6 Flashcards
What are the properties of prokaryotes?
-Domain bacteria and archaea
-No membrane bound organelles
-Circular DNA
-Reproduce via binary fission
-Much smaller than eukaryotic cells
-DNA found in nucleotide
-Plasmids also carry some generic material
What are the properties of eukaryotic cells?
-Domain Eukarya
-have Membrane bound organelles
-Linear DNA
-reproduce via meiosis
-Larger than prokaryotic cells
-DNA found in nucleus
What do all cells have in common?
- Plasma Membrane
- Cytosol
- Chromosomes
- Ribosomes
What is the Endomembrane system?
-A collection of membranes inside of a EUKARYOTIC cell (not prokaryotic.!!)
-all membranes are related via physical contact or through transfer of membrane vesicles
Which organelles are part of the Endomembrane system?
- Nuclear envelope
- Rough and smooth ER
- Vesicles
- Golgi apparatus
- Vacuoles
- Plasma membrane
What composes the nucleus?
- Double membrane envelope (outer and inner membrane)
- The nucleolus
- Nucleoplasm
- Chromatin (Heterochromatin and Euchromatin)
- Ribosomes
- Nuclear pores
What is studded on the double membrane envelope?
Ribosomes
What does the double membrane envelope enclose?
The generic material
What do the ribosomes travel through?
Nuclear pores
Where does rRNA synthesis occur? (Think ribosome synthesis)
The nucleolus
What are the properties and functions of the rough ER?
- Creates secretory proteins and sends them to the golgi
- Studded with ribosomes (that is why jt is rough)
- It is directly attached to the nuclear envelope
What are the properties and functions of the smooth ER?
- Performs many metabolic processes like lipid synthesis (steroids) and metabolism of carbs
- Detoxifies poisons by adding hydroxyl groups to poison and making it water soluble
- Stores calcium ions
Are ribosomes located in Eukaryotic or prokaryotic cells?
Both, stupid!
What are ribosomes responsible for? How do they perform their functions?
-Protein synthesis
-They make polypeptide chains by translating the mRNA strand. There are large and small subunits of each ribosome
Where are ribosomes formed?
The nucleolus with rRNA
What is a bound ribosome?
A ribosome that is attached to the rough ER and that creates secretory proteins (do their work outside of the cell)
What is a free ribosome?
A ribosome that is found somewhere in the cytoplasm
They produce proteins that function wherever they are being formed inside the cell
What is a vesicle?
Where does it come from?
What does it do?
- a membrane bound sac
-comes from the rough ER and the Golgi
-transports vesicles that move proteins to the cell membrane for discretion. The vesicle becomes part of the cell membrane
What are the 3 types of vacuoles (NOT vesicles)? List each one’s function
-Food vacuoles: work via phagocytosis. Eats things in the cell. Digests the rubbish (lysosome)
-contractile vacuole: pumps out excess in protists
-central vacuole: in nature plants, used for water storage, growth, and structure
What is the function if the Golgi apparatus? What is it made of?
-it is the warehouse that accepts proteins from the rough ER, modifies them, and then sends them off to the cell membrane (think Amazon)
-it is made of sacs called cisternae
What is the pathway of the protein through Golgi apparatus?
Nuclear envelope ➡️ rough ER ➡️ Golgi apparatus ➡️ cell membrane
What is the plasma membrane?
A phospholipid bi-layer.
Is the head of the phospholipid bi-layer polar and hydrophilic, or hydrophobic and non polar? What about the tails?
The head is polar and hydrophilic
The tails are non polar and hydrophobic
Properties of the mitochondria
- Plants and animals have them
- Sure if cellular respiration (sugar metabolized)
- Also have their own circular DNA and ribosomes
- Oxygen consumption
Properties of the chloroplast
- Plants only
- Site of photosynthesis (sugar produced)
- Contain chlorophyll in the thylakoid membranes which are nestled in the string
- Contain their own circular DNA and ribosomes
- Oxygen released
Cell junctions:
- Plasmodesma
- Tight junctions
- Desmosomes
- Gap junctions
Plasmodesma
Chanel through the cell walls of PLANTS that connect plant and cells and allows them to transfer materials like cytosol and water
Tight Junctions
-Plasma membranes if neighboring cells are TIGHTLY pressed against each other
-Forms a tight seal and prevents cellular leakage
Desmosomes
-An anchor junction.
-connect to each other with proteins
-Actually connected; not just tightly packed
Gap junctions
- Similar to Plasmodesma in plants m, but not for non plant cells
- Channels are made between cells and molecules are transferred
How do the cell junctions function?
Via glycoproteins
