Cells

• Cells are used for movement, respiration and digestion
• cells take raw materials then it processes these materials to Make new molecules. These molecules can either be used by the cell itself or transported to other parts of the body.
• Cells are so minute that they can only be seen with the help of a microscope
• Light microscope magnifies 1000x
• Electron microscope magnifies 200000x
• Micrographs are photographs captured by the camera found in a microscope
• Light microscope can come out as colored images
• Electron microscope are black and white images but they can be artificially colorized
• A cell structure can be studied by cutting along the length or width
• Stains and dyes are used to color parts of the cell to study the structure
• multicellular organisms are organism made up of numerous cells.
• Amoeba and paramecium are organisms made up of single cell or are unicellula.
• Common features in almost every cell: plasma membrane, nucleus and cytoplasm. They’re responsible for all activities inside the cell and interactions of the cell with its environmen.
• Protoplasm is complexed and jelly-like substance. Many chemical activities that allow the cell to survive and grow are carried out in the protoplasm.
• Cell membrane covers the protoplasm and are made up of lipids and proteins. partially permeable it allows substances to pass through it. It allows the entry and exit of some materials in and out of the cell. It controls the movement.
• Cell wall are only found in plant cells and are made up of cellulose
• Cellulose protects the cell from injury and gives the plant cell a fixed shape
• fully permeable so it doesn’t control the type of substances that enter or leave the cell.
• Cytoplasm is a jelly- like substance that fills the inside of the cell and is enclosed by the cell membrane.
• The cytoplasm is part of the protoplasm between the cell membrane and the nucleus.
• The cytoplasm is where most cell activities occur.
• Organelles is a cellular structure that performs a specific job.
• A nucleus has a double layered covering called a nuclear membrane.
• The nuclear membrane has pores that allow the transfer of material from inside the nucleus to its outside (cytoplasm)
• The nucleus controls cell activities such as cell growth and the repair of worn out parts
• The nucleus is essential for cell division.
• Cells without a nucleus cannot divide such as red blood cells
• The nucleus contains genetic information in the form of chromosomes
• Chromosomes contains the hereditary information from the patterns of the next generation in the form of DNA
• chromosomes are composed of DNA and proteins
• Functional segments of DNA are called genes
• Whenever a cell is about to divide, the chromatin material gets organized into chromosomes
• in some organisms like bacteria the nuclear region of the cells may be poorly defined due to the absence of a nuclear membrane. these organisms are called prokaryotes.
• Organisms with cells having a nuclear membrane are called eukaryotes
• Vacuoles are fluid filled space enclosed by a partially permeable membrane
• Vacuoles store substances within the cell
• Plant cells have a large central vacuole that contains a fluid called cell sap
• Cell sap contains dissolved substances such as sugars, mineral salts, amino acids and some proteins
• Animal cells have many small vacuoles that contain water and food substances
• Vacuoles in animal cells usually exists temporarily