the products in the following reaction: Urease + Urea —> ______________ a) p-nitrophenol b) Maltose c) Proteoglycan pieces d) Glucose e) CO2 f) O2 g) Ammonia h) Amino acides I) H2O
e) CO2, and g) ammonia, tested with a pH strip and sniff test
Which of these foods would give the highest positive Biuret test? a) cookies b) coconut c) butter d) Potatoes e) chicken
e) chicken, it's the highest in protein
Which of the following characteristics is most directly responsible for the specificity of a protein enzyme? a) pH conditions b) its cofactors c) temperature conditions d) its location in the cell e) its three dimensional shape
e) its three dimensional shape
Electrons in the reaction center of Photosystem II are replaced by electrons from _____________. a) NADPH b) CO2 c) Chlorophyll d) O2 e) Ribulose bisphosphate f) H20
f) H2O (when it gets split)
Which of the following is(are) produced during the light reactions of photosynthesis. (Select all that apply.) a) ADP b) NADP+ c) Sugar d) CO2 e) light energy f) NADPH g) O2 h) ATP i) H2O
f) NADPH, g) O2 (1/2), and h) ATP
Which enzyme reaction is going to turn the solution yellow? a) Lysozyme b) Amylase c) Pepsin d) Catalase e) Urease f) Acid Phosphatase
f) acid phosphatase, acts on PNPP and produces P-nitrophenol. Test for it is a pH strip (yellow = positive)
Why are there no chloroplasts in the onion preparation?
onions grow underground and don't need to absorb light
Match the cell structure with the cell function. Plasma membrane, cell wall, central vacuole, chloroplasts, nucleus, nucleoli, plasmodesmata, mycelium, pseudopodia, mitochondria Answer choices: A. cell communication B. synthesis of ribosomal subunits C. protection external to the plasma membrane D. boundary of the cell E. ATP synthesis F. genetic material G. storage H. photosynthesis I. movement J. feeding system
plasma membrane - boundary of the cell, cell wall - protection external to the plasma membrane, central vacuole - storage, chloroplasts - photosynthesis, nucleus - genetic material, nucleoli - synthesis of ribosomal subunits, plasmodesmata - cell communication, mycelium - feeding system, pseudopodia - movement, mitochondria - ATP synthesis
What else do you see on this slide preparation other than cheek cells?
sizing beads, debris
Why did the onion cells plasmolyze when immersed in a hypertonic solution?
the NaCl concentration outside of the cell was higher than the concentration inside of the cell, so water left the cell to dilute the extracellular concentration.
What structures are visible in the methylene blue stained cheek cells that were invisible in the unstained preparation?
the nucleus and membrane were more visible after adding the stain
Which tubes were the controls in the ETC experiment and what did they control for?
the tube filled with water only was one control - showed what no photosynthesis looked like, the tube filled with just chloroplasts and H2O covered in foil showed what very little reaction occurs when there's no electron acceptor or source of light.
Why did the water move in the pipette (in procedure 2 of cellular respiration)?
the water moved down the pipette as it was being consumed by the seeds for cellular respiration and the making of ATP.
What was the control in the enzyme specificity experiment?
water with no enzyme
How could you have made your results more accurate for the "amylase activity in different pH's" experiment?
we could've used a more accurate temperature water bath or put the iodine drops in the test tubes all at the same time.
How could your results for "amylase enzyme activity as a response to temperature" be more accurate?
we could've used devices that stated the exact temperature for all of the test tubes