This document summarizes the key structures and organelles found within animal cells. It describes the cytoplasm, which surrounds the organelles, and lists some of the main organelles such as ribosomes, the endoplasmic reticulum, mitochondria, Golgi complex, lysosomes, centrosomes, and cilia. It then discusses the nucleus in more detail, describing the nuclear envelope, nucleoplasm, and nucleolus. The second document discusses the basic components of cells, including the cell membrane, cytoplasm, and nucleus. It describes the plasma membrane and its role in compartmentalization and transport. It also lists some other common organelles like chloroplasts, the endoplasmic reticulum, lysosomes, and

4. bacteria
protozoans
prokaryote eukaryote
nucleic acids proteins
polysaccharides membrane

5. Principal structures of
an animal cell
Cytoplasm surrounds the cell's specialized structures, or
organelles. Ribosomes, the sites of protein synthesis,
are found free in the cytoplasm or attached to the
endoplasmic reticulum, through which materials are
transported throughout the cell. Energy needed by the
cell is released by the mitochondria. The Golgi complex,
stacks of flattened sacs, processes and packages
materials to be released from the cell in secretory
vesicles. Digestive enzymes are contained in
lysosomes. Paroxysms contain enzymes that detoxify
dangerous substances. The centrosome contains the
centrioles, which play a role in cell division. The
microvilli are fingerlike extensions found on certain cells.
Cilia, hairlike structures that extend from the surface of
many cells, can create movement of surrounding fluid.
The nuclear envelope, a double membrane surrounding
the nucleus, contains pores that control the movement
of substances into and out of the nucleoplasm.
Chromatin, a combination of DNA and proteins that coil
into chromosomes, makes up much of the nucleoplasm.
The dense nucleolus is the site of ribosome production.

7. UNICELLULAR MULTICELLULAR

8. Shape & Size of cell
Shape of cell :
I. The cell have no definite shape
For ex: Amoeba has no definite Shape, unlike other organisms. It keep
change its shape.
Size of cell :
I. The size of cell in living organisms may be as small as a millionth
of metre or may be as large as a few centimeters.
II. The smmallest cell is 0.1 to0.5 micrmetre in bacteria. The Largest
Cell Measuring 170mm to 130mm is the egg of ostrich.
III. The size of the cells has no relation with the size of the body of the
animal or plant.
IV. The size of cell is related to function.

9. Parts of Cell & their Function
cell
Cytoplasm
Cell
membrane
Cell wall
Nucleus
Nuclear
membrane

10. The basic components of a cell are
Cell membrane, Cytoplasm and Nucleus.
The cytoplasm and nucleus are enclosed
within the cell membrane, also called
Plasma membrene.
In biology, the thin layer that forms the
outer boundary of a living cell or of an
internal cell compartment.
The outer boundary is the plasma
membrane, and the compartments
enclosed by internal membranes are called
organelles. Biological membranes have a
dual function: separation of vital but
incompatible metabolic processes
conducted in the organelles; and passage
of nutrients, wastes, and metabolic
products between organelles and between
the cell and the outside environment.
Membranes consist largely of a double
layer of lipids in which are embedded large
proteins, many of which transport ions and
water-soluble molecules

12. nucleus
chloroplast
endoplasmic reticulum
lysosome
cytoskeleton

14. Specialized structure occurring in
most cells (except bacteria) and
separated from the rest of the cell
by the nuclear membrane.
This membrane seems to be
continuous with the cell's
endoplasmic reticulum and has
pores that permits the passage of
large molecules. The nucleus
controls and regulates the cell's
activities (e.g., growth and
metabolism) and carries the genes.
Nucleoli are small bodies often
seen within the nucleus that play an
important part in the synthesis of
RNA and protein. A cell normally
contains only one nucleus.