Test #1 Lab / Quiz / Sg Questions Flashcards
Why does Benedict’s reagent react with glucose but not with starch?
Benedict’s reagent reacts with reducing sugars, sugars with free aldehyde group
Monosaccharides and some disaccharides have a free aldehyde group
Starch does not have the free aldehyde group
Why does iodine stain starch but not glucose?
Starch coils
It hydrogen bonds to itself
Why does the Bradford reagent detect proteins?
Reacts with amino groups
Why does the Sudan dye detect lipids?
Hydrophobic interactions between sudan dye and anything you tested that was hydrophobic
Why does diphenylamine detect DNA but not RNA?
Acidic condition react with the deoxyribose but not the ribose
Why did some amino acids travel farther up the TLC plates than others?
Thin layer chromatography was used to separate amino acids based on the polarity and size
Some amino acids were more attracted to the solvents polar silica… solvent was hydrophobic…. amino acids were hydrophilic
Near bottom = hydrophilic b/c they have to leave through silica gels to move
Near top = hydrophobic b/c they go with the solvent
Why are fats better for storing energy than carbohydrates?
They dissolve easily in water, which makes them easier to digest than carbohydrates.
They have a greater number of energy-storing C-H bonds than carbohydrates.
They don’t dissolve in water, which makes them easier to store than carbohydrates.
They are easier to transport from one part of an organism to another than carbohydrates.
They have a greater number of energy-storing C-OH bonds than carbohydrates.
They have a greater number of energy-storing C-H bonds than carbohydrates.
What limits the maximum size cells can reach?
the number of organelles
number of surrounding cells
diffusion and surface-to-volume ratio
amount of DNA in the nucleus
thickness of the cell wall
diffusion and surface-to-volume ratio
Why can eukaryotic cells grow larger than prokaryotic cells?
Because they have a larger surface to volume ratio.
Because their interiors are subdivided into numerous compartments called organelles.
Because they live longer than prokaryotic cells.
Because they have stronger cell walls.
Because they eat Wheaties.
Because their interiors are subdivided into numerous compartments called organelles.
Smooth ER is likely to be involved in?
garbage disposal
protein synthesis
energy capture
export of proteins
lipid synthesis
lipid synthesis
According to the endosymbiotic theory, eukaryotes arose by:
bacteria engulfing other bacteria which continued to grow and divide inside their host.
fusion of multiple protobionts to form coacervates with internal liposomes.
DNA spontaneously enveloping itself with lipid bilayer membranes because of the hydrophobic effect.
The incorporation of self-replicating RNA molecules into lipid micelles.
Bacteria failing to separate completely after cell division, resulting in multicellular organisms.
bacteria engulfing other bacteria which continued to grow and divide inside their host.
Which of the following is not found in the cytoskeleton?
actin
microtubules
tubulin
intermediate filaments
cell walls
Cell walls
What happens to the width of the field of view when you change to a lens with a higher magnification?
It gets larger.
It gets smaller.
It stays the same.
It depends upon the microscope that you are using.
It changes color.
It gets smaller.
Why is it necessary to provide a scale for your drawings?
To indicate the size of the circle that you drew.
To identify the important objects in your drawing.
To indicate how large the objects in your drawing really are
To indicate how large the objects in your drawing really are
Compared with a solution of pH 7, a solution of pH 5 has:
1/100 of the hydrogen ion concentration
5/7 of the hydrogen ion concentration
7/5 of the hydrogen ion concentration
2 times the hydrogen ion concentration
100 times the hydrogen ion concentration
100 times the hydrogen ion concentration
What is a buffer?
A chemical which acts as a reservoir for water molecules, donating or absorbing them as needed to keep a cell from getting too wet or dry.
A chemical which polishes other chemicals to prevent them from sticking to water.
A chemical which acts as a reservoir for hydrogen ions, donating or absorbing them as needed to hold the pH constant.
A chemical which acts as a reservoir for neutrons, donating or absorbing them as needed to replace neutrons lost through radioactive decay.
A chemical which acts as a reservoir for oxygen atoms, donating or absorbing them as needed to keep the oxidation state of the cell constant.
A chemical which acts as a reservoir for hydrogen ions, donating or absorbing them as needed to hold the pH constant.
Why is all life based on carbon?
Carbon can form bonds with up to 4 other atoms, and can therefore be built into more complex molecules than any other biologically important element.
Carbon is radioactive, so when it decays it causes the mutations needed for evolution to occur.
All carbon-based molecules can dissolve in water.
All carbon-based molecules are hydrophobic.
Carbon is the most abundant element on earth.
Carbon can form bonds with up to 4 other atoms, and can therefore be built into more complex molecules than any other biologically important element.
You have just identified a new antibiotic which prevents bacteria from forming dehydration reactions. Which macromolecules will this prevent bacteria from making?
Carbohydrates
Lipids
Proteins
Nucleic acids
All of the above
All of the above
The final shape of a protein such as hemoglobin which is composed of multiple subunits is an example of
primary structure
secondary structure
tertiary structure
quaternary structure
antiquated structure
quaternary structure
Which of the following components are to nucleic acids what R-groups are to amino acids?
Sugar
Sugar-phosphate
Purine/pyrimidine
3’ OH E. Nucleotide
Purine/pyrimidine
What holds the two strands of a DNA molecule together?
Hydrogen bonds between A::T and G::C base pairs on the two strands
Covalent bonds between the sugars of one strand and the phosphates of the other
Ionic bonds between the acids on one strand and the bases on the other.
Hydrophobic bonds between the sugars on one strand and the phosphates on the other
Covalent bonds between the purines on one strand and the pyrimidines on the other
Hydrogen bonds between A::T and G::C base pairs on the two strands
Why does the Bradford reagent detect proteins?
Sugars in the protein reduce the Bradford reagent from its oxidized blue form to its reduced violet form.
Sugars in the protein oxidize the Bradford reagent from its reduced blue form to its oxidized violet form.
Bradford reagent breaks proteins into individual molecules which interact with diphenylamine to form a blue color.
Amino groups forming the peptide bonds of the protein backbone react with the Bradford reagent and change it from blue to violet.
Amino groups forming the peptide bonds of the protein backbone react with the Bradford reagent and change it from blue to violet.
Some scientists are more successful than others because:
they are better at guessing which hypotheses to test.
their experiments always confirm their ideas.
they do not need to perform experiments to test their ideas.
they do not keep records of experiments that fail.
they drink more coffee.
they are better at guessing which hypotheses to test.
In the t-test, the null hypothesis is:
A. The two populations are null.
B. The difference between the means divided by the combined standard deviation of the two populations. C. The two populations are significantly different.
D. The t-value divided by the degrees of freedom.
E. There is no significant difference between the two populations.
There is no significant difference between the two populations.
