Organelles Structure and Function q Recognise cell structures

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Organelles: Structure and Function q Recognise cell structures under the electron microscope q Outline

Organelles: Structure and Function q Recognise cell structures under the electron microscope q Outline the function of the different cell organelles

CELL ORGANELLES 1 Surrounded by membranes 1) 2) 3) 4) 5) 6) Nucleus Endoplastic

CELL ORGANELLES 1 Surrounded by membranes 1) 2) 3) 4) 5) 6) Nucleus Endoplastic reticulum Golgi apparatus Mitochondria Chloroplasts (plants only) Lysosomes 2 Without membranes 1) Ribosomes 2) Centrioles 3) Cytoskeleton

Structure q Largest organelle q Spherical Function q Dark patches=chromatin q Contains genetic material

Structure q Largest organelle q Spherical Function q Dark patches=chromatin q Contains genetic material q. Surrounded by nuclear q Chromatin consists of DNA and envelope – double membrane proteins q Has nuclear pore - allows q Contains instructions for making large molecules through proteins q. Nucleolus inside q When cells divide, chromatin THE NUCLEUS condenses into visible chromosomes q Nucleolus makes RNA and ribosomes.

Structure: q Consists of flattened membrane-bound sacs cisternae which are continuous with the outer

Structure: q Consists of flattened membrane-bound sacs cisternae which are continuous with the outer nuclear membrane. q RER- Ribosomes q. Smooth ER- no Ribosomes ENDOPLASMIC RETICULUM Function: Smooth ER- Involved in making Lipids RER- Transports proteins made on attached ribosomes

GOLGI APPARATUS Structure: q Stack of membrane-bound, flattened sacs Function: q Receives proteins from

GOLGI APPARATUS Structure: q Stack of membrane-bound, flattened sacs Function: q Receives proteins from the ER q Modifies them, adding other chemicals q Packages proteins into vesicles to be transported inside cytoplasm or to the outside

MITOCHONDRIA Structure: q 2 membranes separated by a fluid filled space q Inner membrane

MITOCHONDRIA Structure: q 2 membranes separated by a fluid filled space q Inner membrane is folded to form cristae q Central part is the matrix. Function q Site where ATP is produced during cell respiration

Structure: q 2 membranes separated by fluid filled space q Inner membrane surrounds a

Structure: q 2 membranes separated by fluid filled space q Inner membrane surrounds a network of thylakoids q A stack of thylakoids is called a granum q Chlorophyll molecules are present on these membranes. CHLOROPLASTS Function: q Site of photosynthesis q Light energy is used to make carbohydrate molecules from carbon dioxide and water

Function: q Contain digestive enzymes which break down materials q e. g. specialised lysosome

Function: q Contain digestive enzymes which break down materials q e. g. specialised lysosome (acrosome) in head of sperm cells helps it penetrate the egg. Structure: q Spherical sacs surrounded by a single membrane

Organelles NOT surrounded by membranes q Ribosomes q Centrioles

Organelles NOT surrounded by membranes q Ribosomes q Centrioles

RIBOSOMES Structure q Very small organelles. Free in the cytoplasm, or bound to rough

RIBOSOMES Structure q Very small organelles. Free in the cytoplasm, or bound to rough ER, or in mitochondria and chloroplasts. q Consist of 2 subunits. Function: q Where the instructions (m. RNA) from the nucleus are turned into proteins – protein synthesis

CENTRIOLES Structure q Small microtubules made of protein. Mother and daughter centrioles with a

CENTRIOLES Structure q Small microtubules made of protein. Mother and daughter centrioles with a very characteristic design. Function: q Form fibres in cell division known as spindles which separate chromosomes.

CYTOSKELETON Structure q Microtubules and microfibrils in the cytoplasm, made of protein. Function: q

CYTOSKELETON Structure q Microtubules and microfibrils in the cytoplasm, made of protein. Function: q Give cells shape and structure q Help cells move or change shape