BIO 121 Lecture Notes - Lecture 7: Endosymbiont, Lysosome, Mitochondrial Matrix

56 views2 pages

ceruleanplatypus574

23 Mar 2018

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

Diffusion is passive- does not require the cell to expend metabolic energy. Active transport requires direct expenditure of energy. Simple diffusion- molecules or ions move directly through the membrane, down their concentration gradient. Facilitated diffusion- specific transport proteins move solutes across a membrane. Ions and hydrophilic substances diffuse across the membrane with the help of a transport protein. Active transport- to move ions or molecules across a membrane against a concentration gradient. Ex: sodium potassium pump uses atp to export three sodium ions and import two potassium ions. Exocytosis- removing large molecules from the cell. Vesicle from interior fuses with the cell membrane and expels contents. Endocytosis- importing macromolecules across the plasma membrane. Receptor mediated endocytosis- a specific signal that receptors recognize specific contents. Eukaryotic cells have internal membranes that compartmentalize their functions. Their genetic instructions are housed in the nucleus and carried out by the ribosome. The endomembrane system regulates proteins traffic and performs metabolic functions.

Related Questions

Read the following scenarios and indicate which of the following processes they describe.

11. Sodium molecules move randomly around a solution of sodium chloride in water, frequently colliding with other sodium ions and chloride ions. secondary active transport diffusion osmosis facilitated diffusion primary active transport

12. Sodium ions (Na+) move through sodium channels in a synthetic membrane. primary active transport secondary active transport facilitated diffusion osmosis

13. Water molecules move into the cytosol of a cell placed in a hypotonic solution. primary active transport secondary active transport facilitated diffusion osmosis

14. Water molecules move into the cytosol of a cell placed in pure water. facilitated diffusion osmosis secondary active transport primary active transport

15. Water molecules move out of a cell placed in a hypertonic solution. facilitated diffusion primary active transport secondary active transport osmosis

16. The action of sodium-potassium pumps moves sodium ions (Na+) out of a cell and potassium ions (K+) into a cell. facilitated diffusion secondary active transport osmosis primary active transport

17. Glucose molecules move into cells lining the intestine against their concentration gradient driven by the movement of sodium ions (Na+) into the cells down their concentration gradient. osmosis secondary active transport primary active transport facilitated diffusion

18. A beaker of water is separated by a selectively permeable membrane that allows the passage of water but not ions. A solution of 4% sodium chloride (NaCl) is placed on one side of the membrane and pure water is placed on the other side of the membrane. The solutions are allowed to equilibrate. At this point, which process is going on? facilitated diffusion osmosis secondary active transport primary active transport

amaranthelk944

1 Which of the following statements is false?

(a) CO₂ and O₂ can diffuse freely across the cell membranes.

(b) The differences in permeability between artificial lipid bilayers and cell membranes arise from variations in phospholipid content.

(d) Cells expend energy in the form of ATP hydrolysis to maintain ion concentrations that differ from those found outside the cell.

2 Cells use membranes to help maintain set ranges of ion concentrations inside and outside the cell. Which of the following ions is the most abundant inside a typical mammalian cell?

(a) Na⁺

(b) K⁺

(d) Cl^â

3 Pumps are transporters that are able to harness energy provided by other components in the cells and drive the movement of solutes across membranes, against their concentration gradient. This type of transport is called _____________.

(a) active transport.

(b) free diffusion.

(d) passive transport.