Exam 1 Lecture 1: Evolution of Microorganisms & Microbiology

What is sterility

absence of anything potentially living

True or False: Sterility exists on earth

false

What are the 6 most essential elements for living things

CHONPS (carbon, hydrogen, nitrogen, phosphorus, sulfur)

Microbes help recycle (blank)

CHONPS

What is an example of a process used to recycle elements that microbes are essential to?

Nitrogenous/ Nitrogen cycle (microbes do 4/8 steps)

Microbes are also a source of (blank)

nutrients

What are some of the general ways microbes benefit society?

photosynthesis (oxygen production), true antibiotics, fermentation (yeast)

What percent of microbes cause disease?

3%

10:1 ratio describes what?

ration of microbes to human cells in the body

What are the two overarching categories of microbes?

Cellular & Acellular

Cellular or Acellular?: ALWAYS has cell membrane, RNA/DNA & is living

Cellular

Cellular or Acellular?: does not have cell membrane, not living

Acellular

Cellular microbes include:

Fungi, Protists, Bacteria, Archaea

The eukaryotic cellular microbes are:

Fungi & protists

Prokaryotic cellular microbes are:

Bacteria & Archaea

Yeast and Mold are:

Fungi

Algae, Protozoa & Slime mold are:

Protists

Escheria coli is:

bacteria

Methanogens are:

archaea

Plasmodium falciparum is what type of microbe and what does it cause?

Protozoa, malaria

Methanogens cause harm to

each other NOT HUMANS

Why do methanogens not cause harm to humans?

live in extreme environments (100+ degrees celcius)

Why do are methanogens usually not studied?

Because they do not cause harm to humans

Acellular microbes include:

viruses, viroids, prions, satellites

What are viruses composed of?

protein & nucleic acid

Ebola, Influenza, SARS CoV-2 are examples of:

Viruses

DNA and RNA are:

nucleic acids

All living organisms have:

DNA, RNA, cell membrane

Viroids are composed of:

RNA

What do viroids cause harm to?

plants ONLY

Satellites are composed of:

nucleic acid in protein shell

What do satellites do in order to replicate?

piggy back off of viruses

Prions are composed of:

protein ONLY

Can have RNA or DNA

viruses

Characteristics of Prokaryotes

no nucleus, no organelle like structures, have circular DNA

Characteristics of Eukaryotes

nucleus, organelles, linear DNA

What is the central dogma?

DNA -> RNA -> proteins (DNA is a template for its own replication. DNA template used for transcription to makes mRNA or RNA. Then translation: mRNA is used to make polypeptides/proteins.)

What processes in the nucleus (for Eukaryotes, cytoplasm for pro) use DNA as the template?

Replication and transcription

Translation occurs where for both Eukaryotes and Prokaryotes?

Cytoplasm

What do ribosomes do?

Take information from mRNA and help produce polypeptide/protein

Who created the Tree of Life

Carl Woese in 1970

What made the tree of life unique at the time?

Organised organisms by genetics rather than physical appearances

What component of organisms did Carl Woese choose in order to differentiate between them in the tree of life and why?

Ribosomes (all living organisms have ribosomes but are slightly different between them)

What are the two parts of the ribosome?

large subunit and small subunit/ rRNA and ribosome subunits

What part of the ribosome was used to compare between organisms and what technique was used to compare them?

small subunit rRNA, Centrifugation to separate by weight (heavier= lower)

What two sizes of rRNA did Woese find and what did they correspond to?

16s (Bacteria and Archaea) & 18s (Eukaryotes)

What technique did Woese use to further classify 16s into Bacteria and Archaea?

Genetic sequencing (comparing nucleotides/genes T not U)

What differentiates bacteria rRNA from archaea?

Shine-Dalgarno sequence ( rare/largely absent in arachaea)

Hair pin structures describe what characteristics of proteins

structures (2ndry can have tertiarty)

True or False: Acellular microbes are part of the tree of life

False

Viroids are made up of

RNA only circular single stranded

What structure do virioids hold?

2ndry (hairpins)

a-helix and B-sheets are examples of:

2ndry protein structures

What is the structural discrepancy in disease causing prions?

misfolded proteins/ changes in 2ndry structure

True or False: Prions disease has no cure

True

What cells do prions disease affect?

Neurons

How does RNA do both cellular work and replicate?

With ribozymes

RNA could have given rise to DNA because of what strucutural difference?

hydroxyl group on carbon 2 that DNA does not which causes it to be more reactive than DNA

How does RNA regulate its own gene expression?

RNAi/ RNA intererons (siRNA & miRNA)

What are the types of RNAi/RNA interferons?

siRNA=lab miRNA=prod. by human cells

Who is LUCA?

Last Universal Common Ancestor

Archae similarities and differences between Bacteria and Eukarya

have central dogma similar to Eukarya however their metabolism is more similar to bacteria (middle ground between two groups)

Cyanobacteria was engulfed to turn into what organelle?

chloroplasts for plant and algae cells

A-proteobacterium (gram negative) was engulfed to turn into what organelle?

mitochondria for animals

In the endosymbiotic theory what occured to the genome of the endosymbiotes that were engulfed?

reduced/ gene reduction (most of mitochondrial DNA was transferred to nucleus)

How many of its own genes did the mitochondria keep?

~31

True or False: the mitochondria can do transcription and translation by itself

True

Mitochondria ribosomes comparison to bacteria & eukaryotes

mitochondria carries ribosome that is same size as bacterial ribosomes 70s cytoplamsic ribosome carries ribosome that is size of eukaryotes 80s

How do most proteins get to the mitochondria?

protein is found in mitochondria but comes from nucleus (transcribed in nucleus translated in cytoplasm then carried to mitochondria)

What was cyanobacteria incorrectly classified as?

blue green algae

(blank) lead to evolution

mutation

What are the 2 overarching categories of reproduction?

sexual & asexual

What type of microbes only do asexual reproduction?

Prokaryotes: bacteria & archaea

True or False: All microbes do asexual reproduction

False

Example of eukaryotic microbe that does sexual reproduction

Yeast

How do bacteria and archaea increase the genetic pool when replicating their chromosome (asexual reproduction)?

horizontal gene transfer

What is horizontal gene transfer?

bacterium gets extra DNA from neighboring cell willingly or non willingly.

What are the 3 ways horizontal gene transfer can occur?

competence, phage (virus), sex pilus

HGT: competence

cell can absorb DNA from the environment

HGT: phage(virus)

Virus infects bacterium and takes pieces of DNA from old bacteria to new bacteria

HGT: conjugation

cell makes sex pilus extends attaches to bacteria moves it closer to together and donor gives DNA to recipient to incorporate or reject as plasmid

Brucella abortus: Which is the genus?

Brucella

Brucella abortus: Which is the species?

abortus

Species

collection of different strains

strains

Descendents from a single, pure microbial culture

Strains are the product of what type of reproduction?

asexual

biovars

Strains that differ biochemically and physiologically

morhphovars

Strains that differ morphologically

serovars

Strains that differ in antigenic properties

type strain

The first strain to be studied

taxonomy

science of biological classification

True or False: kingdoms are used to in microbial taxonomy

False; only used for macroorganisms

Taxa

Domain, phylum, class, order, family, genus, species, strains

Binomial system of nomenclature

Genus species (Escherichia coli)

How did Linnaeus organise organisms?

similar physical characteristics

Bergey’s Manual

published in 1923 first time everyone agreed on nomenclature

ATCC=American Type Culture Collection

collects samples of microbes and cells lines from throughout the world

ATCC ensures (blank)

comparability and replicability of results for particular strains

Robert Hooke

1. created the compound microscope (2 lenses) coined term “cells”

Antione van Leeuhenhoek

2. used single lense microscope to observe bacteria “animalcules”, first person to observe microorganisms