Lecuter 1 Flashcards
(50 cards)
What is a microbe? Exceptions?
Organism too small to be seen by the unaided eye. Exceptions?
What does microbiology study
Study of microbes: prokaryotic, eukaryotic, acellular
How many microbes are estimated?
> 10^30 on the planet
What are the 3 domains of life?
Archaea, Bacteria and Eukarya
Explain the different arrangements of Cocci?
Coccus, diplococci, staphylococci, streptococci, sarcina, tetrad
Different arrangements of bacteria
- Rod-shaped (bacilli)
- Spherical (cocci)
- Spiral
Different bacteria have different morphologies, color T or F
T
What is a heterocyst
Different shapes of cells, specialized structures called heterocyst (H). A heterocyst is a differentiated cyanobacterial cell that carries out nitrogen fixation
Similarities and differences between Eubacteria and Archaebacteria?
Both:
- Prokaryotic
- No nucleus
- Single-celled
- Ribosomes
- No membrane-bound organelles
Eubacteria:
- Peptidoglycan in cell walls
- Cannot survive in extreme environments
- Bacteria and cyanobacteria
Archaebacteria:
- No peptidoglycan in cell walls
- Live in extreme envrionments
- Thermophiles, halophiles, methanogens
Eukaryotic microbes. Explain their cellular nature: protozoa, unicellular algae, fungi?
- Protozoa: no cell wall
- Unicellullar algae: cell wall, energy from sunlight
- Fungi: cell, wall, energy from organic materials
+ Moulds: generally filamentous
+ yeats: generally unicellular
Most fungi are dimorphic: have more than 1 form: yeast, filamentous or mushroom (fruiting body)
Concept of microbial communities
Microbes do not grow individually, they form communities
What are biofilms? How does it affect your body>
Biofilms are a slimy layer of microrganisms that adhere to sticky surfaces. Once the biofilm reaches the blood stream, they can spread to any moist surface of the human body
What are some properties of all living microbes, all cells
- Compartmentalization and metabolism.
- A cell is a compartment and takes up nutrients from the envrionemtn and transforms them, releases waste into the envrionment. the cell is thus an open system.
- Growth: chemicals from the environemnt are turned into new cells under the genetic direction of preexisiting cells
- Evolution: cells contain genes and evlove to display new biological preoprites
What are some properties of some cells
- Motility
Some cells are capable of self-propulsion - Differentiation
Some cells can form new structures such as a spore, usually as part of a cellular life cycle - Communication
Many cells communicate or interact by means of the chemicals that are released or taken up (biofims)
What are some catalytic and genetic functions of cells?
- Genetic functions: transcribe, DNA, replicatio, make proteins
- Catalytic functions:
+ Energy conservation: ADP + Pi -> ATP
+ Metabolism: generation of precursors of macro-molecules (sugars, amino acids, fatty acids,…)
+ Enzymes: metabolic catalysts
The closest relatives of eukaryotes among the prokaryotes are the
Archaea
Role of bacteria in nutrient cycling
- Recylce and transform nutrients: make nutrients available to other organisms
- bacteria are primary decomposers
- Important in numerous cycles:
+ carbon cycle: decompose when species die
Function of microorgansms in the nitrogen cycle
transfer of nitrogen in gas -> nitrogen thats usable for plants. Plants require nitrogen to grow. If you grow something on a certain soil for a long time -> supplemtn w nitrogen or else the plant cannot survive
Function of microorganisms in Sulphur
Sulphur is released from rocks through weathering and assimiltaed by microbes and plants
Microorganisms in bioremediation
Can break down oil, dry cleaning, pollutants, sewage, and can convert it to Co2 and H2o
Relationship between bacteria and plant in wastewater treatment
Plants provide habitat and nutrition to bacteria
while microbes:
- from biofilms
- degrade pollutants
- improve plant health
- denitrification
How many bacteria are there in your body> What functions do they have? Is everyone’s gut biome different? rely on waht?
Approx equal number of bacterial cells to human cells
- walking petri dish
- key functions in digestion and immune system
- symbiotic organism: relying on one another
how does microbiome in your body change over age
increases as you get older (expose to more)
decrease when you are old