Biology Of The Cell Lab Mid Term Exam

Front 1

how would you determine the thickness of a rectangle?

Back 1

LxWxH=cm^3,
Density=M/V,
V = mL = cm^3

Front 2

Given the mass of an object, can you find its density with a beaker and some water?

Back 2

Yes
Density=M/V
measure volume of water before adding object and after adding object. subtract difference. that is your volume value.

Front 3

what is density measuring?

Back 3

Density=M/V
find mass, measure volume
get Density

Front 4

what is the importance of trials?

Back 4

decrease the % of error

Front 5

what is a dependent variable?

Back 5

vertical axis
masses
variable that has no change

Front 6

what is an independent variable?

Back 6

horizontal axis
volumes
variable being measured

Front 7

what is a standard curve? name two ways we have used a standard curve this year.

Back 7

a method of plotting assay data that is used to determine the concentration of a substance.
1.best fit line
2.trindline

Front 8

what are carbohydrates chemically made of?

Back 8

composed primarliy of the elements carbon, hydrogen, and oxygen at a ratio of 1:2:1

Front 9

what are lipids chemically made of?

Back 9

like carbohydrates, made of elements carbon, hydrogen, and oxygen but oxygen is present at a much lower ratio.

Front 10

what are proteins chemically made of?

Back 10

contain carbon, hydrogen, and oxygen, but also nitrogen and some contain sulfur

Front 11

what are some differences between monosaccharides and polyaccharides?

Back 11

monosaccharides are simple sugars and polysaccharides are many sugars liked together.

Front 12

what is the difference between saturated and unsaturated fatty acids?

Back 12

if the carbon atoms in a chain are bonded to one another by a single covalent bond it is saturated.
if some carbons are connected by a double covalent bond is unsaturated.

Front 13

what are some examples of lipids?

Back 13

linoleic acid, steroids, and waxes

Front 14

what are the monomers of carbohydrates?

Back 14

sugars

Front 15

what are the monomers of lipids?

Back 15

fatty acids

Front 16

what are the monomers of proteins?

Back 16

amino acids

Front 17

what is the structure of amino acids?

Back 17

H
H2N-C-COOH
R

Front 18

what is a positive control?

Back 18

is obtained by performing the test under conditions known to always produce the phenomenon (known to contain the substancefor which the test is specific)

Front 19

what is a negative control?

Back 19

is obtained by performin the test under conditions known not to produce the phenomoneon (known not to contain the substance for which the test is specific)

Front 20

how have we used positive and negative controls this year?

Back 20

to determined the presence of a particular substance in an unknown mixture

Front 21

why are positive and negative controls necessary?

Back 21

so that when we test an unknown, we can then compare the results obtained with those obtained with (+) and (-) controls. if the result from the unknown resemble those of the (-) control, we can assume the the category of chemical is not present. if the results resemble the (+) control that class of chemicals probably is present.

Front 22

what is the pH scale actually measuring?

Back 22

the concentration of hydrogen ion in a solution.

Front 23

what happens to an acid when it is added to solution?

Back 23

it caused the pH of a solution to decrease and increased hydrogen acid

Front 24

what happens to a base when it is added to a solution?

Back 24

it causes the pH of a solution to increase.

Front 25

how do the pH scale determine relative concentrations of hyrogen ions?

Back 25

if hydrogen ion concentration is 1x10^-5, pH is 5. 8 has 10x more concentration than 9 and 100xs more than 10.

Front 26

what pH is considered neutral? Acidic? Basic?

Back 26

1-6.9 = acidic
7 = neutral
7.1-14 = basic

Front 27

Methyl orange solution is what color?

Back 27

orange

Front 28

methyl orange solution changes to what color in an acidic solution?

Back 28

red

Front 29

methyl orange solution changes to what color in a basic solution?

Back 29

lighter red

Front 30

brom thymol solution is what color?

Back 30

blue

Front 31

brom thymol solution changes to what color in a acidic solution?

Back 31

yellow

Front 32

brom thymol solution changes to what color in a basic solution?

Back 32

navy blue

Front 33

phenophthanlein solution is what color?

Back 33

clear

Front 34

phenophthanlein solution changes to what color when in an acidic solution?

Back 34

cloudy clear

Front 35

phenophthenlein solution changes to what color when in a basic soltuion?

Back 35

fuschia

Front 36

brom thymol solution changes to what color at pH of 7?

Back 36

green

Front 37

what are the colors of a universal indicator dye at pH levels of 1,3,5,7,9,11,13?

Back 37

1:red
3:orange
5:yellow
7:green
9:dark blue
11:blue
13:purple

Front 38

what is a pH meter and how does it work?

Back 38

the pH meter is a voltmeter designed to measure the voltage difference between a reference electrode and a sensory electrode. the reference electrode usually contains silver chloride solution of known consentration. the pH meter is calibrated so that a certain difference between the voltages between silver cholride and the test solution reads a certain pH value.

Front 39

what is a spectrophotometer and how does it work?

Back 39

An instrument for measuring the intensity of light of a definite wavelength transmitted by a substance or a solution, thus providing a measure of the amount of material in the solution absorbing the light.

Front 40

what is absorbance?

Back 40

the capacity of a substance to absorb radiation, expressed as the common logarithm of the reciprocal of the transmittance of the substance.

Front 41

what is transmittance?

Back 41

the fraction of radiant energy that passes through a substance

Front 42

how do you measure enzyme kinetics?

Back 42

you add an enzyme plus a substrate, which produceds an enzyme-substrate complex, which then produces and enzyme and a product. to stop this reaction you add in another solution. do this at different times, then use a spectrophotometer to determine the absorbance. you can measure the velocity of the reactions and then determine the amount of enzyme extract.

Front 43

define rate.

Back 43

a certain quantity or amount of one thing considered in relation to a unit of another thing and used as a standard or measure. (velocity)

Front 44

define enzyme.

Back 44

proteins that accelerate the velocity of virtually all reactions that ocur in biological systems.

Front 45

how are enzymes named?

Back 45

are denoted by the name of the substrate that is acted upon and the suffix -ase.

Front 46

define substrate.

Back 46

refers to the compound that is acted upon by the enzyme.

Front 47

define active site.

Back 47

the region of an enzyme surface to which a substrate molecule binds before it undergoes a catalyzed reaction.

Front 48

define activation energy

Back 48

extra energy that must be acquired by a molecule in order to undergo a particular chemical reaction.

Front 49

for our experiment designate spectifically what E, S, and P are in this reaction:
E+S->ES->EP->E+P

Back 49

E= enzyme
S= substrate
P= product

Front 50

as a forward reaction progresses, what happens to S and P relatively? and what happens to E?

Back 50

S decreases
P increases then levels out.
E stays the same

Front 51

what are some variables that can effect enzyme kinetics?

Back 51

amount of enzyme in reaction, temperature and pH levels

Front 52

what variables did we manipulate in class ans how did they affect our reaction?

Back 52

temperature
generally as the temperature decreased the reaction slowed causeing the product to decrease.

Front 53

what variable effecting enzyme kinetics did we not manipulate?

Back 53

the pH levels

Front 54

understand the initial velocity and be able to explain how it is calculated.

Back 54

initial velocity is the early time interval when the amount of produt is increasing in a linear manner.
it is the slope of the linear portion of the curve.
nmoles2-nmole1/time2-time1

Front 55

what is the chemical reaction acid phosphatase performs and what are the bi-products of our reaction?

Back 55

acid phosphatase catalyzes the removal of phosphate groups from macromolecules and smaller molecules that are sotred in the wheat seed.
Bi-products: phosphate and nitrophenol

Front 56

what are the two types of DNA sequencing output we looked at in class?

Back 56

autoradiograph and chromatograph

Front 57

what is BLAST and how did we use it?

Back 57

BLAST is an online database that has DNA sequences. we used it to compare our DNA sequences to other sequences in the nucleotide database

Front 58

how do you read a autoradiograph?

Back 58

left to right, bottom to top.

Front 59

what are the 1', 2', 3' and 4' of protein stuctures?

Back 59

1' = individual order
2' = curves sturcture
3' = (+) end curves around near (-) end
4' = multiple polypeptides

Front 60

what function did KOH play in our enzyme experiment?

Back 60

stopped reaction and provided a basic solution for nitrophenol to turn yellow