chp 2 biological chem DAT Flashcards
cells and organelles
what are the cell membrane components ?
phospholipids, carbs and proteins.
3 determinants -
temp , cholesterol and fatty acid sat
temp -
hot ; phospholipids spread out (more fluid)
cold; phospholipids get closer - membrane less fluid and more rigid
cholesterol -
maintains the distance when cold. holds phospholipids together when hot
fluid mosaic model -
cis - unsat fatty acid (bent = H on the same side ) FLUID
sat fatty acid RIGID
trans - unsat fatty acid ( H is on each app side ) RIGID
problem with a barrier -
cells need to move molecules across the membrane . they can cross through passive and active transport
passive transport -
utilizes “passive diffusion” ( substances diffuse DOWN their concentration grad.
NO CELLULAR ENERGY REQUIRED
2 types of passive transport -
simple diffusion and facilitated diffusion
simple diffusion -
small , uncharged , non polar , molecular , OSMOSIS
facilitated diffusion -
large, hydrophilic , charged molecules.
utilizes intergral membrane proteins.
facilitated diffusion ports -
uniport ( one molecule,one way )
symport (several molecule , one way )
antiport ( several molecules, opp ways)
passive transport : facilitated diffusion
channel protein - connect extra and intracellular environment. allowed passage of small polar molecules
carriers proteins : change the shape and only faces one side at a time.
channel proteins -
PORINS
usually not specific
normally allow any hydrophilic molecules
active transport -
3 types
primary active
secondary active
cytosis
primary active
uses energy from TAP hydrolysis , pumps ions against their concentration grad
secondary active
relies on energy source OTHER THAN ATP
transports molecules against their concentration Grad
relies on primary , uses energy another molecule releases
cytosis
facilitate bulk transport (larg polar molecules)
requires energy
2 types of cytosis
endo and exocytosis
Edno - phago,pino, receptor mediated endocytosis
exo
endo -
endocytosis - the formation of vesicle around something extracellular
phago -
cellular eating , undissolved material
pino -
cellular drinking , dissolved materials
receptor mediated endo
specific molecule bind to the peripheral membrane proteins
exocytosis
opposite of endo
meaterials exit the cell
what is the currency for cells ?
ATP
what are integral proteins ?
they will cross the entire lipid bilayer. They will be exposed in the extra and intra cellular membrane. they are receptors and transporters.
what are peripheral membrane proteins?
DO NOT CROSS BILAYER. they are only attached in the surface outside of the cell. they are polar. they act as adhesion and recognition proteins.
fluid mosaic model
it is the flow of the components- it has a lateral movement.
3 determinants of the fluid mosaic model-
temp, cholesterol and fatty acid saturation.
temp
phospholipids spread out when temp is hot and when its cold they are more rigid.
cholesterol
maintain the distance between phospholipids when its cold or hot. it acts as a balancer for fluidity
saturation
saturated - NO double bonds
Unsat - double bonds
trans unsat - double bond on opposite side STRAIGHT
cis unsat - double bond on same side BENT
crossing the cell membrane -
this is a problem for cells because they need to eat and cross waste.
how do cells overcome the cell membrane ?
passive and active transport
what is passive transport ?
diffusion -
no cellular energy is required
moving DOWN its gradient
uses ATP for energy
what are the 2 types of passive transport?
simple and facilitated
simple transport
small , uncharged, non polar molecules.
moving DOWN the gradient
-osmosis is a type of simple trans-
facilitated transport
large, hydrophilic, charged molecules.
uses integral proteins.
uniport, symport,antiport
uni - 1 molecule 1 way
Sym- many molecules 1 way
anti- many molecules pop way
types of integral proteins
channel and carriers
channel- they connect the extra and intra environment and allow small polar molecules to cross
carriers - they change shape and open 1 side at a time
active transport
molecules traveling AGAINST concentration gradient. REQUIRES energy (ATP) and it relies on carrier proteins
3 types of active transport
primary, secondary and cytosis
primary
uses energy from ATP hydrolysis and it pumps ions against concentration grad
secondary
relies on energy OTHER than ATP . transporting molecules against concentration molecules . uses energy molecule releases
cytosis
transporting bulk - large, polar , molecules and requires energy.
2 types of cytosis
endo and exo
endocytosis
cell will grab sometime from extracellular environment and wrap it in plasma membrane (plasma) and take it INSIDE the cell
types of endocytosis
phagocytosis-cellular eating , undissolved material
pinocytosis-cellular drinking , undissolved material or fluids
receptor mediated endocytosis- molecule bind to peripheral membrane
ORGANELLES -
eukaryotic and prokaryotic
e- men bound organelles
p-non membrane bound organelles
what surrounds each organelle ?
phospholipid bilayer
what is the cytoplasm ?
EVERYTHING inside and within the cell
what Is the cytosol ?
the intracellular fluid
DNA
instruction manual , transcription ans translation
DNA in eukaryotes and prokaryotes ?
E - nucleus and P- nucleoid
how do supplies get inside the nucleus ?
nuclear pores - a passage way to the nucleus
nucleus
DNA house
nucleolus
dense region , rRNA production and ribosomal subunit production
how do supplies get inside ?
nuclear pores
ribosomes
protein TRANSLATION
they are not organelles
E: 80 s (60 s and 40s )
P: 70s (50s and 30s)
rough ER
outer nuclear membrane surface
why rough ? because there are ribosomes bound to the surface
rough ER lumen
protein modification (glycosylation )
smooth ER
smooth ? no ribosomes
synthesize lipids, synthesize steroid hormones
detoxify cells and store ions
Golgi app
flatten sacs - cos and trans face
ER product modification (phosphorylation )
destination ; cytosol , cell membrane,extracell space, lysosome , vacuole
lysosome
braking down
acidic enzymes
functions at low pH
when are lysosomes used -
endocytosis,autophagy , apoptosis
vacuole
all plants and fungal cells have this
form by membrane fusing together
types of vacuoles
transport - large transport vesicles
food - merge with lysosomes
central - storage
contractile - pumps put excess water
endomembrane system
nucleus
nuclear envelope
rough and smooth ER
Golgi app
lysosome
vacuoles
cell mem
peroxisomes
not part of the endo system
breaks down fatty acids
detoxification
may break down proteins
generates hydrogen peroxide - oxidizing agent , produces reactive oxygen species
( excessive damages the DNA , potentially cancer)
what prevent this ? catalase
mitochondria
powerhouse , produces ATP
chloroplast
some plants and protist
( algae)
photosynthesis
centrosome
found near nucleus
pair of centrioles
serves as microtubule organizing centers MTOCs
cytoskeleton
lies within the cytoplasm
functions- structure, movement, transport
eurkaryotic cytoskeleton
microfilaments , intermediate microfilaments, microtubules
microfilament - actin
smallest diameter , double helix , rapid dis/assembly
intermediate filaments
medium diameter , many types of proteins (keratin )
long lasting
cellular support ( cell junctions , nuclear lamina )
motor proteins
kinesis and dyneins
transport cargo
ATP hydrolysis
microtubules
largest diameter
hollow tubes
helical shape
grow and shrink rapidly
function; structural support , cell division , cilia and flagella
kinesis
cargo towards the positive end of the microtubule
axonemal dyneins
propagates beating of the cilia and flagella
cytoplasmic dyneins
retrograde transport
cargo towards negative end of the microtubule
MTOCs
creates , extends and organizes microtubules
forms the spindle app
( guides chromes on opp side) anaphase
types of spindle app
kinetochores , polar microtubules , astral microtubules
type of MTOCs
centrosomes
present in animals
1 per daughter cell
centrioles
inhabit the centrosome
hollow microtubule
9 triplets of microtubules
where do centrioles come from
spindle fibers app
centrioles cilium and flagellum
centriole attaches to cell mem. the basal body produces cilia or flagellum
9 doublet of microtubules
E: use tubulin dimmers
P: flagellin
extracellular matrix
carbs , fibrous structural proteins, adhesion proteins
proteoglycans
glycoproteins
lots of carbs
fibrous structural proteins
fibroblast make collagen
strength and rigid
integrins
transmembrane proteins
signals cells about the extracellular environment
(grow, divide, differentiate, apoptosis )
fibronectin
connect integrins to collagen or preoteoglycans
laminin
active component of the basal lamina , similar to fibronectin
cell wall
structures, protection, filtration
plants - cellulose
fungi-chitin
bacteria - peptidoglycan
Archaea - polysaccharides
bacteria
peptidoglycan cell wall
adhesion
protection
cell to cell recognition
cell matrix junction
connect ECM to cytoskeleton
2 types
cell matrix junction type : focal adhesions
ECM to actin
cell matrix junction: hemidesomosomes
ECM to keratin
cell to cell junctions
tight
desmosomes
adhere
gap
tight junctions
water seal
desmosomes
extends across mem-keratin
connects cytoskeleton
adherent
extend across mem-
actin
connects cytoskeleton
gap junctions
connexons made of conexins
membrane channel proteins
tonicity
relative solute concentration of 2 solutions
determines osmosis
isotonic
intra and extra concentration are the same. ( animals cells prefer )
hyper
extra concentration I higher
water leaves the cell
hypo
intra concentration is higher
water enters the cell (plants prefer)
