Introduction to molecular and cell

Question 1

Fundamentals

Answer 1

Genome to transcriptome to proteome to genome (its a loop)
Transcriptome - gene transcribed
Proteome - gene translated
Expression proteome can affect transcriptome as is a cycle, change in one leads to change in all

Cell biology happens across a large scale

Question 2

Case studies

Answer 2

Cystic fibrosis
- In humans ~ present in lungs and gastrointestinal tract
- In mice ~ only gastrointestinal tract
- Mutation in CFTR gene
- Makes proteins misfold ~ get stuck in endoplasmic reticulum
Sustainable food
- Gene editing ~ select new variety e.g increase photosynthesis or crop yield
Biotechnology
- Production of antibodies against diseases

Question 3

Cell theory

Answer 3

Hooke 1665 - concept of cells
- Looked at cork cells, saw hexagonal cells, were empty because cell was dead
- He named cells cells, assumed were building blocks of tissues
Schleiden 1838
-Plants all formed of cells
Schwann 1839
- Animals all made of cells, same basic unit/structure across all organisms
Virchow 1855
- Cells arise from pre-existing cells
Robert Brown
- Using microscope saw nucleus, named centre of cell, Franz Bauer similar observations similar time

Question 4

Universal properties of living cells

Answer 4

Genetic info always same amount, sequence of DNA needs to be the same
DNA code linear sequence of RNA and 3d structures:
- Cell components self assemble (RNA, ribosomes)
- Protein signals get everything to right place
- Cells respond messages in environment
- Feedback mechanism important; composition, growth, differentiation

Question 5

Prokaryotic and Eukaryotic cells

Answer 5

Prokaryotes (Eubacteria and Archaea)
Eukaryotes - came when archaea bacteria engulfed eubacteria
Archaea closer to Eu with mitosis but closer to Pro with metabolism
Pro have no internal organelles, plasma membrane surrounds anything vital (DNA, ribosomes)
Gram positive bacteria - has thick cell wall, peptidoglycan
Gram negative bacteria - has thin cell wall, double membrane
Pro and Eu don’t exist in isolation
Many pro cells harness mammalian host cell using bacterial toxins and virulence effectors causing disease
Main differences:
- Eu have compartments (nucleus, ribosome)
- Eu have cytoskeleton, allows change shape
Compartments protect from change in pH and leads to specialisation
E.g. lysosome pH 4.5, works better if segregated and stops risk of it degrading cytosolic proteins

Question 6

Specialisation

Answer 6

Multicellularity causes:
- Specialisation in tissues and organs
- Command/Control/Communication ~ regulation of activites
- Long/short communication
- Quick/long communication

Question 7

Experimental approaches

Answer 7

Reductionist - Use biochem to reconstruct enzyme reactions, allows examination
Visualisation of biological processes in living cells (microscopes)
Investigating functions based on “omic” data