SUPPLEMENT - Cell organelles Flashcards
what are cell organelles and what do they include?
cell organelles are small structures present in the cytoplasm of the cell. they include mitochondria, vesicles and ribosomes on rough endoplasmic reticulum
what is rough endoplasmic reticulum (ER)?
a complex system of double membranes. contain fluid-filled spaces between the membranes which allow materials to be transported throughout the cell. cells that produce a lot of protein, have large amounts of rough ER
what are membranes called when ribosomes are present on their outer surface?
rough endoplasmic reticulum (ER).
what is the main function of rough ER?
package and transport proteins made by the ribosomes. cells that produce a lot of protein have large amounts of rough ER
how can proteins be made?
small pieces of rough ER may be pinched off at the ends to form small vesicles, in this way proteins can be made and stored in the rough ER and transported around the cell in the small vesicles
what are ribosomes?
they are small organelles that are found in huge numbers in all cells. are about 20 nanometres in diameter in eukaryotic cells but smaller in prokaryotic cells when found free in the cytoplasm not attached to rough ER
what function do ribosomes have?
to synthesise proteins, such as those enzymes involved in respiration
what are mitochondria?
relatively large organelles found in all eukaryotic cells. visible under electron microscope, sausage-shaped structures
features of mitochondria
double membrane, outer one controls the entry and exit of materials. inner membrane forms many folds on which some of the chemical reactions of aerobic respiration take place. often described as ‘power plants’ since they are the sites of aerobic respiration. in large numbers, provide sufficient energy
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