Cell

CellLittle set of organ

Cellula(Latin)

Small room

Cell

Deffination• Cells are the structural and functional units

of all living organisms. • The cell was discovered by Robert Hooke in

1665. In 1835, before the final cell theory was developed, Jan Evangelista Purkyně observed small "granules" while looking at the plant tissue through a microscope.

• The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life

Cell Theory• All living things are made up of

cells. • Cells are the smallest working

units of all living things. • All cells come from preexisting

cells through cell division.

Examples of Cells

Amoeba Proteus

Plant Stem

Red Blood Cell

Nerve Cell

Bacteria

Two Types Two Types of Cellsof Cells

Two Types Two Types of Cellsof Cells

•ProkaryoticProkaryotic•EukaryoticEukaryotic

Pro-karyotic• Cells that lack a

membrane-bound nucleus are called prokaryotes

• Prokaryotic cells differ significantly from eukaryotic cells. instead of having chromosomal DNA, their genetic information is in a circular loop called a plasmid

• Prokaryotic cells feature three major shapes: rod shaped, spherical, and spiral. Instead of going through elaborate replication processes like eukaryotes, bacterial cells divide by binary fission

• bacteria are involved in many nutrient cycles such as the nitrogen cycle, which restores nitrate into the soil for plants.

Eukaryotic• Karyotic cell can be easily

distinguished through a membrane-bound nucleus

• Eukaryotic cells also contain many internal membrane-bound structures called organelles. These organelles such as the mitochondrion or chloroplast serve to perform metabolic functions and energy conversion. Another important member of the eukaryote family is the plant cell. They function essentially in the same manner as other eukaryotic cells, but there are three unique structures which set them apart. Plastids, cell walls, and vacuoles are present only in plant cells .

Difference between pro-karyotic & Eukaryotic cell

Prokaryotic cell Eukaryotic cellSmall cells (<5 um) Larger cells (> 10 um)

Always uni- cellular Often multi cellular

no nucleus or any membrane bound organelles such as mitochondria.

Always have nucleus & other membrane bound organless

DNA is circular without proteins DNA is linear associated with proteins to form chromatin

Ribosome are small (70S) Ribosome are large (80S)

No cytoskeleton Always has a cytoskeleton

Cell division is by binary fission Cell division is by mitosis/meiosis

Reproduction is always asexual Reproduction is sexual/asexual

Huge variety of metabolic pathway

Common metabolic pathways

Type :Eu-caryotic cell Prokaryotic cell

Cell Structure Cell Structure & Function& Function

Cell Structure Cell Structure & Function& Function

http://koning.ecsu.ctstateu.edu/cell/cell.html

Cell

Plasma membrane

Protoplasm

Surrounding the cell

Plasma-membrane

• Outer membrane of cell that controls movement in and out of the cell

• Double layer • Protect inner

organ

Protoplasm

• Reproduction• Chemical• Excretions• Irritability• Movement• Growth

protoplasm

Nucleus Cytoplasm

Protoplasm structure

NucleusBrain of the cell

• Directs cell activities

• Separated from cytoplasm by nuclear membrane

• Contains genetic material - DNA

Nuclear Membrane/Envelope

• Surrounds nucleus

• Made of two layers

• Openings allow material to enter and leave nucleus

http://library.thinkquest.org/12413/structures.html

Chromosomes

• In nucleus• Made of DNA• Contain

instructions for traits & characteristics

http://library.thinkquest.org/12413/structures.html

Nucleolus

• Inside nucleus

• Contains RNA to build proteins

http://library.thinkquest.org/12413/structures.html

Cytoplasm

• Gel-like mixture• Surrounded by cell

membrane• Contains hereditary

material • The cytoplasm has

three major elements; the cytosol, organelles and inclusions.

Cytoplasm

Vacuoles

Centreol

Ribo-some

Lyso-some

Golgi-body

Endoplasomic-reticulum

Mito-conidia

Cytoplasm

Mitochondria (power house)

• Produces energy ATP through chemical reactions – breaking down fats & carbohydrates

• Controls level of water and other materials in cell

• Recycles and decomposes proteins, fats, and carbohydrates

http://library.thinkquest.org/12413/structures.html

Endoplasmic Reticulum(Suicide bag)

• Moves materials around in cell

• Smooth type: lacks ribosomes

• Rough type (pictured): ribosomes embedded in surface .http://library.thinkquest.org/12413/structures.html

Golgi Bodies

• Protein 'packaging plant'

• Move materials within the cell

• Move materials out of the cell

• Hormone secreartion.

http://library.thinkquest.org/12413/structures.html

Ribosome'sEnergy of all

• Each cell contains thousands

• Make proteins• Found on

ribosomes & floating throughout the cell

• Internal messenger• Fat, protein

metabolism• Two type……• 70s & 80s

ribosome'shttp://library.thinkquest.org/12413/structures.html

LysosomeBag of enzyme

• Digestive 'plant' for proteins, fats, and carbohydrates

• Enzyme transfer• Create ATP• Transports

undigested material to cell membrane for removal

• Cell breaks down if lysosome explodes http://library.thinkques

Vacuoles

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

• Contains water solution

• Help plants maintain shape

http://library.thinkquest.org/12413/structures.html

Centrosome

• Strengthen cell & maintains the shape

• Moves organelles within the cell

• Separate  chromosome pairs during mitosis

Overall function of cell• Properties of Life

What defines something as living? • Molecule Transport

The cell must be able to obtain nutrients and other molecules to survive.  

• Reproduction Simply being able to sustain itself is not enough. Cells must be able to produce new generations to ensure the survival of their specie.

• Cellular Metabolism It takes energy to make things happen, even at the cellular level.

SoBuild-up your

cellHealthy &Live long