Decomposition of Large Molecules Flashcards
(126 cards)
1
Q
composed of repeating units/subunits or long chains of smaller molecules
A
large molecules
2
Q
large molecules have high ___ __
A
molecular weight
3
Q
examples of large molecules
A
proteins
nucleic acids
lipids
polysaccharides
4
Q
functions of large molecules
A
cell structure
cell function
information storage and flow
5
Q
A
6
Q
Macromolecules as components of cellular
structures example
A
cytoskeleton protein
RNA and DNA
Cell wall of bacteria
phospholipid bilayer
7
Q
Macromolecules as functional elements of
physiological responses
examples
A
lipids - hormones
carbohydrates - glycoproteins/glycolipids
flagella
8
Q
Are large molecules from the ambient readily used by
microbial cells?
A
No, large molecules from the ambient environment are not readily used by microbial cells due to
-size barrier (polysaccharides or proteins cannot easily diffuse across bacterial cell membrane), –
-enzymatic breakdown required, t—transport limitations
-energy considerations
9
Q
- Protein derived from collagen
A
gelatin
10
Q
the structural protein found in animal connective tissues, skin, tendons, and bones.
A
collagen
11
Q
gelatin is obtained through partial ___of collagen, breaking it down into smaller peptide chains while preserving its ability to gel.
A
hydrolysis
12
Q
This form of processed collagen undergoes further enzymatic hydrolysis, breaking proteins into smaller peptides and amino acids. It is more soluble in water and does not gel, making it easier for the body to absorb.
A
collagen hydrosylate
13
Q
characteristic of gelatin
A
tasteless
odorless
colorless (or yellowish)
soluble in polar solvents
14
Q
gelatin is soluble in __ solvents
A
polar
15
Q
Fatty, Waxy, or Oily compounds
A
lipids
16
Q
examples of lipids
A
fats and oils
phospholipids
waxes
steroids
17
Q
are a broad class of biomolecules primarily composed of carbon, hydrogen, and oxygen, with functions ranging from energy storage to structural components in cells
A
lipids
18
Q
Triglycerides composed of glycerol and three fatty acids.
A
fats and oils
19
Q
are solid at room temperature (e.g., butter, animal fat).
A
fat
20
Q
are liquid at room temperature
A
oil
21
Q
Lipids containing a phosphate group, glycerol, and two fatty acid tails.
A
phospholipid
22
Q
Lipids with long-chain fatty acids linked to alcohol groups.
A
waves
23
Q
Water-resistant protective layers in plants
what example of waves
A
cuticle
24
Q
Found in leaves, fruit skins, and animal secretions for waterproofing.
A
waves
25
lipids characterized by a four-ring structure.
steroids
26
exmaple of steroid hormones
testosterone
estrogen
27
Liquid food produced by mammals
milk
28
is the major protein in bovine milk
casein
29
Tests for enzyme production
(2)
gelatinase
lipase
30
rxn of gelatinase to gelatin
gelatin > polypeptides
H2o and Gelatinase
31
further rxn of polypeptide and gelatinase
polypep > amino acid
H2o gelatinase
32
o Peptone 5.0 g/liter
o Beef extract 3.0 g/liter
o Gelatin 120.0 g/liter
▪ Final pH: 6.8 ± 0.2 at 25°C
what medium
nutrient gelatin medium (NGM)
33
What will a gelatinase + microbe do to NGM?
A gelatinase-positive microbe will hydrolyze gelatin in Nutrient Gelatin Medium (NGM) by breaking down its protein structure into smaller peptides and amino acids.
34
positive gelatinase test
liquefied gelatin
35
Medium for isolation of
lipolytic bacteria
Sierra's medium with tween 80
36
The medium contains lipids (usually Tween 80, an oleic acid ester), serving as a substrate for lipase-producing bacteria.
sierra's medium with tween 80
37
oleic acid ester
tween 80
38
Bacteria that produce lipases hydrolyze Tween 80 into
free fatty acid
39
is a polyoxyethylene sorbitan monooleate and acts as a lipid source.
tween 80
40
Lipase-positive bacteria break down Tween 80 via esterase activity, releasing
oleic acid
41
positive lipase test
halo or opacity change
42
is a differential microbiological test used to observe multiple metabolic
activities of bacteria in a milk-based medium containing litmus dye.
litmus milk test
43
The litmus milk test is a differential microbiological test used to observe multiple metabolic
activities of bacteria in a milk-based medium containing
litmus dye
44
* It is especially useful for identifying lactic acid bacteria, Clostridium spp., and other
fermentative organisms.
litmus milk test
45
litmus reduction differentiates what from other bacteria
enterobacteriaceae
46
Some microorganisms can utilize large molecules as source of
nutrients for energy and growth by synthesizing )___that degrade the
complex molecule into simpler compounds.
enzymes
47
, a protein derived from collagen, the connective
tissues of vertebrates
gelatin
48
degrade gelatin to polypeptides
gelatinases
49
Amino acids are
either incorporated into ___ or ___
cell material
source of energy
50
detects the ability of bacteria to produce gelatinases, and
aids in the identification of Serratia, Pseudomonas, Flavobacterium, Bacillus,
and Clostridium
gelatin hydrolysis test
51
he gelatin
hydrolysis test detects the ability of bacteria to produce
gelatinases
52
The gelatin
hydrolysis test detects the ability of bacteria to produce gelatinases, and
aids in the identification of what bacteria
Serratia
Pseudomonas
Flavobacterium
Bacillus
Clostridium
53
In the assay
medium, ___serves as solidifying agent and substrate for gelatinase.
gelatin
54
Hydrolysis of the gelatin results in ___of the medium
liquefaction
55
produced by microorganisms split lipid into glycerol and fatty acid
that can be used as carbon sources for energy and growth.
lipases
56
, free fatty acid is released upon the hydrolysis of Tween 80
what medium
Sierra's medium
57
In the presence of __, calcium oleate is precipitated, forming an
opaque zone under and around the colony in Sierra's medium
Ca2+
58
In the presence of Ca2+, __ ___is precipitated, forming an
opaque zone under and around the colony in Sierra's medium
calcium oleate
59
In the presence of Ca2+, calcium oleate is precipitated, forming an
___zone under and around the colony in Sierra's medium
opaque
60
is a complex nutritional source that contains proteins (mainly
casein) in an aqueous solution of lactose and minerals
milk
61
s added to
detect pH changes that may occur as a result of these enzymatic reactions.
litmus
62
is used primarily to differentiate members within the genus
Clostridium.
litmus milk
63
Litmus milk is used primarily to differentiate members within the genus
clostridium
64
It differentiates Enterobacteriaceae from other Gram-negative
bacilli based on the ability of enterics to reduce litmus
litmus milk test
65
Litmus Milk is also
used to cultivate and maintain cultures of
lactic acid bacteria
66
Litmus milk
has several components that can be metabolized
lactose
casein
litmus
67
. A number of results may be obtained in
the Litmus Milk test, but there are four main reactions
lactose fermentation
litmus reduction
casein coagulation
protein hydrolysis
68
culture media for litmus milk test
litmus milk (LM) tube (sterilize at 10 psi for 10 mins and refrigerate immediately after sterilization)
69
media for gelatinase test
nutrient gelatin (NG) tube (warm the medium before dispensing tubes)
70
media for lipase test
sierra's medium with tween 80
71
is tween 80 separately sterilized?
yes
72
A. Liquefaction of Gelatin
1. Inoculate B. subtilis (+) and E. coli (-) to two tubes of NG. Incubate at
33°C for 48-72 hours.
2. Place tubes in an ___bath for 15 min. If medium in the ice bath is liquid,
gelatin will be liquefied; otherwise, incubate for another week and observe
again
ice
73
A. Liquefaction of Gelatin
1. Inoculate B. subtilis (+) and E. coli (-) to two tubes of NG. Incubate at
33°C for 48-72 hours.
2. Place tubes in an ice bath for 15 min. If medium in the ice bath is ___,
gelatin will be liquefied; otherwise, incubate for another week and observe
again
liquid
74
B. Lipolytic Activity
1. Divide ST plate into two sections. Streak P. aeruginosa (-) and B.
polymyxa (+) to any of the sections.
2. Incubate at 33°C for 48-72 h.
3. Observe for white ___of precipitation around the line of streak of
lipolytic organism.
zone
75
B. Lipolytic Activity
1. Divide ST plate into two sections. ___P. aeruginosa (-) and B.
polymyxa (+) to any of the sections.
2. Incubate at 33°C for 48-72 h.
3. Observe for white zone of precipitation around the line of streak of
lipolytic organism.
streak
76
pink to red color; lactose is fermented to organic acids
inference in litmus milk rxn?
acid pH
77
acid pH indication in litmus milk
pink to red color
78
indication of positive rxn of casein coagulation
hard curd with clear supernatant
79
supernatant when casein coagulates
whey
80
- hard curd with clear supernatant (whey); acidity
increases and curd becomes solid so the clear liquid is squeezed out.
what rxn of litmus milk
acid curd
81
LM + Ca2+
calcium lactat
82
soft curd followed by peptonization due to a renninlike enzyme which clots casein; precipitation of casein which occurs at
neutral pH; breakdown of lactalbumin
rennet curd
83
83
rennet curd - soft curd followed by
____due to a renninlike enzyme which clots casein
peptonization
84
rennet curd - ___curd followed by peptonization due to a renninlike enzyme which clots casein
soft curd
85
precipitation of casein which occurs at
___pH;
neutral
86
precipitation of casein which occurs at
neutral pH; breakdown of ___
lactalbumin
87
clearing of the medium due to hydrolysis of casein
resulting in an alkaline condition (blue or purple) due to release of
ammonia;
peptonization
88
clearing of the medium due to hydrolysis of casein
resulting in what ph
alkaline condition (blue or purple)
89
peptonization - clearing of the medium due to hydrolysis of casein
resulting in an alkaline condition (blue or purple) due to release of
ammonia
90
peptonization - clearing of the medium due to hydrolysis of casein
resulting in an alkaline condition (blue or purple) due to release of
ammonia; with further incubation, milk clears due to further
hydrolysis of casein peptides and amino acids. This occurs at what pH
alkaline
91
hydrolysis of casein makes the supernatant what color
turbid (brown)
92
breakdown of casein by rennin leads to the formation of
paracasein
93
lso called chymosin, is an enzyme found in the stomachs of young mammals (like calves).
rennin
94
bubbles in coagulated milk indicates
gas production
95
formation of a thick, slimy residue at the bottom of the
tube
ropiness
96
- white; litmus is ___by addition of hydrogen or
electrons to the molecules
reduction
97
a pH indicator is incorporated in the medium for the detection of production of acid or alkali and oxidation-reduction activities.
litmus
98
fermentation of lactose in milk with the production of
lactic acid
99
Fermentation of lactose in milk with the production of lactic acid is demonstrated when the litmus turns from blue to ___as a result of acid production.
pink
100
The accumulation of acid acts on casein, resulting in the formation of clots due to the precipitation of casein as ___ ___
calcium caseinate
101
is identified by the clot which remains immobile when the tube is inverted.
acid curd
102
ome bacteria produce rennin enzymes that act on casein and in presence of calcium ions form paracaseinate that is insoluble and is called
rennet curd
103
it is a semisolid clot that will flow slowly on tilting the tube.
rennet curd
104
Some bacteria possess proteolytic enzyme ___and hydrolyze casein.
caseinase
105
casein hydrolysis results in the release of large quantities of ___that makes the medium alkaline with a foul smell, the litmus turns into a purplish-blue.
ammonia
106
asein hydrolysis results in the release of large quantities of ammonia that makes the medium alkaline with a foul smell, the litmus turns into a ___.
purplish blue
107
observe interpreation of litmus milk medium test
+1
108
allow for flagellar-dependent motility (
flagellin
109
movement due to chemical signal
chemotaxis
110
s a supplement derived from cows, primarily from their hides, bones, and tendons.
bovine collagen
111
example of polar solvents gelatin is soluble in
water
ethanol
acetone
acetic acid
112
lipid with ester bonds T
-
bacteria with lipase w/ esterace activity (t)
tween 80
113
check if microbe to degrade casein as AA Source
litmus milk test
114
interpret results
Solid gelatinase test for E.coli
Gelatin is not hydrolyzed; no
gelatinase produced
115
Molten gelatin for B. subtilis
interpret results
Gelatin is hydrolyzed;
gelatinase is produced
116
P aeruginosa lipolytic activity interpret
P. aeruginosa
hydrolyzes the
Tween 80 which
will result in a
visible halo or
opaque precipitate
around the colonies
(an indicator of a
positive result).
Thus, this presence
of halo or
precipitate is an
indicator of lipolytic
activity. Larger
haloes mean higher
activity.
117
B. polymyxa Growth with clear
zone or halo
around colonies, what result for lipase test?
no lipolytic activity
118
E. coli rxn in litmus milk
The medium will appear
medium pink
white color in
lower portion of the tube.
The medium will appear
medium pink, indicating an
acid reaction due to
lactose fermentation.
Additionally, E.coli can
cause litmus reduction
resulting in white color in
lower portion of the tube.
119
b. subtilis litmus milk rxn
purple or blue medium
indicates protein
breakdown and will be
classified an alkaline
reaction
The medium will appear
blue or purple. This
indicates protein
breakdown and will be
classified an alkaline
reaction. B. subtilis causes
peptonization (bacteria
producing proteolytic
enzymes to break down
casein).
120
P. aeruginosa litmus milk test
The medium turned dark
purple or blue
The medium turned dark
purple or blue, indicating
an alkaline reaction.
121
p. vulgaris litmus milk rxn
The upper layer is light
purple or slightly pink,
while the bottom is clear or
pale yellowish
This
indicates that P. vulgaris
does not ferment lactose
or produce clots but
causes an alkaline
response with
peptonization (clearing).
122
Why are some microorganisms capable of liquefying gelatin? What is the
significance of this capability?
Some microorganisms can liquefy gelatin because of a particular enzyme,
gelatinase. Gelatin is protein-derived that originates from collagen, and gelatinase is a
type of protease. These enzymes target and break down the peptide bonds of the gelatin
molecule, which results in the hydrolysis and conversion of the solid gelatin into liquid.
123
Why does a precipitate form on Sierra’s medium when inoculated with a lipolytic
organism?
A precipitate forms on Sierra’s medium when inoculated with a lipolytic organism
due to the enzymatic hydrolysis of Tween 80 by lipase activity. Specifically, lipaseproducing bacteria break down Tween 80 into fatty acids and glycerol, resulting in the
formation of insoluble calcium salts of fatty acids, which appear as a white precipitate
around the colonies. This precipitate is a visual indicator of lipase activity, confirming the
organism's ability to hydrolyze lipids in the medium.
124
What enzymes are being tested in a litmus milk medium?
Several bacterial enzymes, such as lactase, proteases, reductases, and rennin,
are assessed in the litmus milk test. Bacteria naturally produce these enzymes to allow
them to metabolize nutrients, break down proteins, ferment carbohydrates, and perform
other biochemical functions.
For example, Lactase ferments lactose, producing acid and turning the medium
pink in the process. Proteases, on the other hand, break down casein, leading to
peptonization. Reductases reduce litmus, which causes a white color change in the lower
portion of the tube. Lastly, rennin (or any similar coagulating enzyme) causes curd
formation by precipitating casein.
125
G. Will there be a heterotrophic bacterium that cannot utilize milk as a source of
nutrients? Explain your answer
There can be a heterotrophic bacterium that cannot utilize milk as a source of
nutrients. Some heterotrophic bacteria are unable to grow on milk because they lack the
enzymes needed to break down its key components, such as casein, lactose, and lipids.
Because milk is a complex medium, not all bacteria have the metabolic capacity to use it.
Some may require simpler substrates, certain amino acids, or other carbon sources that
are not present in sufficient amounts in milk. Therefore, only heterotrophs with the
appropriate enzymatic capabilities can effectively grow on milk.
