Lab Midterm Flashcards
(126 cards)
1
Q
what tool(s) will u need to measure the correct amnt of solid material?
A
digital scale, beaker
2
Q
what tool(s) will u need to measure the correct amnt of water?
A
50 mL graduated cylinder
3
Q
SI unit for distance
A
meter
4
Q
SI unit for temp
A
Kelvin
5
Q
you’ve recorded results from an experiment when u weighted the mass of a honey badger that was placed on a restricted diet of cobras every day for one month. You want to graph this weight over time using a line-graph with the independent data on the x axis and the dependent variable on the y axis. what will u label the dependent variable on ur graph?
A
mass of badger
6
Q
u find a pipette in lab that can transfer a maximum of 50ul of liquid. What is the maximum volume expressed in ml?
A
0.05 ml
7
Q
which type of graph would be best for presenting the following data? (line graph or bar graph)
“the population of females in 5 US cities in the Midwest”
A
bar graph
8
Q
which of the following is NOT part of the scientific method?
A
use subjectivity to evaluate experimental results
9
Q
is sample C:
a. reducing or non-reducing
b. monosaccharide or non-monosaccharide
c. non-polysaccharide, branched polysaccharide, or unbranched polysaccharide?
d. galactose, maltose, sucrose, glycogen, or starch?
A
non-reducing
non-monosaccharide
unbranched polysaccharide
starch
10
Q
which of following best describes the rxn that produces a glycosidic bond
A
dehydration synthesis- water molecule is produced in the creation of a bond
11
Q
a plant cell uses __ as an e storage carbohydrate
A
starch
12
Q
Lugol’s iodine reagent reacts with branched polysaccharides which causes a color change from a __ color to a __ color
A
yellow; rust-red
13
Q
sample f contains
A
peptide bonds & 3 amino acids
14
Q
which of the following best describes the secondary structure of a polypeptide?
A
regional 3D structures of a polypeptide
15
Q
the amino acid proline turns the color __ in the presence of 2 molecules of ninhydrin during a TLC experiment
A
yellow
16
Q
which of the following is NOT a reactant or product in the dehydration synthesis of a peptide bond?
A
enzyme
17
Q
the blue-black color result in the Biuret test is a __ for peptide bonds
A
negative
18
Q
in which situation does the enzyme operate over a larger (wider) temp range?
A
from hot springs. relative activity is higher over a larger range of temperatures when compared to humans
19
Q
what is the optimum temp for the enzyme operating the hot springs situation?
A
90ºC
20
Q
in which of the two types of bacteria (living in acidic pools or soil-dwelling) would chitinase exhibit greater activity when the bacteria are placed in a solution of lemon juice (pH 3)?
A
acidic pools
21
Q
an enzyme substrate fits into the ___ of the enzyme like a key fits into a lock
A
active site
22
Q
the name of the enzyme used in the enzymes labs is __ the reaction it catalyzes results in the production of glucose and __
A
sucrase; fructose
23
Q
T or F when an enzyme is denatured, the tertiary structure is affected
A
true
24
Q
in thin-layer chromatography experiment, a polar solvent is used for the mobile phase and the stationary phase is non-polar. Two spots are observed, spot A has an rf value of 0.8 and spot B has an rf value of 0.2. which spot (A or B) is more non-polar?
A
spot B
25
copper is an active ingredient in the __ reagent of the Biuret test
benedict's
26
what tool(s) will u use to divide the solution into 5 equal parts and transfer it to the 5 test tubes?
graduated cylinder (10mL)
27
what tool(s) will u need to measure the correct amount of indicator?
fixed volume micropipettes (5 ul to 10ul)
28
give 2 reasons the metric system is used in science
- it is universal
| - easy to convert from one thing to another
29
convert 35 km-> __ m
35000
30
convert 425m -> __ mm
425000
31
SI unit for mass
grams
32
give 2 functions of carbohydrates in the body
- e storage
| - structural components
33
T or F: the basic chemical structure for a carbohydrate can be written as (CH2O)n
true
34
T or F: amylose is an unbranched polysaccharide that forms an alpha-helix in water
true
35
3 unknown amino acids (AA) produce a chromatograph with a non polar solvent. their rf values are as follows: AA1=0.1, AA2=0.45, AA3=0.75. what can be inferred regarding their polarity (which is most or least polar)? how might that make their rf values different
```
1+0.75+0.45+0.10= 1.30
0.1/1.3=.077
.45/1.3=.35
**0.75/1.3=0.58**
most polar is closer to the top
```
36
SI unit for volume
liters
37
T or F: pie charts are used to plot measurements taken over time
false
38
T or F: the independent variable depends on the dependent variable
false
39
is sample A fructose, lactose, sucrose, glycogen, or starch?
| iodine test: (-)
sucrose
40
is sample B fructose, lactose, sucrose, glycogen, or starch?
| iodine test: yellow
fructose
41
how does the Benedict's reaction work?
the Benedict's rxn indicates a color change from blue to green, to yellow, to orange, to red or no color change at all. It tests for the presence (red) or absence (blue) of a reducing sugar. the positive rxn takes place when Cu2+-> Cu1+
42
T or F: water is added during a dehydration rxn
false
43
how are amino acids chemically different from other biomolecules?
they have an amino group attached to the alpha carbon, have peptide bonds, and have an R group that makes them distinguishable from each other
44
what is the basic chemical composition of a monosaccharide?
(CH2O)n
45
what tools will u need to set up a boiling water bath?
erlenmeyer flask, 100mL beaker, hot plate and a thermometer
46
the components of the TLC are carried by a __ phase which separates the molecules according to their interactions with the __ phase
mobile; stationary
47
is sample C fructose, lactose, sucrose, glycogen, or starch?
| iodine test: black
starch
48
__ is an example of an unbranched polysaccharide
amylose
49
__ is an example of a highly branched polysaccharide
glycogen
50
a peptide bond is formed between the __ group of one aa and the __ group of another
carboxyl; amino
51
in the Sudan IV test for lipids, the sample had a clear layer and a red layer
results because this sentence says the data that was collected
52
triglycerides are formed thru dehydration synthesis of glycerol with three fatty acids
introduction bc this sentence provides background info
53
t or f: when doing an assay, u would make a prediction; when doing an experiment, u would formulate a hypothesis
true
54
lipids perform many functions in biological organisms, including e storage, insulation, hormone formation and structural component of cell membranes
intro bc it states background info on lipids and background info always goes in the introduction
55
in the discussion section, do we draw our conclusions from the results of the experiment or from our initial hypothesis?
in the discussion section, we restate the hypothesis and say if it is correct or not. Then using the results, we explain why or why not it was right or wrong
56
I've designed my experiment to include a positive control in which I add Benedict's reagent to a solution containing glucose. How can I use this same idea to include a negative control? where in the lab report would I include this info?
u can add Benedict's reagent to a non-reducing sugar like sucrose to have a negative control. U would include this in the materials and methods section in the lab report
57
since the sample did not leave a translucent, oily spot on the paper and dissolved in water, it was determined that the sample was not a lipid
discussion bc it is explaining why something happened
58
a student decides to use a quote from the lab manual in the introduction section of their lab report. what 3 things will this student have to do to make sure they are not accused of plagiarism?
- reference the author in text
- cite the reference in works cited
- in text citations (parenthesis around quote)
59
in which situation (inside humans or from hot springs) does the enzyme operate over a smaller (narrower) temperature range?
inside humans the enzymes operate at a smaller (more narrow) range. It operates @ 25ºC-65ºC while hot springs operate at 40ºC-95ºC
60
what is the optimum temp for the enzyme operating in the human body (include units)?
40ºC
61
in which of the 2 types of bacteria (living in acidic pools or soil-dwelling) would chitinase exhibit activity when the bacteria are placed in seawater (pH 8)?
chitinase from soil-dwelling bacteria
62
which data set below best fits chitinase from acidic pool bacteria?
data set Z
| 100,92,90,...
63
enzymes affect rxn rate by __ the activation e
decreasing
64
an enzyme's function is determined by its
shape of the enzyme that results from a, b, and c
65
describe what happens when an enzyme is denatured. It is usually reversible?
when an enzyme is denatured it is unable to perform its normal functions
66
T or F: the suffix for enzymes is -ase
true
67
T or F: enzymes are most often proteins at the secondary structural level
true
68
in which situation (inside humans or from hot springs) does the enzyme operate over a larger (wider) temp range?
from hot springs. Relative activity is higher over a larger range of temperatures when compared to humans
69
what is the optimum temp for the enzyme operating the hot springs situation?
90ºC
70
in which of the 2 types of bacteria (living in acidic pools or soil-dwelling) would chitinase exhibit greater activity when the bacteria are placed in a solution of lemon juice (pH 3)?
acidic pools
71
which data set below best fits chitinase from soil-dwelling bacteria?
data set Y
| 50, 62,78,...
72
an enzyme substrate fits into the __ of the enzyme like a key fits into a lock
active site
73
the name of the enzyme used in the 'Enzymes' lab is __; the rxn it catalyzes results in the production of glucose and __
sucrase; fructose
74
T or F: when an enzyme is denatured, the tertiary structure is affected
true
75
which data set below best fits the bacteria living in humans?
data set X
| 62,100,92,..
76
the temp at which an enzyme displays the highest activity is the __ temp
optimal
77
sucrase catalyzes sucrose into its 2 component molecules: __ and ___
sucrose; fructose
78
describe 2 factors that can denature proteins and what happens to an enzyme's structure when this occurs
pH and temp can denature proteins. The enzyme's structure begins to unfold and lose its shape
79
T or F: protein denaturation is always permanent
false
80
T or F: an enzyme is used up during a chemical rxn
false
81
what is the correct order of steps for the ELISA procedure listed below?
a. unbounded secondary antibody washed from wells
b. antigen added to wells
c. primary antibody added to wells
d. results are determined
e. color-producing enzyme added to wells
f. unbounded primary antibody washed from wells
g. secondary antibody added to wells
h. unbounded antigen washed from wells
b, h, c, f, g, a, e, d
82
ELISA lab: a positive result (+) (antigen present in well) is __ (-) ; a negative result (antigen not present) is ___
blue; colorless
83
what does ELISA stand for
enzyme-linked immunosorbent assay
84
ELISA: color detection occurred because the enzyme reacted with the substrate attached to the __
antigen
85
ELISA: name 2 antibody-based tests that u can buy at ur local pharmacy
- drug test
| - pregnancy test
86
ELISA: how would u interpret the following results? what are some possible reasons that student B's wells were not the same?
student A's wells tested (+). 2/3 of student B's wells tested (-) while one tested (+). This could be due to possible error when washing the wells.
87
which of the following is the most likely result if u skipped the addition of primary antibodies during the ELISA procedure when there is an antigen in the well?
false negative
88
which reagent of the ELISA assay contains enzymes
secondary antibody solution
89
assay
a test used to determine the presence or absence of a substance or its properties
90
monosaccharide
one structural unit
91
disaccharide
two structural units
92
polysaccharide
more than two structural units
93
what is the basic formula for disaccharides?
C12H22O11
94
what is the basic formula for polysaccharides
(C6H1O5)n
95
branched polysaccharides
glycogen, amylopectin
96
unbranched polysaccharides
amylose (starch), cellulose
97
Benedict's test: non-reducing carb
reactive aldehyde/ketone is part of bond formed in dehydration
and cannot react with
Benedict’s reagent
**blue color
98
Benedict's test: reducing carb
aldehyde/ketone is not part of bond, can react with Benedict’s reagent, reducing the copper from 2+ to 1+ (Cu2 -> Cu1+)
**rust-red color
99
monosaccharides: 3 C
triose
100
monosaccharides: 5 C
pentose (ribose)
101
monosaccharides: 6 C
hexose (glucose, galactose, fructose)
102
Barfoed's test: negative
pure blue, no precipitate
103
Barfoed's test: positive
dirty blue with dash of dark color (red)
104
lugol's iodine test: negative
yellow/orange (no polysaccharide)
105
lugol's iodine test: positive -branched
light brown (glycogen)
106
lugol's iodine test: positive -unbranched
dark blue (starch)
107
antigens
large molecules, often proteins, found on the surface of cells and some non-living substances, such as toxins and foreign particles, that help to identify that organism or substance.
108
antibodies
specialized proteins produced in response to the presence of antigens. The “Y” tips of the antibody are designed to be specific to a particular antigen, so they will only recognize and bind to that antigen
109
steps of ELISA lab
1) antigen binds to the surface of the well
2) primary antibody binds to antigen
3) secondary antibody binds to primary antibody
4) enzyme with colorimetric agent binds to secondary antibody
110
why is it important to wash the wells between each step?
to remove any unbound proteins/antibodies and to eliminate the chance of getting a false positive or a false negative
111
conversion trick
```
K H D b D C M
king henry died by drinking chocolate milk
km, hm, Dm, base unit (m, L, g), cm, mm
kilo: 1000
hecto: 100
deca: 10
U: unit
deci: 0.1
centi: 0.01
milli: 0.001
*micro: 0.000001 or 10^-6
*nano: 0.000000001 or 10^-9
```
112
Benedict's test for __
reducing sugars
113
Barfoed's test for __
monosaccharides
114
Lugol's iodine test for __
polysaccharides
115
what are the 4 major forms of organic molecules?
1) fats
2) proteins
3) carbohydrates
4) nucleic acids
116
proteins and aa contain..
- N
- C
- H
* some have S
117
amino acids
- have a carboxyl and amino group
- have a distinguishable R group
- have an alpha C
118
rf value
number where line is / final number
119
3D protein structure binds __ so rxn can occur more easily
substrate
120
what happens when a protein is denatured?
its secondary, tertiary, and quaternary structures can be disrupted by temp, pH, and other chemicals and conditions
121
can protein denaturation be reversed?
yes often times, once the influencing condition has been removed
122
optimal conditions of enzymes
- human mouth, stomach, and small intestines
| - bacteria that live in extreme environments like hot springs
123
primary structure
sequence of amino acids
124
secondary structure
interaction of groups in the peptide backbone
ß-sheet
a- helix
*regional 3D structure
125
tertiary structure
final folded shape of a globular protein
- Stabilized by a number of forces
- Final level of structure for proteins consisting of only a single polypeptide chain
126
quaternary structure
arrangement of individual chains (subunits) in a protein w/ 2 or more polypeptide chains
