Fundamental Unit of Life - Cell

ATP (Adenosine Triphosphate)

After cellular respiration, the energy is stored in the former of ATP in mitochondria.

Cell Wall

Cell wall is made of cellulose. It is somewhat hard but permeable to most substances. It is found in plant cells.

Shape and Size of Cells

Cells come in all shapes and sizes. Some are spherical in shape while some are sprindle shaped or long and narrow. Some are microscopic and cannot be seen with the naked eye while some are larger and can be observed to an extender without needing a microscope.

Mitochondria

It is a capsule like structure. It is a double membrane structure. It is the site of cellular respiration. It has its own DNA and ribosome and can thus produce it's own protein. It helps in cellular respiration and is thus known as the powerhouse of the cell.

Cell

It is the fundamental and structural unit of life. Everything is made up of cells. A cell is capable of independent existence and can carry out functions which are necessary for a living being.

Plasma Membrane

It is the outermost foreign of the cell that separates the contents of the cell from its external surroundings. It's composed of proteins and lipids. It is a semi/selectively permeable membrane, that is, it only lets specific substances enter the into and out of the cell.

Endoplasmic Reticulum

It's a mesh like structure which is composed of numerous tubes. It extends from the plasma membrane to the nuclear membrane. There are two types of er: rough er and smooth er.

Function of plastids

Leukoplasts store food. Chromoplasts import various colours to parts of a plant. Chloroplasts give green colour to the leaves and is the site of photosynthesis.

Vacuoles

These are fluid Chambers present in a cell. These can be large and take up the entire space in a plant cell. Vacuoles are smaller in animal cells.

Plastids

They are found in plants. There are two types of plastids. Chromoplasts and Leukoplasts. Chromoplasts are coloured plastids while Leukoplasts are colourless. Chloroplasts are green in colour and are found in the green parts of the plant.

Golgi Complex

Composed of many sac like structures stacked one above the other. It is responsible for packaging substances in the cell.

Ribosome

Tiny dot like structures present of rough er and are responsible for protein synthesis.

Cell Theory (Schleiden, Shwann and Virchow)

-all living organisms are composed of cells. -the cell is the basic unit of structure, function and organisation in all organisms. -all cells arise from pre-existing cells.

Prokaryotes

-nucleus is absent. -not bound by a cellular membrane. Eg: bacteria

Eukaryotes

-nucleus is present. -membrane bound. Eg: all organisms other than bacteria.

Robert Hooke

Discovered cell

Leeuwenhoek

Discovered free living cells in pond water

Robert Brown

Discovered nucleus

Purkinje

Discovered protoplasm

Schleiden and Schwann

Cell theory

Nucleus

It is the brain of the cell. If plays am important role during cell division. It controls all the functions of the cell.

Function of er

Packaging substances in the cell and transportation of substances from the cell membrane to cytoplasm to nucleus and vice versa.

Lysosome

Sac like structures derived from Golgi complex. Contains digestive enzymes.

Suicide bag

The enzymes in the lysosome digest foreign particles and destroy them. Sometimes the lysosome may burst open and it's contents end up digesting the contents of the cell. The cells die in the process. This is why they're know as the suicide bags of the cell.