Revision Lect 4,5 Flashcards
Microbial growth requires
Chemical
Physical
C/O/N/S/P/ trace elements
Temp/Ph/osmotic pressure
Temperature
High
Low
Min
Max
Optimum
Denture enzymes and proteins
Solidify membrane
Min for survival
Max for survival
Avg of both best growth
The 5 temp microbes
Psychrophiles (-5> 15) arctic glaciers
Psychrotrophs (20-30) food spoilage
Mesophiles (25-40)pathogens
Thermophiles (50-60)hot springs+ compost piles
Hyperthermophiles (80+) volcanos, sulfur is important in their metabolism
The 3 ph microbes
Most grow at abt
Effect of not suitable ph
Acidophiles 0-5.5
Neutrophiles 5.5-8
Alkaliphiles 8-11.5
6.5-7.5
Disrupt plasma protein + inhibit enzymes
Ph applications
Food preservation by acids from bacterial fermentation
The 3 osmotic microbes
Most prefer
Osmotolerant wide range
Osmophile sugar hyoertonic
Halophile salt hyoertonic
Most microbes prefer isotonic, most bacteria hypotonic, gram -ve may burst
Most cannot live in hyoertonic
Carbon
Autotrophs and heterotrophs
Both have chemo and photo
What are organic growth factors
Essential organic compounds the bacteria or unable to synthesize like vitamins which are obtained from the environment
P?
N+p ?
N+ s?
S?
Phospholipids
DNA/RNA/ATP
Protein synthesis
Amino acids/ vitamins
Trace ements
Iron copper molybdendem zinc
Cool factors for enzymes very small amounts or required to naturally present in tap water
Mgcl2 co-factor for tag polymerase enzyme in PCR
Dangers of oxygen
When oxygen enters in a reaction it results in Ros single oxygen super oxide ion hydrogen peroxide hydroxide radical these are toxic and unstable and requires enzymes to neutralize it
The enzymes
Super oxidedismutase peroxidase catalase
Bacteria acc to oxygen
Oblique aerobes full
Microaerophiles full
Facultative anaerobes full
Aerotolerant anaerobes partial SOD only
Obligate anaerobes no
Culture media acc to consistency
Solid»currently determination by morphology
Semi solid»microaerophilic bacteria and bacteria motility
Liquid /broth»fermentation and tests.
Culture acc to composition
Natural»milk urine
Semisynthetic»potato dextrose
Synthetic»all chemical composition known/metabolic nature
Agar acc to purpose 6
Selective»only one type grows and inhibits the others
Enrichment»increases the growth of desired type
Differential»visually difference due to metabolism
Enriched»wide range of nutrients fastidious
Assay»antibiotic /vitamins
Maintanance»maintain viability no glucose
Key element of gram +ve bacteria
Teichoic and lipoteichoic acids
DNA in prokaryotes is
Nucleoid
Cell wall
Algae
Fungi
Yeast
Protozo
bacteria
Cellulose
Chitin
Glucan+mannan
Pellicle(flexible)
Peptidoglycan
Key elements of eukaryotes
Plasma membrane
Cytoplasm
Ribosomes
Nucleus
Sterols that resist lysis+ endocytosis
Cytoplasmic streaming to distribute nutrients
80s ribosomes
Presence of nucleus + histones + double membrane and nuclear pores
Where is rRNA synthesised
In nucleus
Then assembled with proteins in cytoplasm to form ribosomes
ER sacs
SER stores
Cisternae continuous with nuclear membrane
Lipids and steroids
Golgi vesicles
Golgi synthesis
Transport» ER to golgi
Transfer» cisternae to another
Secretory» golgi >out
Glycoproteins /glycolipids/ lipoproteins
Vacoules
Peroxisomes
Cytoplasmic space enclosed by tonoplast from golgi
Stores toxins and metabolic waste
Endocytosis
Water up take for rigidity
Catalase and oxidase enzymes, ROS to neutral
Oxidises toxins
