WK6 P2 Cell bio

winniesmith's version from 2017-01-04 19:23

Section 1

Question Answer
What do ion pumps in bacteria,yeast and plant cells doactively transport H+ out of the cell.
What happens as a result of H+ being pumped out of stomach lining cellsacidity of gastric fluids.
Are the pumps which actively transport H+ into lysosomes and endosomes similar?No, they are structurally distinct.
What is the name of the H+ pump in mitochondria & chloroplasts?ATP synthase. These pumps operate in reverse, with the movement of ions down the electrochemical gradient used to drive ATP synthesis.

Section 2

Question Answer
What is the structure of an ABC transporterhave highly conserved ATP-binding domains or ATP-binding cassettes.
How many members of the ABC family have been identified in pro/eukaryotic cells100+
What do ABC transporters use energy forto transport molecules in one direction
What do ABC's do in bacteriathey transport nutrient molecules into the cell including ions, sugars, and amino acids.
What do they do in Eukaryotic cellsTransport toxic substances out of the cell
What does mdr stand formultidrug resistance
What is the effect of the 2 eukaryote ABC's which are products of mdr genesThey remove potentially toxic foreign compounds. They are often expressed at high levels in cancer cells, and can remove a variety of chemotherapy drugs

Section 3

Question Answer
What does the cystic fibrosis gene encode for a protein (CFTR or cystic fibrosis transmembrane conductance regulator) in the ABC transporter family. Molecular
What happens in cystic fibrosisdefective Cl– transport in epithelial cells results in abnormally thick, sticky mucus which obstructs respiratory passages.
What is coupled transportSome molecules can be transported against their concentration gradients using energy from coupled transport of another molecule in the energetically favorable direction.
Give an example of coupled transportGlucose transporters in the apical domain of intestine epithelial cells transport two Na+ and one glucose into the cell.
How does coupled transport work?Flow of Na+ down its electrochemical gradient provides the energy for transport. In the basolateral domain, glucose is transferred to the underlying connective tissue by facilitated diffusion. The system is driven by the Na+-K+ pump, also found in the basolateral domain.

Section 4

Question Answer
symporttransport of two molecules in the same direction (such as glucose and Na+)
uniporttransport of a single molecule (ex. facilitated diffusion of glucose)
antiporttwo molecules are transported in opposite directions.
2 examples of an antiport Ca2+ is exported from cells by the Ca2+ pump and by a Na+-Ca2+ antiporter that transports Na+ in and Ca2+ out. Na+-H+ antiporter transports Na+ into the cell and H+ out, preventing acidification by H+ produced in metabolism. Examples
What does endocytosis doallows cells to take up macromolecules, fluids, and large particles such as bacteria
How does endocytosis workThe material is surrounded by an area of plasma membrane, which buds off inside the cell to form a vesicle containing the ingested material.