Lecture 3: Microbial Growth And Nutrition Flashcards
Macronutrients
- Elements required in LARGE amounts to build macromolecules (b/c you req. a lot of it)
- The building blocks of cell material
- screw to build house is a macronutrient b/c you need A LOT of it to build the house
List some macronutrients and how much of the dry weight of the cell do they make up?
C,H,O,N,P and S makeup >90% of the dry weight of the cell
What does “dry weight of the cell” mean?
dehydrated
- water makes up 60-80% of the weight of cell, this will skew the #’s too much so you consider cell in dehydrated state to see how the atoms will be req.
Protein
Polymer of made of building blocks – amino acids
C,H,O,N(andS)
• > 50% of cell dry weight
Why do proteins make up greater than 50% of the cells dry weight?
proteins are the work horse of the cell (enzymes, structural proteins, transmembrane proteins)
Protein–C,H,O,N(andS); which are from where?
C,H,O,N - backbone of an AA
S - 2/20 AA’s (cysteine/methionine)
Lipids
C,H,O(andP)
- phosphate; head groups of phospholipid structure
- C H- contribute to non polar character
- O; within carboxyl group and glycerol component of neck of structure
- Building blocks = fatty acids and glycerol
- Ex) Phospholipids
Carbohydrates
C, H, O (and N)
• Building blocks = sugars
(monosaccharide (building blocks) form polysaccharides that take on specific terms like PD)
• Ex. Polysaccharides and peptidoglycan
C: 1
H: 2
O: 1
(glucose C6H12O6)
If a sugar contains N what does that mean?
sugar derivative
- if it contains N its a sugar derivative never part of glc fructose ribose deoxyribose structures
Nucleic acids
C,H,O,N,P
• Building blocks = nucleotides
• Ex. DNA and RNA
Protein is ____% of dry weight
55
RNA is ____% of dry weight
20.5
Describe where each Nucleic acids–C,H,O,N,P are part of
C,H,O - part of sugar (ribose or deoxyribose)
N - part of nitrogenous base
P - part of phosphate group
Why does RNA make up such a high percent of the dry weight of a cell?
Bc its a precursor to proteins
transcript
Carbon is ___% of dry weight
55
backbone for all organic macromolecules
Hydrogen is ___% of dry weigh
8.2
only forms 1 cov. bond
Selenium is ___% of dry weight
<0.01
- used to form selenocysteine (an AA MODIFICATION)
- even though its small you still need it
inorganic ions
Other Macronutrients K, Mg, Ca, Fe)
- Often serve as metabolic co-factors
• Non-protein component required for enzyme function
- enzyme itself is a PROTEIN
• Enzymes involved in protein synthesis require K+
• Cytochromes (e- carriers) require Fe2+
( complexing together with iron affects reduction potential which affects e- affinity so those e- carriers will have diff. affinity (pull/desire for those e-‘s) which will correlate with amount of energy that’s released)
co- factors
like a sidekick
- can’t function without the sidekick
Describe glycolysis
glucose –> glucose 6-P
glucose –>(hexokinase - protein; has cofactor of Mg2+, allowing formation of G-6P) glucose 6-P (-)ly charged
Mg2+ (NON-protein) (+)ly charged (therefore provides temporary relief for charge repulsion that (-) charges will have with 1 another
ATP –> ADP Pi comes off and goes to form G-6P
List some other functions of inorganic ions
- Mg2+ helps stabilize membranes and nucleic acids to relieve charge repulsion
- Ca2+ helps stabilize cell walls (dipicolinic acid), and plays a role in heat stability of endospores
What needs to be considered when making a media?
**All of the macronutrients should be considered when making media
- when making a growth medium with intention tp grow something in the lab you need to be absolute certain your feeding them all these things
not all organisms like the same thing
- concentrations will be off b/c they are wrong
Are we able to grow everything in the lab?
NO
- be they are specific
Micronutrients
• Elements required in very small amounts (trace elements)
- doesn’t mean they are unimp. ( they are CRITICAL for their function)
- just b/c you don’t need a lot of something, doesn’t mean you can remove it & it still will lead to an unhindered life (absolutely critical you always have this material in the cell for full growth & success & viability)
- Usually serve as cofactors for enzymes (provide ionic stability, can’t function without them)
- Ex) Mn, Zn, Co, Ni, Cu, Mo
• Se is required to make the unusual amino acid selenocysteine(derivative of cysteine AA (has S); been modified - allowing add. function/diversity)