Chapter 3 Flashcards
Coccus morphology
Spherical shape
Bacillus morphology
Rodlike shape
Vibrio morphology
“U” shape
Spirillum morphology
Rigid and wavelike shape
Spirochete morphology
Corkscrew or helical shape
Bacteria that divide in one plane and found in pairs?
Indicated by the prefix diplo-
Bacteria that divide in one plane and found in chains?
Indicated by prefix strepto-
Cocci that divide in multiple planes and found in clusters?
Staphylo-
Cocci that divide in multiple planes and found in groups of 4?
Tetra-
Cocci that divide in multiple planes and found in packets of 8?
Sarcinae
What can easily pass through the selectively permeable membrane?
Small, hydrophobic molecules, gases, water.
Sugars, ions, amino acids, ATP, macros do not
Flow of passive transport?
With the concentration gradient from areas of high solubility to areas of low solubility
What type of membrane transport do bacteria usually use?
Active transport
Flow of active transport?
LOW to HIGH, against (up) the concentration gradient! Need energy input.
Cotransporters..
use potential energy like proton motive force, no binding
What is the proton motive force?
It is an electrochemical gradient that provide energy to power transport systems, ATP synthesis, and motility.
What is advantageous about prokaryotes’ size?
Excrete waste efficiently, but vulnerable to parasites and competitors
What is the function of the cell wall?
Maintaining shape, preventing dehydration, and protects from changes in osmotic pressures.
What does the cell envelope contain?
Cell wall, cytoplasmic membrane, and capsule if present.
Membrane in prokaryotes?
Phospholipid bilayer embedded with proteins. Hydrophobic tails point in, and hydrophobic heads point out.
Function of proteins in membranes?
Serve as selective gates, homeostasis maintenance, information about external environment transmitted, drift laterally, enzymes
Hypotonic vs Hypertonic
Water flows from hypotonic to hypertonic
ABC Active Transport
Use ATP. Binding proteins
Group translocation
Form of active transport that uses chemical energy to alter transport molecule, usually by phosphorylation
What converts food into energy in prokaryotes? In eukaryotes?
Pro- cytoplasmic membrane
Eu- organelles
ETC?
ETC embedded in cytoplasmic membrane. Moves protons out of cell, and electrons stay in. Forms gradient. Attraction keeps both protons and electrons close to membrane gradient– has energy called proton motive force that can be harvested for energy when protons are moved back into the cell.
Secretion?
Moves synthesized proteins out of cell
Signal sequence
In amino acids, indicates which proteins to be secreted
Peptidoglycan
Gives bacterial cell walls strength. Sugar chain with amino acids.
Can sugars and aminos pass through cell wall? Cell mem?
Yes cell wall, but needs active transport for cell mem
Gram pos structure?
Negatively charged teichoic acids bind sugars and cations; extend above peptidoglycan layer. THICK outer later of peptidoglycan. Gel like medium between peptidoglycan and inner membrane
Gram neg structure?
Very outer membrane is a lipid bilayer with proteins (LPS) that is super strong and keeps a ton of stuff out. Then periplasmic space. then THIN peptidoglycan cell wall. then periplasmic space. then inner mem.
LPS
LPS makes up very outer membrane of gram negative bacteria. It is also present inside the cell as a molecule the body uses to tell if a gram negative bacteria has invaded.
Contents of LPS?
Lipid A: indicator of bacteria. Anchor
O-antigen: away from mem. chains sugar molecules used for species ID
Function of penicillin?
Prevents cross linking of chains that form outer membrane of gram neg bacteria.
Gram neg or gram pos more susceptible to penicillin?
Gram pos more susceptible, gram neg outer layer keeps stuff out
True or false: penicillin can’t be used to treat bacteria without a cell wall?
True
True or false: protists have a cell wall.
False
Mycobacterium have a WAXY cell wall, true or false?
True
Cells that retain red with acid staining?
Acid fast, waxy cell wall
Cells that turn blue with acid staining?
Non-acid fast
Mycoplasma lack a cell wall, true or false?
True
Archaea have peptidoglycan, true or false?
False
Archaea structure?
Single membrane, s-layers of protein, CONTAIN CELL WALLS, no peptidoglycan
Algae and fungi have cell walls, true or false?
True
Flagella in prokaryotes?
Controlled production, mobility causes to spin like propellers, proton motive force powers. Has hook, filament, basal body.
Flagella in eukaryotes?
Powered by ATP, movement is whiplike
Pili
Shorter and thinner than flagella, but similar structure.
When sex pili aren’t made, cell cant join to other bacterium or transfer DNA
Chromosome
Single, circular, dsDNA. Located in nucleoid.
Plasmids
Smaller and circular dsDNA involved in horizontal gene transfer.
Storage granules.
Storage of sugars, produced when there is absence of nitrogen
Gas vesicles
protein bound compartment, provide buoyancy, controlled density, float close to the surface to get sunlight
Endospores
Resistant to heat, UV, etc. Extra layer outside of the cell for protection. Forms as response to environmental cues.
Germination?
Spore coat and cortex crack, vegetative cell grows, can rise to endospore. However, no increase in number of cells.
How many chromosomes do bacteria possess?
One, usually, but varies
Lysozyme vs penicillin?
Lysozyme damages peptidoglycan that has already synthesized, whereas penicillin prevents cross linking of gram neg’s LPS outer membrane
Capsule
Allow bacteria to adhere to specific surfaces. Allows some organisms to evade body’s defense system and cause disease. Layer outside cell wall.
Facilitated diffusion
A form of passive transport that uses a transport protein to move substances that cannot diffuse through the lipid bilayer. It doesn’t require energy. It uses the gradient, but it can’t create one.
Why don’t prokaryotes use facilitated diffusion very often?
Prokaryotes typically grow in nutrient poor environments. Concentration of nutrients is lower outside of the cell than it is inside. Facilitated diffusion can only move down a concentration gradient.
What is the purpose of secretion?
Moving synthesized proteins out of the cell. Sometimes, these proteins are enzymes that function outside of the cell to break down nutrients into small subunits. Subunits can be transported into the cell, while the macromolecules cannot be transported without these proteins breaking them down into subunits.
