Unit 3: Endomembrane System (inc. nucleus & ribosomes) Flashcards
Material in the nucleus
A cell’s genes
AKA chromosomes, AKA DNA
*most of them, at least
Surrounds nucleus
Nuclear envelope
Describe the
Nuclear envelope
Two layers of membrane that enclose the nucleus, which connect at the pores
Nuclear envelope
Chromatin
Also correct: nucleoplasm*
*you don’t need to memorize this
Nucleolus
(nu-clee-oh-lus)
Nuclear pore
Define
Chromosomes
Condensed DNA and proteins
Only found in cells that are dividing
Define
Chromatin
Loose / unwound DNA and proteins
Found in cells that are not dividing
Helps coil DNA
Histone proteins
Function of the
Nuclear pore complex
Regulating what enters and leaves the nucleus; especially the RNA
Function of the
Nucleolus
Make ribosomal RNA
Types of molecules that ribosomes are made of
Ribosomal RNA (rRNA) and proteins
Two parts of a ribosome
Large and small subunit; each made of rRNA and proteins
Function of the
Ribosomes
Assemble amino acids into polypeptides using instructions from DNA
Importance of histone proteins
Coils eukaryotic DNA so it can all fit within nucleus
Free ribosomes make…
proteins that stay in the cytosol
Bound ribosomes make…
proteins that go into a vesicle or membrane
Location of ribosomes
(two “types”)
Free: in cytosol
Bound: on ER
No ribosome is always free or bound; it’s based on current location
Parts of the endomembrane system
- Nuclear envelope
- Endoplasmic reticulum
- Golgi apparatus
- Transport vesicles
- Other vesicles (lysosomes, etc)
- Vacuoles
How do materials move between parts of the endomembrane system?
Transport vesicles
Define
Cisternae
Stacks of membranes that make up the ER and Golgi
Define
Lumen
Spaces inside the ER, Golgi, or other membrane-bound structures
List the
Functions of the Smooth ER
- Make lipids
- Detoxification
- Calcium ion storage
- Other metabolic stuff
List the
Functions of the Rough ER
- Modify proteins made by bound ribosomes
- Make membranes
The Golgi is like the _ of the cell
Always think of
Warehouse & Shipping Center
Functions of the
Golgi apparatus
- Receives / modifies chemicals made by ER
- Sorts / packages chemicals into vesicles
Describe
Movement through Golgi
- Materials enter via transport vesicle on cis face
- Move through cisternae
- Exit via transport vesicle on trans face
Describe
Lysosome
Vesicle full of digestive enzymes
Functions of
Lysosomes
- Break down & recycle damaged cell organelles or macromolecules
- Digest material in food vacuole
- Digest foreign materials (ex: bacteria)
List
3 types of vacuoles
- Food
- Contractile
- Large central
Describe & provide function
Contractile vacuole
Membranous sac of water, which can be expelled from a cell rapidly to cause the cell to move
Describe
Large Central Vacuole
Membranous sac of water and other nutrients that take up the majority of many plant cells
Functions of
Large Central Vacuole
- Water and nutrient storage
- Provides turgor pressure to plant cells (outward pressure against cell walls)
Endoplasmic reticulum
*Rough ER
Golgi apparatus
Smooth ER
Vesicle
(may be lysosome, peroxisome, transport, etc)
Be specific
Cis face of Golgi
Be specific
Lumen of Golgi
Be specific
Trans face of Golgi
Be specific
Cisterna of Golgi
Cisternae, pl
Bound ribosome
