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Cell Biology S1
semester one of cell biology
Term | Definition |
---|---|
principles of cell biology | -all organisms have 1+ cells -cell= basic unit of life -all cells come from cells |
haflick limit | cells enter a senescent (deterioration) phase and stop dividing |
compound microscope | light passes through an object, then 2+ lenses |
transmission electron microscope (TEM) | electron beams transmitted through specimen for detailed study of internal structure of cells |
fluorescence microscopy | filters allow certain wavelengths of light through- light of one wavelength is absorbed and a different wavelength is emitted |
flow cytometry | measuring cells while they pass through detectors 2 main parts: fluidics and optics |
visible light spectrum | short wavelength - high energy - 400-550nm long wavelength - low energy - 550-700nm 700+nm beyond naked eye |
eukaryotic organism types | -fungi -protists -yeasts |
protists | "all eukaryotes that are not plants/animals/fungi" -algae -protozoa (animal-like protists) -fungus-like protists |
yeasts | "single celled fungus" divide by budding |
animal-like protists | heterotrophic take in preformed carbon to power cell mostly unicellular 4 movement types: mastigophorans, sarcodines, apicomplexans, ciliates |
mastigophorans (animal-like protists) | move via flagella |
sarcodines (animal-like protists) | usually amoeboid |
apicomplexans (animal-like protists) | parasitic and immobile |
ciliates (animal-like protists) | move via cilia (cover most of surface) largest group of protozoans cilia used for movement and food gathering |
paramecium (ciliates) | free-living predatory reproduces asexually (binary fission) or sexually (conjugation) can have endosymbiotic algae or bacteria cilium move in flow motion |
pellicle | tough outer layer/membrane in ciliates |
trichocysts | 'barbs' containing protein threads in ciliates can be shot out for hunting/defense |
dictyostelium (slime molds) | single celled for part of life but come together to become multicellular using cAMP as a chemokine when cells starve settles in a spot, becomes 'slug' with spore and stalk time of starvation and cellular Ca2+levels determine if cell is stalk or spore |
DNA structure | usually double helix but can exist as a single stranded molecule composed of individual nucleotides supercoils and coils around histones |
components of DNA nucleotides | phosphate group, deoxyribose sugar, nucelobase |
nucleobases (pyrimidines) | thymine (uracil in RNA) and cytosine |
nucleobases (purines) | guanine and adenine |
phosphodiester bonds | bonds between phosphates and sugars that hold together nucleotides linkage forms between 3' C in one base sugar and the P of the phosphate group in the complementary base, condensation reaction to form bond (water is lost) C-O-P-O-C |
central dogma of gene expression | 1. DNA stores the genetic code 2. DNA transcribes (transfers) the code to RNA 3. RNA code is transcribed into proteins that handle the cell's functions |
DNA replication | occurs in S phase of cell cycle -topoisomerase and helicase unwind the DNA helix -DNA polymerase and ligase join individual nucleotides and synthesize new DNA strands semi-conservative: one strand of the parent DNA is conserved in each new strand |
regulatory elements of genes | enhancers and promotors that interact with transcription factors to control where and when genes are active |
stages where cells can regulate gene expression | 1. transcriptional 2. post-transcriptional/translational 3. post-translational |
processing of raw mRNA | 1. adding a cap 2. adding a tail 3. removal of introns (splicing) processed in the nucleolus before moving to cytoplasm for translation into proteins enables nuclear export, stabilizes mRNA, aids recognition by translational ribosome complex |
introns | non-coding sections of DNA in between exons |
alternative splicing types | 1. constitutive splicing 2. exon skipping 3. alternative 5' splice site 4. alternative 3' splice site *allows for creation of 100,000+ proteins with only 20,000 human genes |
types of cellular RNA | mRNA:messenger:transcribe DNA code to aminoacid sequence of polypeptide tRNA:transfer:connect genetic code to aminoacid sequence in ribosomes during translation rRNA:ribosomal:w/ ribosomal proteins, make up structure of ribosomes sRNA:small:many types |
5' end cap on mRNA | adds a modified base connected by its 5' carbon to the 5' end of the primary transcript by a 3 phosphate bridge protects mRNA from degradation and stabilizes it |
polyadenylated (adding a poly tail to mRNA) | poly A polymerase enzyme trims RNA and adds a polyA 3' tail (AAAAA) |