Eukaryotic Cells Flashcards
Where does transcription occur?
In the nucleus
The nucleus is surrounded by which two membranes?
Inner + Outer
What is the fluid in the nucleus?
Nucleoplasm
What allows for the exchange of materials both into and out of the nucleus?
Nuclear pores
How are nuclear pores selective with what can be transported?
They need to recognize signal in order to transport
The Nucleolus is the center of the Nucleus and is the site of
Ribosome assembly
How does the Nucleolus allow for Ribosome assembly?
It contains rRNA that is assembled with proteins to become ribosomes
The nucleus membrane is also connected with
Endoplasmic Reticulum
The Nuclear Envelope is composed of
Inner + Outer membranes + nuclear pores
Mitochondria is the site of
Cellular respiration
What happens in the Mitochondria?
Glucose (Pyruvate) is transformed into ATP
The Outer membrane of the Mitochondria is made of a
Lipid bilayer permeable to small molecules
The Inner membrane of the Mitochondria is made of a
Lipid bilayer not permeable to small molecules
The Inner membrane has folds called
Cristae
What is the function of cristae?
They increase SA, more room for cellular respiration
Where does ETC happen in the mitochondria?
In the inner membranes
Describe inner membrane of the Mitochondria
- Studded with enzymes
- More acidic due to H+ ions
Mitochondria having its own genome allows for it to
- Make some proteins for ETC
- Produce parts of protein synthase
The mitochondria has its own system of
Transcription and translation
The ER is a
Folded, continuous membranes
What is the site of protein synthesis?
ER
The ER sends proteins to the
GA
What is the site of protein synthesis?
The RER
What happens to the proteins synthesized by the RER?
- Secreted into EC environment
- Become integral proteins
- Might remain in the ER, GA, or in lysosomes
RER proteins that become secreted or become part of the cell membrane follow which pathway?
The secretory pathway
What is the secretory pathway?
The pathway a protein takes from when it’s synthesized until when it leaves the cell / becomes part of cell membrane
When does a protein follow the secretory pathway?
When it receives a signal sequence, which is detected early on in translation
What is the function of the SER?
It synthesizes lipids, metabolizes carbs, and detoxifies drugs
The GA is found near the
ER
What is the GA?
Groups of sacs stacked together
The modified RER proteins are sent to the
GA
What is the function of the GA?
- It sorts and sends proteins to proper destinations
- Synthesizes certain molecules that need to be secreted in the cell
Where does the vesicle merge into the GA?
At the cis-stack
In the GA, the protein undergoes modifications and is transferred into the
Medial stack
What happens when the protein is in the trans-stack of the GA?
It can leave and can either go to cell membrane or into a lysosome
What is the function of the Lysosome?
It digests molecules + substances
What are the two functions of the Lysosome?
- Autophagy
- Crinophagy
What is Autophagy?
Lysosomes digest organelles part of the cell itself
Macrophages of the immune system display
Autophagy
Crinophagy is when
Lysosomes digest excess secretory products
What is the function of the Peroxisome?
It breaks and detoxifies lipids
Peroxisome isolates peroxides and uses catalase to
Break it into water and oxygen
What are introns?
Bits of DNA that are cut out by molecules found in the nucleus
What is differential splicing?
Different combinations of introns can be cut out to form variations on a protein
Both prokaryotes and eukaryotes have repressors which function to
- Bind DNA at promoter site
- Regulate transcription
Mitochondrial DNA disorders are transferred through the
Maternal line
What are Gangliosides?
Glycolipids attached to acids
Microfilaments are made out of
Actin
What is the function of Microfilaments?
They work with myosin filaments to contract the cell
Microtubules are components of
Flagella and Cilia
What is the function of Intermediate filaments?
They help the cell retain its shape in the face of mechanical stress
What is the function of the sarcoplasmic reticulum?
It helps store calcium
The smooth endoplasmic reticulum in muscle cells allows for
Efficient contractions
Where are proteins made?
- Ribosomes
- On Rough ER
Microtubules are involved in
- Cell structure
- Motility
Microtubules can be found in
Mitotic spindles
