Cell Structure Some quick revision… nucleus cytoplasm cell membrane We will be spending 2 weeks looking at the contents of the cytoplasm
Cell Structure The cytoplasm is not a featureless soup. It is a matrix full of structures (organelles). Each organelle has a specific structure and function
Cell Structure • HT • Smooth/rough ER • Golgi apparatus • Mitochondria • Lysosomes • Chloroplasts • Plasma membrane • Cilia • MN • Nucleus • Nucleolus • Centriole • Ribosomes
This Weeks Objectives: Describe the structure & function of…… • Smooth/rough ER • Golgi apparatus • Mitochondria • Lysosomes • Chloroplasts • Plasma membrane • Cilia
Endoplasmic Reticulum (ER) Definition: • A system of membranes found • in both animal and plant cells • They can with the nucleus or • be detached. • They can with lined with ribosomes
Rough ER or Smooth ER? Most of the ER is encrusted with small granules called ribosomes – this is the rough ER. The smooth ER does not have any ribosomes
FUNCTIONS OF ER: Synthesis & transport of proteins Rough ER Synthesis & transport of lipids & steriods Smooth ER
The Golgi Apparatus Definition: • A system of membranes and • folded vessicles found in both • animal and plant cells • Involved in storage and transport of • products that are secreted from the cell. • e.g. hormones and enzymes
The Golgi Apparatus Lots of substances that leave the cell are GLYCOPROTEINS GLYCOPROTEINS are a mix of carbohydrate and protein Where are proteins synthesised? Rough Endoplasmic Reticulum (RER) So the Golgi Apparatus must be closely associated with the RER!
The Mitochondria What do you already know? Produces E for the cell An organelle What do you need to know?
The Mitochondria Task: You have 5 minutes to find 10 characteristics of mitochondria
Ave. 1000 per cell Sausage shaped Have an inner & outer membrane Inner membrane is highly folded, Producing fingers called CRISTAE Fluid filled internal area - matrix It is the site of respiration ATP is produced here
The cristae are folded to increase the surface area increased respiration More E cell need = more mitochondria rqd. Sperm tails Wings of insects Mammalian muscle fibres
Lysosomes Definition: A membrane bound sac found in A&P cells Contain digestive enzymes WHY?
Digestive enzymes break up: bacteria old organelles foreign bodies How? Task: 5 minutes to get the order correct on the next slide!
Lysosomes fuses with membrane around unwanted structures Old/wanted structures break down Cell reabsorbs products back into cytoplasm Membrane surrounds old/unwanted structures Lysosome releases digestive enzymes into membrane
Membrane surrounds old/unwanted structures Lysosomes fuses with membrane around unwanted structures Lysosome releases digestive enzymes into membrane Old/wanted structures break down Cell reabsorbs products back into cytoplasm
Chloroplasts: What do you know? Site of P Contain chlorophyll Green Plants only