The document summarizes key concepts about solute transport across membranes in plant and animal cells. It discusses passive diffusion of small molecules, facilitated diffusion mediated by carrier and channel proteins, and active transport driven by ATP hydrolysis including sodium-potassium pumps and co-transport. It also describes bulk transport mechanisms like phagocytosis, pinocytosis, and receptor-mediated endocytosis as well as exocytosis for exporting materials. The seminar was presented to discuss these transport mechanisms in detail.

1. DEPARTMENT OF BOTANY RTMNU NAGPUR UNIVERSITY NAGPUR
SEMINAR BASED ON
SOLUTE TRANSPORT ACROSS MEMBRANE
SUBMITTED TO
Dr. NM. DONGARWAR SIR

2. ABOUT MY INFORMATION
NAME :- SUHEL ANEESH ANSARI
CLASS :- M.SC II SEMESTER
SEMINAR BASED ON :- SOLUTE TRANSPORT
ACROSS MEMBRANE

3. TRANSPORT OF SMALL MOLECULES
o The internal composition of the cell is maintain because of the
plasma membrane is selectively permeable to small molecules.
o Most of the biological molecules are unable to diffuse phospholipids
bilayers, So the plasma membrane forms a barriers that block the
free exchange of molecules between the cytoplasm and the
external environmental of the cell.
o Specific transport proteins ( Carriers protein and channel
protein) then mediate the selective passage of small molecules
across the membrane allowing the cell to control the composition of
its cytoplasm

4. PASSIVE DIFFUSION
 The simplest mechanism by which molecules can cross
the plasma membrane is passive diffusion.
 During passive diffusion, a molecule simply dissolve in the
phospholipids bilayers, diffuse across it, and then dissolve
in the aqueous solution at the other side of the
membrane.
 No membrane protein are involve and the direction of
is determined simply by the relative concentration of
the molecule inside and outside of the cell.
 The net flow of molecules is always down their
concentration gradient from compartment with high
concentration to one with a lower concentration of
the molecule.

5. PASSIVE DIFFUSION CONTINUE......
 Passive diffusion is thus a non selective process by
which any molecule able to dissolve in the
phospholipids bilayer is able to cross the plasma
membrane and equilibrate between the inside and
outside of the cell.
 Importantly, only small, relatively hydrophobic
molecules are able to diffuse across the
phospholipids bilayer at significant rate.

7. FACILITATED DIFFUSION AND CARRIER PROTEIN
 Facillated diffusion like, passive diffusion,
involve in the movement of molecules in the
direction determined by their relative
concentration inside and outside of the cell.
 No external source of energy is provided, so
molecules travel across the membrane in the
direction determine by their concentration gradient
and, in the case of charged molecules, by the
electric potential across the membrane.
 Instead, their passage is mediated by protein that
enables the transported molecules to cross the
membrane without directly interacting with its
hydrophobic interior.

8. FACILITATED DIFFUSION AND CARRIER PROTEIN
 Facilated diffusion allow polar and charge molecule,
such as carbohydrates, amino acids, nucleotides and
ions to cross the plasma membrane.
 Two classes of protein that mediated facilitated
diffusion have generally been distinguish:-
 1) Carrier protein:- Carrier protein bind specific molecules
to be transported on one side of the membrane. They then
undergoes conformational changes than allow the molecule to
pass though the membrane and be released on the other side.
 2) Channel protein:- Channel proteins open pores thought
the membrane, allowing the free diffusion of any molecules of the
appropriate size and charge

9. FACILITATED DIFFUSION AND CARRIER PROTEIN
oCarriers proteins are responsible for the facilitated
diffusion of sugar, amino acid, and nucleotides across the
plasma membrane.
oThe uptake of glucose, which serves as a primary
source of metabolic energy is one of the most important
transport or provides a well known example of a carrier
protein.

10. THE GLYCOPHORIN AND GLUCOSE TRANSPORTER

11. THE GLYCOPHORIN AND GLUCOSE TRANSPORTER

12. IONS CHANNELS
 In contrast to carrier proteins, channel protein form
open pores in the membrane, allowing small
molecules of appropriate size and charge to pass
freely throw the lipid bilayer.
 One group of channel proteins is the porins with
permits the free of ions and small polar molecules
through the outer membrane of bacteria.
 The best characterized channels proteins, however
are ions channel mediate the passage of ions across
the plasma membrane.
 They have especially well studied in nerve and
muscle, where their regulated opening and closing is
responsible for the transmission of electric signals.

13. IONS CHANNELS CONTINUE…
 Three properties of ions channels are central to
their function.
 1.Transport thought channel is extremely rapid. More than millions ions
per second flow thought open channel a flow rate approx. a thousand
times greater than the rates of transport by carrier proteins.
 2. Ions channels are highly selective because narrow pores in the
channels proteins restrict passage to ions of the appropriate size and
charge. Thus specific channel protein allow passage of Na+, K+, and Cl-
across the membrane.
 3. Third must ions channel are not permanently open. Instead the
opening of ions channels is regulated by gates that transiently open in
response to specific stimuli ( called ligands-gated channel) open in
response to the binding of neurotransmitter or other signaling molecules,
other (voltage-Gated channel) open in response to change in electric
potential across a membrane.

14. LIGANDS AND VOLTAGE GATED CHANNEL

15. TRANSMISSION OF IMPULSE

17. ACTIVE TRANSPORT DRIVEN BY ATP HYDROLYSIS
 The net flow of molecule by facillated diffusion through
either carrier protein or channel protein, is always
energetically downhill in the direction determine by
electrochemical gradient across the membrane.
 In many cases, however the cell must transport
molecules against their conc. gradient.
 In active transport energy provided by another couple
reaction (such as the hydrolysis of ATP) is used to
drive the uphill transport of molecules in the
energetically unfavorable direction.
 The ions pumps responsible for maintaining gradients
of ions across the plasma membrane provide
important example of active transport driven directly
by ATP hydrolysis.

18. Na+ - K+ PUMP

19. COUPLE TRANSPORT AND SECOUNDARY ACTIVE
TRANSPORT
 Many molecules are transport into cell up a
concentration gradient thought a process that uses ATP
indirectly.
 The molecules move hand in hand with sodium ions or
protons that are moving their conc. gradients. This type
of active transport, called Cotransport.
 1) Establishing the down gradient:- ATP is used to
established the sodium ions or protons down gradient, which is
greater than the up gradient.
 2) Traversing the up gradient:- Cotransport proteins (
also called couple transport proteins) carry the molecules are
either a sodium ions or a protein together across the membrane.

20. COUPLE TRANSPORT AND SECONDARY ACTIVE TRANSPORT
CONTINUE….

21. BULK TRANSPORT
 In this process the plasma membrane extends
outwards and envelops food particles.
 Cell use three major types of endocytosis:-
Phagocytosis, pinocytosis and receptor mediated
endocytosis.
 Phagcytosis and pinocytosis:- If the material the cell
takes in its particulate( made up discrete particle), such as an
organism or some other fragment of organic matter, the process
is called phagocytosis.
 If the material the cell takes in is liquid it is called pinocytosis.
 Pinocytosis is common among animal cells. Mammalian egg
cells for example “nurse” from surrounding cells, the nearby cells
secrete nutrients that the motoring egg cell taken by pinocytosis.
 WBC ingest 25% of their cell volume each hour.

23. RECEPTOR MEDIATED ENDOCYTOSIS

24. EXOCYTOSIS
The reserve of endocytosis is exocytosis the discharge of material from
vesicle at the cell surface.
In plant cell, exocytosis is an important means of exporting the material
needed to contrast the cell wall through the plasma membrane.
Among protist, contractile vacuole discharge is a form of exocytosis.
In animals cell, exocytosis, proides a mechanism for secreting many
hormones, neurotransmitter, digestive enzyme an other subtances.

25. SUMMARY

26. REFRENCES
 Cooper G.M, R.E Hausman 2007, The cell a
molecular Approach.
 Raven Johanson, Biology, 2010
 Nelson D.L, M.M Cox, Lehninger principle of
Biochemistry, 2013
 L. Taiz, E. Zieger, 2003, Plant Physiology.
 G. Karp, 2016 Cell Biology
 Lodish, Berk, Krieger, Bretshier, Poegh Aman Scott,
2016 Molecular Cell Biology.
 E.D.P de Robertis 2003, Cell and Molecular Biology.
 Pravin kumar Jha, Mina Usha, Life Science I
 Source of Internet.

27. “GOOD THOUGHT”
“ If you want to live a happy life, tie it to a goal not to
people OR things”
-Albert Einstein

28. LOTS OF THANKS
Mr. Punit Kumar Patle
Mr. Umesh Chandewar
Mr. Adesh Walde
And My Beautiful Cute Sisters

29. DEDICATED TO ALL MY BEAUTIFUL SISTERS

30. IF ANY QUESTION??????
Ek Baat Hmesha yaad rakhna merii “ Aristotle Always
says…. Satisfaction is not always 100%
And My best Teachers Says….. Your Marks cannot Judge
your Talent…….