Chapter 5 Flashcards
What is compartmentislidiaom and why useful?
The formation of sepwrate membrane bound areas in a cell
1) allows different conditions which sre protium for that organelle to be set snd not affect others
2) lrotects other comoinets from potentially damaging comoonetdlike hydrohokic enxymes
3) incompatible resctions occur in the cell now happen compatibility as they by the, delved !
So incompatible now compatible , protected from danger, and optimum set
What use of plasma membrane?
- soeatea cekk contents from outside barrier
Controls what goes in and out of cell thus protecting its
# allows cells to communicate
And recognise foreign / self cells
Organelle bound membrane d
- another reason why do apt,entsiksisiton inirgsneles bound membranes is that dna is isoskted, which does tar,unneeded to be protected
So how is the plasma = cell surfsce membrane and other membranes organised?
A phospholipid bilateral
- here the phosphate heads of a phospholipid are charged snd so are hydrohokic in aqueous solutions, on the other hand the fatty acid chains are non polar and thus hydrophobic .
- thus phospholipid bilateral is arranged in two layers of ohopliipds such that the heads face the aqueous interior and exterior whereas the tails are sandwhiche in dtween
Here the ojiohste hesdsorinsye themselves to end on outside snd tsils on inside, and this allows the bilayerto interaction with both aqueous interior and exterior whilst protecting the fatty acid chsijdm d
What makes membrane known as fluid mosaic model?
- fluid = lhophlioirs are able to move in various positions relative to one another , g icing flexibility
- mosaic, due to the various ways the membrane is embedded with different intrinsic and extrinsic proteins such as gkycolipid glycoproteins etc , similar to a moadiac
Also phospholipid bulayer with two layers where hewds outside tail insiden
Ohophliodi mvoement
Why are they fluid ?
They can move laterally like 10^7 times per second , but flip flops once per month
This is because they are held by WEAK interactions which allows them to be fluid, but this is rehuakted by chrlostero,
What differen components lsit
Intricate and extrinsic proteins
Carrier proteins channel gkycomlipds glycoproteins chloelsetok
Different ekntrinsic snd extrinsic
The difference is that intrinsic proteins are embedded across BITH LAYERS OF THR MEMBRWNE whereas extrinsic is just in one layer
Intrinsic proteins have amino acids with HYDROPHOBIC R GROUPS ON OTUSIDE OF SURFSCE A, which interacts with hydronic fatty acid tails keeping them in place,
Okay so intrinsic = sloth layers, hdyriboc r gouonotusode, extrinsic = one layer can move snd hydrohokic on outside
Intrinsic interest with hydronic core whereas extrinsic the ohophste
What intend and extrinsic
Intrinsic = carrier protein and channel protein
Extrinsic = glycoproteins and lipids
Chleodtrol is bruh
Intrisnic csrrier protein
Intrinsic channel protein
Allows for passive transport but ALSO ACTIVE TRANSPORT , and this is done using atp to change shape of this protein to transfer molecules Against concentration gradient
This allows for simple diffusion down a conc gradient m but here they allow for POLAR MOLECULES SND IONS TO PASD THROUGH (often sftersimple diffusion, and this happens as the inside of channel protein had hydrohokic r groups
So carrier active and normal l channel normal but for hydrohokic thigns
Extrinsic glycoproteins
This is an,ossified protein with a cabrihdyrste chain on it
The function of these is to act as RECEPTORS for chemical signals
Basically when a chemical like a hormone or something binds to the glycoproteins , it causes a response from cell, w chin then can cause a cascade of evejts inside the cell, and this process is called CELL SIGNALLING
For example, chemical neutrandmitters across the synapse binds to gkycoltins which ilkcirt a response and carries the signal over
Or even red
Doors for honest like glucose on which caused breakdown of glycogen badly to glucose .d
It also plays a role in cell adhesion, joining cells to make tissues. The main thing is to be a receptor for chemical signals and play roles in cell signalling where receptor bind elicit reposnecsdcde event
Attached chain of carbohydrate snd varying length
What function if glucliods!
Theee instead are LIPIDS made SER modified with attached csbrihdyrste chains of varying length
Their function is to act as CELL MARKERS / antigens so that they can be recognised by cells as self or. Non self
Here glycoproteins = recorotd for cell signalling
Glyco,ions = cell markers an antigens
They both extrinsic
Cholesterol structure and unction
Structure = chleodterol is a lipid , with a 4 ring csrbin chsin that is hydronic snd a hydroxyl group which is hydrohokic due to being polar on another end
The function if chelosteol is to regulate the fluidity in the oholioid membrane and it can do with many ways
Cholesterol binds to the FATTY AFID TAILS , but interacts with the lhohohste heads by the hdyroyxlngrouo which is hydrohokic am father 4. Ring carbon hydrbici bidns with the fatty acid tsild
How does cholesterol regulate fluidity
In low temps it prevents them from cuts sliding snd msked more fluid by not allowing ohopkiidos from coming to close to become a solid
In high temps it stops from becoming too fluid as interactions between head and tail pull thrnoholplipids together
Finally it caused the phiplipidsto pack closer together which lead them MORE STABLE without making them more rigid, need some packing
So fluid in low temps by not making crystalide
Fluid high trmosby holding together so not too fluid
But also gives stability sithout making rigid
Proteins need to be in specific places for chemicsl resctiojsnto happen at
Dependent reactooms. Cirsitse contain all enxymes needed for repsirsiton
Micothdor inner network membrane cristae and Luddite matrix
Chloroplast has inner networks membrane called
Fluid is storms
Those make grans
Grans held by membranes called lamelase
Inenr. Network thylakoids, muktuoke trhkulods are granum grans held by lamellar , GRANS HOLD SLL THE Chlropkhll where light doendent photodytnrthid happend
Internsonkekbrsnes have all proteins
Factors affecting steufture e
Tmeorrtsur e
Chleodltro
Solvent
Temp increase
Increase temp phoplidpid have more kinetic energy which mesns increased movement snd thus increased fluidity
- increased fludity leads to LOSS OF STEUFTURE , and this leads to icnresdes pemesbiltu to the membrwne
If increase more, then eventually you hit the densturing point if all the proteins in the membrane. This leads to an even grester loss of steufture l but also as some proteins like channel snd csrrier affect the transport now permeability is increased all the way here too
So summary = kinetic energy increases fluidity which leads to loss of steufture snd lemrens,iTunes + denature into if the proteins lead sot more Leo’s of steufture snd oermsniltu but slsoqq root Enid involved in tensmsport denature then that indewse perkshiluntoo
Low temoe
Dedcresd rtemp they pack together fevresidng kduity snd smoked rigid
This forms ice crystals and thidnouncutrd the membrane and increased permeability
Someprotins may denature here which sgsin leads to loss structure and icnresse pemensiltu
Water esdneitls to formation of ohloplidh belayer
Because it caused the heads to orisntteat themselves to face water snd tsild to be on inside so bilateral forked
Organic solvents affect t membranes?
Organic solvents slime alcohol are non polar, these will disovoev the membranes didurping cells , and this is way they are used in antiseptic wipes.
Basically non polar substances organic dissolve membranes by ENTERING CELL MEMBRSNES AND making it lose structure, gain fludity and thus gain pemanktu
Again solvents enter the cell membranes , make them more fludity amd lose structure and thus uncrease oermsniktun
This explains behavioru if peopel when diring , as it disrupts the membranes of nerve cells and nit function well,nwhcih edplains why people ge tipsy
Basically some cells need perfectly intact membranes too function, and so when this is disrupted, then people get tipsy. Vey ray sting organic solvents can dissolve membrsnes sommcunt hat they completely die
Okay so investigation if temperature using memnrsne permsntikyt
Bsidslky inside bettroto there is vacuole which contains a red pigment , we are seeing how easy it is to increase permaniktybenough so that the red pigment goes through bith tonolast snd cell surface membrane . The more the membrane disuroted, the mor epigeknt release,d so we can use this as indication
1) cut equal discs of beetroot , same beetroot to cintrol , same surface area etc
2: then throughly wash to get rid of already present pigment = control the time spent too
3) add them to 100mL distilled water each , and each of them controlled
4) now place them into different remoertsure water baths but for the same time controlled
Gonna run blue light wavelentgj8
Should see increadethen drsmrisifllsu increase
Leave them here for a certain amount of time the same
5) then take them out , remove the discs each and test colorimetric for sbdorbsnce , the more absorbed , the more die released and so more membrane dsmsged explained by kinetic energy snd densturing of proteins which should show after certain temp it wrnt up a lot
Repeat three timed, use a control in colorimetric and a control each time at each tmeoertsurentonshow that tut was not heating of water causing it
To imroive x
Edpeiment use equipment that cure better esch time, blot tbeofreto get ride of die , and use SMALLER TEMOERTSURE RSNGED , because this allows you to acuucrysleu find where they probably denatured
Internally movemnt
Internally movemnt I’d movement of substsnces between cell membrane orgsnelles so in the cell, externally isnoutside of the cell
Here lsssive is due to the NATURAL MOTION OF PSRTICLED , and utiiskie that energy , whereas active movement required energy from external dorude in shsoenor atp
Diffusion
The net movement of particles from an area of high concentration to an area of low concentration down a concentration gradient until ewukibrkum is essybskished
Passife mkfment = required no energy
