Week 1 Flashcards
Biology review / Scientific Literature (20 cards)
Prokaryotic Cells
Features
- capsule
- cell wall
- large internal compartment
- nucleoid (circular DNA)
- DNA, RNA, proteins, ribosomes in cytoplasm
- flagellum
- pili (hairs on outside)
Two Types: Bacteria and Archaea
Eukaryotic Cells
features
- nucleus and other organelles
- mitochondrial & chloroplast DNA code for proteins specific to each organelle
First enzyme isolation
- 1833: Payen and Persoz extract and precipitate unknown substance from malt capable of converting starch into maltose.
- named “diastase” aka amylase
First DNA isolation
- 1869, Swiss chemist Friedrich Miescher
- isolated leukocytes from pus
- first to document isolation of “nuclein” rich in phosphate and nitrogen
First determination of molecular structure of protein
- myoglobin (stores molecular oxygen inside cells)
- 1957: Kendrew via x-ray crystallography
Protein functions
a few examples
- Cell structure and movement
- Metabolism
- Environmental sensors
- Enable cell-cell communication
- Molecular transport
Phenotype determining factors
- genotype
- environment
- life history
- epigenetics
lac operon
features
- presence of lactose causes enzymes for catabolism (breakdown) of lactose to be produced
- allows cell to utilize lactose as carbon source
- lacI, promoter, operator, lacZ, lacY, lacA
lac operon
lactose absent
- lacI gene -> lacI repressor protein
- lacI protein binds to operator sequence,
- RNA can’t transcribe lac proteins
lac operon
lactose present
- lacI gene -> lacI repressor protein
- Lactose binds to lacI protein
and inactivates repressor - RNA transcribe lac proteins (lacZ, lacY, lacA)
- lac proteins use lactose as energy source until depleted
- lac1 protein binds operator to repress lac protein production
Transcription regulation
mechanisms (2)
- DNA methylation
- Chromatin remodeling
Translation regulation
mechanisms (6)
- mRNA half life
- Codon choice
- Cellular tRNA levels
- Ribosome binding sites
- RNA Splicing
- RNA interference
Protein regulation
mechanisms (3)
- Chemical modification (e.g. phosphorylation)
- Inhibition
- Allosteric change
-Omics
definition
the comprehensive quantification of complete groups of biological molecules (e.g., all proteins, all RNA molecules, etc.) from a sample under different conditions (e.g.,
diseased vs non-diseased cells) to get insights into the biology in question
epigenomics
focuses on entire set of modifications to genome, which affect how genes can be expressed
metagenomics
- focuses on genomes in an environmental niche, not just the genome of one organism
- can try to piece together what kinds of microorganisms live in that environment and what kinds of chemical reactions can be carried out by the organisms in that environment
transcriptomics
- focuses on RNA and aims at a comprehensive study of RNA molecules present in a cell
- how RNA levels change in response to certain stimuli or environmental conditions
- what genes get transcribed, when, and to what extent
genomics
study of the entire set of genetic instructions in an organism
proteomics
focuses on entire set of proteins inside cell
metabolomics
- focuses on smaller chemicals within cell, (metabolites)
- How levels of metabolites in cell change under various conditions
- lipids, sugars, etc
