module 4

• cell wall

  -It is the covering of the plant cell which

  is present only in plants. It is

  predominantly made up of cellulose.

  It has a rigid covering that

  protects the cell, provides structural

  support, and gives shape to the cell.

  -It is located outside the cell

  membrane.

  -The primary function of the it is

  to protect and provide structural

  support to the cell..

  
• plasma membrane

  is a phospholipid bilayer with embedded proteins that

  separates the internal contents of a cell from its surrounding environment.

  It is a semi-permeable membrane that controls the passage of organic

  molecules, ions, water, and oxygen into and out of the cell. For this reason, cell

  membranes are known as semi-permeable or selectively permeable

  membranes.

  
• Endoplasmic reticulum

  -It is a series of interconnected

  membranous sacs and tubules within the

  cytoplasm that collectively modifies

  proteins and synthesizes lipids.

  
• Cytoplasm

  -The entire region of the cell between

  the plasma membrane and the

  nuclear envelope.

  -it consists of an aqueous

  substance cytosol in which a variety of

  cell organelles and other inclusions

  like insoluble waste and storage

  products (starch, lipid etc.) are

  present.

  
• ribosome

  -function of it is for

  protein synthesis. Protein synthesis is

  an essential function of all cells

  including enzymes, hormones,

  antibodies, pigments, structural

  components, and surface receptors.

  -It appears either as a cluster

  (polyribosomes) or single, tiny dots

  that float freely in the cytoplasm.

  
• Golgi body

  .-Sorting, tagging, packaging, and distribution of lipids and proteins destined to leave the cell and for use within the cell takes place in it

  
• Lysosomes

  -Membrane-bounded digestive

  vesicle that catalyze the rapid

  breakdown of proteins, nucleic

  acids, lipids, and carbohydrates.

  -Uses destroy pathogens

  that might enter the cell

  through phagocytosis or

  endocytosis.

  
• Peroxisomes

  -are small, round

  organelles enclosed by single

  membranes.

  -They carry out enzymes that

  involve oxidation reactions that

  break down fatty acids and amino

  acids

  -it detoxify many poisons that may enter the body.

  Enzymes safely break down the

  
• Mitochondria

  -The powerhouse of the cell or energy factories because they are

  responsible for making adenosine triphosphate (ATP)

  -ATP: the cell's main energy-carrying molecule.

  
• Chloroplast

  -are plant cell organelles that carry out photosynthesis

  -it contains the photosynthetic pigment chlorophyll that gives most

  plants their green color that is used in photosynthesis.

  -Plants are autotrophs, while animals are heterotrophs

  
• Vacuole

  -Plant cells also have specialized

  membrane-bounded structures

  -It plays a major role in regulating

  the cell’s concentration of water in

  changing environmental

  conditions.

  -Remove and store harmful foreign

  products so they don’t damage the

  cell. Also stores nutrients.

  The central vacuole also supports

  the expansion of the cell.

  
• cytoskeleton

  Within the cytoplasm there is a network of protein fibers that help maintain the shape of the cell,

  secure some organelles in specific positions, allow cytoplasm and vesicles to move within the cell,

  and enable cells within multicellular organisms to move.

  Three types of fiber:

  Microfilaments for cellular movement and provides rigidity and shape,

  Intermediate filaments for structural and maintaining the shape of the cells and anchoring the

  nucleus and other organelles in place,

  Microtubule composed of tubulin, resist compression

  
• Nucleus

  Governor of the cell

  It controls all the activities of every organelle

  Houses the DNA and directs the synthesis of protein and ribosomes.

  
• The nucleus in a cell is surrounded by a nuclear envelope
• This nuclear envelope is punctuated with pores called nuclear pores
• The nucleoplasm is the semi-solid fluid inside the nucleus, where we find the chromatin and the nucleolus.
• Microfilaments for cellular movement and provides rigidity and shape,
• Intermediate filaments for structural and maintaining the shape of the cells and anchoring the

  nucleus and other organelles in place,
• Microtubule composed of tubulin, resist compression