Chapter 2 Flashcards
What are the 3 parts to the cell theory?
1) All organisms are composed of one or more cells
2) The cell is the basic unit of all living organisms
3) Cells cannot be created, but come from existing cells (mitosis)
What are the four types or microscopes?
Light microscope
SEM- Scanning electron microscope
TEM- Transmission Electron Microscopy
Synchrotron
How much bigger you can make an object appear dependent upon the lens system:
a) Magnification
b) Resolution
c) View
d) Contrast
a) Magnification
The ratio between the image and the specimen’s actual size
Inside or outside of the cell, type of light:
a) Magnification
b) Resolution
c) View
d) Contrast
C) View
Ones darker then the other, stands out from the background:
a) Magnification
b) Resolution
c) View
d) Contrast
d) Contrast
Define Resolution
What is it dependent upon?
Measure the clarity of the image or the ability to differentiate between two dots
Dependent upon the wavelength of the light used
Seeing a car from far (looks like one head light), as it gets closer you can see there are two headlights.
This is an example of what?
Of resolution.. The ability to distinguish as seperate objects
Which type of light will provide better resolution?
Red or Blue?
Blue because it has a shortwe wavelength then red
Light microscope:
- Used ___ light and simple lenses to see ____ objects
- Magnification =
- Resolution=
- Uses ____ for illumination
- ___ versatile
- Visible light, Small objects
- 1000x
- 0.2µm
- light
- very versatile
Light micrograph:
- Uses properties of ___ and ______
- Most animal cells are _____
- Euglena is a photosynthetic microbe with ______
- Light and chromophores
- colorless
- chlorophyll
What type of cells use a cell plate when dividing?
Plant cells
What are dyes and protein fluoresce used with microscopes for?
Used to give off light when light is shone on them, allow us to see particular parts of the cell
TEM:
- Uses an ____ beam
- Magnification =
- must have ___ and very ____ sectioned samples
- _____ resolution
- ____ versatile
- Shows contrast with ___ + _____
- electron beam
- >100 000x
- fixed and very thinly
- high resolution
- less versatile
- Led and metal
How do we provide contrast for TEM?
Heavy metals are used as general stains, attached to the macromolecules
SEM:
- Objects are coated with an electron dense material often ____ or ______
- what part of the cell is visualized?
- Lead or gold
- only the surface
What is GFP?
Where was it first isolated from?
Which microscope allows us to see GFP?
- It is a green fluorescent protein used to track things in organisms in order to see it more clearly
- from a jellyfish
- Fluorescence microscope
How did they contribute to GFP?
- Osamu Shimomura
- Douglas Prasher
- Roger Tsien
- Isolated the GFP protein from jellyfish
- had the idea to create GFP fusion protein to use in other types of cells (clone)
- Made great advances in our understanding of how protein chemistry affects fluorescence of GFP
What are traits of Prokaryotes? (5)
- ______ OR ______
- Have a _____ _______ organization
- Lacks a ____________ ________
- _______ microorganisms of ____ size
- No _______ _________
- Divide by _______
- Bacteria OR Archaea
- Have a simple structural organization
- Lacks a membrane - enclosed nucleus
- Unicellular microorganisms of small size
- No subcellular compartments
- Divide by binary fission
What are Eukaryotes?
- ______ or _____ cell
- _____ evolutionarily advanced= more ____ _______
- Have _______
- Have more _____ and ________
- can carry out ____ ____ _______
- _____ cell size = more extensive use of _______
- Divide by ______
- Animal or Plant cell
- More evolutionarily advanced= more complex internally
- Have a nucleus
- Have more organelles and compartments
- can carry out specialized chemical reactions
- Larger cell size = more extensive use of membranes
- Divide by mitosis
What is the plasma membrane?
The border between a cell’s exterior and its interior
What is a phospholipid bilayer?
What are the two parts ?
Which one likes water?
Creates a barrier that encloses the cytoplasm
Hydrophilic head - likes water
Hydrophobic tail - hates water (so it hides in the middle)
What is the cytoskeleton? and where is it located?
- Located in the cytoplasm of a cell
- Forms structures such as flagella, cilia and lamellipodia
- Plays important roles in both intracellular transport (the movement of vesicles and organelles, for example) and cellular division.
What are te 3 types of cytoskeleton?
1) Microtubules
2) Intermediate filaments
3) Microfilaments
What does this in the cytoplasm?
- Cell shape
- Chromosome sorting
- Organelle positioning
- Cell motility
- Internal structure of cilia and flagella
- Long, hollow cylindrical structure about 15 nm in diameter
- Composed of protein tubulin
Microtubules
What does this in the cytoplasm?
- Cell Shape
- Mechanical strength
- Anchor cell membranes
- Only in multcellular organisms
- Help maintain shape and rigidity
- Bind in stagered array to form a twisted rope like structure of 8-12 nm
Intermediate Filaments
What does this in the cytoplasm?
- Cell Shape + Strength
- Muscle contraction
- Movement (amoeba)
- Intracellular transport
- cytoplasmic streaming
- Made up of two strands of actin (5-7 nm)
- Near plasma membrane
Microfilaments
OR
Actin Filaments
Microtubules can only grow from ____ end, and shrink from ____ end
one end
either end
What is Cytoplasm?
In the interior of the cell, the space between mitochondria and ribosomes
Define Ribosomes
Ribosomes are vey large complex cellular machines that are made from RNA and proteins
What is the function of Ribosomes?
- function is to interpret the genetic code and make proteins by combining amino acids in the correct sequence
T or F: Ribosomes are organelles
False;
They are enzymes, big enough to see with TEM
Where are ribosomes found?
Floating freely in the cytoplam, or attached to the membrane of the endoplasmic reticulum (ER)
Ribosome subunits:
In Prokaryotes?
In Eukaryotes?
- Prokaryotes: large subunit= 50S
Small subunit = 30S
Overall = 70S - Eukaryotes: large subunit =60S
Small subunit = 40S
Overall = 80S