Organelles Flashcards
Describe the nucleus.
It contains genetic material and has a double membrane.
Decribe the ribosomes.
They translate mRNA. Free ribosomes make cystolic proteins and are incorporated into the cytoskeleton, mitochondria. Bound ribosomes are attached to the exterior surface of the RER and make proteins that are incorporated into the membrane, transported out of the cell or inside organelles.
Describe vesicles.
They are small membrane-bound sac and have a role in the transport between components of the endomembrane system.
Describe the endoplasmic reticulum.
It is a network of internal membranes. SER: smooth endoplamic reticulum, w\o ribosomes attached for the synthesis of lipids, CA++
RER: rough endoplasmic reticulum, w\ ribosomes attached for the synthesis and modification of proteins for the cell membrane or for out of the cells.
Describe the golgi complex.
It is made of flattened, stacked membrane sacs called cisternae. It modifies proteins within the transport vesicle.
Describe the lysosomes.
They are membrane bound sac of enzymes used for intracellular digesiton with an internal pH of 4.8. Used for programmed destruction, recycling of organelles and destroy bacteria.
Describe vacuoles.
Membrane bound sac larger than vesicle, food vacuoles formed by phagocytosis, site of intracellular digestion fuse with lysosomes. Contractile vacuoles, found in fresh water protozoa to pump excess water out of cell. Central vacuole in plants storage site.
Describe peroxisomes.
Single membrane bound organelles that contian enzymes such as oxidases to transfer an H to oxygen.
Describe mitochondria.
it is the site of aerobic cellular respiration. It can grow and reproduce it possess its own set of DNA and ribosomes.
Describe microtubules.
They are hollow rods of tubulin dimers that shape and support cells, intracellular transport, chromosome division and motion of flagella.
Describe microfilaments.
Solid rods of actin in a twisted doucle chain that offer support and help for muscle contractions.
Describe intermediate filaments.
They are two rods twisted in a helix the support and shape the cell and form junctions that hold cells together.
