Module 4 - SET C (Part 2)

Question 1

instrument that uses focused laser beams to create piconewton (10-12 N) size forces that can be used to hold and manipulate microscopic particles, even as small as a single molecule or atom

Answer 1

optical tweezers

Question 2

the phenomenon of focused laser beams holding a single particle in place in three dimension

Answer 2

optical trap

Question 3

optical tweezers is also sometimes referred to as

Answer 3

optical trap

Question 4

can be used to hold and manipulate particles anywhere from 0.1 nm (about the size of an atom) to 10,000 nm in size (about the size of a bacterium) and have been used to trap single viruses, DNA molecules, bacteria, living cells, and organelles

Answer 4

optical tweezers

Question 5

particularly useful for investigating the mechanics of and forces associated with molecular motors

Answer 5

optical traps

Question 6

used for sorting and separating cells of various types or for measuring the forces necessary for bending or breaking a DNA molecule

Answer 6

optical traps

Question 7

technique used in electrophysiology to measure and characterize electric currents in cells, particularly excitable tissue cells such as neurons (nerve cells)

Answer 7

voltage clamp

Question 8

What is the basis of voltage clamp?

Answer 8

ability to insert a very fine microelectrode into the cell, with another electrode in contact with the fluid outside of the cell

Question 9

can be used to measure (and manipulate) the voltage or current across the cell membrane

Answer 9

electrodes

Question 10

the voltage is clamped, or held constant, through a feedback mechanism

Answer 10

voltage clamp technique

Question 11

value of voltage that is held constant

Answer 11

comman voltage

Question 12

allows us to measure the cell’s electric current under a variety of conditions

Answer 12

voltage clamp

Question 13

range of command voltages to discover and characterize voltage-gated ion channels which are proteins found in some cell membranes that allow ions to pass through the membrane only when the voltage is within a particular range

Answer 13

voltage clamp

Question 14

technique similar to the voltage clamp, except that the electron feedback mechanisms is used to keep the current (across the membrane) constant while allowing the voltage to vary

Answer 14

current clamp

Question 15

measure how the cell varies the voltage across its membrane in response to a particular current or other condition

Answer 15

current clamp

Question 16

an alternative technique for applying electrode to the cell

Answer 16

patch clamp

Question 17

the electrode is placed inside a micropipette filled with an electrolyte solution, and the membrane is placed against the cell membrane

Answer 17

patch clamp

Question 18

forms tight seal between the micropipette and the cell membranes

Answer 18

gentle suction

Question 19

has a high electrical resistance (1 to 10 megaohms) electrically isolating the small patch of membrane under the electrode

Answer 19

tight seal

Question 20

measure of energy in the form of heat

Answer 20

calorimetry

Question 21

instrument designed to measure heat energy

Answer 21

calorimeter

Question 22

used to measure the amount of energy absorbed or released in the course of biochemical reactions, conformational transitions, or ligand binding.

Answer 22

calorimetry

Question 23

can be used to determine the amount of energy necessary to unwind a piece of DNA helix

Answer 23

calorimetry

Question 24

can also be used to measure the binding strength of various drugs to a particular protein

Answer 24

calorimetry

Question 25

useful for measuring the very small amount of energy associated with many biophysical processes

Answer 25

microcalorimeters