M1 Flashcards
The phenomenon in which a chemical absorbs light at one wavelength and emits it at a specific and longer wavelength is called:
fluorescence.
To visualize cells by immunofluorescence microscopy, the cells must be:
permeabilized
The fluorescent properties of dye fura-2 can provide information on the:
concentration of Ca2+ ions in specific regions of the cell
The disruption of a cell is necessary to release its organelles and contents for subsequent isolation. One method, called__________________, uses ultrahigh-frequency sound to disrupt the cell plasma membrane.
sonication
The advantage of light microscopy over electron microscopy is that:
light microscopy allows one to view dynamic processes in living cells.
A primary objective of cell fractionation is to:
separate organelles to study their functions.
Which of the following correctly lists the order in which cellular components will be found in the pellet when homogenized cells are treated with increasingly rapid spins in a centrifuge?
nucleus, mitochondria, ribosomes
Which type of organelle is primarily involved in the synthesis of oils, phospholipids, and steroids?
smooth endoplasmic reticulum
Which structure is the site of the synthesis of proteins that may be exported from the cell?
rough endoplasmic reticulum
Organelles other than the nucleus that contain DNA include:
mitochondria, chloroplasts
The chemical reactions involved in respiration are virtually identical between prokaryotic and eukaryotic cells. In eukaryotic cells, ATP is synthesized primarily on the inner membrane of the mitochondria. Where are the corresponding reactions likely to occur in prokaryotic respiration?
on the plasma membrane
biologist ground up some plant leaf cells and then centrifuged the mixture to fractionate the organelles. Organelles in one of the heavier fractions could produce ATP in the light, while organelles in the lighter fraction could produce ATP in the dark. The heavier and lighter fractions are most likely to contain, respectively,
chloroplasts and mitochondria.
Green fluorescent protein (GFP) can be used to fluorescently label a specific protein in cells by genetically engineering cells to synthesize the target protein fused to GFP. What is the advantage of using GFP fusions to visualize specific proteins, instead of staining cells with fluorescently labeled probes that bind to the target protein?
GFP fusions enable one to track changes in the location of the protein in living cells; staining usually requires preserved cells.
Which of the following types of molecules are the major structural components of the cell membrane?
phospholipids and proteins
_______comprise one of the two divisions of prokaryotes, typically found in hostile environments such as hot springs or high concentration of salt.
Archaea
