Chem/Phys Flashcards
Explain the difference between the speed of a wave that travels through different mediums for sound waves versus light waves.
First, the speed of a wave is largely determined by the medium in which it travels. Light waves tend to travel slower in more dense mediums, but sound waves follow the opposite trend, traveling faster in denser mediums and more slowly in less dense mediums. Therefore sound wave travels fastest in the solid state.
What is the structural difference between gram negative and gram positive bacteria?
The only structural difference between the two is that gram negative bacteria have an outer membrane whereas gram positive do not.
All Gram positive and Gram negative bacteria have peptidoglycan in their cell walls.
What are some ways you can manipulate the magnitude of current?
Since V = IR, the current and the resistance are inversely proportional to one another. Thus, to increase I, one must make a change that decreases R.
Resistors in parallel always have total resistance values lower than the lowest resistor in parallel (1/Rtotal = 1/R1 + 1/R2), so adding another resistor in parallel will decrease the resistance by allowing an alternative pathway for current.
If you added another resistor in series, the total resistance will increase since resistors in series add together and the total resistance is always larger than the largest resistor in series (Rtotal = R1 + R2). Therefore, this change would increase resistance, and therefore decrease current.
Thinner wires cause more resistance (and thicker gauge wires cause less resistance).
If you remove the resistors entirely and create an open circuit, you will have zero current because current can only flow through a closed circuit.
Explain the relationship between the Bernoulli effect and the Venturi effect.
The Venturi effect describes the decrease in fluid pressure that is observed when a fluid in a pipe passes through a narrow or constricted section and fluid velocity increases. This is explained by Bernoulli’s equation, and so it is sometimes called the Bernoulli effect.
Explain the roles of Fatty acyl-CoA, acyltransferase, and Glycerol-3-phosphate in fatty acid synthesis.
The synthesis of a triacylglycerol molecule requires three fatty acids, which are bonded to a glycerol backbone via three ester linkages.
Fatty acids are long chain carboxylic acids and fatty acyl-CoA is a fatty acid bonded to CoA.
Glycerol-3-phosphate serves as the glycerol backbone structure during triacylglycerol synthesis.
Acyltransferase is the enzyme that is used to transfer a fatty acid from CoA to the glycerol backbone.
Explain the mnemonic PRI and NVU.
A positive lens is convex (converging), which means that the focal point is behind the lens, creating a real image. For single lens systems PRI and NVU always go together; which are acronyms for Positive, Real and Inverted, and for Negative, Virtual, and Upright. Once you can definitively determine one of these characteristics, you can predict that the other variables will be those in the same pair: PRI or NVU.
Explain what you would see on a Lineweaver-Burke plot for each of the types of inhibition
Competitive inhibition: the inhibited and uninhibited curves share the same Y-intercept, the X-intercept gets closer to 0 (Km increases).
Noncompetitive inhibition: the uninhibited and inhibited curves would have the same X-intercept, the Y-intercept increases (Vmax decreases).
Uncompetitive inhibition: the inhibited and uninhibited curves would be parallel (Both Km and Vmax decrease).
Mixed inhibition: the intercept of the two curves would be on neither the x-axis nor the y-axis (they do not intersect at the line on the axis).
