This document discusses metal ion transport and storage in biological systems. It outlines the general properties of transport systems like ionophores, ion channels, ion pumps, and carriers. Mechanisms of metal ion storage involve ferritin and metallothionein, which allow organisms to accumulate high intracellular levels of metals without toxicity. Specific metal ions like sodium, potassium, calcium, and iron are discussed in terms of their importance, transport mechanisms, and how concentration gradients are maintained across membranes. Problems associated with metal ion transport include maintaining selectivity to accumulate beneficial ions while excluding toxic ones.

1. Metal Ion Transport and Storage

2. Inorganic chemistry
• By
Anwish Nawaz Abbasi
Bilal Qadeer Kyani
Muhammad Ahmed ALI
Hamza Tariq

3. Outlines
• Metal Ions Bioavailability
• General Properties of Transport Systems.
• Mechanisms of metal ion storage & resistance.
• Specific Metal Ions
K / Na
Fe
Ca
• Problems of Metal Ion Transport.

4. Introduction
• Chemical Properties.
• Catalyze oxidation & reduction.
• Act as Lewis acid in hydrolytic enzymes. eg: Zn
• Structural Cofactor.
• Problems.
• Genetic diseases.

5. Metal Ion Bioavailability.
• Bioavailability term implies more than just the
incidence of an element on Earth and includes
its prevalence in environment where life is
found.
Nickel in the Earth's core.
Zinc sulfide in the biosphere.
Molybdenum in the ocean

6. Bioavailability.
• Fe is fourth most abundant element in Earth’s
crust.
• For mammalian cells, the source of metal ions
is the blood plasma.

7. General properties of transport
systems.

8. Ionophores
•special carrier
molecules that wrap
around
•metal ions.
•Pass through the
membrane by
diffusion.

9. Ion Channels
•Large pores in
membrane.
•Allow to
movement of
substrate across by
diffusion

10. Ion pumps
Molecules using energy to
transport ions in
one direction through a
membrane.
Primary active transport system.

11. Carriers
•Bind to substrate
on one side of
membrane.
•Confrmatinal
change.
•Release the
substrate on
opposite side of
membrane.

12. Mechanisms for membrane Transport
• Passive Transport :
• Movement of ions
• Due to concentration gradient.
• Requiring no energy source.
• Ionophores
• , Ion channels.
• Active Transport :
• Movement of ions.
• Against the concentration gradient.
• Requiring energy from ATP hydrolysis.
• Ion pumps.

13. Mechanisms of metal ion storage &
resistance
• Organisms store metal ions.
• It have more benefits.
• Allow the accumulation of high intacellularLebels
of metal ions without the toxic.
• Understood
• mechanisof metal ion storage are,
Ferritin
Metallothionein

14. Ferritin

15. Metallothionein

16. Metallothionein
cytopalmic
• metal
• binding protein.
• Involved in ion storage & detoxification.
• Small ,cysteinerich proteins that bind Zn2+,Cd2+
Cu2+ & cysligands
• Found in cyanobacteria,fungi,plants,insects
&vertebrates.
• Bind metal ions with high affinity.

17. Sodium Na+
• Major
• cationin human body
• Important for
• membrane function
• Nerve impulses
• Muscle contraction
• Prevent blood clotting
• Present in stomach walls, gallbladder and

18. Potassium K+
• Important for
• Membrane function
• Maintaining osmotic balance
• Cofactor in photosynthesis and respiration

19. Sodium &Potassium
Concentration of [Na+] &[K+] –nside red blood cells
[Na+] =0.01M [K+] =0.09M–Outside red blood
cells[Na+] =0.16M [K+] =0.01M
• Ion pump is required to maintain concentration
gradient
• Also
• Ionphore
• Ion channel are used for Na & K ion transport

20. Sodium &Potassium pump

21. Selectivity of the process
Depends upon
• Differences in ionic radii.
• Coulomb forces
• Bases stronger than H2O bind preferentially to
the hard acid Na
• Bases weaker than H2O –bind preferentially to
the hard acid K

22. Calcium
Present in bones, enamel, shells
• Important for
• Signal pathways
• Skeletal material
• Maintaining potential difference across
membranes
• Concentration
• Outside cell = 0.001M
• Inside cell = 10-7 M

23. Calcium Regulaton.
Ca is in cytoplasm.
• pumped in to sarcoplasmicreticulum (A form of
endoplasmic reticulum)
• Up to 0.03M
• Inside SR Ca is bound by calsequestrin
• Hormone induced ion channels releases Ca from
SR to muscle cell
• Muscle contraction is triggered by sudden release
of Ca

24. Calcium pump

25. Transport & storage problems.
Capture of trace ions from the environment
• Control the concentration.
• Bulk ones present in high concentration.
• Trace ones actively accumulated &insoluble.
• Selectivity of ion uptake is essential.
• Toxic ions excluded.
• Beneficial ions accumulated.
• Specialized molecules have evolved.

26. Transport & storage problems
Charged ions pass through a Hydrophobic
Membrane.
• Neutral gases & low charge density ions move
directly but high charge density require help.
• Metal ions transport to their location for use
& storage.
• Release from ligand & storage require
additional molecules.