Chapter 8 : Cell : The Unit of Life Flashcards
(134 cards)
1
Q
What are unicellular organism capable of ?
A
independent existence
metabolism
2
Q
Who saw and described the first living cell?
A
Anton Von Leeuwenhoek
3
Q
Who discovered the nucleus and what was the reason ?
A
Robert Brown due to the invention of microscope
4
Q
Who was Matthais Shleiden and what did he propose?
A
he was a botanist and he noticed that the plants are composed of cells that futher organise to form tissue
5
Q
Who was T.Shwann and what dd he observe?
A
he was a zoologist and he noticed that the cells have a thin membrane which is now known as plasma membrane
he also noticed that the presence of cell wall is unique character of plants
he also proposed the hypothesis that the bodies of animals and plants are composed of cells and products of cells
6
Q
Who formulated the cell theory?
A
M. Shleiden and T. Shwann
7
Q
Who modified the cell theory and what was his statement , what change did he do ?
A
Rudolf Virchow, he first explained that cells divided and new cells are formed from pre-existing cells
his statement was – Omnis Cellula e Cellula
8
Q
What is the cell theory?
A
1) all living oragnisms are composed of cell and are products of cells
2) al cells arise from pre existing cells
9
Q
What is an eukaryotic cell ?
A
these are the cells that a membrane bound cell
nucleus
10
Q
What is a prokaryotic cell?
A
they do not have a membrane bound cell nucleus
11
Q
What are organelles?
A
these are the distinct structure in the cel body that are responsible for carrying out various biological processes .
12
Q
Name the organelle where ribosomes are found?
A
mitochondria, chloroplasts and rough ER
13
Q
Which is the smallest cell and what is its length ?
A
Mycoplasma 0.3 micro meter
14
Q
What is a gram -positive/ negative cell wall?
A
some cells can be stained by gram stain but others are not
gram positive and gram negative cell wall
15
Q
What are the membraneous extensions into the cell cytoplasm in a cyano bacteria called?
A
chromatophores they contain pigments
16
Q
What is a flagella ?
A
thin filamentous extension from the cell wall\
17
Q
What is the average size of a bacterial cell ?
A
3 -5 micro meter
18
Q
What is the largest isolated cell?
A
ostrich egg
19
Q
What is the average diameter of human RBC?
A
7 micro meter
20
Q
What is the longest cell?
A
nerve cell
21
Q
Give some examples of prokaryotic cell?
A
bacteria , blue green algae , mycoplasma , PPLO
22
Q
What is the full form of PPLO?
A
pleuro pneumonia like organism
23
Q
What are the four basic shapes of bacteira?
A
bacillus
coccus
spirilla
vibrio
24
Q
What is the only prokaryote that does not have a cell wall?
A
mycoplasma
25
What are the characteristics of prokaryotes?
```
they have a cell wall
cytoplasm
no well defined cell wall
gentic material is naked no nuclear membrane
DNA is single chromosome/ circular DNA
```
26
Which organelle is the characteristic of a prokaryote?
the mesosome is the characteristics of a prokaryotes
27
What is the mesosome derived from ? What is their function ? What is its special funciton that makes it very unique ?
it is derived from the cell membrane
1) they are in the form of vescicles , tubules and lamellae
2) they help in the cell wall formation
3) DNA replcation
4) distribution of daughter cell
5) RESPIRATION
6) secretion processes
7) increases the surface area of plasma membrane and enzymatic content
It is equivalent to mitochondira .( RESPIRATION) (AEROBIC RESPIRATION)
28
What are the common organelle in prokaryotes and eukaryotes?
ribosome
they dont have any other common cell organelle
29
Which organelle is the characteristic of a prokaryote?
the mesosome is the characteristics of a prokaryotes
30
What are the layers of the cell envelope ?
outer glycocalyx
cell wall
plasma membrane
31
What are the two types of bacteria and what is the basis of their systemization?
```
gram positive( they take the gram stain)
gram negative (they dont take gra stain)
```
in their basis of getting stained by gram stain
32
Does glycocalyx determine the shape of the cell ? What are the two types of glycocalyx layer?
NO is doesnt determine the shape of the cell
SLIME LAYER
CAPSULE
33
What is the function of a proaryotic cell wall?
they help in giving the cell a shape and stop it fro BURSTING or COLLAPSING
34
What are the extensions of the cyanobacteria called?
they have membranous extensions called the CHROMATOPHORES and they contian PIGMENTS
35
What helps the bacteria to attach itselp to tissues?
FIMBRAE : helps in attachment of the bacteria to the tissue and surfaces like streams
36
What are the functions of pilli and fimbrae ? Where do they derive from?
they derive from the cell membrane
PILLI ( they are made up of protein, they are TUBULAR ,they help in secual CONJUGATION)
FIMBRAE (they are NOT TUBULAR , help ATTACH bacteria to sufaces, like streams and tissues )
37
What helps the bacteria to attach itselp to tissues?
FIMBRAE : helps in attachment of the bacteria to the tissue and surfaces like strems
38
What is the average size of a ribosome and where are they usually present in the prokaryotes? What is 70s and 80s made up of ?
15- 20 nm
they are usually associated with the cell membrane
70 = 50 + 30
80 = 60 + 40
39
What is polysome?
several ribosome attached to a single mRNA
40
What are inculsion bodies ? Do they have any membrane and give some examples?
reserve material in prokaryotic cell are stored in the cytoplasm in the form of inclusion bodies
NO MEMBRANE they lie freely in the cytoplasm
phosphate , glycogen , cyanophycean granules
41
Where are the gas vacuoles found ?
blue green algae and purple and green photosynthetic bacteria
42
What are the differneces that makes a plant cell and animal cell differnet?
PLANT CELL : have cell wall, plastids , and a large central vacuole which is absent in animals
ANIMAL CELL : centrioles ( they are absent in almost all plant cells)
43
What is the basis of categorizing the two types of protein and what are they?
on the basis of ease of extraction
PERIPHERAL and INTEGRAL protien
44
What is rhe cell membrane composed of and what are their percentages?
lipids (40 %)
proteins( 52%)
carbohydrate
45
What is the singer nicholson model also known as and when was it proposed? What does it state?
fluid mosiac model ( 1972)
according to thos the quasi fluid nature of the lipid enables the lateral movement of the protien within the overall layer , this ability to move within the membran is measured as its fluidity
46
What is fluidity? What does it help in?
ability of protein to move within the membran is measured as its fluidity
cell growth, formation of intercellular junction, secretion, endocytosis, cell division
47
What moves across the cell membrane by passive, water ,facillitated, active transport ?
passie : neutral solutes
water : osmosis
facillitates: ions w/ carrier protien
active transport : Na+/ K + pump
48
What are functions of cell wall in eukaryotes?
gives the shape to the cell
protects the cel from mechanical damage and infection
cell to cell ineration
provide barrier to undesirable material
49
What is the algael cell wall composed of?
| What is the fungal cell wall composed of ?
cellulose , galalctans , mannans and mineralslike CaCO3
fungal cell wall : chitin
50
What is the plant cell wall composed of?
cellulose , hemicellulose , pectins , protien
51
What is the middle lamellae made up of?
Ca pectate
52
What is ER ? How does it divide the cytoplasm? What are its two types?
it is hte network of tubular structures scattered in the cytoplasm
intracellular / extra cellular
SER / RER
53
Which ER is seen continous with the membrane of the nucleus?
RER
54
What is the funciton of RER and SER?
RER: protien
SER: lipid, steriodal hormones
55
Who discovered golgi bodes and when?
1898 by CAMILLIO GOLGI
56
What is the diameter of golgi body ?
1 - 0.5 micro meter
57
What are the two faces of the golgi bodies? Which one faces the nucleus?
cis and trans face
cis face faces the nucleus
58
What is the function of golgi body ?
packaging material to be delivered intra ceullular or to extra ceullular targets
59
What is the most important site of formation of glycoprotein and glycolipids ?
GOLGI BODIES
60
What is the organelle that is responsible for the formation of lysosomes?
golgi bodies
61
What are the enzymes present in the lysosomes and what is their desired pH?
lipase, protease , carbohydratase,
optimal pH = 5 which is ACIDIC
62
What is vacuole and what deos it contain ? What is its membrane known as?
it is a membrane bound structure
contains : water, sap, excretory product , other excretory material which is not useful for the cell
it membrane is known as tonoplast
63
How does the tonoplast aid in the ionic balance of the plant cell?
they can actively pump ions in the cell sap
64
What is the funciton of contractile vacuole ? What is the function of food vacuole?
important for osmoregulation and excretion
its function is to active move susbtances lke ions and other material inside the sap
65
What is a food vacuole ?
they store food
66
What is the stain used to stain the mitochondira, What are its dimnesions ? How many membrane does it have? What is its funciton? How does it divide ?
janus green B
(0.2 - 1) ( 1.0 -4.1 ) micro meter
it has 2 membranes
aerobic respiration
fission
67
What is present in the inner compartment of mitochondia?
matrix
| single circular DNA , few RNA, 70s ribosomes for protein synthesis and protein
68
What are cristae?
they are the inner infolding of inner mmebrane of hte mitochondria
69
Where are plastids found ? What are its dimensions?
in plants and euglenoids
70
On what basis are the plastids divided and what are they ?
on the basis of pigements present in it
chlorophyll, chromoplast, leucoplast
71
What is the pigment present in chloroplast, chromoplast and leukoplast?
chlorpolast : chlorophyll
| chromoplast: carotenoid(carotene, xanthophyll)- gives red, orange color
72
What are the different types of leukplast?
amyloplast : cabohydrate
aleuroplast :protein
elaioplast : fats
73
Where are the majority of the chromoplast present?
most of them are found in the mesophyll of the plant
74
How many chloroplast are present in mesophyll cell? Which cell has the least number of chloroplast and ho wmany does it have?
20-40 per cell
chlamydomonas ( 1 per cel )
75
What is teh average size of a cholroplast ?
2-4 micro meter
| 5 -10 micro meter
76
What the space inside the uner membrane of a chloroplast called?
stroma
77
Where are thylakoid present ( which part of achoroplast) and what is the space inside it called? What is grana ?
they are present in the stroma of the chloroplast
the space inside it is called lumen
the stack of thylakoid is called a grana
78
What is stroma lammella?
the flat membranous tubules that connects the thylakoids are called stroma lamellae
79
What are the things present in the stroma of a chloroplast?
carbohydrates , proteins
small circular dsDNA
ribosomes
80
Where are the chlorophyll pigments present in the chloroplast?
in the thylakoids
81
What is the type of ribosoems present in the chloroplast?
70s
82
What is the difference between stroma and matrix(mito) in composition ?
stroma has carb and protien
| mito has protien
83
Who discovered ribosomes and when ? What is ribosomes composed of? does it have anu membran?
George Palade in (1953)
RNA and protien
NO
84
What does the S stad for in ribosomes? What are its types?
svedberg unit
70s : 50 + 30
80 = 60 + 40
85
What are the parts of cytoskeleton? What is their function?
microtubules , microfilaments , intermediate filament
SUPPORT, MOTILITY , MAINTENANCE , SHAPE OF THE CELL
86
What is the funciton of cillia and flagella?
cilia : mvemnt of external stuff or the cell
flagella : only the cell
87
What is the flagella surrounded by ?
plasma membrane
88
What is the core of flagella caled?
axoneme
89
What is meant by 9+2 ?
9 peripheral doulets and + 2 centrally located mircotubules
90
What is centrosome ?
it is composed of centriole
91
What is the centrosome surrounded by ?
amorphorous pericentriolar material
92
How are the microtubules in the centrosome located?
in cartwheel shape
93
What is the composition of centriole?
it has 9 peripheral triplets
94
Are the adjacent triplets linked in the centriolr?
no
95
What is the central part of the centriole ?
it is proteineceous hub
96
How are the peripheral triplets connected to the hub?
they are connected with the tubules with RADIAL SPOKE
97
Who first described the nucleus of the cell ?
Robert Brown
98
What is the chromatin described by flemming ?
it is the part of the nucelus that is stained by a basic dye is called chromatin
99
Can we have more than one nucleus?
yes
100
How many nuclear membrane do we have in nuclear envelope and what is the space between them called and what is the width of it ?
2 nuclear membrane in nuclear envelope
PERINUCLEAR SPACE
10 - 50 nm
101
What is perinuclear space?
it acts as a barrier between the material present inside the nucleus and that of the cytoplasm
102
What are the organelle that is associated with the outer nuclear membrane?
endoplasmic reticulum
| ribosomes
103
What leads to the formation of nuclear pore and what is its funciton?
it forms due to the fusion of the outer and the inner membrane
is aids the movement of RNA and protein both ways
(in and out of the nucleus)
104
Give an example of a cell with more than one nucleus and one with no nucleus?
a cell with more than one nucleaus : PARAMOECIUM
| a cell with no nucleus : ERYTHROCYTES
105
What is nucleoplasm and what does it contain?
nucleaoplasm
| it contians nucleaolus and chromatin
106
Does the nucleolus contain any membrane?
no membrane
107
Where does the sythesis of the ribosome take place
it is the size of ribosomal RNA sythesis
108
What does the chromatin contain?
DNA , basic protein HISTONE, and non histone protein and also RNA
109
What is the approzimate length of the human DNA?
2m
110
What is centromere ? What does it do ?
it is the primary constriction of the nucleus
| it attached two chromatids
111
What is the basis of the classification of the various types of the chromosome ? What are the different types of chrosomes
on the basis of hte position of the centromere
| METACENTRIC, SUB-METACENTRIC, ACROCENTRIC, TELOCENTRIC
112
What is satellite of a chromosome ?
it is the part of hte chromosome beyond the secondary chromosome
113
What are microbodies? What do they contain?
they are the membarne bound minute vescicles ,
| they contain various enzymes,
114
Are microbodies present in only animals or plants?
they are present in both animals and plants
115
What is the structural difference between pilli and fimbrae?
pilli are thick tubular and are longer and fewer
| fibrae are thin short and more in number
116
When does the fimbrae grow?
in response to F+ or fertility factor in Gram -ve bacteira
117
What type of biomolecule is spectrin ?
it is a protien
| extrinsic protein
118
What is the ER composed of ?
it is composed of CISTERNAE, TUBULES and VESCICLES
119
What is teh difference in the shape of cisternae and tubules?
cisternae are cylindrical in shape
| tubules are circular
120
How does the SER help in detoxifying?
by releasing cytochrome P450
121
What is the meaning of glycosidation and glycosylation?
glycosidation : LIPIDS + SUGAR
| glycosylation: PROTEIN + SUGAR
122
Which organelle shows polymorphism? What are the different phases? Describe them?
lysosomes
1) PRIMARY LYSOSOMES : contain inactive enzyme
2) SECONDARY LYSOSOME: contain things to be digested
3) RESIDUAL RIBOSOME : contain undigested material
4) AUTOPHAGIC LYSOSOME : formed by union of primary and dead organelle
123
Where do vacuoles form from?
Endo plasmic reticulum
124
What is the sedimentation coefficent of mammalian ribosome?
55s
125
What is the functional unit of mitochondria?
oxysome, F1-F0 complex
126
Which membrane of hte mitochondria is more permeable? Why ?
the outer membrane is more permeable because of the presence of porins
127
What are the three types of RNA?
mRNA , tRNA and rRNA
128
What are the two types of chromatin on the basis of how much stain they take ? Which one is more active and which one takes more stain ?
heterochromatin : more stain , genetically less active
euchromatin : gentetically active and less stain
129
Where are the microtubules present?
in cillia, flagella , centrioles , basal bodies
130
Where are microfilaments present ?
actin : globular protien they help in movement of the cell
131
What are intermediate filaments?
they non contractil hollow filements of acidic protein
132
What are the things included in the mitotic apparatus/
centriole , microtubules connecting them
133
What are the enzymes present in the peroxisomes and what is their funciton?
peroxide : they make peroxide
| catalase : they destroy the peroxide
134
What is the arrangement of centriole and cillia/flagella
cetrioe : 9 + 0
| fialgella+ cillia : 9 + 2
