science p.p.t .animal cell's
TRANSCRIPT
CELL:-
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 .The cell was discovered by Robert Hooke in 1665. The word cell comes from the Latin cellula, meaning "a small room". The descriptive term for the smallest living biological structure was coined by Robert Hooke in a book he published in 1665 when he compared the cork cells he saw through his microscope to the small rooms monks lived in
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Multicellular organisms
Unicellular organisms
Category Animal Cell Plant Cell
Shape: Round (irregular shape) Rectangular (fixed shape)
Chloroplast: Animal cells don't have chloroplastsPlant cells have chloroplasts because they make their own food
Vacuole:One or more small vacuoles (much smaller than plant cells).
One, large central vacuole taking up 90% of cell volume.
Centrioles: Present in all animal cells Only present in lower plant forms.
Plastids: Absent Present
Cell wall: Absent Present
Plasma Membrane: only cell membrane cell wall and a cell membrane
Lysosomes: Lysosomes occur in cytoplasm. Lysosomes usually not evident.
IMPORTANT PARTS OF
ANIMAL CELL
CELL MEMBRANE
CYTOPLASM
NUCLEUS
ENDOPLASMIC RECTICULUM
GOLGI APPARATUS
LYSOSOMES
MITOCHONDRIA
VACUOLES
CELL MEMBRANEThe cell membrane or plasma membrane is a biological membrane that separates the interior of all cells from the outside environment. The cell membrane surrounds the cytoplasm of a cell and, in animal cells, physically separates the intracellular components from the extracellular environment. Fungi, bacteria and plants also have the cell which provides a mechanical support for the cell and precludes the passage of larger molecules. The cell membrane also plays a role in 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. On December 29, 2011, chemists at Harvard University reported the creation of an cell membrane
CYTOPLASMThe cytoplasm is the gel-like substance residing between the cell membrane holding all the cell's internal sub-structures (called organelles), except for the nucleus. All the contents of the cells of prokaryote organisms (which lack a cell nucleus) are contained within the cytoplasm. Within the cells of eukaryote organisms the contents of the cell nucleus are separated from the cytoplasm, and are then called the nucleoplasm. The cytoplasm is about 80% water and usually transparent.It is within the cytoplasm that most cellular activities occur, such as many metabolic pathways including glycolysis, and processes such as cell. The inner, granular mass is called the endoplasm and the outer, clear and glassy layer is called the cell cortex or the ectoplasm.The part of the cytoplasm that its not held within organelles is called the cytosol. The cytosol is a complex mixture of cytoskeleton filaments, dissolved molecules, and water that fills much of the volume of a cell. The cytosol is a gel, with a network of fibers dispersed in water. Due to this network of fibres and high concentrations of dissolved macromolecules, such as proteins, an effect called macromolecular crowding occurs and the cytosol does not act as an ideal solution. This crowding effect alters how the components of the cytosol interact with each other. Movement of calcium ions in and out of the cytoplasm is thought to be a signaling activity for metabolic processes
NUCLEUSThe nucleus is a membrane bound structure that
contains the cell's hereditary information and controls
the cell's growth and reproduction. It is commonly the
most prominent organelle in the cell.
The nucleus is surrounded by a structure called the
nuclear envelope. This membrane separates the
contents of the nucleus from the cytoplasm. The
cell's chromosomes are also housed within the nucleus.
Chromosomes contain DNA which provides the genetic
information necessary for the production of other cell
components and for the reproduction of life.
ENDOPLASMIC RECTICULUMThe endoplasmic reticulum (ER) is
an organelle of cells in eukaryotic organisms that forms
an interconnected network of tubules, vesicles, and
cisternae. Rough endoplasmic reticula are involved in
the synthesis of proteins and is also a membrane factory
for the cell, while smooth endoplasmic reticula are
involved in the synthesis of lipids, including oils,
phospholipids and steroids, metabolism of
carbohydrates, regulation of calcium concentration and
detoxification of drugs and poisons. Sarcoplasmic
reticula solely regulate calcium levels.
The lacey membranes of the endoplasmic reticulum
were first seen by Keith R. Porter, Albert Claude, and
Ernest F. Fullam in 1945
GOLGI APPARATUSThe Golgi apparatus, also known as the Golgi
complex or Golgi body, is an organelle found in
most eukaryotic cells. It was identified in 1898 by the
Italian physician Camillo Golgi and named after him.
Part of the cellular endomembrane system, the Golgi
apparatus packages proteins inside the cell before they
are sent to their destination; it is particularly important in
the processing of proteins for secretion
Due to its fairly large size, the Golgi apparatus was one
of the first organelles to be discovered and observed in
detail. The apparatus was discovered in 1898 by
Italian physician Camillo Golgi during an investigation of
the nervous system
LYSOSOMESLysosomes are cellular organelles that contain acid hydrolase enzymes to break down waste materials and cellular debris. They can be described as the stomach of the cell. They are found in animal cells, while their existence in yeasts and plants are disputed. Some biologists say the same roles are performed by lytic vacuoles. Lysosomes digest excess or worn-out organelles, food particles, and engulf viruses or bacteria. The membrane around a lysosome allows the digestive enzymes to work at the 4.5 pH they require. Lysosomes fuse with vacuoles and dispense their enzymes into the vacuoles, digesting their contents
MITOCHONDRIAMitochondria are the cell's power producers. They
convert energy into forms that are usable by the cell.
Located in the cytoplasm, they are the sites of cellular
respiration which ultimately generates fuel for the cell's
activities. Mitochondria are also involved in other cell
processes such as cell division and growth, as well
as cell death. Mitochondria are bounded by a double
membrane. Each of these membranes is a phospholipid
bilayer with embedded proteins. The outermost
membrane is smooth while the inner membrane has
many folds. These folds are called cristae. The folds
enhance the "productivity" of cellular respiration by
increasing the available surface area.
VACUOLESA vacuole is a membrane-bound organelle which
is present in all plant and fungal cells and
some protist, animal and bacterial cells Vacuoles
are essentially enclosed compartments which are
filled with water containing inorganic and organicmolecules including enzymes in solution, though
in certain cases they may contain solids which
have been engulfed. Vacuoles are formed by thefusion of multiple membrane vesicles and are
effectively just larger forms of these. The
organelle has no basic shape or size; its structure
varies according to the needs of the cell.
The function and importance of vacuoles varies greatly
according to the type of cell in which they are present, having
much greater prominence in the cells of plants, fungi and certain
protists than those of animals and bacteria. In general, the
functions of the vacuole include:
•Isolating materials that might be harmful or a threat to the cell
•Containing waste products
•Containing water in plant cells•Maintaining internal hydrostatic pressure or turgor within the cell
•Maintaining an acidic internal pH
•Containing small molecules
•Exporting unwanted substances from the cell
•Allows plants to support structures such as leaves and flowers
due to the pressure of the central vacuole
•In seeds, stored proteins needed for germination are kept in
'protein bodies', which are modified vacuoles.