Cell Structure Intro Flashcards
What is a cell and are they specialised?
A cell membrane structure consisting of 70% cytosol and various organelles
What is protoplasm?
Cytoplasm + nucleus + cell membrane
Three points of cell theory
1.cells are structural and organisational unit of life
2.All living things are composed of cells
3.All cells come from pre-existing cells
How many cells in average human?
37.2 Trillion Cells within the average human
What is the ratio of non-human to human cells?
3:1
What is the main difference between prokaryotic and eukaryotic cells?
Eukaryotic cells have a nucleus
Two differences in DNA between prokaryotes and eukaryotic cells
1.Prokaryotes: Naked, circular, no introns
2.Eukaryotes: bound to protein, linear, has introns.
Two differences in organelles between prokaryotic and eukaryotic cells
1.prokaryotes:70s ribosomes, non-membrane bound
2.Eukaryotes: 80s, membrane bound
Two differences between the size and reproduction between P and E cells
1.P: 1-5um, binary fission
2.E:10-100um, mitosis/meiosis
What is the main difference between plant and animal cells?
Plant cells have a cell wall for support and are rectangular compared to rounder animal cells
What organelles does a plant have that animals don’t?
Vacuole, Chloroplasts
Plants do not have centrioles, lysosomes
What are the 4 main types of tissues in animals?
1.Muscle tissue
2.Nervous tissue
3.Epithelial tissue
4.Connective tissue
What cell types are present in all cell types?
Cancer cells and stem cells
Three types of muscle cells
1.Skeletal
2.Cardiovascular
3.Smooth
Describe a Sarcomere
Sarcomere is a bundle made of thick myosin and actin filaments assembled by the Z and M lines (responsible for muscle contraction)
Name two types of Neural cells
Neurons and neuralgia
Two types of connective tissues
Connective proper
Specialised
How far can the naked eye, light microscopes, and electron microscopes see?
Eye = 10^-4m
Light microscopy = 10^-7m
Electron Microscopy = 10^-10m
Why are cells so small and abundant?
Surface area to volume ratio must be adequate to facilitate oxygen, nutrients, and waste
What does increased epithelial surface area do?
Means increased area of absorption
Name two types of light microscopy
1.Brightfield
2.Fluorescence microscopy
Name two types of Electron microscopy
1.Scanning Electron Microscopy (SEM)
2.Transmission Electron Microscopy (TEM)
Pros and cons of Brightfield Microscopy
It’s cheap and works on living cells
However lack of contrast, low res 0.2um, and staining is effort
Pros and cons of Fluorescence microscopy
Living cells can be used, greater contrast, always improving and 3D confocal lenses
However low 0.2um res, staining is effort, kinda expensive too
What nuclear stains are used in FM and what colour do they produce?
DAPI stains DNA into a blue/purple colour
What cytoskeleton stains are used in FM and what colours do they produce?
Green for microtubules/MTOC and red for actin filaments
Discuss immunisationing and GFP
Immunostaining is where dyed secondary antibodies attach to primary antibodies attached to a target cell.
Green fluorescent proteins are acquired from jellyfish and can bind to any other gene, also many other colours have been created.
What does scanning electron microscopy do?
Reveals topography of a sample however sample must be sputter-coated with an electron absorbing material like gold
Pros and cons of SEM
Pros: Highest res, magnification still improving and less that 0.5 um is achievable
Cons: Expensive, Effort, requires specialist knowledge, fixed specimens only, sensitive to vibration and electromagnetic fields
What order is cell fractionation carried out in?
Pestle sample > strain for connective tissues > Spin for nuclei and unbroken cells > then mitochondria and lysosomes > then ribosomes, ER,golgi, and pieces of cell membrane
What is cell biology about?
Microscopy, cell culture, cell staining, protein biochem, and molecular bio
What are the two types of cell cultures?
Primary cultures and cell lines
Pros and cons of primary cultures and cell lines
- Primary cultures are derived from tissues and pros are they are real cells increasing accuracy, cons are costly and animal use means limited cell numbers
2.Cell lines are immortalised cell lineages and can be propagated in the lab indefinitely, pros are it’s cheap easy to manipulate and loads of cells, cons are a model system so may not give true results
