Lesson 4 - Eukaryotic cells 2 Flashcards
meaning endoplasmic reticulum
a 3D network of membrane-bound cavities in the cytoplasm that links the nuclear membrane and makes up a large part of the cellular transport system as well as playing an important role in the synthesis of many different chemicals
meaning 80S ribosomes
the main type of ribosome found in eukaryotic cells, consisting of ribosomal RNA and protein, made up of a 60S and 40S subunit. They are the site of protein synthesis
meaning 70S ribosomes
found in the mitochondria, chloroplasts and prokaryotic cells. Made up of 30S and 50S subunit.
meaning Rough Endoplasmic Reticulum (RER)
endoplasmic reticulum that is covered in 80S ribosomes, which is involved in the production and transport of proteins
meaning exocytosis
the energy-required process by which a vesicle fuses with the cell surface membrane so the contents are released to the outside of the cell
meaning Smooth Endoplasmic Reticulum (SER)
a smooth tubular structure similar to the RER, but without the ribosomes, which is involved in the synthesis and transport of steroids and lipids in the cells
meaning Golgi Apparatus
consists of stacks of membranes that modify proteins made elsewhere in the cell and package them into vesicles for transport, and also produce materials for plant cell walls and insect cuticles
meaning lysosome
an organelles full of digestive enzymes used to break down worn out cells or organelles, or digest food in simple organisms
meaning apoptosis
programmed cell death - the breakdown of worn out damaged or diseased cells by the lysosomes
where are 70S ribosomes produced
in the mitochondria and chloroplast independently when the cell divides
what is the ratio of RNA : protein in 80S ribosomes
1 : 1
what is the ratio of RNA : protein in 70S ribosomes
2 : 1
why does the RER have a large surface area
for efficient storage, synthesis and transport of proteins
which type of cells have the most amount of RER
cells that secrete lots of materials
how are proteins brought from the RER to the Golgi apparatus
brought in vesicles, pinched off from the RER where they were made
how does the Golgi apparatus modify the proteins
vesicles with proteins inside fuse with the membrane sacs of the Golgi apparatus, and proteins enters the Golgi sacs. As the protein travels through the Golgi apparatus, they are modified
describe the difference between the inner and outer areas of the Golgi Apparatus
-the inner areas, nearer to the RER, is rich in enzymes that modify proteins
-the outer areas, have many finished protein products
