Eukaryotic Cell Flashcards
Description Nucleus
Largest organelle, roughly spherical- at least one nucleolus
Surrounded by nuclear envelope (double membrane) with pores
Nucleus contains chromatin (DNA a bonded to a protein)
Function of nucleus
Controls the cell activities (transcription of DNA)
DNA contains instructions to make proteins
Pores allow substances to move between the nucleus and the cytoplasm
Nucleolus - site of ribosome
production
Provide information for protein synthesis
- part in the control of cell growth and division
Description of mitochondria
Oval shaped
Have outer and inner membrane
—> inner membrane is folded to from Cristae which gives a large surface area surrounded by a fluid matrix
—> contains small 70s ribosome , small circular DNA and enzyme involved in aerobic respiration
Contains own genetic material - to replicate themselves during cell division
Function of mitochondria
Site of aerobic respiration producing ATP for energy release
Cells like muscle or cells in the liver contains lots of mitochondria
Little mitochondria
- white fat storage cells
Description of centrioles
Two found in each cell. Each a bundle of nine tubules
Hollow fibre made of micro tubules
Two centrioles at right angles to each other form a centrosome
Function of centrioles
Pull apart to form a spindle of microtubles in mitosis
Cell division
When a cell divides , the centriole pull apart to produce a spindle of micro tubules that involve in the movement of the chromosome
Description of ribosome
One large subunit and small subunit
Not membrane bound
Each ribosome is a complex of ribosomal RNA (rRNA) and proteins
Found freely in the cytoplasm of all cells or as part of the rough endoplasmic reticulum in eukaryotic cells
Function of ribosome
Site of protein synthesis specifically translation
Description of rough endoplasmic reticulum (RER)
Bound by system of membranes
Formed from continuous folds of membrane continuous with the nuclear envelope
Function of RER
large SA for the synthesis of proteins
Protein synthesis for extracellular protein
Ribosome - protein synthesis for intracellular proteins
Protein synthesis occur in ribosomes - RER isolates and transports these protein as transfer vesicle pinch of the cisternae and travel to golgi body
Folds polypeptides to secondary or Tertiary structure
Packages to vesticle, transport to Golgi apparatus
- cell that secrete material have large amounts of RER
Description SER
Tubular cisternae - no ribosome
Same as RER without ribosome
Function of SER
Involved in the production , packaging and storage of the lipids carbohydrates and steroids
Involve in the synthesis and transport of lipids
Description of Golgi apparatus
Stacks of parallel , flattened membrane pockets formed by vesticle from the endoplasmic reticulum fusing together
Made up of stacks of flattened parallel, membrane pockets called cisternae, found near the nucleus. Transfer vesticle from the sER fuse to form these
Function Golgi apparatus
Modifies proteins and packages them into vesticle
Modify protein by adding carbohydrates chains to make glycoproteins
Modify protein by adding lipids to make glycolipida
Modifies protein by folding them into their 3D shape
Modify files proteins and packages them into vesticles( transport of cell surface membrane for exocytosis) or lysosome
Also makes lysosomes carbohydrates to protein form glycoproteins
- carbohydrates can be added to protein to form glocoprotein
- secretory vesticles containing proteins bud off the cisnae at the trans golgi
- some fuse with the outer cell membrane to release protein ie extracellular enzyme
- involved information + secretion of lysosome
Lysosome description
Round organelle surrounded by a membrane
Bags of digestive enzyme
Vesticle containing a powerful mix of digestive enzyme
