Cell biology Flashcards
What are the types of proteins that don’t finish translation in the cytosol (finish in rough ER)?
1) Secreted protein
2) Transmembrane protein
3) Lysosomal protein
4) ER/Golgi resident proteins
What do proteins that finish their translation in the rough ER have?
A signal sequence
Where does transcription occur?
Nucleus
Where does translation begin?
Cytosol
What proteins finish translation in the cytosol?
Cytosolic proteins
Information on the signal sequences in secreted proteins or lysosomal proteins?
1) Signal is first few amino acids translated
2) Signal is removed upon completion of translation
Information on the signal sequences in membrane bound proteins?
1) Signal can be anywhere in the amino acid sequence of the protein
2) Signal can appear several times
3) Signal is not removed but remains as part of the transmembrane protein
Steps for protein translation of a secreted protein
1) Ribosome with protein docks on docking site
2) signal recognition particle goes through the translocator pore and docks the protein in the ER lumen
3) Protein keeps being translated and gets pushed into the lumen
4) Signal sequence is clipped and the protein is put into a vesicle and transported to a specified location.
What are components of the cell membrane?
1) Phospholipids
2) Cholesterol: increases fluidity and stabilizes membrane
3) Proteins: channels
4) Carbohydrates: cell surface markers (glycoproteins, glycolipids)
What is a van’t hoff factor
Number of ions produced as a result of dissolving ionic substance
Eg: NaCl = Na and Cl = 2 van’t hoff factor.
Eg: CaCl2 = Ca and 2Cl = 3 van’t hoff factor
What are the four colligative properties?
1) Freezing point
2) Vapor pressure
3) Boiling point
4) Osmotic pressure
Which colligative go down when number of solute particles increase?
Freezing point and vapor pressure
Which colligative go up when number of solute particles increase?
Boiling point and osmotic pressure
What is freezing point depression equation?
Tf = -kf * i * m
What is the boiling point elevation equation?
Tb = kb * i * m
What is the equation for osmotic pressure elevation equation?
i * m * r * t
What is diffusion?
Movement of particles down a gradient
What is osmosis?
Movement of water down a gradient
Hypertonic vs Hyoptonic solutions
More particles vs less particles