Lab Mid: Summary qu Flashcards
dr. smith wants to examine whether a new drug increases the maze running performance of older rats. Dr. Smith teaches two groups of older rats to find a piece of rat chow in the maze. One group of rats is given the new drug while they are learning the maze. The second group is not given the drug. One week after having learned the maze he retests the rats and recorders how long it takes them to find the rat chow. Write a hypothesis and identify the control, independent & dependent variable,
Hypoth: If given the new drug, the rats will have a have a higher maze running performace
IV: Drug presence
DV: maze running time
Control: Rats without the drug
How many times more or less H+ would be present in a solution with a pH of 8 vs. a pH of 5
x1000 less
How many times more or less H+ would be present in a solution with a pH of 2 vs. a pH of 4
x100 more
which household item has the highest pH
Amonia
Human blood has a pH of 7.35-7.45, Does this mean that human blood is slightly acidic or slightly basic
slightly basic
When lemon juice (an acid) is added to a buffer, the pH remained constant for some time. describe how the buffer was able to accomplish it
the base in the buffer abosorbed the H+ that was added
If ammonia was added to a buffer, describe what we might expect to observe in pH change
The pH would eventually begin to raise
Solution A has a pH of 6 while solution B has a pH of 2. This means that solution A has _______x fewer hydrogen ions than solution B
10,000x fewer
Solution C has a pH of 7, while solution D has a pH of 10. This means that solution D has ______x fewer hydrogen ions than solution C
1,000x fewer
When using benedicts reagent, what is indictated by a color change from blue to red/orange?
positive
what must be done to the test tubes containing the bendicts reagent and solutions before observing final color
it has to be boiling
Which test tube contained the highest amount of simple sugars in exercise 3
Glucose
Regarding the benedict’s test, which sample is the positive control and which sample is the negative control:
glucose, oil, or water
Neg: water
Pos: Oil
Which reagent is used to detect the presence of complex carbohydrates (starches) in a solution
Iodine-potassium Iodide
Regarding the test for complex carbohycrates (Exercise 3), which test tube is the positive control? Explain whether any of the remaining tubes may serve as a negative control
Potato flake, water, sucorse solution, glucose solution
Neg: water
Pos: Glucose
Since we know that the other are negative, we can use them as controls
Which reagent is used to detect proteins in a solution?
biurets reagent
Regarding the test for proteins in a solution, identify which samples are the positive control and the negative control:
Albumin, starch, water
Pos: Albumin
Neg: water
Explain why Sudan IV changes color when added to il, but not glucose. Which sample was the control?
Oil has lipids and glucose doesn’t. Oil was the control
Explain how to distinguid prokaryotic cells from eukaryotic
Prokaryotic are smaller, have a cell wall, and no mitochondria. They also have pilli and sometimes a capsule
Which cell was the only anucleate cell viewed? explain why it many be benefical for this cell type to lack a nucleus
The red blood cell is anucleate and lacking a nucleus allows them to have a concave shape and therefore higher surface area. It also allows the cell to carry more hemoglobin and therefore carry more oxygen
Describe what it means to say that a cell is squamous. how does the squamous shate relate to the function
flat cell, it allows the cell to cover a surface for protection
Explain why plant cells have a cell wall surrounding the cell membrane while animal cells only have a membrane
For structure and support, it allows teh plant cell to have its rectangular shape
Explain how the structure of the neuron relates to its function of sending electrical signals
The “arms” on the star shaped cell helps it communicate with other cells easier
Human red blood cell size is abt 7.5um-8um. Human capillaries are abt 8um in size. Explain what these facts suggest abt the relationship btw structure and function of the red blood cell
Capillaries are extremely narrow, allowing only1 rbc at a time. The flexible biconcave shape of red blood cells enables them to squeeze through capillaries, facilitating efficient gas exchange. This ensures oxygen delivery and carbon dioxide removal
Prokaryotic cells contain DNA but lack a nucleus. Describe how a prokaryotic cell stores its DNA
it is stored in the nucleiod region as one long chromosone
Explain why sketetal muscle cells and sperm cells contain a very large number of mitochondria
They need alot of energy for alot of movement
Explain why both mitochondria and chloroplast are found inside a plantcell
to make, store, and convert energy
mitochondria provide energy, while chloroplasts enable photosynthesis in plant cells
Briefly describe how gram pos and gram neg cell walls differ structurally
The cell wall of gram pos has more peptidoglycan (90%) while the gram neg has less (20%) and a second outermembrane
What color does crystal violent stain gram positive bacteria
purple
What color does crystal violent stain gram neg bacteria
purple
What color is gram positive bacteria after decolorization
purple
What color is gram negitive bacteria after decolorization
clear
What is the color of gram negative bacteria after the safranin counterstain
red
What is the color of gram pos bacteria after the safranin counterstain
purple (it was not decolorized)
What is the color of gram negative bacteria after using iodine mordant
purple
Why would scientist perform a gram stain in the lab or clinical setting
to make sure a proposed antibiotic would be recepted to the bacteria since the cell membrane differs between the two
What morphology did the gram positive bacterial have? what was the morphology of the gram negative bacteria
Pos: Round cluster: Staphylo coccus
neg: rod cluster: strepylo baccillis
The bacteria used in Exercise 6 is staphylococcus epidermis and E. coli. Which was gram positive and which is gram negitive. What color was each after the staining process
Pos: staphylococcus epidermis; purple
Neg: E. Coli; red
Describe the look of red blood cells when exposed to the isotonic solution, why do they look this way?
they appear normal, this is because this is the solution they prefer and have equal movement in and out of the cell
Describe the look of red blood cells when exposed to the Hypertonic solution, why do they look this way?
they are shriveled (crenated) since the water is drawn out of the cell
Describe the look of red blood cells when exposed to the Hypotonic solution, why do they look this way?
The cell is swollen since it absorbs the water and eventually lyses
Explain what it means to say that a solute moves down the concentration gradient
it moves from high concentration to low concentration; if there is less concentration inside the cell (hypotonic) the solution outside is going to move to the lower concentration to reach equalibrium
Predict what would happen if a red blood cell was placed into a 1.2% NaCl soltion (body is 0.9% NaCl)
It would shrink and crenate
The isotonic glucose for red blood cells is 5%, what does this mean
there is a 5% concentration of glucose in the red blood cell
What would happen to a red blood cell if it was placed into a 5% glucose solution (body is 5% glucose)
nothing, it is isotonic and at equalibrium
Describe what would occur if a red blood cell was exposed to a 8% glucose solution
It would shrink and crenate
What would happen to a flaccid potato strip if you were to place it inside a Petri dish containing pure water (0% NaCl) for 30 minutes
The cells would swell since there is a higher concentratoin of water outside
Describe the difference between the size of the central vacuole in the Elodea cells in hypotonic solution vs. the Elodea cells in hypertonic
Elodea has a lager vacuole in the hypotonic soluton because it absorbs the water
Did the entire elodea cell shrivel in the hypertonic solution? why or why not
yes, there was more solution outside
What is the ‘optimal’ temp for catalase?
37 degrees celcius
Explain the reaction rate you observed in ice water for exercise 8 (enzymes)
the reaction took slower to begin but then rapidly begain to react
Explain the reaction rate you observed in 100 degree water for exercise 8 (enzymes)
The enzymes were denatured and therefore inactive
Based on the rate of bubbling (oxygen produced), which tissue contained catalase?
Liver, potato, chicken, or apple
Liver
What is the optimal pH for catalase
7
Explain the effects of pH or temperature for catalase activity in bacteira
the catalyst will denature when heated or has a significant pH change
What represents control in exercise 9
water, yeast, glucose, combonation
water
What is the independent variables in exercise 9 (fermentation)
solution proportion
What is the dependent variables in exercise 9 (fermentation)
Gas bubble height (CO2 output)
If the parafiml was removed, would fermentation still occur?
no, oxygen inhibits fermentation, cells would take glucose to form ATP
What ratio of water, yeast, and glucose resulted in the highest rate of fermentation (fermentation lab)
3w, 6y, 6g
Which steps are common to both fermentation and cellular respiration? describe how the 2 processes can have common steps
Glycolosis is the first step before oxygen divides the two
Glycolosis is the only intake of energy for fermentation
Which pathway (aerobic/anarobic) produces the most energy during the catabolism of glucose
aerobic
Humans use mostly aerobic respiration. What is the advantage of aerobic respiration vs anaerobic
Aerobic produces more ATP (32 vs 2 in anaerobic)
