Chem/Phys

Question 1

an individual with dry skin with a resistance of 10ˆ4 Ω comes in contact with a high voltage DC current. to rescue the individual, another person with wet skin makes contact with the first, forming a parallel connection. consequently, the time required for 10 C of charge to exit the power source will:

Answer 1

decrease

wet skin will have a lower resistance

adding resistors in parallel decreases the overall resistance of a circuit which will cause the total current passing through the circuit to increase

current = Δcharge/Δtime so if the current increases, the time must decrease

Question 2

what is current?

Answer 2

Δcharge/Δtime

Question 3

what does adding resistors in parallel do?

Answer 3

adding resistors in parallel decreases the overall resistance

this causes an increase in total current

Question 4

what elements are best for conducting electricity? why?

Answer 4

elements with metallic character are best for conducting electricity and lower resistance to help shock better

Question 5

what is the equation for blood pressure?

Answer 5

BP = CO * total peripheral resistance

BP = P(systolic) - P(diastole)

Question 6

what is a ketal?

Answer 6

R
          |
RO -  C - OR
          |
         R

stable in basic solution

Question 7

how can you form a ketal?

Answer 7

a carbonyl group is reacted with an alcohol (diol)

Question 8

what does LAH do?

Answer 8

lithium aluminum hydride reduces

it will reduce an ester group to an alcohol and would also reduce a keno to an alcohol

Question 9

how can you activate a carboxyl group?

Answer 9

reacting it with SOCl2

the chlorine atom would replace the COOH hydroxyl group and produce an acyl chloride

acyl chloride is the most reactive carboxylic acid derivative

Question 10

what would happen if you react a carboxyl group with excess alcohol and HCl?

Answer 10

you would end up replacing the hydroxyl group by an alkoxide group (RO)

Question 11

what’s an alkoxide group?

Answer 11

OR

Question 12

what kind of environment is a cell membrane?

Answer 12

hydrophobic

Question 13

if the graph of radioactive decay was transferred to logarithmic graph paper, what would the result be?

Answer 13

a straight line with a nonzero slope

Question 14

what is ionizing an auto?

Answer 14

when sufficient energy is absorbed to remove an electron from an atom

hello ionization energy!

Question 15

MRI subjects hydrogens in tissues to a magnetic field and in response the protons emit radio frequency radiation which is imaged as bright area. what tissue is least likely to show up as a bright region in an MRI scan?

Answer 15

femur

MRI images protons

protons in biological tissues are found in water so which tissue would have the lowest water content?

soft tissues like internal organs and muscles have high water content than bones

Question 16

what is the log of 1000?

Answer 16

3

10ˆ3 = 1000

Question 17

what is power?

Answer 17

power = intensity*area

power = energy/time

watts* mˆ2

Question 18

what is the doppler effect?

Answer 18

the idea that the speed of both the source and detector of a wave will influence the perceived frequency of that wave

Question 19

what affects the intensity of a sound wave experienced by a detector?

Answer 19

the surface area of the detector and its distance from the source

Question 20

what will affect the frequency of sound waves traveling through the air as measured by a detector?

Answer 20

speed of the source of the sound

the doppler effect

Question 21

how do you write the electron configuration of a cation?

Answer 21

remove electrons beginning with the highest principal quantum number!!

ex. Ar(3d10) as a +2 cation would be [Ar]3d10

Question 22

what is a Lewis base? lewis acid?

Answer 22

an electron donor

ex. glutamate is an electron donor, Zn+2 is an electron acceptor and would be a lewis acid

Question 23

what is electrostatic form?

Answer 23

different atoms will experience different electrostatic force from some outside electric field because they carry different charges

Question 24

what’s the conversation between lnx and logx?

Answer 24

lnx = 2.3logx

Question 25

what is the relationship that relates G and Keq?

Answer 25

ΔG = -RTlnK

Question 26

how could you measure the resistance of the human body?

Answer 26

have a subject hold the positive terminal of a known voltage source with one hand and the negative terminal with the other hand while the physiologist measures the current

Question 27

what is a bronsted-lowry acid?

Answer 27

donates protons

Question 28

what is a bronsted lowry base?

Answer 28

accepts protons

Question 29

what happens at the equivalence point of a titration of an acid and base?

Answer 29

equivalents acid = equivalents base

Question 30

what do you need to determine the equivalence point during a titration?

Answer 30

an indicator

the pKa of the indicator should be +/-1 the pH at the equivalence point or else the end point won’t accurately tell you the equivalence point

Question 31

units of torque?

what is the force equal to at rotational equilibrium?

Answer 31

N•m

T = rFsinθ
F = T/rsinθ
F = mgl/rsinθ

l: length of arm

Question 32

what is arachidonic acid?

Answer 32

a fatty acid

it has a carboxylic acid head with a long aliphatic tail

Question 33

what happens when you combine a carboxylic acid and HN3 and the decarboxylate the intermediate?

Answer 33

NH3 = amine

Question 34

what’s an amine?

Answer 34

NH3

Question 35

what’s nitrate?

Answer 35

NO3

Question 36

what’s nitrosyl?

Answer 36

NO - M

NO bonded to transition metal

Question 37

what would a decrease in cross sectional area of a vessel result in?

Answer 37

increased resistance so blood flow decreases

Question 38

how does the speed of sound waves change for different tissues?

Answer 38

a sound wave will travel faster in muscle than in blood

sound is a mechanical wave that relies on molecular collisions for propagation so it would travel fastest in solids where molecules are closes together and slowest in gases

Question 39

what can contribute to the hydrophobic nature of surfactant in the lungs?

Answer 39

both phospholipids and proteins can contribute to its hydrophobic properties

phospholipids have two hydrophobic fatty acid chains

proteins can have hydrophobic side chains

Question 40

how do you convert between normality and molarity?

Answer 40

if you know the molarity, you can convert to normality by multiplying the molarity * number of hydrogens or hydroxide ions in the acid or base

Question 41

what is a colloid?

Answer 41

a suspension of particles that are larger than the size of an individual molecule

light shone through a colloidal mixture will be scattered

ex. muddy water

Question 42

what AA form disulfide bonds?

Answer 42

cysteins can be reduced to cystitines

Question 43

organic vs. inorganic acids?

Answer 43

organic acid: only carbon and hydrogen (ex. acetic acid)

inorganic acid: mineral acids (ex. HCl, H2SO4, HNO3)

Question 44

what are the colors of visible light in the order of increasing energy and frequency?

Answer 44

(low) ROYGBIV (high)

infrared is lower than red in energy

untraviolet is higher than violet in energy

Question 45

malonyl-CoA is produced from acetyl CoA through the action of acetyl-CoA carboxylase. what are the byproducts of this reaction?

Answer 45

ADP + Pi

a carboxylase enzyme adds a CO2 molecule to acetyl-CoA so CO2 can’t be a byproduct

Question 46

how does the lipid composition in animals change during hibernation?

Answer 46

animals want to maintain membrane fluidity when temperatures are low

so they’ll replace saturated fat acids that pack well with unsaturated fatty acids

Question 47

is palmitic acid saturated or unsaturated fatty acid?

Answer 47

saturated

palm tree = skinny, saturated, no kinks

Question 48

is linoleic acid saturated or unsaturated fatty acid?

Answer 48

unsaturated

line, it’s not a line….unsaturated….