MEMBRANES
This membrane component makes the membrane less fluid at high temperature but more fluid at low temperature.
Answer: What is cholesterol?
A mutation in this transporter would cause sodium to build up inside the cell, potassium to decrease inside the cell, and the resting membrane potential to become less negative.
Answer: What is the Na+/K+ pump?
This organelle is the major site of new membrane synthesis.
Answer: What is the ER?
These cytoskeletal elements are strongest and rope-like.
Answer: What are intermediate filaments?
A protein is synthesized on free ribosomes in the cytosol and has no signal sequence. Where will the protein remain?
Answer: What is the cytosol?
These fatty acid tails increase membrane fluidity because they contain double bonds.
Answer: What are unsaturated fatty acid tails?
This type of gated channel is used by auditory hair cells.
Answer: What is a mechanically gated channel?
This organelle is not apart of the endomembrane system because it imports most of its proteins directly from the cytosol rather than through vesicles.
Answer: What is the mitochondrion?
This motor protein moves toward the plus end of a microtubule.
Answer: What is kinesin?
A protein is synthesized on ER ribosomes in the cytosol and has no signal sequence. Where will the protein end up?
Answer: What is the extracellular space?
This structure keeps proteins from diffusing between the apical and basolateral sides of epithelial cells.
Answer: What are tight junctions?
This event immediately triggers neurotransmitter release from a neuron.
Answer: What is opening of voltage-gated Ca2+ channels?
This molecule must bind GTP in order for cargo to be released inside the nucleus.
Answer: What is Ran?
These proteins prevent microtubules in cilia from sliding apart.
Answer: What are (nexin) linking proteins?
A cell line forms coated pits normally, but vesicles never pinch off from the membrane. This protein is most likely missing.
Answer: What is dynamin?
This substance is used to remove membrane proteins from the lipid bilayer.
Answer: What is detergent?
This type of transport is used when glucose enters a cell together with sodium.
Answer: What is symport or Na+-coupled cotransport?
This protein pinches off a coated vesicle from a membrane.
Answer: What is dynamin?
This actin-binding protein binds Ca2+ during muscle contraction.
Answer: What is troponin?
A cell is treated with a drug that destroys a specific cytoskeletal protein but leaves the others intact. The cell can still crawl and contract, but proteins stop moving from the ER to the Golgi and mitosis fails. Which cytoskeletal structure was destroyed and why do these two processes depend on it?
Answer: What are microtubules? Vesicle transport and the mitotic spindle require microtubules.
A transport vesicle containing a membrane glycoprotein fuses with the plasma membrane. The carbohydrate portion of the glycoprotein ends up on this side of the plasma membrane.
Answer: What is the noncytosolic or extracellular side?
A toxin blocks one type of voltage-gated ion channel during an action potential. The membrane depolarizes normally, but returns to resting potential much more slowly.
Answer: What are voltage-gated K+ channels?
This acidic compartment causes receptors to release their cargo after receptor-mediated endocytosis.
Answer: What is the endosome?
This structure nucleates microtubules in animal cells using γ-tubulin ring complexes.
Answer: What is the centrosome?
A muscle fiber is given Ca2+ and a nonhydrolyzable ATP analog. The muscle remains relaxed because this step in contraction cannot occur.
Answer: What is the myosin power stroke