Saint Francis BIOL 223 Microbiology Section 2 – Flashcards
Unlock all answers in this set
Unlock answersquestion
| In Vitro Growth |
answer
| refers to the cultivation of bacteria "in a liquid nutrient growth medium". No nutrients are added during cultivation and no waste is removed. |
question
| Bacterial Growth refers to an increase in cell size. T or F? |
answer
| False |
question
| Prokaryotic cell division is always asexual. True or False? |
answer
| True |
question
| Bacteria undergo mitosis. T or F? |
answer
| False |
question
| What is the process used by prokaryotic bacteria to reproduce? |
answer
| Binary Fission |
question
| How long is generation time for most bacterial species? |
answer
| Less than an hour |
question
| What are the four bacterial growth phases in vitro? |
answer
| 1. Lag phase 2. Log phase 3. Stationary phase 4. decline phase |
question
| In which bacterial growth phase are cells metabolically active, but no significant increase in number? |
answer
| Lag phase |
question
| In which bacterial growth phase are cells at maximum growth rate? |
answer
| Log phase |
question
| In which two bacterial growth phases do we see the number of cells remain constant with some dying? |
answer
| Stationary phase & decline phase |
question
| What are three reasons bacterial cells die in the stationary phase? |
answer
| 1. nutrient depletion 2. toxic waste buildup 3. oxygen deficiency |
question
| Mycobacterium leprae causes what disease and is grown where? |
answer
| Hansen's Disease (leprosy) and is grown in the footpads of armadillos. |
question
| Treponema pallidum causes what disease and is cultivated how? |
answer
| syphilis and is grown in rabbits |
question
| What are obligate parasites? |
answer
| organisms that can be cultivated ONLY inside living hosts. ex. Rickettsia ex. Chlamydia |
question
| Fastidious microbes |
answer
| refers to microorganisms with special nutritional needs that are often very difficult (or impossible) to cultivate on lab media. |
question
| Synthetic media |
answer
| Contains know quantities of precisely defined chemicals. Useful for cultivating fastidious bacteria. |
question
| Complex Media |
answer
| ingredients in each "batch" vary slightly in chemical composition. |
question
| List some ingredients used in complex media |
answer
| blood serum beef extract soybean extract yeast extract |
question
| List four types of media commonly used to cultivate bacteria |
answer
| 1. Brain Heart Infusion Broth 2. Nutrient Broth 3. Nutrient Agar 4. Trypticase Soy Agar (TSA) |
question
| Potato Dextrose Agar (PDA) |
answer
| the most commonly used media to cultivate fungal plant pathogens |
question
| What are the ingredients in Potato Dextrose Agar (PDA)? |
answer
| dextrose, potatos, AGAR, water |
question
| What are three types of special-purpose complex media? |
answer
| selective differential enrichment |
question
| MSA |
answer
| Mannitol Salt Agar |
question
| What are the ingredients in Mannitol Salt Agar? |
answer
| mannitol, salt, and phenol red (a dye) MSA is used to differentiate between staph species. |
question
| Blood Agar |
answer
| contains live red blood cells (RBCs) used to grow and identify strep species |
question
| Chocolate Agar |
answer
| media is enriched with sheep's blood and sodium bicarbonate. used to grow Neisseria gonorrhoeae |
question
| What are three microbial growth requirements? |
answer
| 1. Water 2. Inorganic Ions (Na+, Cl-, K+, Mg++) 3. Organic Molecules |
question
| Define Metabolism |
answer
| All the biochemical reactions carried out by living organisms. |
question
| Name Four Different Salts |
answer
| Sodium (Na+) Chloride (Cl-) Potassium (K+) Magnesium (Mg++) |
question
| What are three functions of organic molecules? |
answer
| 1. Provide energy for cells to do work. 2. Accelerate the rate of biochemical reactions. 3. Serve as the structural component of cells. |
question
| Describe the metabolic pathway |
answer
| A sequence of chemical reactions in which the product (p) of one reaction serves as the substrate (s) of the next reaction. Each reaction is catalyzed (speeded-up) by an enzyme (e) |
question
| What are the two basic kinds of metabolic pathways? |
answer
| anabolic and catabolic |
question
| In catabolic pathways, organic molecules are oxidized. True or False? |
answer
| True |
question
| What are two kinds of Catabolic pathways? |
answer
| 1. Aerobic respiration 2. Fermentation |
question
| Oxygen is required for fermentation. True or False? |
answer
| False |
question
| Define glycolysis |
answer
| The oxidation (breakdown) of glucose |
question
| Glycolysis is an aerobic process. True or False? |
answer
| False It is an anaaerobic process |
question
| What re two end-products of glycolysis? |
answer
| -pyruvic acid -2 ATPs per glucose |
question
| All fermentative pathways occur in the cytoplasm. True or False? |
answer
| True |
question
| What are the three sequential pathways of Aerobic respiration? |
answer
| 1. glycolysis 2. Krebs Cycle 3. Electron Transport Chain |
question
| The electron transport chain is anaerobic. True or False? |
answer
| False It is anaerobic. |
question
| How many units of energy are created in aerobic respiration? |
answer
| 38 ATPs of energy |
question
| What does ATP stand for? |
answer
| adenosine triphosphate |
question
| What are the three sequential pathways in Anabolic respiration? |
answer
| 1. Molecules are synthesized 2. Chemical bonds are formed 3. Energy output is required |
question
| What is the primal source of energy for all life of earth? |
answer
| The sun |
question
| What are Heterotrophs? |
answer
| organisms that use organic molecules (i.e. glucose) as their source of carbon |
question
| What are Autotrophs? |
answer
| organisms that use Carbon Dioxide (CO2) as their source of carbon |
question
| Anabolic |
answer
| building up |
question
| Aerobic |
answer
| tearing down |
question
| What are two kinds of heterotrophs? |
answer
| chemoheterotrophs * photoheterotrophs |
question
| What are two kinds of autotrophs? |
answer
| chemoautotrophs * photoautrophs |
question
| Chemoheterotrophs |
answer
| *Use organic molecules * most bacterial species *ALL fungi, protozoa & animals |
question
| Photoheterotrophs |
answer
| * use light *a few rare bacteria |
question
| Chemoautotrophs |
answer
| * use inorganic compounds * a few bacterial species that make organic nitrogen available to plants. |
question
| Photoautrophs |
answer
| * use light * green plants * cyanobacteria * algae photosynthetic organisms |
question
| Aerobes |
answer
| - molecular oxygen is required for metabolism Two types: a) obligate aerobes b) microaerophiles |
question
| Anaerobes |
answer
| molecular oxygen is NOT required for metabolism. -metabolism is via fermentative pathways. two kinds: a) obligate anaerobes b) aerotolerant anaerobes |
question
| Faculative Anaerobes |
answer
| -metabolism is by: a) aerobic respiration (when O2 is available) b) fermentation (when O2 is NOT available) |
question
| Obligate (strict) aerobes |
answer
| *Thrive in ambient air (20% O2) *In broth cultures - grow near the surface. * have two enzymes able to break down two toxins present in aerobic environments 1. Superoxide 2. Hydrogen peroxide |
question
| What are the two enzymes present in Obligate (strict) aerobes? |
answer
| 1. Superoxide dismutase 2. Catalase |
question
| Microaerophiles |
answer
| * Thrive in environments of low O2 and High CO2 * In broth cultures, grow in a narrow zone, slightly below the surface. Examples: Helicobacter Pylori - causes gastric ulcers Neisseria gonirrhoeae - causes gonorrhoeae Campylobacter jejuni - food poisoning |
question
| Obligate (strict) anaerobes |
answer
| * Grown only in anaerobic environments * are killed by Areobic environments Example: Clostridium species |
question
| Aerotolerant anaerobes |
answer
| * not killed in aerobic environments * Metabolism is always fermentative (no O2 used) *Grow everywhere in a broth culture *Example: Lactobacillus spp. |
question
| Faculative anaerobes |
answer
| * grow everywhere in a broth culture *metabolism: 1. Aerobic respiration 2. Fermentation examples: E. Coli Bacillus species Streptococcus species Staphylococcus species |
question
| Neutrophiles |
answer
| (pH = 6.5 - 7.5) *Live in environments near neutral pH (7.0) *Found in most fertile soils and inland bodies of water. *Most bacterial species are neutrophiles. *Most human pathogenic bacteria are neutrophiles. |
question
| Alkaliphiles |
answer
| pH 8.0 - 12.0 *found in marine environments *ammonia rich soils (with manure) example: Vibrio Cholerae likes a pH of 9.0 |
question
| Acidophiles |
answer
| (pH of less than 6.0 *found in drainage waters from sulfur and iron mines. Volcanic soils Vaginal wall *most bacterial species do not grow well at acidic conditions. *Fungi prefer slightly acidic condiitons |
question
| Bacteria thrive in acidic conditions. True or False? |
answer
| False |
question
| Most bacteria grow over a temperature range of _______degrees Celsius. |
answer
| 30 degrees C |
question
| Optimal growth rate for enzymes is near the upper or lower limit of the temperature range? |
answer
| Upper |
question
| Psychrophiles |
answer
| *cold loving bacteria (0-20 C/32-68 F) found in cold water, soil, some refrigerated foods. |
question
| Mesophiles |
answer
| *grow at moderate temperature (25-40 C/75-100 F) *most microbial species *ALL human infectious microbes and normal flora |
question
| Thermophiles |
answer
| *like very warm to hot temps (above 40 C/105 F) *found growing in compost heaps, hot springs |
