ion transport mechanism in cells

1. ION TRANSPORT
PRESENTED BY,
MANASA K N
2ND M.SC BOTANY
TERESIAN COLLEGE
MYSORE

2. CONTENTS
• INTRODUCTION
• TYPES OF ION TRANSPORT
• ACTIVE TRANSPORT
• PASSIVE TRANSPORT
• DIFFERENCE BETWEEN ACTIVE AND PASSIVE TRANSPORT
• CONCLUSION
• REFERENCES

3. INTRODUCTION
• The movement of ions across biological membranes.
• The transport of ion species can be passive (facilitated) or active.
• Facilitated transport is mainly mediated through ion channels
• where as active transport can be either conveyed by primary active
(ion pumps) transporters and secondary active (ion cotransporters and
exchangers) transporters

4. Types of Ion Transport
• Active transport
• Passive transport

5. https://differbetween.com/storage/img/images_3/what_is_the_di
fference_between_active_and_passive_transport_across_the_pl
asma_membrane.png
Passive transport is the movement of substances across the membrane without the expenditure of cellular
energy. In contrast, active transport is the movement of substances across the membrane using energy
from adenosine triphosphate (ATP).

6. A. ACTIVE TRANSPORT
• “Active transport is the movement of molecules across a membrane from a
region of lower concentration to a region of higher concentration against the
concentration gradient, often assisted by enzymes and requires energy”
• AT always leads to accumulation of molecules or ions towards one side of the
membrane.
• this process uses ATP – Adenosine triphosphate to pump molecules through a
concentration gradient. Complex sugar, ions, large cells, proteins and other
particles are transported in this process. There are two types of Active transport:
Primary Active transport
Primary active transport: the energy from hydrolyzing ATP is directly coupled to the
movement of sodium ions across a biological membrane
https://images.app.goo.gl/VAsg63QRKrjj8ePeA

7. Secondary active transport
• Secondary active transport: where one substrate moves down its
concentration gradient while the other moves against the concentration
gradient. Two types of transporters are employed: symporter (left),
when the directions of movement of two substrates are the same,
and antiporter (right) when the movement of two substrates are in the
opposite directions.

8. B. PASSIVE TRANSPORT
• The movement of substances down a concentration gradient from an
area of high concentration to an area of lower concentration without
the need for energy to be used.
• Passive transport is the fundamental movement of ions and other
molecular substances within the cells along the concentration
gradient, without any external energy. It is also known as passive
diffusion.

9. 3 types are passive transport
• Simple diffusion - The diffusion process occurred without any help of
transporter.
• Facilitate diffusion - The diffusion process occurs with the help of
transporter, that is mainly a protein that act as a channel or carrier. -
• Osmosis - water molecule move through the membrane

10. Simple diffusion
https://media.geeksforgeeks.org/wp-
content/uploads/20230328093309/Osmosis-vs-Diffussion.png
a simple diffusion is a form of diffusion that does not require the
assistance of membrane proteins. In essence, the particle or substance
moves from higher to lower concentration. However, its movement
does not need a membrane protein that will help substances to move
downhill.
EX; Diffusion of respiratory gases such as oxygen and carbon
dioxide in and out of the cell

11. Facilitated diffusion
• Facilitated diffusion is the passive movement of molecules or ions
across a plasma membrane by means of a transport protein in the
plasma membrane.
• Diffusion involving the presence of protein carrier molecules to allow
the passive movement of substances across a plasma membrane
EX; 1. Transport of biomolecules such as glucose, amino acids and
nucleic acids inside the cell
https://media.geeksforgeeks.org/wp-
content/uploads/20230328093233/Facilitated-Diffusion.png

12. https://www.sciencefacts.net/wp-content/uploads/2020/02/Simple-Diffusion-vs-Facilitated-Diffusion.jpg

13. Significance of Diffusion
• The significance of diffusion can be outlined as follows:
• Cells depend on the process of diffusion to transport various molecules like
glucose, oxygen, and ions across the membranes, carrying cellular processes.
• It occurs in various biological processes absorption of nutrients in cells, gas
exchange in lungs, etc.
• In chemical industries and chemical labs, it facilitates the mixing of reactants,
allowing chemical reactions.
• The process of diffusion occurs in plants. They absorb nutrients and water from
the soil through the process of diffusion.
• Diffusion affects the movement of ions in the neurons and generates electrical
charge.
• In the process of respiration, the carbon dioxide gas is diffused out through the cell
membrane into the blood.

14. Osmosis
• A special case of diffusion is osmosis.
• The movement of water or solvent molecule from the solution of
lower concentration to the solution of higher concentration to the
place of its lower concentration through a semi permeable
membrane.
• Endosmosis - movement of water into the cell
• Exosmosis – movement of water out of the cell
https://media.geeksforgeeks.org/wp-
content/uploads/20230328093309/Osmosis-vs-Diffussion.png

15. Active Transport Passive Transport
Requires cellular energy. Does not require cellular energy.
It circulates from a region of lower
concentration to a region of higher
concentration
It circulates from a region of higher
concentration to a region of lower
concentration
Required for the transportation of all the
molecules such as proteins, large cells,
complex sugars, ions, etc.
Required for the transportation of all
soluble molecules, including oxygen,
water, carbon dioxide, lipids, sex
hormones, etc.
It transports various molecules in the cell.
It is involved in the maintenance of the
equilibrium level inside the cell.
Active transport is a dynamic process. Passive Transport is a physical process.
It is highly selective. It is partly non-selective
Active transport is a rapid process.
Passive transport is a comparatively slow
process.
Difference between Active and Passive transport

16. Transpires in one direction. Transpires bidirectionally.
Active transportation is influenced by
temperature.
Passive transportation is not influenced by
temperature.
In active transport, carrier proteins are
required
In passive transport, carrier proteins are not
required
This process reduces or halts as the oxygen
content level is reduced.
This process is not affected by the level of
oxygen content.
Metabolic inhibitors can influence and stop
active transport.
Passive transportation is not influenced by
metabolic inhibitors.
Different types of Active Transport are –
Exocytosis, endocytosis, sodium-potassium
pump
Different types of Passive Transport are –
Osmosis, diffusion, and facilitated diffusion

17. CONCLUSION
• Ion transport is extremely important in the vital activity of all
organisms.
• A cell continually exchanges molecules and ions with its environment.
• When a cell transports a substance against its concentration gradient,
the cell must expend energy.

18. REFERENCES
• N.Arumugam(2017),Cell Biology and Molecular Biology,SaraS
Publications. Pp(117-121).
• https://www.ncbi.nlm.nih.gov/books/NBK537088/
• https://sciencefacts.net/simple-diffusion-vs-facilitated-diffusion.html

19. THANK YOU