Cells & Microscopy Flashcards
What do animal cells have, that plant cells don’t?
Centrioles
What do plant cells have that animal cells don’t?
Cell wall
Vacuole (permanent)
Chloroplast
What does the RER do?
Folds and packages proteins to send to Golgi apparatus
What does SER do?
Synthesises lipids, such as cholesterol
What does Golgi apparatus do?
Modifies and transports proteins
What do ribosomes do?
Site of protein synthesis
What do mitochondria do?
Site of aerobic respiration, ATP produced here
What do chloroplast do? And structure?
Site of photosynthesis
Membrane sacks within chloroplast called thylakoids. A stack of thylakoids is called a Granum.
What does cellulose cell wall do?
Provide strength and support to plant cell
What does mitochondria’s inner membrane fold into?
Cristae
What is a plasmid?
Ring of DNA
What do flagella do?
Allow bacteria to move
What are pili?
Projections which allow bacteria to adhere to host cells, or each other
What is resolution?
Minimal distance between two objects where they can still be distinguished as two
What type of cells do light and electron microscopes view?
Light- dead or living
Electron- dead
What defines a transmission electron microscope?
Image produces is 2D, black and white
Beam of electrons passed through specimen
What defines a scanning electron microscope?
Imagine is 3D, can be coloured
A beam of electrons is passed across a specimen, shows surface of specimen
TEM resolution and magnification
0.2nm
x500,000
SEM resolution and magnification?
0.2nm
x100,000
Difference between wet and dry mount?
Dry- specimen placed directly on side
Wet- water or immersion oil placed on slide first, cover slip placed at an angle
Why are specimens stained?
Provides contrast to distinguish between organelles in sample (e.g. Golgi apparatus)
To allow organelles to be identified
What is differential staining?
More than one stain used at once, as different chemicals bind to different structures
Example of stain and what it stains? (x3)
Methylene blue- DNA
Iodine- plant cell walls
Eosin- cytoplasm (red)
Magnification equation?
Magnification= image size/ actual size
Millimetres to micrometers conversion?
X1000
Micrometers to nanometers conversion?
X1000
What is an eyepiece graticule?
Transparent ruler, used to measure size of specimen by fitting to eyepiece lense
What is used to calibrate eyepiece graticule?
Stage micrometer
What are centrioles?
Small hollow cylinders, made of microtubules
what do lysosomes do?
digest invading cells, break down worn out components, and contain digestive enzymes
what do vesicles do?
transport substances in and out of cell or between organelles
4 steps of protein production?
1- proteins produced at RER (on ribosomes) are folded and processed
2- transported from RER to Golgi via vesicles
3- further processing at Golgi
4- proteins enter more vesicles which fuse with plasma membrane, protein released
what is the cytoskeleton?
network of protein threads running through cytoplasm
what components make up cytoskeleton + what are their roles?
microtubules and microfilaments
-support the cells organelle, keeping it in position
-strengthen cell, and maintain shape
-transport of organelles and material within cells
- cell movement
differences between eukaryotic and prokaryotic cells?
-eukaryotic cells larger
-DNA is linear in eukaryotes, circular in prokaryotes
-eukaryotes have membrane bound organelles, prokaryotes don’t
-ribosomes larger in eukaryotes
-DNA contained in eukaryotes, not in prokaryotes
