Microbial Metabolism & Growth

1. Microbial Metabolism & Growth

2. Basic Organic Chem Review • Four Basic Types of Macromolecules • A) Proteins (Made up of Amino Acids) • B) Nucleic Acids (Made up of Nucleotides) • C) Carbohydrates (Mainly Carbon, Hydrogen, and Oxygen in a 1:2:1 ratio) • D) Lipids (Mainly Carbon & Hydrogen)

3. A. Proteins • consist of long, complex chains of amino acids (20 kinds) • the most abundant organic components of microbes • function as structural materials as well as __________ • destruction of the proteins in an organism usually results in death

4. Protein structure: amino acids • AMINO ACIDS are the building blocks of proteins a specific amino acid

5. Protein structure: amino acids NOTE: All amino acids look alike except for the highlighted portions. This is important in building many different proteins.

6. Peptide bonding of amino acids • Proteins are built by linking amino acids end to end. Each link is a ____________.

7. Protein structure: Primary

8. Protein structure: Secondary

9. Protein structure: 3 dimensional • The 3 dimensional shape of a protein dictates its function. • If the 3 dimensional shape is altered, the protein is destroyed.

11. Protein structure: Quaternary (Hemoglobin)

12. Protein _________ Altered 3-D shape = destroyed protein

13. B. Nucleic Acids • Two types function in all living things: • _____ ( deoxyribonucleic acid ) acts as the genetic material of the chromosome • _____ ( ribonucleic acid ) functions in the construction of proteins • Both DNA and RNA are composed of repeating units called nucleotides • As with proteins, the nucleic acids cannot be altered without disrupting the organism or killing it.

14. C. Carbohydrates • 1. general formula = (CH2O)n • 2. sugars, starches, cellulose, etc • 3. have a vital function as energy sources in cells • 4. also found in several cellular structures such as cell walls and bacterial capsules • 5. monosaccharides are the simplest carbohydrates, the building blockse.g. ________, fructose C6H12O6

15. Carbohydrates • 6. disaccharides are double sugars (2 monosaccharides bonded together) • e.g. _______(table sugar) is one glucose and one fructose • C12H22O11: one H2O lost when bond forms Dehydration Synthesis (Putting together) Hydrolysis (breaking apart) glucose fructose NOTE: 2 monosaccharides linked together.

16. Macromolecules (How to Make Them) CH2OH CH2OH CH2OH CH2OH O O O O H H H H H H H H H H H H2O OH H H H H H H OH OH OH O HO OH HO OH HO OH H OH H OH OH OH H H Dehydration Synthesis Hydrolysis

17. C. Carbohydrates • 7. complex sugars are called polysaccharides or complex carbohydrates (e.g. starch, cellulose ) • long chains of sugars:sugar—sugar—sugar—sugar—sugar—sugar—sugar—

18. D. Lipids • Broad group of organic compounds that dissolve in oily solvents (e.g. acetone, or benzene) and alcohol but generally do not dissolve in water • Mostly composed of carbon and hydrogen

19. D. Lipids glycerine fatty acid • 1. Best known lipids are fats • serve living organisms as important energy sources • consist of glycerol and up to three long-chain fatty acids • 2. Modified fats called phospholipids are the major components of membranes • 3. Other types of lipids include waxes and steroids

20. Fatty Acids + Glycerol

21. Fats

22. Other important lipids you should know! Phospholipids Steroids such as cholesterol

23. I. MICROBIAL PHYSIOLOGY • _____________: the sum of all biochemical processes taking place in a living cell. Two phases: • _____________: constructive metabolism; the synthesis reactions; small molecules bonded into larger molecules; energy is “used up” • _____________: destructive metabolism; decomposition reactions; large molecules split into smaller molecules; energy is released

26. A._________ • the enzymes present in an organism determine the nature of its physiology • enzymes are biological catalysts (catalysts are agents that speed up chemical reactions) • Enzymes “arereusable protein molecules that brings about a chemical change while remaining unchanged itself”

27. ________________= the amount of energy required to do the reaction

28. Without enzyme lactose glucose + galactose activation energy without enzyme net energy released from splitting of lactose Activation Energy = the amount of energy required to do the reaction With enzyme lactose glucose + galactose activation energy with enzyme net energy released

29. __________= what the enzymes works on Enzymes ________ = what is made

30. Enzymes Active Site Allosteric Site Competitive Inhibitor Noncompetitive inhibitor

31. Action of enzyme inhibitors • Examples of inhibitors: • 1. Competitive=sulfa drug (sulfanilamide) 2. Noncompetitive=Certain poisons, such as cyanide and fluoride (enzyme poison in bacteria)

32. Factors influencing enzyme action: • a. Terms: • optimum: the environmental state where the enzyme works the fastest. • maximum: The maximum environmental limit where the enzyme works at all. • minimum: The minimum environmental limit where the enzyme works at all. • e.g. temperature: every enzyme has its optimum temperature (where it works fastest). Curve is unusual:

33. enzyme activity vs temperature

34. pH • Measurement of acid/base balance • Logarithmic scale • 0-6.9 = acid • 7.1-14 = basic (alkaline) • 7 = neutral (like pure water)

35. enzyme activity vs pH • every enzyme has its optimum pH (where it works fastest). Bell curve

36. Naming of enzymes • names end with -ase • name of substrate + ase e.g. sucrose is digested by sucrase • kind of reaction + asee.g. an enzyme that causes oxidation is called oxidase

37. Types of Enzymes based on location • endoenzymes: remain inside of the cell (work internally) • enzymes of cellular metabolism • vulnerable enzymes • exoenzymes: released to the exterior of the cell (work externally) • digestive enzymes and enzymes of virulence

38. Constitutive vs Induced Enzymes • ___________ enzymes: • always present • necessary for life of cell • __________ enzymes: • produced only when substrates are present • e.g. digestive enzymes • provide efficiency and adaptability

39. B. Energy and ATP • Energy released from catabolism of foods is stored in a compound called ATP (adenosine triphosphate) • a molecule of ATP acts like a portable battery—it’s instant energy for a cell to use • ATP molecules are used everywhere in a cell to meet energy needs. (When the supply is exhausted, the cell dies)

40. ADP + Phosphate + Energy = ATP releases heat captures heat

41. ATP • Although ATP molecules are used everywhere in the cell to meet energy needs, they are not suitable for storing energy. The molecules are large and bulky, and surplus takes up too much space in a cell. • Therefore, cells synthesize or obtain small molecules such as glucose or lipids for energy storage. When needed, these energy storage molecules can be converted to ATP! • glucose is a principle source of energy for ATP production.

42. C. Pathways of Energy Production • Most of a cell’s energy is produced from carbohydrate catabolism • Glucose is the most commonly used carbohydrate: • C6H12O6+ 6 O2+ 38 ADP + 38 P 6 CO2+ 6 H2O + 38 ATP

43. To produce energy (ATP) from glucose, microbes use 2 general processes: • 1. respiration • in which glucose is completely broken down • 2. fermentation • in which glucose is partially broken down • Both processes usually start with the same first step (glycolysis), but follow different subsequent pathways

44. Glycolysis • the first stage in the breakdown of glucose (energy glucose source ) series of controlled reactions releasing a little ATP 2 pyruvic acid

46. Overview of Respiration & Fermentation glycolysis fermentation respiration pathways pathways Aerobic= CO2 + H2O + 38 ATP an organic end-product (like alcohol or lactic acid) with low ATP yield

47. Classification of organisms by oxygen use (study table 6.1) • 1. obligate aerobes: (= strictly aerobic): must have oxygen to grow (go dormant without oxygen) • 2. microaerophiles: grow best at low oxygen levels (less than atmospheric) • 3. facultative anaerobes: use oxygen if it’s present, but can also grow anaerobically (capable of growing at any oxygen level, but greater growth with oxygen present) • 4. aerotolerant anaerobes: never use oxygen, but not inhibited by it • 5. obligate anaerobes: grow only in absence of oxygen (inhibited by oxygen)

48. Growth at different oxygen levels

49. E. Growth at different temperatures • Each species has different temperature requirements • minimum growth temperature: lowest temperature at which growth will occur (very slow growth at this temp) • below the minimum, most microorganisms go dormant, but do not die • optimum growth temperature: temp at which most rapid growth occurs • maximum growth temperature: highest temp at which growth occurs • above this temp, enzymes are denatured and death might occur • NOTE: Growth parallels rate of enzyme activity.

50. Growth speed vs temperature Growth Speed