Download FYBSc MIROBTOLoGv pApER U21.. Nov-olG/ qF-SddI

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FYBSc MIROBTOLoGv pApER U21.. Nov-olG/
:3h
qF-SddI
Nucleoside: A nuclcoside consists a nitrogcnous base and a S-carbon sugar cither
ribose or
deoxyribose.
Pleornorphisnr; Pleomorphism is the abitity of some bacteria to alter their shape
or size ln
response to environmental conditions.
True or false :
Peptidoglycan is an example of heteropolysaccharide.-TRUE
Ribosomes are involved in protein secretion-TRUE
Pseudomonas aeruginosa has lleritrichous fl agella.-TRUE
Proteosomes are involved in lipid synthesis.-FALSE
The cell membrane of eukaryotic cell bas cholestercll.-TRUE
Iilacterium possessing PFIB granules. - Bacillus
Fatty acids found in bacterial cell menrbrane.
ll.od shaped ba cterivm.Ps eudomonas
Vaccine developed by Louis pasteur.Anthrax Vaccine
Stmctural Polysaccharide .Chondritin sulphate
Select the most appropriate:
Penicillin was discovercd by FLEMING
A glyoosidio bond is present between two SUGARS
Teichoic acid is present in CELL WALL
I'he smooth andoplasmic reticulurn is involved in syrthesis ofLIpIDS
PHOSPHODIESTER bond is found in nucleic acicls
Q2
i)
acquired
infc
ns .Discuss
es:Page
4-5
ge 8-10
ii)
Discuss in briefthe different {ypes ofnrrcleic acids
DNA & RNA Discuss,compoirents ,structure .
tu,,
Dillerentiate between: Bacterial endospores and vegetative cells.
tle
safe pmctices
tcr
Pts
Composition
Stress resistant
Requires sporulation media fQr growth/normal media for growth
Formation
Structure
examoles
Q3
1201
A
(16
i)
plant and animal diseases,
degradation oforganic
Importance of soil
o
It
Involved innutrient
Decomposition of
Role in microbial
Participate in humus
of microbiology dealing with plant-associated microbes and
deals with the microbiology of soil fertility, such as microbial
soil nutrient transformations.
)
process
components of plant and animal tissuc
Predator to nernatodes
Surface blooming reduceN erosion losses
Improves soil structure
Maintenance of biologica]l equilibrium
gella and Iimbriae
ole of flagella in classification
iD
ll.
Prescott page no 52-53)
lczar)
membrane ol bacteria.(Prescott page no 42-44)
iiD
w)
Do as directed :
B
(4)
Contribution of scientists
I'the
:
Mi
for his work on the
as
Father of
van Leeuwenhoek, Robert Koch
was a Dutch hadesman and scientist. He is commonly
known
, and considered to be the first microbiologist. He is best known
lgoj of .th:microscopeand for his contibutions towards the
. Using his handcrafted microscopes, he was the flrst to observe
i,
he originally refened to as animalcales
(from
...which
Most of the "animalcules"
multicellular organisms in
now referred to
as
unicellular organisms, though he observed
rd water. He was also the firJt to Oocumeii microscopic
bacteria, spermatozoa, and blood flow in capillaries.
Van
books; his discoveries came to light through cone'spondence
with
ted his letteis.
modern bacteriology, he is
of tuberculosis, cholera, and
infectious disease .In additi
physician and pioneering microbiologist. As
the founder of
rwn for his role in identifying the specific causative agents
th11 and.-f91 e1ui"g experimental support for the concept
of
to his trail-blazing studies on these disiases, Koch created
and
microbiology, and made key
discoveries in public health.
h's postulates, a series offour
generalized principles linking
ic diseases that remain today the
'rgold standard" in medical mi
liology.-Koch's early research in this laboratoryproved to yield
one of his major contributions
the field of microbiology, as it was there that [e
developri
technique of growing bactsria. As a result ofhis groundbreaking
research on tuberculosis, Koch
received the Nobel prize in
riology or Medicine in 1905.
tt.
Answer briefly any 2 lout of14l
Explain the decontamination hn<l s
Decontamination is a term usbd to
inskument, or environmental surfa
all forrns of decontamin
dec
Each
apparatus should be
preferred method.
its proper handling.
stored, or discarded. Autoclaving is the
ous material should be responsibie for
Levels of decontamination
The effoctiveness of decontaniinatioa ranges from high-level sterilization to
simple cleaning with
soap and water. Levels olf decbntamination include:
r
o
o
.
Sterilization uses a phy(icalor chemical procedure to destroy all microbial life, including
highly resistant bacierial endospores.
Disinfection uses a liquld chemical to eliminate virtually all pathogenic miqoorganisms,
with the exception ofbapterial spores, on work surfaceJandiquipirent. Effectiveness is
influenced by the kinds_ Nnd.numbers of organisms, the amouni oiorganic matter, the object
to be disinfected, and cb]emical exposue time, temperature, and concentration.
Antisepsis is the applica[ion of a liquid antimicrobial chemical to skin or living tissue to
inhibit or destroy micro$rganisrns. It includes swabbing an injection site on a person or
animal and hand washinp with germicidal solutions. ManufaChrrer reoommendations for
appropriate'se of germilcides should
t-"::I"Till""i;
required stcp
reduces the number of
niicroorgan,r-r.#lt:lilsuch
be
ion
of
as
Methods
are 4 main categories o{physical and chemical means of clecontamination: (l) heat; (2)
liquid disinfectioq (3) vapors [nd gases; and (4) radiation. Each category to be discussed
fhele
Heat sterilization (wet or dry)
Liquid disinfection
Vapors and gases
Radiation (ionizing or non-ionfzing)
Explain the structure and firnc{ion ofchloroplast.
Plastids are cytoplasmic orgfnelles of photosynthetic protists and plants that often possess
pigments such as chlorophylls and carotenoids, and are the sites ofsyrthesis and storage oftooa
re-seryes. The most important type of plastid is the chloroplast.Chloroplasts contain chlorophyll
and use
light energy to conver! CO2 and water t( carbohydrates and 02. That is, they are the siie
ofphotosynthesis. Although cliloroplasts are quite variable in size and shape,they share many
stuctural features. Most often fhey are oval with dimensions of 2 to 4 m by 5 to l0 m, but some
algae possess one huge chlorofllast that fills much of
encompassed by two membranbs.A matrix, the strom
DNA' ribosomes, lipid droplet$, starch granules, and
most prominent components at'p flattened, membrane-delimited sacs, the thylakoids. Clusters of
two or more thylakoids are disfersed within the stroma of most al-gal chloroplasts . In some
photosyrthetic protists, severafi disklike thylakoids are stacked on iach other like coins to form
grana (s., granum).Photosynthttic reactions are separated structurally in the chloroplast just as
electrontransport andthe trica{boxylic acid cycle are inthe mitochondrion. The tapping oflight
energy to generate ATP, NADPH , and 02 is referred to as the light reactions.
(4)
These reactions are located irl the thylakoid membranes,where chlorophyll and electron transport
components are also found. Tlhe ATP and NADPH formed by the light reactions are used to form
carbohydrates from CO2 and water in the dark reac-tions. The daik reactions take place in the
gtroma. The chloroplasts ofnfany algae contain a pyrenoid , a dense region ofprotein sunounded
by starch or another polysacc$aride. Pyrenoids participate in polysaccharide synthesis.
;ffi"""}i.i:l3,'31,i?,1"'?l"n* and
iii)
c3P
Explain the fbllowing terms :Ipysosomes,autophagy ,endocytosis,phagocytosis
Lysosomes are roughly sphedcal and enclosed in a single membrane; they average about 500 nm
in diameter, but range from 50 nm to several m in size. They are involved in intracellular
digestion and contain the enzymes needed to digest all types of macromolecules. These enzymes,
called hydrolases, catalyze ttie hydrolysis of molecules and function best under slightly acidic
conditions (usually around pH 3.5 to 5.0). Lysosomes maintain an acidic environment by
pumping protons into their intFrior. Endocytosis and phagocytosis.
Phagooytosis involves the uge of protrusions from the cell surface to sunound and engulf
particulates' It is carried out $y certain immune r ystem cells and rnany eucaryotic microbes. the
endocytic vesicles formed bJ phagocytosis are called phagosomes. Other types of endocytosis
also involve invagination of the plasma membrane. As the membrane invaginates, it encloses
liquid, soluble matter, and, ifi some cases, particulates in the resulting endocytic vesicle. One
example of endocytosis by i$vagination is clathrin-dependent endocytosis. Clathrin- dependent
endocytosis begins with coatpd pits, which are specialized membrane regions coated with the
protein clathrin on the cyto$lasmic side. The endoclic vesicles formed when these regions
invaginate are called coated yesicles. Coated pits have receptors on their exhacellular side that
specifically bind macro-molelules, concentrating them before they are endocytosed.Therefore this
endocytic mechanism is referred to as receptor-mediated Endocytosis. Clathrin-dependent
endocytosis is used to ingesf such things as hormones, growth factors, iron, and cholesterol.
Another example of endocytfsis by invagination is caveolae-dependent endocytosis. Caveolae
("little caves") are tiny,flask-sfiraped invaginations of the plasma membrane (about 50 to 80 nm in
diameter) that are enriched in pholesterol and the membrane protein caveolin. The vesicles formed
when caveolae pinch off are palled caveolar vesicles. Caveolae-dependent endocyosis has been
implicated in signal transducfion, transport of small molecules such as folic acid, as well as
transport of macromole- culep. There is evidence that toxins such as cholera toxin enter their
target cells via caveolae. CavQolae also appear to be used by many viruses, bacteria, and protozoa
to enter host cells.
Autophagy
Materials for digestion can alqo be delivered to I
endocytosis. Cells selectively digest and recycle
such as mitochondria) by a prqcess called autoph
digested are surrounded by dopble membrane.Th
been suggested that a portion ofthe ER is used.
endosome in a manner similar to that seen for ph
rD
Discuss the modc of movemerlt of eukaryotic flag
Cilia (s., cilium) and flagella (s., flagellum) are
motility. Althouglr both are wtriplike and beat to
one another in two ways. Fi(t, cilia are tlpi
100 to 200 m long. Second, tlieir patterns of
an undulating fashion and gengrate planar or heli
the wave moves from base (o tip, the cell is p
the base pulls the cell througlf the water. Someti
If
flimmer filaments (thicker, qtiffer hairs are
c
flagellar action so that a warfe moving down
instead of pushing it. Such a1 flagellum often i
flagellum is refened to as a {hiplash flagellum.
with two distinctive phases. Itrr the effective sho
fluid like an oar, thereby propNlling the organism
The cilium next bends alonl
preparation for another effe
so that some of its cilia are
shoke. This coordination al
its lengh whi
tive stroke. A
recovery
t the
are carrying out their effective
rws the organism to move smoothly tf,rougfrifr.
*ui.,
Do as directed
Q4
B
r)
State the signifi;ance of-mi(
Microtubules serve at least tl
microfilaments in cell
'ee
pu{poses:
(l)
they help maintain cell shape, (2) are involved
with
movements, and (3) participe e in intracellular
transport
processes.
Microtubules are found in
(long, slender,
rigid
l
rng, thin cell structures
pseudc rodia)
re
quiring support such as the axopodia
pr.r*t in stuctures that
of protists Microtubuies utro u."
participate in cell or organellr movements
the mitotic spindle,
ciliq
and flagella.
(16)
Statc ths function of inner mr nbrane
of mitochondria
The inner membrane has spec
surface area. The shape ofiri
mitochondria from various sp
flagellates may have cristae sl
caryotes; however, amoebae <
cristae in the shape ofvesicler
mafix containing ribosomes,
Qs
al infoldings called cristae (s., crista),
which greatly increase its
he differs in
cies. Fungi.have platelike
(laminar) cristae, whereas euglenoid
ryed like disks. Tubular cristae are found in a variety
.n
possess mitochondria
with
of eu_
The inner membrane encloses the mitochondrial
matrix, a dense
lNA, and often large calcium phosphate granules.
give examples ;Aldoses & ketoses
nd give examples ofeach
ses
altose,Cellobiose & sucrose
Explain the tertiary and quatErnary structure
of r protcin.Give biological rore of proteins.
Tertiary Structure
The overall three-dimensionpl shape o.f an
entire protein molecule
protein molecule will bend
fnd twist in such o *uy u,
gn9rry {ate. Although the t4ree_dimensional shape of a
it is fashioned
u.y
,T
groups of the amino acids.
n'r"/rt"Tlirt";;;..Ju,
is
the tertiary
structure. The
lowest
ura
fjr,i?
ns of neutral, non-polar amino acids such
interior of the protein molecule therebv
etween
"11"1'^,f,":Tlf :-11'::r
t:*t* "'9
Many proteins are made up oflmultiple--pollpeptide chains,
often refemed to as protein subunits.
These subunits may be the sarhe ot aire..ni . Th.
quutr*ury structure refers to how these
protein
to form a larger aggregate
again stabilized by various
salt bridges.
protein
interact
Protein function
(foreign
system to
ilizing them so that they can be destroyed
Contractile Proteins - are responsible for movement. Examples include
actin and myosin. These
proteins are involved in muscle contraction and movement.
Th
actions.
include the
Pepsin is
Hormonal Proteins - are meslenger proteins
Examples include insulin, oxytdcin, and somat
controlling the blood-sugar con{entration.
childbirth. Somatohopin is a grQwth horm
"
as catalysts
i,ljlil i"
amples include keratin,
skin, hair, quills, feathers,
tissues such as tendons and
is
iuruuBu
'[€ uroo(l vra reo Dlooo pells. uytochromes operate in the electron transport chain as
elechon canier proteins
Discuss-simple lipids with ttleir biological
function
Simple lipids - definition
Functions
: l)As storage
compounds 2)components
4)componenets of subcutanqous tissue ripio.
Simple lipids : Neuhal fats ahd waxes
Discuss :Triglyceriders,fatty pcids (Define
sjni.-ones
of cell membrane 3)In nerve fibres
6)As vitamins zjComponents of enzyme
and give examples)
ical system Watet i
ortant to biological
composes roughly 7g percQnt
liquid, gas), it also
of the human body. The
uniqueness of water comes from its
a polar covalent molecule, it has a slight positive
and slight
Water molecule has two important characteristics.
Fint, notice
e and negative ends. Second, observe that water is
a
bent
molecule' not linear or straigfrt. Because water is
a bent, partially polar molecule, it possesses
the
following biologically imporfant characteristics of what
is formed by the joining of many water
molecules-all of them are qritical to the creation and
support of life on Eu.tt, wur", molecule
has
Polarity simply means that tle molecule has both
a positively and negatively charged end. More
important, the polarity of w{ter is responsible for
effectively dissolving other polar molecules,
such as sugars and ionic compounds such as
salt. Ionic compounds dissolve in water to form
ions.
This is important to remembdr because for most
biological
reactions to occur, the reactants must
be dissolved in water. Becausp water is able to
dissolve so many common substances, it is known
as the universal solvent. subsfances that cannot
be dissolved by water (such as oils) are called fat
soluble and are nonpolar, nQnionic compounds
that are strongly covalently bonded. Insoluble
substances make excellent co{tainers of water,
such as cell membranes and cell walls.
Hydrogen Bonding
when water molecules align with each other, a weak bond
is established between the negatively
charged oxygen atom of one water molecule and
the positively charged hydrogen atoms of a
neighboring water molecule. The weak bond that
often forms between hydrogen atoms and
neighboring atoms is the hydrpgen bond. Hydrogen
bonds are very cornmon in living organisms;
for example, hydrogen bondq form between the bases of DNA
to help hord the DNA chain
together' Hydrogen bonds gif'e water molecules two
additional characteristics: cohesion and
surface tension.
Cohesion
Because ofthe extensive hydrqgen bonding in water,
the molecules tend to stick to each other in a
regular pattern' This phenomefon' called cohesion,
is easily observed as you carefully overfill a
glass with water and observe
water molecules
lthe
holding together abov" the rim until graviry
overtakes the hydrogen bonding and the water molecules
spill down the side of the glass.
Likewise, the cohesive proPe4y of water allows tall trees
to bring water to their highest leaves
from sources below ground.
Surface Tension A special type ofcohesion is surface
tension. The tension on the surface ofwater
occurs when water molecules ofo the outside of the system
align and are held together by
hydrogen bonding to create an Qffect similar to a net made
of atoms. For example, the surface
tension of water allows water sgiders to literally walk
on water.
Glycine NH"STCOO!
and Glyceraldehyde CsHeC