lec 2 Flashcards

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1
Q

name the 3 domains of al microorganisms

A

bacteria, archaea, eukarya

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2
Q

how did eukarya got evolved

A

bacteria and archaea had the same ancestors, then they evolved and divided into the current domains of microorganism. Then archaea evolved into eukarya

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3
Q

prokaryotes

A

bacteria and archaea

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4
Q

agar plate

A

solid media which micro-organism grow on.

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5
Q

in an agar plate the —- increases over time and it may eventually generate a —–

A

biomass, colony

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6
Q

name the properties of all cells

A

1) metabolism
2) growth
3) evolution

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7
Q

1: metabolism

A

all cells can take up nutrients and modify them into building blocks or generate nrg. i.e. cell wall components
the resulting functions carried by the cell are:
1) genetic: replication, transcription, translation
2) catalytic: nrg, biosynthesis

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8
Q

2: growth

A

when the biomass is favourable, nutrients consumed by the cells are converted into new cell materials in order to create daughter cells

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9
Q

3: evolution

A
  • key characteristic of life
  • cells do this in order to acquire new traits or skills
  • sometimes they may specialize
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10
Q

impacts of specialization

A
  • cells might lose genes that t eh don’t need

- as a result they waste less nrg on unwanted sources

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11
Q

—– capture evolutionary relationships

A

phylogenic trees

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12
Q

name the properties of some cells

A

1) differentiation
2) communication
3) genetic exchange
4) motility

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13
Q

differentiation

A

e. g. some cells can differentiate into spores

- capacity to perform specific set of functions

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14
Q

communication

A

cells communicate via chemical messages

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15
Q

genetic exchange

A

cells can inset their DNA into the recipient cell

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16
Q

microbial cells exchange DNA via ——

A

horizontal gene transfer (reproduction)

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17
Q

motility

A

swim and crawl

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18
Q

what is a cell

A

a cell is a closed compartment that is constantly doing chemical reactions to make more of its constituents and make another cell

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19
Q

organize the following based on increasing in size:

virus, polio, vacuole

A

polio –> virus –> vacuole

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20
Q

what is the limit in cell size

A

0.5 micrometer - 750 micrometer

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21
Q

animal cell size

A

10 micrometer wide

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22
Q

the — of the cell affects the size

A

shape

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23
Q

surface volume ratio

A

as volume increases, there is less surface available

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24
Q

why is the cell size a limited number

A

because the surface can handle a certain amount of volume in order to transfer nutrients and other compounds

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25
Q

to feed the whole volume, surface must be —- bigger

A

x2

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26
Q

what is the cue for the cell to divide

A

just before the cell reaches the upper limit, it divides into 2 cells

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27
Q

bacterial shapes

A

spherical,rod

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28
Q

nucleoid

A

rough region with no physical barriers

- prokaryotes store their DNA in this region

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29
Q

functions of the cell membrane

A

1) permeability barrier
2) protein anchor
3) energy conservation

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30
Q

cell membrane – permeability barrier

A
  • prevents form leakage

- functions as a gateway: controls what enters and washes out

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31
Q

cell membrane – protein anchor

A
  • site of many proteins that participate in transport, bioenergetics and chemotaxis
  • sensors, adhesins, tranposerters, enzymes
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32
Q

the cell is — % protein and. —-% phospholipid

A

50, 50

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33
Q

cell membrane – nrg conservation

A

since the membrane is impermeable to charged molecules, a membrane potential is created
- the membrane potential forces the passage of ions, therefore pmf is generated

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34
Q

typical phospholipid found in bacteria

A

phosphatidylehtanolamine

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35
Q

in bacteria and eukarya the glycerol backbone is connected to the fatty acids via —- linkage

A

ester

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36
Q

in archaea the glycerol backbone is connected to the fatty acids via —- linkage

A

ether

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37
Q

what are the differences among the phospholipid structure of archaea vs. bacteria and eukarya

A

1) ether linkage

2) the lipid part is made of isoprene

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38
Q

how does one polymerize isoprene

A

,you start with a phosphoglycerol and keep adding morello the chain one by one —> making it a monolayer

39
Q

why does the monolayer nature of archaea makes them resistant

A

1) they become more solid and heat resistant

2) instead of dissociating, they always stay together

40
Q

they lipid bilayer is stabilized by —-

A

sterols

41
Q

structure of sterols

A

polar head (OH) - attached to 4 fused rings - hydrocarbon tail

42
Q

name of the sterol in

1) animal cells
2) fungi
3) plant cells and some protozoans

A

1) cholesterol
2) ergosterol
3) stigma sterol

43
Q

in bacteria and archaea sterols are —-, therefore, they are stabilized by —-

A

absent, hopanoids

44
Q

ribosomes are composed of — and —-

A

DNA, RNA

45
Q

location of ribosomes in bacteria and archaea

A

free in the cytoplasm or attached to the cytoplasmic membrane

46
Q

location of ribosomes in eukarya

A

free in the cytoplasm or bound to the ER membrane

47
Q

ribosomes in prokaryotes

A

50 S + 30 S = 70 S

48
Q

ribosomes in eukaryotes

A

40 S + 60 S = 80S

49
Q

Svedberg unit

A

describes the rate of sedimentation of a particle in an ultracentrifuge. proportional to the size, shape and density of the particle – relationship is not linear

50
Q

a cell wall is absent in —- and most —-

A

animals, protozoans

51
Q

functions of a cell wall

A

it forms a tough, rigid, barrier that helps protect the cell and gives it its shape

52
Q

the cell wall of eukaryotes is usually composed of —-

A

polysaccharides

53
Q

name the polysaccharides present in the cell walls of the following:

1) plants
2) fungi

A

1) cellulose: polymer of glucose

2) chitin: polymer of N-acetylglucosamine

54
Q

the genome of eukaryotes is packed into —-

A

chromatin fibre

55
Q

chromatin fibres are organized into —-

A

chromosomes

56
Q

name the 2 types of chromatin

A

1) euchromatin

2) heterochromatin

57
Q

euchromatin

A

loosely packed, actively transcribed, needs to be unwinded for transcription

58
Q

heterochromatin

A

densely packed, low level of transcription

59
Q

Replication and transcription of DNA in eukaryotes occurs in the —-

A

nucleus

60
Q

translation occurs in the —-

A

cytoplasm

61
Q

where does the mRNA for cytoplasmic proteins travel into for translations

A

free in the cytoplasm

62
Q

where does the mRNA for membrane proteins travel to for translation

A

directed to the ER

63
Q

what is the endoplasmic reticulum

A

it is a set of channels and sacs around the nucleus

- main function: conducts specific enzymatic activity

64
Q

what is the ER composed of

A

phospholipid bilayer

65
Q

rough ER

A

studded with ribosomes, and important for protein synthesis and modification

66
Q

smooth ER

A

no ribosomes, involved in the synthesis of lipids

67
Q

Golgi body

A

a set of membrane compartments involved in further processing of proteins and their distribution.

68
Q

how are proteins transported from the Golgi body

A

they are packages into vesicles

69
Q

cis Golgi

A

cis Golgi is on the cis side of the Golgi body and its function is to receive the biosynthetic output from the ER

70
Q

trans Golgi

A

on the existing face of the Golgi, where the processed materials leave

71
Q

most of the ATP required by cells is produced in the —-

A

mitochondria

72
Q

structure of the outer membrane of mitochondrion

A

many porin proteins –> makes the membrane very permeable to small molecules

73
Q

structure of the inner membrane of mitochondrion

A

75% proteins, 25% lipids. contains transport proteins, enzymes, cytochromes, ATPase
- produces most of the ATP

74
Q

Matrix

A

contains the enzymes for citric acid cycle, DNA and ribosomes (70S)

75
Q

outer membrane of chloroplasts

A

porins, similar to mitochondria

76
Q

inner membrane of chloroplasts

A

regulated transports of proteins

77
Q

thylakoid

A

closed system of interconnecting sacs and tubules, bordered by membranes where most photosynthetic reactions happen
- contains enzymes and pigments that harvest light nrg and the ATPase uses this to generate ATP

78
Q

stroma

A

circular DNA, 70S ribosomes, enzymes of the Calvin cycle

79
Q

In what senses are eukaryotes and mitochondria and chloroplast similar to bacteria

A
  • 70S ribosomes
  • double membranes
    circular chromosomes
80
Q

protein filaments that make up the cytoskeleton:

A

1) microtubules: alpha tubulin
2) actin filament: actin
3) intermediate filaments: keratin, desmin, vimentin
* similar protein filaments are found in non spherical prokaryotes

81
Q

microtubules grow form the —-

A

centrosomes

82
Q

structure of microtubules

A

helical and hollow

83
Q

function of microtubules

A

create a network of roads inside the cell - proteins known as kinesins walk on these, by picking up vesicles from the Golgi, chloroplast, … and taking them to their destinations.

  • powered by ATP
  • Another protein that uses these paths is dyenin
84
Q

function of centrioles

A

act as organizing centres for other microtubules arrays

85
Q

construction of centrioles

A

9+0 contractions, with 400 nm and 200 nm arms

- triplets of one complete, and 2 partials arms

86
Q

centrosomes have —- centrioles

A

2

87
Q

basal body

A

when the centriole is located closer to the cytoplasmic membrane –> essential for flagella and cilia generation

88
Q

flagella

A

used by protozoans or other cells for swimming in a liquid

89
Q

cilia

A

short extensions that surround the cell for movement

90
Q

flagella and cilia constructions

A

9+2 –> 2 extra in the centre

- 9 sets of doubles ( one complete, 1 partial, 2 pariah in the centre)

91
Q

what are flagella and cilia covered by in eukaryotes

A

cytoplasmic membrane

92
Q

what are flagella and cilia covered by in prokaryotes

A

plasma membrane

93
Q

role of dyenin

A

the grab the arms and slide them past each other in a coordinated movement following the microtubules
- creates stress