Experimental Design
What is positive and negative control?
Positive control is a sample that confirms what a positive result looks like and confirms that the test is working.
Negative control is a sample that does not contain what the test identifies.
Why do samples need to be boiled for the Benedict's test?
Sugars can exist in linear (carbonyl groups) or ring structures
What are the 3 bacteria shapes?
Spheres = Cocci
Rods = Bacilli
Spirals = Spirilla
What is osmosis?
Diffusion of water
Identify the phases of mitosis including interphase.
Interphase: G1, S, G2
PMAT
What's the difference between an independent and dependent variable? Provide an example for each.
IV = Manipulate (ex. temperature)
DV = Measure (ex. enzyme activity)
When you add iodine to an unknown solution, the final color is blue-black. Why?
Starch is present
Tri-iodide nestles into the coiled structure of starch
Is the Paramecium:
fungi or protist?
unicellular or multicellular?
ciliated or non-ciliated?
Protist
Unicellular
Moves with Cilia
How does the steepness of concentration gradient affect osmosis? Include evidence from potato cells.
Rate of diffusion increases as the concentration gradient increases
The greater the difference in concentration, the more rapid the diffusion
Which phase has centromeres divide and chromatids separate as new chromosomes?
Anaphase
What is the independent and dependent variable being tested in the diffusion/osmosis lab?
effect of solute size on diffusion across a semi-permeable membrane
IV: solute size
DV: diffusion rate
What is needed to be present for the amino acid chain to complex with cupric ions?
Only when peptide bonds are present!
Is the Amoeba proteus:
fungi or protist?
unicellular or multicellular?
dynamic or constant?
What does it use to move?
Protist
Unicellular Eukaryote
Changes shape
Moves with pseudopodia
In which of the following would you expect osmosis to occur the fastest over time (sucrose cannot penetrate the membrane)?
a. Cell with 15% sucrose solution, sitting in a 30% sucrose solution
b. Cell with 20% sucrose solution, sitting in a 25% sucrose solution
c. Cell with 5% sucrose solution, sitting in a 30% sucrose solution
d. Cell with 8% sucrose solution, sitting in a 15% sucrose solution
Molecules will move from a high concentration to a low concentration.
Check which one has the biggest concentration difference.
C
What makes up the mitotic spindle?
tubulin
What is the relationship between molecular weight (mw) and diffusion?
Smaller molecules move faster
smaller mw = faster diffusion
TEST
Benedict's Red
Biuret Blue
Iodine Yellow
Based on these test results, what does your solution contain?
Large amount of reducing sugars, no protein, and no starch
Which muscle tissue has long, cylindrical, multinucleate cells with obvious striations?
Skeletal
What is tonicity?
hypo, iso, hyper
What occurs in the G1, S, and G2 phase?
G1= cell growth
S= DNA synthesis
G2= cell growth
What is the relationship between temperature and diffusion? Why?
High temp = Higher rate of diffusion
Molecules move faster at higher temps because molecules gain KE
When they are heated, they vibrate and then bump into each other
According to physics, heat is the amount of energy flowing from one body to another DUE TO TEMP DIFF
What are the tests used to identify the presence of each macromolecule? Then, tell me how each works and the color results for each test.
Refer to lab notes
Provide me the # of layers and cell shape for the following simple epithelium tissues:
-squamous
-cuboidal
-columnar
-pseudostratified
flat/scale like, 1 layer
box, 1 layer
tall/column, 1 layer
varied heights, 1 layer
Which of the following solutions were hypertonic to the potato cells?
Conc. of Salt Soln. Change in wt/Change in time
0 0.03
0.9% 0.02
2% 0.003
10% -0.01
15%. -0.05
When a cell is in hypertonic solution, it will shrivel up (dry out)
If the cell dries up, that would mean it weighs less
The weight is negative meaning that the cell must be shriveled up
Negative wt/time at 10% and 15% conc.What is the difference between prophase and telophase?
Telophase: chromosomes decondense, division of cytoplasm, mitotic spindle disappears