ch 2- cells and organelles Flashcards
what membrane proteins have polar and non polar parts and what membrane proteins have only polar parts
integral- amphipathic
peripheral
function of integral proteins
cell signalling/ transport
agonist vs antagonist
agonist- bind to receptors and functionally activate target
antagonist- bind and preventother molecules from binding inhibiting prodcution of a response
what molecules undergo simple diffusion across a lipid membrane
O2
CO2
H20
lipid soluble molecules like steroids
small uncharged
facilitated transport and examples
diffusion through channel proteins
large or charged
K
Na
glucose
sucrose
Cl
down concentration gradient
active transport and example
against conc gradient using CARRIER PROTEINS
Na/k pump establishing membrane potential
primary- using ATP hydroysis
secondary- using free eenrgy relased when OTHER things go DOWN thier conc gradient
another name for cotransporter
sumporter
secondary active tranport pairs one element going down its concentration graidient to power the movement of another against its concentration gradient
cytosis
bulk transport of hydrophillic molecules
active transport
cytosol vs cytoplasm
cytosol- fluid aqueous intracellular
cytoplasm- cytosol AND organelles
what occurs in the nucleus
DNA replication and transcription
nuclear envelope
2 phospholipid bilayers with a perinuclear space
nuclear lamina
provides structural support to the nucleus and regulates DNA and cell division
nucleolus
produces rRNA and assembles ribosomal subunits consisitng of rRNA and proteins
what are ribosomes
not organelles
ribosome assembly
in euk- in nucleoplasm we make the 40 and 60s and the 80 s is made in the cytosol
prok- 50 and 30 s are made in the cytosol and 70s is also made here
free floating vs Rough ER riboomes
free floating- make proteins that function in the cytosol
rough ER ribosomes- make proteins that are sent out of the cell or to the cell membrane
what are the types of connective tissue
blood
bone
cartilage
adipose/ fat
dysplasia
evelopment of phenotypically abnormal cells in a tissue that can lead to cancerous growth
metaplasia
somatic cell undergoing transformation into another spcialized type of somatic cell
hyperplasia
inc in number of cells in organ or tisssue that appear normal under microscope - seen in begining of cancer
hypertrophy vs atrophy
hyper- inc in cell size due to inc metabolic activity
atophy- dec in cell size due to a dec in metabolic activity
what is continuous with the outer membrane of the nuclear envelope
the rough ER
proteins synth in the rough ER ribosomes…
are sent to its lumen to be modified (glycosylation)
function of smooth ER
synth lipids and produce steroid hormones and detoxify cells
what organ would be high in smooth ER
liver
what is the function of the golgi
store, modify, export proteins that will be secreted from the cell
made up of crisernae that are flattened sacs
golgi and ER connection
vesicles come from ER to the cis face of golgi and they leave on the trans face that is closest to the cell membrane
lysosomes
what do they contain
organelles that break down substances taken in by endocytosis through hydrolysis
also contain digstive enzymes that function at low PH
carry out autophagy and apoptosis
autophagy
break down of cell machinery
proteasomes
simiar funciton to lysosomes
protein complexes
degrade unneeded or damaged proteins that are tagged by UBIQUITIN by proteolysis
tonoplast
in central vacoules - helps cell rigidity - storage and material breakdown
what do storage vacoules store
starches, pigments, toxic substances
contractile vacoules
in single celled organisms and fucntion to actively pump out excess water
endomembrane system
grop of organelled and membranes that work to modify,package,and transport proteins that are entering or exiting the cell
nucleus
rough and smooth ER
gogli
lysosomes
vacoules
cell membrane
ECM component
proteoglycan
collagen
integrin
fibronectin
laminin
proteoglycan
type of glycoprotein that has high proportion of carbs
collagen
most common structural protein
organized into collagen fibrils- fibers of glycosylated collagen secreted by fibroblasts
integrin
A transmembrane protein that facilitates
ECM adhesion and signals to cells how to respond
to the extracellular environment (growth,
apoptosis, etc.).
fibronectin
A protein that connects integrin to
ECM and helps with signal transduction.
laminin
Behaves similarly to fibronectin.
Influences cell differentiation, adhesion, and movement. It is a major component of the basal lamina (a layer of the ECM secreted by epithelial cells).
what provides structural support for cells with low or no ECM
cell walls- carb based strcutures
what are cell walls found in
plants- cellulose
fungi- chitin
bacteria- peptidoglycan
archaea
primary component of bacterial cell walls
peptidoglycan- polysaccharide with peptide chainsg
glycocalyx
is a glycolipid/glycoprotein coat found
mainly on bacterial and animal epithelial cells. It helps with adhesion, protection, and cell recognition.
cell matrix function
connects ECM to cytoskeleton
focal adhesion
hemidesmosomes
focal adhesion
ECM connects via integrins to actin microfillaments inside the cell
hemidesmosomes
ECM connects via integrins to intermediate fillaments inside the cell
tight junctions
Form water-tight seals between
cells to ensure substances pass through cells and
not between them.
desmosomes
Provide support against
mechanical stress. Connects neighboring cells via
intermediate filaments.
adherens junctions
Similar in structure and
function to desmosomes, but connects
neighboring cells via actin microfilaments.
gap junctions
Allow passage of ions and small
molecules between cells. Formed from
transmembrane proteins known as connexons.
Gap junctions are only present in animal cells.
middle lamella
only in plant cells
sticky cement similar in fucntion to tight junctions
plasmodesmata
Tunnels with tubes between
plant cells. Allows cytosol fluids to freely travel
between plant cells.
microtubules
largest in size
structural integrity
hollow
walls made of tubulin protein dimers
form centrioles used in cell division
found in cilia and flagella
kinesin and dynein
motor proteins that transport cargo along microtubules
kinesin- anterograte- towards positive side- edges of cell
dyenin- retrograte- towards negative size- centre of cell
MTOCs
microtubule organizing centres
present in euk cells and organize microtubule extension
centrosomes
made of a pair of centrioles made of microtubules at 90 degrees
when do centrioles replicate
during the S phase givinig each cell one centrosome (pair of centrioles)
cilia
only in euk
locomotion - motile cilia - move cell or fluid
non- motile cilia- act as cellular antennas that recieve signals from neighbouring cells and enviroment
what are cilia made of
microtubules made of tubulin- produced by a basal body- formed by the mother centriole
composed of polymers of tubulin with 9+2 array
flagella
both euk and prokaryotes
prokaryotic flagella
polymers of flagellin - no 9+2 array
NOT MICROTUBULES
move in rotary motion
proton driven
rotary motor
eukaryotic flagella
composed of polymers of tubulin with 9+2 array
move in bending motion
larger and more complex
ATP driven
complex sliding fillament system
peroxisomes
hydrolysis of stored fatty acids
detocification
generate hydrogen peroxide- can become ROS that can cause damage through free radicals
contain catalase- break down peroxide to water and oxygen
mitochondirla inheritance
maternal
plastid
example- chloroplasts
double membrane organelles fonud exclusively within plant cells and algae
fucntion in photosynth and storage of metabolites
intermediate fillaments
between microfilaments and microtubules in size.
more stable than microfilaments and
help with structural support. example, keratin, Lamins are a type of intermediate filament in nuclear lamina (network that supports the nucleus)
microfillaments
smallest structure of the cytoskeleton, and are composed of a double helix made of two actin filaments.
cell movement
quickly assemble and dissasemble
cleavage furrow
cyclosis
muscle contraction
ACTIN AND MYOSIN
cyclosis
(cytoplasmic streaming): The flow (or
stirring) of the cytoplasm inside the cell. It is driven
by forces via actin (microfilaments) and myosin
movement, in a manner similar to muscle
contraction.
