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A-level Biology > Module 2.5 > Flashcards

Module 2.5 Flashcards

1
Q

In previous videos we saw

A

-We have looked at the strucutres of triglyceriedes nd phospolipids .
-W esw that tirglycerides have three fatty acid moleucles onded to one moleucle of glhycerol .
-Triglyceride moelcules are nonpolar making them hydrophobic (AKA insoluble in water .)

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2
Q

WHEREAS PHOSPHOLIPS

A

-Two fatty acids bonded to a glycerol .
-REMEMBER –> these fatty acids are hydrophillic .
-Flycerol is also bonded toa phosphate group .
-Phosphate group is higly charges , so this part of the moleucle is polar . Menaing the PHOSPHATE goup is hydrophillic .

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3
Q

MEANING WHAT BREH

A

-phospholips have ahydrophobic region consisting of the fatty cid .
-+a hydrophillic region consisiting of the phosphte grup .

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4
Q

Chceck sheet , rather than drawin a phosphatee=lipie , scientsits acc raw iy out like thi .

A

circle with two tails .
-AS a phospholipd contain both hydrohpilic region and hyrdophobic trhio , IF WE place them inw ater they arrange themslevs like this , CHECK SHEET .
-

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5
Q

-the hydrophillic part of the phospholipd moelcules phosphte group can INTERACT WITH WATER .

A

-However ,t he hydrophobic parts in other words the FATTY ACIDS are buried int he center way from th water .
-SCIENTISTS cll this the phospholipid bilayer .

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6
Q

-PHOSPHOIPID bilayer is the BAISSI of ALL CELL mEMBRANES .

A

-Including the cell surface membrane and rhe memranes tha surround organelles , suc as lysosmes and mitochondira .
-Membranes carry out a range of functions inc ells .

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7
Q

One fucntion of phospholipd bilayers

A

-Act as BARRIERS betweent he internal contents of the cell and the external environemnt .
-OR , between the contents of n organele and cytoplasms .
-Someitmes memranes separare one part of an organelle froma nother part (we will see more detai into this when we looka t mitchodnira)/

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8
Q

second fucntion of phospholipid bilhyers

A

Mmebranes are also a locaion for chmeical eaxcctions (stages inr edpirtion )

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9
Q

third funciton of phospholipdi bilayer

A

membranes are also inovved in cell sinalling .

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10
Q

like we said before ,t he cell surfce membrane provides a barriwr between the cytoplasms and the ecternal enviornment of the cell .

A

BECAUSE the cell surfce membrane contrians a hydrophobic center and hydrohpbic moelcules such as steroid hormone can EASILY pass thorugh the cell memerane .

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11
Q

HOWEVER , the hydrohobic cener prevents hydrphillic water soluble moelcules frome sasily passing through /

A

As HYDROHPHILLIC SUBSANCES ARE POLAR AKA THEY HAVE CHARGE ,
-These substances cannot eaisly pass through the non-polar refion of the memrbane .

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12
Q

REMEMBER ; water moelcules can ass thorugh the cell memrbane even htough water moelcuesl re polar .

A

As Water moelcules are extremely smll .
-Even so , gthis tkes plce at a slow rate .

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13
Q

-The cell ,e,brane is based int he phospholipd bilayer , HOWEVER it contains other parts as well .

A

FIRST THING TO NOTIE
-Cells urfaxe memrbane contins a large number of portein moelcuels .
-Som of these portiens are onlyon one side of the memrbaine .
-Whereas oher poreins span the memrane frm onse side to the otoher .

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14
Q

-The cell ,e,brane is based int he phospholipd bilayer , HOWEVER it contains other parts as well . (2)

A

The cells urface memrbane also contains choelstrol (saw int eh videos on lpds .)
-SEE STRCUUTRE OF CHOESTROL ONS HEET .

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15
Q

Cholestrol moelcules hve a polar hydrophillic grouop at the end .

A

-This group cn effect the poar hwad gorups on the phospholipd moleucles .
*The rest f the cholesrrol moelcule is non-polar +hydophobic .
-This part of the cholestrol mopecule cana trxt the non-polar fatty acids int he phospholipds . .

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16
Q

-So ebcuse choelstorl interacts withphospholipids . IT increses the strenght of the cells ufrace merae .

A

Making the memrbane more stbale nd less liekly to et damaged .

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17
Q

Another unction of choelstrol .
-CholesroL ALSO REDUCES THE SIDE WAYS MOVMEMNT OF THE PHOSPHOLIPDS AND OTHER MOECLUSL ITHIN THE MERBAEN.
-Helping to cotnrol the fulididty of the memrbane .

A

-Preventing the memrane from becoming too fluid under wam condirons and too rigid under cool conditons .

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18
Q

final dfucntion of cholestrol

A

-by packing the spaces begtwween the phosphoipds , cholesrol helps o reduce he movemnt of warer soluble sacorss hr cells urfce memrane .

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19
Q

Scienitsts call the strucutre of the cell surface memrbane the FLUID MOSIC MODEL.
-Need to be able to describe wht his means .

A

-The word “fluid” because the phospholipd molcule cn mvoe around wit each layer .
Menang the moelcule is flexbile nd cn change shape .
-The word “mosic” as the membranes is studed with protien moelcules .
-The rrangeemtn of the poretein molcuels varies like tile in amosaic .

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20
Q

-Looking into detail into the porteins we find in the cell memranes
-All membanes can be divided into two different catgeories

A

-Intrinsi or intergal proteins .
-Extrinsic or perpherl protins .

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21
Q

Intrinisc porteins

A

are fully EMedded from onse side to the toehr .
-As they pass right thorugh the ipid bilayer . Inrinisc proteins hae hydrohphobic amino cids ont heoutside surface of hte portein .
-The h ydrohpbic aminoa cids cna interact with the hydrohllic fatty acid tils in phospholipd bilayer .

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21
Q

rane porteins can be divided into two categories

A
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22
Q

There are two types of intrinsic porteins . Wchi is one of them
-PROTEIN CHANNLESLS

A

-potein channels contain a channel running thoruhgh he center .
-This channel is lines with the hydrohpillic amino acids and filled with water moleucles .
-Protein channels allow water-soluble moelcules nd ions o diffus htourgh .

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23
Q

Another type of intrinsic porteins

A

Carruer porteins .
-These can change thier or postion to transger moelcules or ions fromo ne side of the merbane to theo hter .

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24
IN CONTRAST TO ITNRISNC PROTEINS EXTRISNIX porteins DO NOT spn the memrbane .
-Instea are found on one side od rh wmwmenW OE OTHER . -Someiime extrinsic protein are attached to intrinsic proteins .
25
Extrinisc porteins ahev a range of functions
1. some play a strcutural role within the mebrne . 2.others can act as enzymes 3.some are recepros for other moelcules like hormones .
26
Many membrnaes protiens lso contain a carbhodhyrate moelule atached . Scientitss call these GLYCOPROTEINS .
-GLycoprotein have a range of functions within thr ell . 1.some glycoprotens allows cell to attach to echothe to form tissues such as nervous tisue.
27
glycoproteins (2)
-other glycoproteind play a role in the immuneytem , prsenting antigentd to vrlls .
28
glycoproteins (3)
-Other glycoproteins act as rece[tprs fpr hormoenes . -Carbodhyrates can aspp e found attached to phosholipid moelcules . -These are called GLYCOLIPIDS.
29
GLYCOLIPDS
-glyclipds are oftrn used when cells come into contact with rsvhother . -glycoipids on the surfce of onne cell , csn be recognised by anothder cell -we can deeterminr ehenever cells come into c ontact 2.glycolipds can alo act a antigrns --->determining bloood group.
30
diffusion box -btir in hr vrner -bpth dsides of the brrier contain the sme concentrtionn of gs A . -The cocnentrationo f gas A i he ame across oth sides of of the barrie r.
-However , oe side of the brrier contins a higher concenration of a different gas (gasB). -Bear in mind all the prticles have kinetic energy , as they are moving ranodly . -Particles are consttntly collidign with eachother .
31
If we was to remove the barrier ...
-we now have a higher concentration of gas b on the left hand side and a low concnetrtion of gas b on the right hand side . -scientists call this concentration grdient. -overtime , as particles move randomlu , the particles of gas b will spread out through the container . -at a certain point ,t he concneration of gas B will br yhr dsmr rveryehre . THERE IS NO CONCNETRATION GRADIENT .
32
THE spreading of [articles is clled diffussion .
diffuion if thr net movement of partices , from an area of higher concentration to a region of lower cocnentrtion (downwn the cocnetraiton grdien t) .
33
meaning of net movement .
-in diffusion , mor prticles re movng in one direction than another . -so netmovement just men overll movement .
34
co2 levels wthn cell
-co2 is higher on theiside than on the outside . -we have a oxnxentrrion gradient for co2 molecules whixh diffuse from an area of high concnetraauon \9in the cell) to an area of lower ocnenctration (otuside the cell ) , . Eventully the concentraation of co2 iwll be the same ont he outside and th einside of the cell ., EQUILLIBIRUM WILL BE REAACHED - AT EQUILIRUM , T HERE IS NO NET MOVEMNT OF PARTICLES DO DIFFUSION DOES NOT TAKE PLACE.
35
1. key poit aout diffusion
difusion is a passive processs . -Meaning it does not require metabolic energy to take place . -Metbaolic enetgy means energy released by respiration .
36
2. key point bout diffusion
As some chemicals can eeasily diffuse thorught he cell membrane while other chemcils cann;t the cel membrne is described as partilly permemable .
37
FCATROS AFFECING RATE OF DIFFUION (1)
Gretaer the concnetration grdient , thr greater the rate of difusion .
38
FCATROS AFFECING RATE OF DIFFUION 2
-AS THE CEell membrnae contains hdyorphobic center , chrged partilcles like ions will noy be bale to diffuse htourgh the memrnae -eter meolcule alhotugh they re polar yhry cn pass htourhg as they re very small . -contrasting ot uncharged moelcules lieke oyxgen where it candiffuse rpildy xross the membrn
39
FCATROS AFFECING RATE OF DIFFUION 3
size o th prticles is lso impront as wlel -generally smaller particles will iffuse faster than lager one s.
40
FCATROS AFFECING RATE OF DIFFUION 4
temeprtrue -inw rmer condtions , particles hae more kineti eegry nd diffuse at fasterrate t codler contions . (nt porblem or mammals and birds however as they maintain constn body temperature .)
41
FCATROS AFFECING RATE OF DIFFUION 5
Surface area -diffusion takes plce more reaplidly if he memrne has aLARGER surface aew compared toa smlle sufrce area .
42
FCATROS AFFECING RATE OF DIFFUION 6
distance that diffusion tkaes palce over . -greater the istnce ,s lwoer the rate of diffusion . explaining why CELL MEMRBANES ARE EXTREMEENT THIN .
43
THIN .FCATROS AFFECING RATE OF DIFFUION 7
lastly the presence of PROTEIN CHANNELA (facciliatte diffusion) , or carrrier porteins in the membrnae . KEY we are looking at specical type of ddiffusion clled FCILITTED DFFUSION .
44
-not all susbtnaces diffus e across the cell memrbane at the same rate .
as the center of the cell membrane is hydorphobic due to the fatty aicd tials of the phospholipd moelcules .
45
-Hydrophobic susbtnaces - steroid homroes can diffuse RAPIDLY across the memrbane .
-However , hydrohphillic substnses ,s uch as ions + polar moelcules , cnnot diffuse across the memrbane . -An excpetionto this is wtaer as ti is small.
46
-HYdro[hillic susbtances cannot diffue across membranes . -This is a porblem forcells as many of thee subsagnces are required fo rporceses isnisde the cell .
-to solve this problem , cells use facillitated diffusion
47
-In faciliated diffusion , hydroophillic suvstances iddfuce acreoss he cell memrbne via portein moelcuels .
-These portein moelcules allow the hydrophillic susatcnes to cross the memrbae without interacting with the hdyrophobic cente rof the phospholipid bilayer .
48
There are two tpes of protien movlueles involed in fcilaited diffusio .
-Both of these are example iof intrinsic / integral membranes plrotiens (compelelys pan the memrane from one side to the other )
49
Carrur oriteus
-Carrier porteis hae a bining site for a specific chemical . -When thar chemial bind s, it causes the tertairys trcutrue of the carrier porein toc hange . -This chnage in tertiary trucutre , broings the CHEMICAL ACROSS the memrbne where the chemical is no released /
50
Protein channels
A protein channel is a portein witha central pore . -Thsi pore or channle is lined with a hydrohillic amino acid + contians water . -Hydrophilic substances can pass thorgh the channels from ONE SID EO FTHE MEMERBAN ETO THE OTHE R.
51
IMPORTANT POINT BOUT PROTIEN CHNNELS 1
-Protrien channels are selectie for the chemical tht can pass thoruhg . -Menaing onlyc ertain chemicals can pass thoruh each rype of portein chnnel .
52
IMPROTANT PROTEIN ABOUT PROTEIN CHANNELS 2
-While soem types of protein channels are always open , othe rporteinc hannels only open in repsonse to certain trigger . -This could be a chemicla bdinging to the protein channel .. For exmpale a neurotransmitter . -Or a change int he voltage across the mwwbrane (see in enrvou system ).
53
KEY THINGS TO REMEMBER BAOUT FACILITATED DIFFUSION.
Facilitated idffusion is STILL idffusion . -Eventhough cttier proteins and channel protiens are used to diffus echemcials . -Chemcials still moe forma n area of highc onc to an area of low conc . -SECONDLY metabolic energy is not required .
54
-Looking at direct active transport
exmpale -lrge cocnentrio of lacium ions outise the celll and lwoer inside the cell . -This is a=common as calicum ions play a role in cell signlling .
55
-So cells re cosntntl trsnsferring calicum ions fromt he cytoplstm to outside the cell
-Int his case , calcium ions are moving orm a reion witha lwoer concentration to a region with a higher cocnentration . -Cells use active transprot to do this .
56
-In active tranpsort , crrier proteins in the memrbane tranpsort a chemical froma reion o lower concenration to a region of higher concentration ( agains tthe cocnentration fradient ,)
...
57
Active tranpsort requires metbolic enery --> porvided by ATP MOLECLE .
Actie tranpsort used to mvoe lots of dierent meolcuels + ions .. Both into + pt of cells ut always against the cocnetrationg raidient .
58
How does active tranpsort work (1)
-durign acrive tranpsort ,t hemoleucle or ion to be rransported ,a ttaches to a receptror ont he site of the crrier portein . -This takes palc eont he side of the meebrance which the chemical is ata a LWOER concnertation
59
How does active transport owrk (2)
A m oelcule of ATP then binds to the catier potein .
60
How does active transport work (3)
-Next ATP moelcules undergoes hydrolysis and porduce phospahte +a moelcue of ADP -Phospahr attaches to a carrrier portein + causes it to change shape .
61
How does active transport work (4)
-This shape chnge cuses the carrier protein to transport the moelcule or ion to the other side of the membrane where it is releasse d.
62
How does active transport work (5)
Phosphagte now leaves hte portien , causing it to reutn to it previous shap e.
63
How does active tranpsort work m(6)
Th adp + phsophte will alet retun into ATP inr espirtion /
64
key thing about active transport (1)
-active tranpsort uses A LTO OF TP . -So we find lots of it in mitochodnira in cells that carry out active tranpsort .
65
Key thing about active tranpsort (2)
-Carrier portiens used ina ctive tranpsort are specific . -So each carrier portein willonly transport one type of moelcule or ion .
66
one differenebtween faicliated idffusiona nd active transport .
Carrier porteins are DIFFERENT betweent he two prcesses
67
another difference betwen facilaited iffusiona dn active tranpsort
Howeve rin fiscliated idffusio , chemical sare moved odwn the conentration grandient and fcilited iffusion as a passiv process .
68
check sheet
on the left hand ide ,w e have pure water . -Right hand side we have a solution . -partially permemabme memrbane . -SKS s dolute is dissolved inw ter . -AS we said , the mwemrbane is partially permemabel , so the water meolcules can pass frelly around the meemrbane . -But the solultemoelcules cannot menaing they have to stya ont he right hand side of teh memrane.
69
LHS --> high cocnenraiton of wate r. -RHS has a low cocnentraion of water .
Menaing water moelcuels will diffuse fromt he lHS to the right hand side . -This diffusion of water -osmosis . RMEMEBER - OSMMOSIS IS A PASSIVE PORCESS .
70
Defention of osmosis
Omosis si the movoemet of water moleucles froma region of HIGH WATER POTENITAL to a region of lwoer water potential through a partially (or selectively)permemwbael memrbane .
71
Go back to the drawn diagram on the sheet
-Got water moelcules on both sides of the memrbne . -These water moeluels are COLLDIIGN WITHT HE MEMBRBANE . -These collisosns means that the water moelcles apply a PRESSURE ot the ememrbe . -Sciensits cllt hsi pressure the WATER POTENTIL . -Water potentil has a symbol SAI chek sheet . -bECAUSE WATER POTENITAL IS A MEASUR EOF PRESSURE THE UNIT IS kilopadscals.
72
Like we saw , the LHS od the memerbane has more water molecules than the rhs . -Menaing the pressure due to the waer moelcules is GREATER on the LHS than on the right . -Due to this ,t he water potential is GREATER ont he LEFT than on the RIGHT .
-HIgh water potenital on the LEFT than ont her ight . -Watermolcuels will moe by osmiss formt he left hand side to the right . -at soe point , boths ides of the emmbrane will ahve the same wate rpotential ,a t this point we have reched equlibrim so osmosis stops .
73
-Water moelcules will still be moving acorss the membrane , but hte SAME NUMBER of water moelcules will be moving in each direction .
-so the net . ocerall moememnt of eater moelcules =zero.
74
-Pure water has the highest possible water poteintal .
-This is becaus eprue water has the highest possible concnetration of water movlues .
75
Scienitsts have set the wate rporteital of pure water as 0 . -Meanign that the wate rpotential of an solution , MSUT BE less than zero (a negative numer)
-A MORE COCNENTRATED SOULTIOn ahs a lower wter potenital than a LESS COCNENTRATED SOLUTOIN .
76
CHEKC SHEET , what side willw aer move to .
water movlues iwll move by osmsosis froma reion of highw ate potenitl to a lwoer wate rpotential .
77
IN ODLER TEXTBOOKS
may see osmsos sdescriebs a s hyeprtonoc hyptonic isotonoci . -No longer used as osmsosis is descirbed int erm sof waterpotenital .
78
79
an animal cell example - red blood cell -the cytoplasm of all animal cells contains a number of solutes dissolved in water.
-these solutes include sugar glucose+ mineral ions sucha sthe sodium ion . -these dissolves solutes means that the cytoplasms has a negaite water poeintioal.
80
red blood cells are surroudned by w watery soltuion called blood plasma ,
-The water potenital of the blood plasma is the same as thee water potenital of the cytoplasms in red blood clls . check sheet for ysmbol erion .
81
as the water potenital is the same both INISDE + Outisde the red blood cll . -osmosis is not taking place.
-however , water oelcues are still moving across the cell memmbrnae . -but the rate of movement inwarss is the same as the movement outwards . -so no net , overall movment of water molecles as occured .
82
-now if we was o take an animal cll ,r ed blood clls nd plce into prue water which we know hs th ehighests water potential .
-the water potentila otuside the cell is now greater thsn the wter [ptenital isnide . -meniang water molcues now move inside the cell by somsosis . -this mvomeemnt of wate r movleucles , causes hte pressure inside ht eclel to iocnrease . -Scienitss call this h ydrstaic pressure .
83
What is the probelm with this ?
Cell emmrbane is not strong enough tow ithstand a significan tincreas eint he hysrostatic pressures isndie the cell . #-So if , wter emoclues move isnide the cell , this can cause hte cll memrbante to RUPTUTRE AND CELL to burst (check sheet)
84
-In the case of a rd blood cell , this is haemolsis .
...
85
-now palce the cell ina soluton with a LOWER WATER POTNEITL THAT CYTPOPLAMSS (OLUTIO OF GLCUOSE0
-int hsi case , water will move OUT of tcell by osmsosis causing the clel to SHRINk ,. -RHIS EFFECT WILL HAOE TI ALLC ELLS NOT JUST RED BLOOD CELLS .
86
-In animals , the water potential , of the lqiuid round the cells is TIGHTLY CONTROLLED . -SO its the same as the water potneital of the cytoplasms
...
87
PLANT CELLS SIMPLEID DIAGRAM -omitted evpeyreying apart fom vacuole and nucleus .
-unlike animal cells , plant cells are surroudned by a cellulose cell wll . -[lant cells contain a large permanent cvacuole with a soltuoin of susgar + minerla ions . -Beteeen the vacuole and clel wall , we have the PORTOPLAST .
88
-Tne protopoalst consists of the clel memrban e, the cytoplasms and the orgnelles found in the cytoplasms .
-due to the dissoles solids , the ienteriorr of the palnt cell ahs a relarivley LOW wate rpotneital . -Unliek in amimals , plants CANNOT eaislyc otnrol the enviornemtn aroun hteir cells . -SOmeitmes , plant cells ar surroudned bya very ILUTE solution or COENCNTRAD oslution .
89
What happens if we palce a paltn cell in a pure water ?
-Becuse te water potenital outside the cell is greater than insid e,w ater ENTERS the cell bys osmsis s . -Causing the hdyrostatic pressure inside the cell to icnrease . - BECAUE OF THIS , the portopolaast passes outwards agaisnt the cell wal .
90
REMEMBER ,T HE CELL WALL is amde of cellulsoe which is ery DSTRONG . -So rather than nrsing , the plant cell eocmesFIRM .
SCIENITSTS AY THE PLANT CELL IS TURGID . -The itneral pressure called turgor pressure. -At cetrain point ,t he turgpr pressur epreents anymroe wate enetring the clel by osmsis .
91
-Plant cell is placed ina solution which has a Lower WATER POTENITAL THAN INSIDE HTE CELL (CONCENTRATED GLUCOSE SOLUTION )
Int his case ,w ater moves OUT of the cell by osmosis , causing hte ortoplast ot PULL AWAY FROM THE CELL WALL . -Scienitsts all this plasmolyiss . -The plant vell is sid to be plasmolsyed .
92
-Whrn plsymolssis occurs ,t he space between the cell membrane + cellwall is now filled iwth asoltuoinw hich surrounds the plant cell
...
93
-IN many cases , cells require larg particles or moelcules o pass aross the cell memrbane .
-Inclluding large protein moeluls which are exported from the cell - e.g enzymes + anitobdies .
94
Larhe particles can also pas into th cell . Like antignes + bacteira
Ina ll of these cases , the particles or moelcules are TOO LARGE to cross t cell memerane , nu coaoted diffsion +active tranpsort .
95
Instead cells sue endocytosis and exocytossi . -In both processes , alrhe particles or moelcuels are transferred across the cell memrbane .
-Both processses can transfer a lrge uanitth of mateiral . -so scineittsts refer to these poresses as BULK transport .
96
What happens in endocytoiss ?
-Particles or moelcules are tranpsorted into the cell . -including large moelules such as proteins+ cells like bacteira.
97
s1 of endocytoiss
-cell memrbane folds inwards a form a cavity around the particles . -sceinitsts clal this porcess invaginaition. -the aprticles to be ransported are now in the cavity .
98
s2 of endocytosis
the particles to be transportd sre now int he cavity .
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s3 of endocytoiss .
next the meembrane compeltely encicrcles the particles to form a vesicle like this .
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s4 of enodcytosis
now the vescile movies into the cell . At this stage , what takes palce depends ont he mateirl int he vesciel . -for exmple acteria re diegsted in lssosmes .
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s5 of endocytosis
other materials can eb delievred to differen tprt of ht ecellw here htey are needed .
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there are two types of endocytsois . NUMBER ONE phagocytosis
-when solid mteirals sucha sbacteria are tkane into cells by endocytossis .
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second type of endocytoiis pinocytosis .
when endocystosis is used to transfer FLUID into the cells . -for example liwuid surroudning the cell . this is called pinoccystosis .
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what is exocytosis
-exocytosis moves material out of the cell . -This incldues secreted porteins uscha s hormoens +c eretain enzymes .
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s1 of exocytosiss
-At the start of exocytosis ,t he proteins are found in the golgi apparatus . -Here the porteins are modifieded before beindg ecreted .
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s2 exocytosis
next vesicles contain the portein , bud off the golgi apparatus + amk thier way towaeds h cell memabne . -the vescles hen fuse with the cell memrbane + the porteins secretd .
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KEY ; borh endocytosis +exocytoiss require energy .
e.g to move esicles to + from the cell emrbane , -this enegry is produces by the molecule ATP .
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inorganic ions are charged atoms / molecules that fall into two categories
-Cations - positively charged -anions -negaively charged
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What is the purpose of inorganic ions ?
-Inorganic ions are essential for life because ; -DNA -phosphate ions -Haemoglobin FE2+
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Inorganic in respiration .
-Inorganic ions are classed also as macronutrients (large NO3) traces of micronutrients
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if organisms do not manage to acquire enough of a particular ion , they become deficent .
calcium = ca2+ cation FUNCTION ; -Helps with the movement of organisms by regulating , transmission of impulses , from neurone to neurone . -helps to harden body part such as bones , teeth and exoskeleton .
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other functions of calcium
-Helps with the movement of organisms by regulating transmisssion of impusles from neurone to neurone . -stimulates muscle contraction . -Also helps to regulate protein channels , which affects the permeability of cell membranes . -many enzymes are activated by calcium , making it a key regulation in many biolgivla reactions .
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other improtant roles of calicum
also0 important for formation of blood clots . -calcium also has an important role in plants , development of the middle lamella in-between plant cell walls .
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Sodium ions
important inorganic ions na+, plays an important role in regulating osmotic pressure which is important in . -Helping planta remain turgid . -regulating absorption of water in the kidneys / nerves . -also important for the transmission of nervous impulses
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sodium ions (2)
-Also important in maintaining PH levels (7) -Sodium also involved in active transport and aids it and glucose + amino acids in the intestine .
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Potassium ions
important role in neurones transmissions \9like sodium ) . -Also involves in osmotic pressure +active transport . -also needed to help grow healthy leaves flowers in plants . -Plays roles in synthesising proteins + glycogen and breakdown of glucose .
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Hydrogen ions
-In photosynthesis and respiration in driving the production of ATP . -Hydrogen ions also determine the Ph of bodily fluids . -Blood Ph which affects its function of haemoglobin . ctyoplasmic ph which affects the function og enzymes .
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ammonium ions (inorganic ion )
-ammonia is a source of nitrogen which is many biological molecules subtles . -amino acids , which make proteins . -organic base which are components of nucleic aics liek DNA+Rna . -nirgoen makes vitamins lie vitamin B . -Chlorphylll
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ammonium ions
are also a formed from ammonia by accpeting a h dyorgen ions so they help maintain ph . -ammonium ions are also a aprt of the ntirogen cylve .
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nitrate ions
no3- -like ammonium nitrate ions are also used as a sorce of nitrogen for making . -aminoa cids which make up proteins / -ORGANIC BASES , whcih are components of nucliec aicd dna + rna
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vitamins also need nitorgen + used in chlorphyll
nitrogen ions are also a part of the nitrogen cycle .
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Hydrogen carbonate ;HCO3-
hydrogen carbonate ions -why co2 dissolves in blood. -Hydrogencarbonate ions therefore important in transport of co2 in the blood and regualtion of the .
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phopshate
-important in components of many biological molecules such as ; NUCLEOTIDES ; making nucleic acids like NDA /RNA ATP -Phosphoric acid . -Phosphate also important in the breakdown of glucose in respiration .

A-level Biology (26 decks)

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