Describe this picture. What is the basic substance required to make this structure.?

BRICKS ACT AS BUILDING BLOCKS TO CREAT THE BRICK BUILDING.

What are we made up of?

So what is the definition of a cell??

They are building blocks of all living things and they are the basic unit of life !!!!!

What do you think the ‘building block of a dog is ?

So what are the various points you can think of to describe a cell?

Cell TheoryAll living things are made up of cells. Cells are the smallest working units of all

living things.They are the structural and functional unit of

life. (why?)All cells come from preexisting cells through

cell division.

A cell is the smallest structural and functional unit of life.

Cell TheoryAll living things are made up of cells. Cells are the smallest working units of all

living things.They are the structural and functional unit of

life. (why?)All cells come from preexisting cells through

cell division.

A cell is the smallest structural and functional unit of life.

Examples of CellsAmoeba

Plant Stem

Red Blood Cell

Nerve Cell

Bacteria

adult human

tallest trees

chicken egg

frog embryo

most eukaryotic cells

mitochondrionmost bacteria

virus

proteins

atoms

diameter of DNAdouble helix

http://waynesword.palomar.edu/images/plant3.gif

http://web.jjay.cuny.edu/~acarpi/NSC/images/cell.gif

Organelles

Cell MembraneIt is the Outer membrane of an animal cell. It is

located below the cell wall in the plant cell. Its main function is to control the movement of

substances in and out of the cell.It is a Double layer called lipid bi layerScientists say that the cell membrane is

selectively permeable, which means that only certain substances can permeate (go through) the membrane.

It is found in both plant and animal cellsIt also helps give shape to the cell

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

Cell membrane

Cell WallMost commonly found

in plant cells & bacteria. NOT present in animal cells

Surrounds the cell membrane in a plant cell

Most important function is to give the cells shape and rigidity.

It also Supports & protects cells.

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

CytoplasmJelly-like substanceSurrounded by cell membraneAll cell organelles are embedded in this.It contains the chemicals which are

necessary to carry out all the reactions that happen within a cell.

Important chemical reactions occur in the cytoplasm whereby some of the products are utilized by the organelles.

Nucleus Easiest organelle to see under the microscopeControl center of the cellDirects cell activitiesSeparated from cytoplasm by nuclear membraneContains genetic material – DNAControls the production of proteins in the cellsAll the information regarding the cell and its

activities are stored here.

Nucleus

ChloroplastUsually found in plant cells. Also present in

trace amounts in Bacteria, fungi and algae. It is not present in animal cells. Surrounded by two membranes (inner and

outer) Contains a green pigment called chlorophyll

which traps light energy and converts it into food through photosynthesis.

It contains its own DNA.

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

Chloroplast

MitochondriaProduces energy through chemical reactions

– breaking down food.Surrounded by two membranes (outer and

inner membrane). The inner membrane is folded several times.

Controls level of water and other materials in cell

Recycles and decomposes proteins, fats, and carbohydrates

Contain their own DNA.http://library.thinkquest.org/12413/structures.html

VacuolesMembrane-bound sacs for storage,

digestion, and waste removal Vacuoles may contain large food

particles, enzymes, water, or many other substances. 

Usually one large vacuole is present in plant cell (takes up 95% of space)

Animal cells have small vacuoles but they are more in number.

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

RibosomesEach cell contains thousands of ribosomes. Produced in the nucleus of a cellThey act as factories of the cell to produce

Proteins.They can be found either in their free form

in the cytoplasm or attached to an organelle (The rough Endoplasmic Reticulum.)

It is made up of a large sub unit and a small sub unit.

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

LysosomeDigestive organelle. They contain acid enzymes to break down food

particles,waste materials and cellular debris. It can also destroy organelles that have been damaged. If the celllacks an adequate amount of food, the lysosomes may actually digest healthy organelles to provide the cell with energy.

Found only animal cellsShould the lysosome break and release its

powerfulenzymes, the entire cell can be destroyed, which is why the lysosome is sometimes called the "suicide sac."

Endoplasmic ReticulumTwo types – Smooth and

rough ERRough ER – as they have

ribosomes attached to their surface. Protein synthesis occurs here.

Smooth ER – Carbohydrate metabolism and lipid and steroid synthesis. No ribosome present.

Extends from the Nucleus