La celula: la teoría celular, estructura y función. La división celular

La célula - Cell

1. Valorar la importancia de la teoría celular.

2. Conocer la célula y sus componentes (estructura).a) Membrana: control de intercambio e interacción.b) Citoplasma: orgánulos celulares.c) Núcleo: la información genética (ADN).

3. Conocer las funciones celulares.a) La función de los orgánulos celulares.

4. Tipos de células:a) Procariota y eucariota.b) Animal y vegetal.

5. La división celular:a) Mitosisb) Meiosis

OBJETIVOS:

CONTENIDOS:

1. Teoría celular2. Funciones de la célula:

a) Nutrición.b) Relación.c) Reproducción.

3. Tipos de células

4. La célula eucariota:a) Estructura.b) Orgánulos celulares y función,

5. La reproducción:a) Mitosisb) Meiosis

Cell theory

• Robert Hooke – first person to see cell (1665) • Leeuwehoek – first person to see living cells in pond water (1673)• Schwann – zoologist who observed tissues of animals had cells (1839)• Schleiden – botanist, observed tissues o plants contained cells (1845)• Virchow – reported that every living thing is made of vital units, known as cells (1850)• Remak - discovers cell division and affirm that cells come only from pre-existing cells.

1. All living things are made of cells

Longitudinal section of a root tip of Maize (Zea mays) by Science and Plants for Schools on Flickr (CC) http://flic.kr/p/bNNM6M

Unicellular organisms are single-celled and can carry out all of the functions of life independently.

Multicellular organisms have specialized cells to carry out specific functions.

2. Cells are the smallest units of life.

Paramecium multimicronucleatum by Proyecto Agua on Flickr (CC) http://flic.kr/p/7W7J3y

Organelles cannot survive alone.

Specialized structures within cells (organelles) carry out different functions.

3. Cells come Only from Existing cells

Cells multiply through division:

• Mitosis results in genetically identical diploid daughter cells.

• Meiosis generates haploid gametes (sex cells).

4-cell stage of a sea biscuit by Bruno Vellutini on Flickr (CC) http://flic.kr/p/daWnnS

WHAT´S A CELL?A cell is the smallest unit that is capable of performing life functions

Nutrition

Reproduction

Responsiveness

Cell Structure• All Cells have:

an outermost plasma membrane

cytoplasm, the region where chemical reactions take place. Comprises cytosol and the organelles.

genetic material in the form of DNA

Cell Structure

• All Cells have:an outermost plasma membrane

• Structure – phospholipid bilayer with embedded proteins

• Function – isolates cell contents, controls what gets in and out of the cell, receives signals

Cell Structure

• All Cells have:genetic material in the form of DNA

• Eukaryotes – DNA is within a membrane (nucleus)

• Prokaryotes – no membrane around the DNA (DNA region called nucleoid)

Cell Structure

• All Cells have:cytoplasm with organelles

• Cytoplasm – fluid area, gel-like, inside outer plasma membrane and outside DNA region

• Organelles – is a specialized subunit within a cell that has a specific function, and it is usually separately enclosed within its own lipid membrane

Eukaryotes cellscells that contain nuclei

Eukaryotic Cells• Structures in all eukaryotic cells

– Nucleus– Ribosomes– Endomembrane system

• Endoplasmic reticulum – smooth and rough• Golgi apparatus• Vesicles• Lysosome

– Mitochondria– Chloroplast– Cytoskeleton

Cell boundaries 1• Cell membrane Thin, flexible membrane that

surrounds the cell.

Cell Membrane - structure✔ Lipid Bilayer:

• Double-layered sheet of phospholipids.• Membrane protein.• Glycoside.

Cell Membrane - structure Anchoring the

cytoskeleton to provide shape to the cell, and in attaching to the extracellular matrix and other cells to help group cells together to form tissues.

Responsiveness.

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Outer membrane of cell that controls movement in and out of the cell (selectively

permeable).

Cell membrane - funtion

• Passive transport (Facilitated diffusion) – when the plasma membrane “helps” particles pass through protein channels.

No energy used

Cell membrane - funtion• Active transport – when the plasma

membrane uses energy to move particles against a concentration gradient.

•Cell walls Rigid layer around the membrane found only in bacteria, fungi and plants.

Cell boundaries 2

Cytoplasm• Area enclosed within the cell membrane.• Contains hyaloplasm or cytosol: jelly-like

mixture of cytoskeleton filaments, dissolved molecules, and water (80%).

• Contains all the organelles.• It is within the cytoplasm that most cellular

activities occur, such as many metabolic pathways.

Mitochondrion

• Produces energy through chemical reactions – breaking down fats & carbohydrate

Chloroplast

• Contains green chlorophyll• Where photosynthesis takes place

RE and Golgi apparatus

Endoplasmic reticulum• Moves

materials around in cell:

• Lipids and carbohydrates in smooth type

• Proteins in rough type

Golgi apparatus

• Protein 'packaging plant'• Move materials within the cell and out

of the cell by using vesicles

Vacuole

• Membrane-bound sacs for storage, digestion, and waste removal

• Help plants maintain shape

Lysosome• Vesicles containing enzymes, which are capable of

breaking down virtually all kinds of biomolecules.• Transports undigested material to cell membrane

for removal

RibosomesMolecular complex of protein synthesis (translation).Found on rough endoplasmic reticulum (RER) and

floating throughout the cell.Consist of two components:

• small ribosomal subunit which reads the RNA• large subunit which joins amino acids to form a

polypeptide chain. It is composed of: ribosomal RNA (rRNA) and a

variety of proteins.

Cytoskeleton Support organelles and cell shape

Place a role in cell motion

Centrioles

Lead cromosomes movement during cell division

Control flagella and cilia vibration

Nucleus• Nuclear membrane, lipid bilayer. • Contains genetic material – DNA.• Nucleolus: rRNA, ribosomal proteins, immature ribosomes.

Cell division

MITOSISDivisión por mitosis - Manuel Antonio Medina

Stages of mitosis – McGraw-Hill

Fases de la mitosis – John Kyrk

http://www.juntadeandalucia.es/averroes/manuales/materiales_tic/Cell_anim_archivos/Cell_anim_archivos/mitosis_Medina.swf

http://www.juntadeandalucia.es/averroes/manuales/materiales_tic/Cell_anim_archivos/Cell_anim_archivos/mitosis_citoknsMCGRAW.swf

http://www.johnkyrk.com/mitosis.html

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MEIOSISDivisión por meiosis – Manuel Antonio Medina http://www.juntadeandalucia.es/averroes/manuales/materiales_tic/Cell_anim_archivos/Cell_anim_archivos/meiosis_Medina.swf

Stages of meiosis – McGraw-Hillhttp://www.juntadeandalucia.es/averroes/manuales/materiales_tic/Cell_anim_archivos/Cell_anim_archivos/meiosisMcGraw.swf

Fases de la meiosis – John Kyrkhttp://www.johnkyrk.com/meiosis.html

http://es.allreadable.com/5d90GNE COMPARACIÓN MITOSIS-MEIOSIS