Cytoskeleton- The network of protein fibres and microtubules found within the cell that gives structure to the cell and is responsible for the movement of many materials within it. Two types of protein fibre make up the cytoskeleton:
Actin - These are fibres like the protein fibres found in muscle cells.
Role: White blood cell movemen Organelle movement.
Tubulin- These protein fibres form cylinders called microtubules.
Role: Movement of a cell through liquid.Waft a liquid past the cell. Organelle / Chromosome movement.
Prokaryotic and Eukayotic differences
Functions of organelles continued
Lysosomes- Contain / release digestive enzymes Digest / break down organelles Chloroplasts- Photosynthesis CO2+ H2O---- C6H12O6+ O2 Plasma Membrane - Controls entry/exit of substances into/out of the cell - Acts as a barrier separating the cell contents from the environment Centrioles - Formation of spindle fibres during cell division Flagella - Movement of cell Cilia - Wafts mucus and bacteria trapped within away from lungs
Cytoplasm - Site of chemical reactions
Cell Wall - Gives cell shape / strength / support - Prevents bursting- Fully permeable Vacuole - Storage of salts / sugars / pigment - Provides turgor support / controls water potential
Roles of the cytoskeleton
Provides strength / stability / support to the cell
Determines shape / moves membrane for endo / exocytosis
Movement of organelles / RNA / protein / chromosomes / chromatids
Movement of flagella for cell movement
Movement of cilia to move mucus containing bacteria etc
Attachment to / hold organelles in place
Make up centrioles / spindle fibres
Prokaryotic- organism having cells without a ture nucleus or membrane bound organelles.
Mitochondria& Chloroplasts similarities and differ
An organsim having cells with a true nucleus and membrane bound organelles.
Cilia and Flagella
Flagella- few and long in length,called undulipodia in eukaryotic cells.
Cilia- many and shorter in length, move in wafting motion.
Both have the same structures:
Both contain microtubules, 9 pairs of these are arranged in a circle, 2 form a central bundle, called 9+2 arrangement.
Both help movement by using energy from ATP
Functions of organelles
7 characteristics of life
MOVEMENT (all living things move – even plants!)
RESPIRATION (oxygen + glucose ---------- carbon dioxide + water + energy)
SENSITIVITY (detecting and responding to changes in the surroundings)
GROWTH (remember an organism ‘grows’ by producing more cells)
REPRODUCTION (making more of the same - can be sexual or asexual)
EXCRETION (expelling waste products, e.g. carbon dioxide and urea)
NUTRITION (taking in and using food)