Microscopy and Structures

Question 1

Conventional Light Microscopy

Answer 1

~200 nm resolution, may be used to study whole unstained living cells, limited subcellular detail - cells and tissues can be fixed and stained as well

Question 2

Fluorescence Microscopy

Answer 2

Special type of light microscopy that uses fluorescent dyes to detect specific macromolecules within cells. Some dyes bind directly to target while other are linked to a molecule that bind. Different excitation and emission wavelengths can be use to visualize different macromolecules in a single cell

Question 3

Indirect immunofluorescence

Answer 3

One of the most common forms - combines fluorescent dyes w/ antibodies that bind selectively to particular macromolecules - primary antibody binds to antigen, secondary antibody binds to primary

Question 4

Transmission Electron Microscopy

Answer 4

~2 nm resolution, used to study subcellular structures in great detail. Uses beam of elections, dark areas are electron dense.

Question 5

Scanning electron microscopy

Answer 5

~10 nm resolution - used to view surfaces of whole cells and tissues rather than subcellular organelles - focused beam of electrons moved across specimen, creates 3D image

Question 6

Plasma membrane through Electron Micrograph

Answer 6

think darkline demarcating the outer boundary of the cell - may be highly convoluted

Question 7

Nucleus through Electron Micrograph

Answer 7

largest organelle in the cell - typically mottled gray w/ irregularly shaped staining (where heterochromatin is), surrounded by double membrane of nuclear envelope

Question 8

Nucleolus through Electron Micrograph

Answer 8

large darkly staining roundish structure w/in nucleus

Question 9

Nuclear envelope through Electron Micrograph

Answer 9

double membrane surrounding the nucleus - nuclear pores can be seen, may also be able to see ribosomes attached to cytoplasm

Question 10

Rough ER through Electron Micrograph

Answer 10

rough ER consists of elongated flattened sacs - looks like long thin compartments that are fairly uniform in thickness, can be straight or curved, have ribosomes if rough ER

Question 11

Smooth ER through Electron Micrograph

Answer 11

Smooth ER consists of elongated interconnected tubules - shows up as complex mixture of oddly shaped vesicles

Question 12

Peroxisomes through Electron Micrograph

Answer 12

small round structures, 1 membrane - uniform medium gray, have an electron dense (dark) core, containing high concentration of oxidative enzymes

Question 13

Lysosomes through Electron Micrograph

Answer 13

Darkly stained organelles that are typically round and vary in size, may be many in a single cell

Question 14

Mitochondria through Electron Micrograph

Answer 14

round or oblong and present in large numbers - surrounded by double membrane - inner membrane is extensively folded to form cristae

Question 15

Golgi apparatus through Electron Micrograph

Answer 15

series of flattened sacs (similar to rough ER), but typically only 4-8 sacs and a large # of vesicular structures. No bound ribosomes and lumens of golgi tend to be narrower than the ER - located near the nucleus