CELL TRANSPORT Flashcards
What is Cell transport ?
refers to
the movement of
materials across the cell
membrane - passive
transport & active
transport’
What is active transport
the
movement of molecules
across a membrane from
a region of lower
concentration to a
region of higher
concentration against
the concentration
gradient.
Assisted by enzymes and
requires energy.
Primary active
transport?
uses
energy from ATP to
move molecules
across the cell
membrane against
their concentration
gradient
Secondary active
transport?
uses the
energy stored in an
electrochemical
gradient to move
molecules across
the cell membrane
Passive transport
movement of
materials across the
cell membrane
without the use of
energy.
❑Occurs when
substances move from
an area of high
concentration to an
area of low
concentration.
❑There are three types
of passive transport:
simple diffusion,
osmosis, and
facilitated diffusion.
❑Simple diffusion
molecules move from an
area of high concentration
to an area of low
concentration until they
reach equilibrium.
Osmosis
-the diffusion of
water across a selectively
permeable membrane from
an area of high water
concentration to an area
of low water
concentration.
-❑Facilitated diffusion
the
movement of molecules
across the cell membrane
with the help of a carrier
protein
CELL MEMBRANE: endocytosis
❑In endocytosis, the
cells absorb, large,
solid particles and
then deposit them
into a cell.
❑Membrane-bound
sacs form that pinch
off from the cell
membrane.
❑This process is often
used to bring large
particles, including
glucose into the cell.
CELL MEMBRANE: exocytosis
❑Exocytosis is the
opposite of
endocytosis.
❑Materials deposit to
the outside of the cell
from the inside
instead.
❑Vesicles are then
formed & are filled
with the materials
that are going to be
sent outside of the
cell.
❑They then fuse with
the cell membrane &
release the contents
outside of the cell. i
FOOD APPLICATION:
There are two membrane
separation techniques used
in the food industry:
1. Membrane filtration –
includes microfiltration,
ultrafiltration,
nanofiltration,
hyperfiltration & reverse
osmosis.
2. Electrodialysis - used for
separation of gas mixtures
growing interest in the food industry
There is growing interest in the food industry to develop
approaches for large-scale production of bioactive molecules
through continuous downstream processing, especially from
sustainable sources. Membrane-based separation technologies
have the potential to reduce production costs while incorporating
versatile multiproduct processing capabilities. This review
describes advances in membrane technologies that may facilitate
versatile and effective isolation of bioactive compounds.
FOOD APPLICATION (DIARY
INDUSTRIES):
Basic differences
between conventional
dead-end filtration and
cross-flow membrane
filtration.
Spectrum of
application of
membrane
separation
processes in
the dairy
industry.
.The membrane separation techniques utilized in the
dairy industry serve different purposes:
❑ RO – used for dehydration of milk, whey, UF
permeate and condensate
❑ NF – used when partial desalination of milk, whey,
UF permeate or retentate is required
❑ UF – typically used for concentration of milk
proteins in milk and whey and for protein
standardization of milk intended for cheese,
yoghurt and some other products, but it is also
used for clarification of fruit- and berry-juices
❑ MF – mostly used for reduction of bacteria in skim
milk, whey and brine, but also for defatting whey
intended for whey protein concentrate (WPC) and
for protein fractionation
