Lecture 8 Flashcards
How big is the nucleus of eukaryotes?
~5 um in diameter
What is the nuclear envelope?
It has double membrane that encloses the nucleus
What is the nuclear lamina?
Network of proteins on the inside face of the nucleus that maintain the shape
What are nuclear pores?
An area in the nucleus that material (proteins, RNA) enter and leave the nucleus through
What is chromatin?
DNA (in chromosomes) is bundled with proteins in a compact form
What is Nucleolus?
During interphase, ribosomal RNA and proteins form dense granules
Where are ribosomes located?
- in the cytosine of prokaryotes (free)
- in the cytosol and attached to the internal membranes of eukaryotes (bound)
What are ribosomes made of
Composed of proteins and rRNA made in the nucleus, large and small prokaryotes and eukaryotes
What do free/ bound ribosomes do
- free - make cytosolic proteins
- bound- make protein that’s are inserted into membranes
What is the eukaryotic endomembrane system? And what are the components
- Membranes within the cell, continuous or connected via transfer by vesicles
- 50%of total membrane
- nuclear envelope
- endoplasmic reticulum
- Golgi apparatus
- vesicles and vacuoles
- lysosomes
What are smooth rough and lumen. In the endoplasmic reticulum?
Lumen- space inside
Smooth lacks ribosomes
Rough has ribosomes
What are the functions of smooth ER
Synthesize lipids
Metabolizes carbs
Detoxifies poison
Stores calcium
What are the functions of rough ER
Modifies proteins
Distributes transport vesicles
Produces membranes
What are cisternae in the Golgi apparatus
Flattened membranous sacs
What does then Golgi apparatus do
- Modifies products of the ER
- manufactures macromolecules
- encloses materials in transport vesicles
What are vacuoles?
-Vesicles from the plasma membrane, ER, or Golgi
What do central vacuoles do in many mature plant cells?
Hold organic compounds and water
What forms food vacuoles?
Phagocytosis
What is a lysosome?
- Membranous sac of hydrolytic enzymes (low PH)
- joins vacuoles, digests macromolecules
What is phagocytosis?
Cell engulfs and digests material that was outside cell
What is autophagy?
Cell digests and recycles own organelles and macromolecules within cell
What is a peroxisome and what does it do
- single membrane
- breaks down fatty acids, detoxification
What do glyoxysomes in plant seeds do?
Covert fatty acids into sugar
mitochondria has how many membranes?
2, smooth outer and folded inner called cristae
What does the inner membrane in a mitochondria separate?
Intermembrane space and mitochondrial matrix
What makes proteins in the matrix for the mitochondrion
Free ribosomes
Describe membrane protein production
-protein is synthesized by bound ribosomes attached to ER, then proteins enter ER through the a pore, start to fold into shapes, protein then wrapped in ER membrane, that becomes a transport vesicle, vesicle moves and joins Golgi then something else but half the word are missing lol
