Flashcards in Cells and viruses Deck (51)
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1
What does the cell theory state
New cells are formed from other existing cells and that a cell is a fundamental unit of structure, function, and organisation in all living organisms
2
What is an exception to the cell theory rule
Viruses are an exception because they aren't made up of cells
3
In complex organisms, what do cells make
Specialised cells -->Tissue-->Organs-->System-->Organisms
4
Give an example of prokaryotes
Bacteria
5
What is bacteria made up off
.Cell wall
.Plasmids
.Nucleotides
.70S ribosome
6
Describe the cell wall of bacteria
.Made up of peptidoglycan which is very thick and protective. Some retain purple stain = gram-positive
.In others the cell wall is thin and does not hold the purple stain. This is known as Gram-negative. The stain turns red
7
Describe the Plasmids in a prokaryote
.Smaller,circular, a single length of DNA
.They often contain genes that aid the bacterium survival
8
Describe the Nucleoid in a prokaryote
.Circular DNA molecule
.DNA is folded in a region which is the nucleoid
9
Describe the 70S ribosomes in prokaryotes
.They make proteins
.Size of the ribosome is 70s in prokaryotes
10
What are Eukaryotes made up of
.Nucelolous
.Nucelus
.Centrioles
.Lysosome
.Golgi apparatus
.Mitochondria
.80S ribosome
.sER
.rER
11
Describe the nucleolus
.Region of dense DNA and protein which makes ribosomes
12
Describe the nucleus
.Surrounded by a double membrane with pores
.Stores DNA
13
Describe the centrioles
.Two hallow cylinders
.Arranged at right angles to each other
Makes a spindle in cell division
14
Describe the lysosomes
.Enclosed by a single membrane
.Containing digestive enzymes
.Destroys old organelles and pathogens
15
Describe the Golgi apparatus
.Seres of single, curved sacs enclosed by a membrane
.Each sac is smaller than the previous one
.Many vesicles luser around it
.Modifies proteins and packages them in vesicles for transport
16
Describe the 80S ribosome
.Site of protein synthesis
17
Describe the mitochondria
.Creates ATP in a process known as cellular respiration
.Can survive on its own as it has its own DNA and ribosome (endosymbiotic theory)
.Contain folded inner membrane = cristae
.Stalked particles and matrix are also within the organelle
18
Describe the sER
.A series of single, tubular sacs made of membrane
.Lipids are made here
19
Describe the rER
. A series of single, flattened sacs enclosed by a membrane
.Ribosomes on the surface
.Protein made here
20
How is image size calculated
Image size = actual size X magnification
21
What is meant by resolution
Being able to see two objects as distinct
22
What is the resolution of the following:
a)Human
b)Light microscope
c)Electron microscope
a)0.1mm
b)0.2 micrometer
C)1 nanometer
23
What's the wavelength of:
a)Light
b)electron beam
a)500nm
b)1nm
24
When does light microscope work
When light passes through a specimen so that it can enter the eye
The specimen must be thin
25
What is staining used to do
To give structure color and contrast and allow identification
26
What are 4 common stains used
what are they used for
1)Iodine solution -stains starch blue-black
2)Ethanoic orcein - stains DNA reddish-purple
3)Methylene blue - stains nuclei and chromosomes blue
4)Phloroglucinol - Stains lignin, found in plant cells, red
27
Explain the disadvantage of the EM
1)All specimens are examined in a vacuum so it is impossible to look at living material
2)The treatment is likely to result in artefacts
3)EMs are still extremely expensive to buy, run and maintain
28
What is a light microscope
LM is a relative sample piece of equipment but it must be set up and used correctly to get the best results
29
What is the set-up of the light microscope
1)Revolve the turret so that the low power lens is pointing down
2)Place the slide on the stage
3)Look through the eyepiece and adjust the mirror to bring light into the field of view
4)Turn the coarse focus knob until the specimen is in the focus
5)Adjust condenser for best lightening
6)Move to a higher power lens when necessary by revolving the turret, readjusting the condenser if needed
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