cells mostly microscopic –light microscopy upto 1000x passes light through e.g. typical plant...
TRANSCRIPT
Cells
• Mostly microscopic– Light microscopy upto 1000x
• Passes light through• E.g. typical plant & animal
cells
– Electron microscopy upto 100000x
• Scans sample with electron beam
• E.g. molecules (DNA)
• Prokaryotic– Bacteria and bacteria-like
• Eukaryotic– Fungi, Protista, Plants,
Animals
Prokaryotes vs. Eukaryotes
• Simpler• Smaller size• DNA without nucleus• Cell wall & other crude
protective layers• Lack organelles
• Complex• >10x larger• DNA in nucleus• Cell membrane
– Some also have cell wall
• Membrane bound organelles– specialization
Nucleus
• Genetic control center• DNA
– Replicates during cellular division
– Fibers = chromatin
• Sends instructions as RNA (in nucleolus) through pores – To synthesize proteins
(writes amino acid sequence)
Endoplasmic Reticulum
• Rough ER• Studded by ribosomes
– Assembles proteins for further processing
• Membrane system– Continuous with
nuclear membrane• Creates compartments• Acts as highway or
conveyer belt
Smooth ER
• Continuous with Rough ER
• Lacks the ribosomes• Uses enzymes to make
lipids– In sex cells, SER makes
sex hormones– In liver cells, SER
detoxifies– In muscle cells, SER stores
and releases Calcium for muscle contraction
Golgi apparatus• Shipping / Receiving department
– Receives proteins from ER, modifies, packages, labels for destination, within or outside of cell
Lysosomes – breakdown bodies
• RER packaged enzymes
• Golgi modified• Digests:
– Food in vacuole– Bacteria in blood– Damaged organelle
(recycles)
Vacuoles
• Membranous sacks w/o digestive enzymes
• Carry food in
• Storage– Water– Chemicals– Waste– Pigments– Poisons
Contractile vacuoles
• Water regulation– Water continues
to seep inside• Osmotic
properties and differences in concentrations
– Pump out excess– Prevents cells
from over-swelling or burst
Chloroplasts
• Photosynthesis = converts solar E to glucose• Continuous double membrane/compartment
system– Fluid stroma– disks or grana = solar power packs
Mitochondria
• Converts glucose (stored E) into cellular E (ATP)– Potential E to chemical
E to Kinetic E– Via cellular respiration
• Double membrane & compartment system– Fluid matrix– Folds or Cristae to
increase Surface Area
Cytoskeleton – structural proteins• Microfilaments – cell structure & cell contraction• Intermediate filaments – cell structure and anchoring• Microtubule – organelle support & movement
Cilia & Flagella
• Locomotor microtubules
• Short, numerous• Long less numerous
Cell Surfaces
• Cell wall, plasma membrane, or capsules
• Plant cell wall– Cellulose fibers for
structure & support– E.g. wood is almost all cell
wall material– Plasmodesmata for
intercellular communication• Animal cell membranes
– Tight junctions = leakproof– Anchoring junctions =
strength– Gap junctions =
intercellular communication