Cell Transport
The type of molecule that move diffuse through cell membranes most rapidly
What is small and nonpolar
This is the cell structure responsible for making proteins
What is a ribosome
A cell placed in this type of solution will stay the same size
What is isotonic
Which macromolecule is the major structure of the plasma membrane
Lipids
This type of cell has a relatively low surface area to volume ratio
What is a large cell
If a substance diffusing across the cell membrane reaches equilibrium, do molecules still cross the cell membrane?
Yes, there is no longer a NET movement
This organelle packages and places a chemical tag on molecules in order to deliver the molecule to the correct location in an organism
Golgi Body (apparatus)
A cell placed in this type of solution will shrink
What is hypertonic
Define "selective permeability" in one sentence.
The membrane allows some substances to cross more easily than others, controlling the internal environment.
Describe one structural difference between prokaryotic and eukaryotic cells and explain how that difference affects compartmentalization.
Eukaryotic cells have membrane-bound organelles; prokaryotes do not. This allows eukaryotes to compartmentalize processes (e.g., transcription in nucleus separate from translation in cytosol).
If a cell needs to keep a large concentration of K+ inside of its membrane, this process is used
Active transport
This organelle synthesizes lipids and steroids
Smooth ER
A cell is placed in a hypertonic solution. After 24 hours, you would expect the cell to now be _____ with the solution
isotonic
Predict whether small nonpolar molecules (like O2) pass through the lipid bilayer easily or poorly
Pass through easily
Name two organelles that are thought to have originated by endosymbiosis and give one piece of evidence supporting that origin for either organelle.
Mitochondria and chloroplasts. Evidence: double membranes, their own circular DNA, and ribosomes similar to prokaryotes.
This is the name of the process where a cell takes in a large quantity of molecules rapidly
Endocytosis
During endocytosis, cells can take in nutrients from their surroundings and then store them using these organelles.
Vacuole
If a cell with a 10% solute concentration is placed in a solution with a 15% solute concentration, what direction will water move?
Out of the cell
Why don't plant cells burst
Plant cells have cell walls
Predict how increasing the proportion of unsaturated fatty acids in a membrane's phospholipids affects membrane fluidity at low temperatures, and explain.
More unsaturated fatty acids increase fluidity at low temperatures because the cis double bonds introduce kinks that prevent tight packing of phospholipid tails.
When a cell is exporting a protein in mass quantities, what 3 organelles are involved?
Rough ER, Golgi Body, Vesicle
This organelle can fuse with a vacuole to destroy unnecessary cellular components.
Lysosome
A cell is placed in an open container. Both the cell and the solution are at 27 C and contain 1.0 M of solute. The cell contains glucose while the solution contains Calcium Chloride. Which way will the water move?
Out of the cell
What role do integral (transmembrane) proteins often play? Give one example
Integral proteins often function as channels, carriers, or receptors — e.g., a channel protein for ions.
Explain how the endomembrane system (e.g., rough ER, Golgi, vesicles) contributes to the transport and processing of proteins destined for secretion.
Proteins synthesized on rough ER are translocated into the lumen, packaged into vesicles, modified in the Golgi, sorted, and sent to their destinations via vesicular trafficking