The cell

STRUCTURES AND FUNCTIONS

THE CELL

THE CELL

The basic structural, functional and origin unit of life.

CHARACTERISTICS

• Size from less than 1 µm to 3 m lenght.

• Variables shapes and forms.

CHARACTERISTICS

• EVOLUTION

• SIGNALING

• DIFERENTIATION

FUNCTIONS OF LIFE

• NUTRITION

• REPRODUCTION

• RELATIONSHIP

STRUCTURES

• PLASMA MEMBRANE

• Selective permeability.

• Protection.

• It acts as a division between the celular environment

and the exterior of the cell.

• Sense and reacts to external stimulus.

• It´s a limiting barrier that covers the cell surface.

PLASMA MEMBRANE

• Double layer of lipid

molecules containing

embedded proteins.

• Phospholipids are

amphipathic

molecules:

• One end has charged

or polar region,

• And the tails, which

consists of two long

fatty acid chains, and

is nonpolar.

WALL CELL

• Plants, Fungi and Multicelular Protists

• Much more resistant membrane

• Protection

• 70% Celulose

CYTOPLASM

• Cytosqueleton.

• Cytosol.

NUCLEOUS

CELL STRUCTURES

• RIBOSOMES

• GOLGI COMPLEX

• ENDOPLASMATIC RETICULUM

• SMOOTH

• ROUGH

• LISOSOMES

MOTILITY

FLAGELLUM

• Is a lash-like appendage.

• Defined by function not structure.

• Bacteria, Archaea and Eucariotictypes.

CILIA

• Are slender protuberances that project from the much larger cell body.

• Motile and non-motile

TURGENCY PRESSURE

• VACUOLES AND CENTRAL VACUOLE:

• Responsable of mantaining the pressure inside the cells.

• Storage of substances, specially water.

Peroxysome:

• organelle thatneutralizes toxins, like the hydrogenperoxyde.

Lisosomes:

• organelle thatproduces digestiveenzymes and actsas the digestiveorgan of the cell.

CELLULAR TRANSPORT

OSMOSIS

• When membranes are impermeable to some molecules because of their size, polarity, etc. and only the smaller solvent molecules like water molecules will move across the membrane.

• It works with osmoticpressure.

Diffusion

• Molecules to move from higher concentration to low, just based on thermal energy.

• The motion from areas of high concentration to low is called diffusion.

Facilitated Diffusion

• Is when the cell uses a carrier protein tomove the substanceacross themembrane.

CELLULAR TRANSPORT

• If a molecule is to be transported from an area of low concentration to an area of high concentration, work must be done to overcome the influences of diffusion and osmosis. Since in the normal state of a cell, large concentration differences in K+, Na+ and Ca2+are maintained, it is evident that active transport mechanisms are at work.

• Active transport mechanisms may draw their enegy from the hydrolysis of ATP, the absorbance of light, the transport of electrons, or coupling with other processes that are moving particles down their concentration gradients.

CELLULAR TRANSPORT