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1
Q

what is needed before replication can occur

A

initiator protein must bind to the origin of replication

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2
Q

what does DNA topoisomerase do

A

aids unwinding process

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3
Q

what does DNA helicase do

A

breaks hydrogen bonds between bases

form two single strand template strands

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4
Q

where is the RNA primer needed

A

added to 3’ end

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5
Q

what does DNA primase do

A

synthesises short RNA primer (5-10 nucleotide bases)

attaches primer to 3’ end of template

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6
Q

what does DNA polymerase do

A

reads template strand 3’ to 5’
causes nucleotide addition to primer
cataylses the phosphodiester bond forming between 3’ carbon of last nucleotide and 5’ phosphate of incoming nucleotide

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7
Q

what does DNA ligase do

A

joins okazaki fragments to form DNA strand

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8
Q

translocation in eukaryotes

A

scans 5’ UTR
mRNA unwound and more proteins added/bind
mRNA attaches to complex with poly (A) tail at end
tRNA brings methionine, binds to form a large complex

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9
Q

what is rho-dependent

A

rho interacts with elongating RNA transcripts

disrupts interaction causing RNA polymerase to ‘fall off’

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10
Q

what is rho-independent

A

RNA forms hairpin loop due to inverted repeats in DNA
hairpin loop stops RNA polymerase transcribing
followed by uracil poly tail - only weakly bound to poly A sequence so RNA falls off as no strong connection between DNA and RNA

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11
Q

eukaryotes transcription termination

A

AAUAA cleavage signal
signals RNA ending
specific endonuclease cleaves off poly (A) tail added

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12
Q

eukaryotes translation termination

A

termination codons at end of protein-coding sequence
tRNAs don’t have complementary anticodon
release factors bind to ribosome
release mRNA from ribosome-complex falls apart

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13
Q

prokaryote initiation

A

ribosome dissociation
IF2 and GTP complex with formyl methionine tRNA
tRNA brought to mRNA, complementary to AUG codon on mRNA
form 30S initiation complex
IF3 lost
GTP hydrolysed to GDP (+Pi) produces energy
energy displaces IF1 and IF2 so 50S can re-associate

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14
Q

prokaryote elongation

A

EF-Tu binds with GTP to next complementary tRNA in mRNA sequence
tRNA brought to A site, binds = release EF-Tu and GTP
peptide bond forms between amino acid in P site and A site
catalysed by peptidyl transferase
GTP hydrolysed = energy for ribosome to be shifted three nucleotides right till reach stop codon

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15
Q

what is the cell pathway in eukaryotes

A

contractile microfilaments of cytoskeleton - lines of tension in cell
energy transmitted through these lines, lets cell move across

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16
Q

what is the cell pathway in extracellular matrix

A

extracellular matrix has fibronectin fibres
each cell orientated to position of fibronectin fibres
follow fibronectin trails

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17
Q

how do adheren junctions form

A

cadherin proteins cross intracellular space link to catenins
catenins linked to actin filaments
actin filaments anchored to cytoskeleton

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18
Q

how do desmosomes form

A

cadherins cross intracellular, other proteins link cadherins to intermediate filaments
attached to skeletal proteins inside cell
anchored to intermediate filaments of cytoskeleton

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19
Q

how do tight junctions form

A

tightly packed row of protein ridges linking adjacent cells

ensure adjacent cell membranes held together

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20
Q

how is a lateral root formed

A

outer tissue disformation and cell separation
signals outside cells to release cell wall modifying enzymes
allow cells around to stretch move and disengage with each other - can grow through
lateral root contains all same material as primary

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21
Q

what is sclerenchyma and its function

A

provide structure and support to plant tissue

cell walls are thick lignified secondary walls made of cellulose and hemicellulose - often die when age

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22
Q

what is special about phloem cell wall

A

perforated using sieve plates to allow compounds to travel through

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23
Q

what is the sclereid and its function

A

keeps plant together

gives structure and strength without preventing it moving in water

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24
Q

what is the collenchyma and its function

A

elongated cells with thick cell walls
provide structure and support
cellulose and pectin are irregularly thickened at corners

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25
what are hydrophytes
important for aquatic plants stomata only on top of leaf epidermal layer very little strengthening in stems = not rigid AERENCHYMA form air channels for gas exchange
26
what is the plasma membrane function
coordinates synthesis and assembly of cellulose microfibril control substances in/out cell via transmembrane protein relay hormonal and environmental signalling factors
27
what is the function of the perioxisome
detoxes cell help cell survive in toxic environment hydrogen peroxide is a metabolic waste product, toxic to cell perioxisome converts it to water
28
golgi body function
provides a network of vesicles for secretory purposes sorts - proteins know where need to go, packages for transport modifies products from rough ER
29
what is the vacuole function
regulate turgidity by regulating water in cell
30
what is a vacuole
membrane bound organelle filled with cell sap | often acidic pH, many have toxic/bitter compounds - stop being eaten
31
what is lytic infection
host cells destroyed - virus particles released normally clears in couple days - immunity some hosts not immune = epidemic
32
what is latent infection
lack of gene expression, normally in sensory and autonomic ganglia - immunocompromised lasts lifetime of host UV can reactivate - re-enter lytic cycle
33
what is persistant/chronic infection
virus does not cause cell death slow virus release if not good immunity can last long time
34
what is a germ cell
cell containing half the number of chromosomes of a somatic cell and is able to unite with one from the opposite sex to form a new individual - a gamete
35
what is heterogametic
X- Y- hemizygous for genes (only has one copy of genes)
36
what is polyploidy
condition in which cell/organism has more than two sets of chromosomes
37
what is the paracellular route
materials cross through junctions between cells where there is a gap
38
what do motor proteins do
change the position of things in the cell
39
what is endocytosis
a living cell takes up matter via an invagination in the cell membrane
40
what is exocytosis
vacuole contents released to exterior as vacuole membrane fuses to cell membrane
41
what is pinocytosis
liquid ingested into cell due to small vesicles budding off cell membrane
42
what is saltatory conduction
transmit change by reversing local electric field that passes along nerve axon - active signal. Regenerated along axon
43
intracellular inclusions
contain insoluble chemical deposits used as storage organs bounded by non-unit membrane
44
what is the effect of a bacterial phospholipid bilayer
``` hydrophobic core - barrier to most water soluble molecules protein permeases (membrane transport protein) allow selective transport of molecules in ```
45
what are the benefits of cytoskeleton on plant cell
vesicles from ER and golgi travel along monorails it provides growth in particular direction involved in positioning organelles
46
what is a heterotroph
relies on carbon from complex compounds
47
what is a phototroph
photosynthetic microbes
48
what is binary fission
transfer of genetic material before septum formation or will not be viable cells
49
what is a bacterial endospore
dormant structure can permit for long time dehydrated, no biochemical reactions occur germination and outgrowth lead to new vegetative cell
50
what were Kochs postulates
gene found associated with pathogen mutation attenuates virulence of pathogen transfer of gene can give other organisms disease
51
what are exotoxins
extracellular diffusible toxins | normally proteins secreted during exponential growth
52
how does an enveloped virus enter/exit cell without destruction
envelope pinches off bit of plasma membrane envelope glycoprotein on outside of capsomere fuses with outside of cell release nuclear capsid into cytosol
53
what is the capsid function
encapsulates nucleic acid - no harm interact with cell organelles genome delivery - binds to receptor using spikes
54
what is a transposon
small DNA pieces = replicate and move round in genome insert themselves
55
where can clostridium botulinum be found
associated with meat or canned foods not reheated before eating heat sensitive but germinates in cooled food
56
where can bacillus cereus be found
spores are heat resistant and germinate in cooled food after cooking cereals and rice survives in reheated foods
57
where can clostridium perfringens be found
natural part of animal gut microflora spore found in faeces associated with cooked meat products
58
where can campylobacter be found
mainly from poultry or other raw meat | natural habitat is bird intestine
59
where can listeria be found
normal habitat is mammal intestine, soil and plants can grow in refrigeration temperatures many sources e.g. dairy, salad, cold meat
60
what is post transcriptional gene silencing
Gene silencing small interfering RNA cause mRNA degrade, can't be translated to proteins
61
what must happen for eukaryote transcription initiation to occur
several transcription factors bind to core promoter TATA box - must be specific combination of TFs for RNA polymerase to bind

Genes + Cells (23 decks)

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