Bacterial Cell Structure Flashcards
Phospholipids are composed of
A polar head (glycerol and phosphate group)
2 fatty acid tails (Non-polar)
The purpose of phospholipids
Make up the lipid bilayer which is the major lipid component of the membrane
Hapanoids
Maintains membrane homeoviscosity in bacteria
Facilitated diffusion
Spontaneous passive transport pf molecules or ions across a membrane with specific integral proteins
Active transport
Movement of ions or molecules across a cell membrane into a region of higher concentration with the assistance of enzymes requiring energy
Respiration (Electron Transport System): proton gradients
The energy-released pumps released pumps hydrogen out of matrix space. The gradient created by this drives hydrogen back through the membrane, through ATP synthase. As this happens, the enzymatic activity of ATP synthase synthesizes ATP from ADP
Photosynthesis
Light goes through the ETC to split water as a source of electrons to produce oxygen
Ion gradients as driving force for co-transport
When driving ions and molecules pair up and move in the same direction
Environmental sensing and signal transduction
The process by which a cell responds to substances molecule move in outside the cell through signaling molecules found in the surface and inside the cell
Cytoplasm
Water, Macromolecules (proteins, DNA, RNA), Molecular building blocks and metabolites (AA, nuclei acids, sugars), Inorganic ions (K+,Na+, Cl-)
Nucleoid
Biggest structure in a cell and holds all the genetic information in a bacterial cell
How do cations (Mg^2+, K+, Na+) help tightly pack DNA?
They associate with the phosphate groups to neutralize the charge
How do small positive charged proteins help to tightly pack DNA?
They act as scaffolding for the bacteria to wrap around which also neutralizes the charge
How do topoisomerases help tightly pack DNA?
They preform supercoiling
Is the nucleoid an organell?
Not membrane-bound so no
Polyhydroxybutyrate
Used for carbon storage
Cyanophycin
Used for nitrogen storage
Volutin
Used for phosphorus storage
Where are sulfur globules observed?
Thiomargarita namibiensis
What do sulfur globules consist of?
Elemental sulfur
Gas vesicles
Provide buoyancy to the cells allowing the cells to regulate their position in a water column in response to light or nutrient levels
Carboxysomes
Contains RuBisCO which is involved in the conversion of inorganic carbon into organic matter during photosynthesis
O2 competes with CO2 for RuBisCO
Ensures an oxygen-free environment for carbon fixation
O2 fixation produces 2-phosphoglycolate
Inhibits some of the other enzymes involved in photosynthesis: accumulation is toxic