Exam 2 Structural/Membrane 10/3 Flashcards
Membrane proteins?
Peripheral
Integral
- can move laterally
- may exist as micro domains
How do organisms take up nutrients?
microbes only take in dissolved etc
Active Transport
energy dependent process
move molecules against gradient
concentrated molecules inside cell
involves specific carrier proteins (permeases)
3 types of Active transport
Primary
secondary
group translocation
ABC transporters
secondary active transport
The plasma membrane
group translocation phosphotransferase System (PTS)
PEP-Sugar (outside) —> putivate + sugar-phosphate (inside)
Bacterial PTS Transport
Schematic
Iron uptake special case of active transport
microorganisms require iron
ferric iron is very insolvable so uptake is difficult
microorganisms secrete siderophores to aid uptake
The plasma membrane
PM can be used to capture energy
embedded electron transport chains help create proton motive force (PMF)
used for respiration/photosynthesis
used to derive energy for motion
PM can hold sensory systems
proteins in the PM can be used to detect environment changes
the cell can use the detected changes to alter gene expression to respond
Siderophores
molecule secreted outside of cell
co translational secretion
- in cognition if signal peptide
rest of protein production
messenger rna and slightly synthesize peptide and rhybosomes are produced this way
Some secretion systems of gram negative bacteria
Components may have needle like structure to inject or secrete
Schematic
Bacterial Cell Wall
Peptidoglycan (murein)
rigid structure that lies just outside the cell membrane
two types based in Gram stain
- gram positive
- gram negative
Cell wall functions
maintains shape
helps protect cell from osmotic lysis
protect from toxic materials
may contribute to pathogenicity
