Lecture 2 Flashcards
Prokaryotes
differ from eukaryotes in size and simplicity
Most lack internal membrane systems
Prokaryotes =
Bacteria and Archaea
Bacterial Cell Shape
Cocci and rods most common
Bacterial Cell Arrangement
Determined by plane of division
Determined by separation or not
Mycelium
Network of long, multinucleate filaments
Pleomorphic
Organisms that are variable in shape
Bacterial Cell Organization
Cell envelope – 3 layers
Cytoplasm
External structures
phospholipids
Polar ends
Non-polar tails
Polar ends
Hydrophilic
Interact with water
Membrane Proteins
Peripheral (20-30% of total membrane protein) and are loosely connected to the membrane
Membrane Proteins
Integral (70-80% of total membrane protein)
Amphipathic – embedded within membrane
Amphipathic
Possessing both hydrophilic and hydrophobic qualities
hopanoids
Stabilize membrane
Macroelements
C, O, H, N, S, P
Micronutrients
Trace Elements
Amino acids
Needed for protein synthesis
Purines and pyrimidines
Needed for nucleic acid synthesis
Vitamins
Function as enzyme cofactors
Heme
Iron
Uptake of Nutrients
Facilitated diffusion – all microorganisms
Active transport – all microorganisms
Group translocation – Bacteria and Archaea
Endocytosis – Eukarya only
Facilitated Diffusion
carrier proteins
Movement of molecules is not energy dependent
Active Transport
Energy-dependent process
ATP or proton motive force (PMF) used
Move molecules against the concentration gradient
Three types of Active Transport
Primary active transport
Secondary active transport
Group translocation
Primary active transport
ATP-binding cassette (ABC) transporters
Secondary Active Transport
Use ion gradients to cotransport substances
Group Translocation
Energy dependent transport that chemically modifies molecule as it is brought into cell
Cell Wall Functions
Shape, Lysis, toxic materials,
Gram-positive
stain purple
Gram-negative
stain pink or red
Peptidoglycan Structure
N- acetylmuramic acid (NAM)
N-acetylglucosamine (NAG)
