1 Cells and Microscopes Flashcards
(49 cards)
How are proteins made and secreted? - (from gene to leaving the cell)
- gene coded instructions
-instructions are transcribed into a length of mRNA and exits nucleus through nuclear pores
-goes to ribosomes, instructions are translated
-insulin molecules are assembled
-everything passed into the cisternae
-vesicles pinched off, pass via microtubules + motor proteins
-vesicles fuse to the Golgi Apparatus
-insulin protein molecules may be modified
-these are then processed and packaged
-vesicles are pinched off
-move to plasma membrane
-vesicles fuse to plasma membrane
-opens and released the molecules out of the cell.
Prokaryotic cells
-no nucleus
-diameter of cell is 0.1- 0.5 micrometers (um)
-lack cytoskeleton
-no membrane bound organelles
-cell wall is made of peptidoglycan
-divide by binary fission
-70s ribosomes
-bacteria cells
Eukaryotic cells
-10-100 micrometers (um)
-cell wall is made of cellulose
-divide by mitosis, meiosis
-80s ribosomes
-Yeast, amoebae, plant and animal cells
Chloroplasts
What are the fields called, what they are made of and the liquid found in chloroplasts?
fields- grana
grana is made of thylakoids
liquid- stroma
Mitochondria
what is the folded membrane called?
cristae
Flagellum
cell movement
pilli
-transfer genetic material
-hold to surfaces
Villi, microvillus
-very thin
-increase surface area
cytoskeleton
-support cell shape
-direct substances + organelles
What are the 3 types of fibers?
-Microfilaments
-intermediate filaments
-microtubules
Shape and diameter of microfilaments
-Thread-like
- 3-6 nm diameter
Shape and diameter of intermediate filaments
-rope like
- 10nm
shape and diameter of microtubules
-hollow
- 24nm
Electron micrograph
A photo of an image seen using an electron microscope
Magnification
The number of times larger an image appears compared with the size of the object
Organelles
Small structures within cells, each of which has a specific function
Photomicrograph
Photo of an image seen using an optical microscope
Resolution
The clarity of an image, the higher the resolution = the clearer the image
Total Magnification (calculation)
Magnifying power of the objective lens (times)
magnifying power of the eyepiece lens
Optical microscopes
- cheap (relatively)
-easy to use
-portable
-used in schools, colleges etc.
Laser scanning microscopes
how it works and how its seen
-laser light to scan an object point by point
-displayed on a computer screen
-depth selectivity
Electron microscope
both types (similarities)
-Great deal of skill to use
-training needed
-large and expensive
-beam of fast traveling electrons
-electrons get fired from a cathode
-focused by magnets onto a screen or photographic plate
Transmission electron microscopes
-specimen
-2D or 3D
-color or b+w
-electrons
-Specimen is dehydrated and stained
-electrons pass through
- 2D image
-Black and White image
Scanning electron microscope
-2D or 3D
-color or b+w
-electrons
-do not pass through, electrons ‘bounce off’
-3D image
- black and white image but false color can be added