Lesson 2.1 Cell structure and functionDisediakan oleh:NUR SUHAIDAH SUKORSMK SANDAKAN, SABAH
IntroductionCell Theory1. All organisms are composed of cells.2. Cells are the smallest living things.3. Cells arise only from pre-existing cells.All cells have certain structures in common.1. genetic material – in a nucleoid or nucleus2. cytoplasm – a semifluid matrix3. plasma membrane – a phospholipid bilayer
Nucleus Spherical stores the genetic material. DNA is organized with proteins to form chromatin. Func: controls all activities of cell.
Rough endoplasmic reticulum (RER) Membranes that create a network of channels throughout the cytoplasm Attachment of ribosomes to the membrane gives a rough appearance. Synthesis of proteins to be secreted, sent to lysosomes or plasma membrane 6
Smooth endoplasmic reticulum (SER) Relatively few ribosomes attached. Functions: -synthesis of membrane lipids -detoxification of drugs 7
Vacuoles spherical or oval shapedfilled with fluid. cell sap contains sugar,salts, amino acid and wastesubstances. bounded by semi-permeable membranecalled tonoplast.There are different typesof vacuoles: -contractile vacuole -food vacuole 13
MitochondriaMitochondria -cylindrical shape -two layers of membrane (inner membrane is folded)Func –site for cellular respiration. -oxidise glucose to release energy in the form of ATP. 14
Cell wallStructure -rigid outer layer of plant cell -made of cellulose -permeableFunc –mantains the shape of plant cell -protects the cell from brusting -give support to the cell
CytoplasmaStructure –jelly like mediumFunc –place for biochemical reactionsCentriolesStructure –small cylindrical structuresFunc –form spindle fibers -synthesis cilia and flagella of small organism.
Plasma MembraneStructure -thin, semi permeable membrane. -consists of protein, phospholipids.Function -regulates and control the movement of substances in and out of cell.
The density of certain organelles related to its functionTypes of cells Function Density of certain organellesSperm cell To swim towards Mitochondria need to fallopian tube to fertilise produce energy the ovumFlight muscles For movement Mitochondriainsect and birdCells in meristem For growth, produce new mitochondria cellsPalisade mesophyll cells photosynthesis ChloroplastLiver cells Detoxification of drugs Smooth endoplasmic reticulumPancreatic cells Produce enzymes Rough endoplasmic reticulum, golgi