Exam 1 - Part 1 Flashcards
Chapter 1 and 2 Evolution of Microorganisms and Microscopy
Top causes of death in the US
- heart disease
- cancer
- stroke
- chronic lower respiratory diseases
- influenza and pneumonia
- septicemia (bloodstream infection)
- top ten causes of death worldwide also include HIV, diarrheal diseases, and tuberculosis
Louis Pasteur
- swan neck flask experiments
- disproved theory of spontaneous generation
- yeast fermentation to make alcohol
- pasteurization
Robert Koch
- etiology of anthrax
- Koch’s postulates
- still used today to establish the link between a particular organism and a particular disease
what was the first living creatures on planet earth?
microbes
what are the characteristics of microbes?
- are more diverse than plants and animals
- are more abundant than any other living thing
- grow in every ecological niche on earth that has a source of liquid H20
- can transform the geosphere
- can affect the climate by production/use of CO2, N2, O2, and CH4
- participate in symbiotic relationships with other organisms
- only a small fraction of microbes causes diseases
what are diseases caused by microbes called?
infectious diseases
basic research microbiology
by kind of organism, by process, or in relation to diseases
applied microbiology
disease relation, environmental, and industrial
what are the three domains of microorganisms
bacteria, archaea, and eukarya
how are the three domains of living structures classified?
by size, nuclear membrane, cell wall, and presence of organelles
what do life forms obey?
-the laws of physics and chemistry
what are life forms made of?
- molecules
- polymers of proteins
- carbohydrates
- lipids
- nucleic acids
what are the three types of chemical bonds? are there others?
- ionic
- covalent
- hydrogen bonds
- hydrophobic interaction
- van der Waals force
what are the 6 major bio-elements? are there others?
Carbon, hydrogen, oxygen, nitrogen, phosphorous, sulfur
magnesium, zinc, iron, sodium, and potassium
what is the role of water in life?
- H bonds between water molecules contribute to a high boiling point
- H bonds hold and absorb energy that make water a temp buffer
- water is a polar molecule and capable of forming H bonds with other, which makes water an excellent solvent
endergonic
requires energy
exergonic
releases energy
chemical reactions
a change in energy that occurs during any chemical reaction. may be classified as endergonic or exergonic, and could include activation energy, catalysts, and enzymes
what can organic compounds be?
- acidic or basic
- polar or nonpolar
- hydrophilic or hydrophobic
polymers
a long stretch of identical/similar molecules (monomers)
sugars
polysaccharides
fatty acids
lipids
nucleotide bases
nucleic acids
amino acids
proteins
carbohydrates
sugars/polysaccharides
what are the important roles of carbohydrates?
- contribute to structural support
- serve as nutrient and energy stores
- important components of cell membrane
cellulose
found in plants and algae
peptidogylcan
found in bacterial cell walls
lipopolysaccharide
complex of lipid and polysaccharide (endotoxins)
glycocalyx
found on the outer surface, functions in attachments, role in biofilm
monosaccirides
glucose, fructose, galactose, ribose, deoxyribose
disacchrides
sucrose, lactose, maltose,
polysaccrides
starch, gylcogen, and cellulose
triglycerides
storage including fats and oils
glycerol
3-carbon alcohol with 3 OH groups that serve as binding sites
fatty acids
long-chain hydrocarbon molecules with a carboxyl group (COOH) that binds with glycerol
what is the difference between saturated and unsaturated fatty acids?
saturated are solid at room temp, and unsaturated are liquid at room temp
membrane lipids
- hydrophilic region from the charge on the phosphoric acid-alcohol head
- hydrophobic region n the long, uncharged rail
- these lipids naturally assume single and double layers (bilayers), which contribute to their biological significance in membranes
what does RNA serve as?
- intermediate between DNA and protein (mRNA)
- functional molecule as in tRNA
- structural molecule as in rRNA
what are the three components of DNA and RNA?
- nucleotide bases (A,C, G, T)
- sugar (ribose and deoxyribose), and phosphate
what are proteins made out of?
amino acids
what are the essential purposes of proteins in the cell?
- as enzymes catalyze chemical reactions
- regulate cellular processes
- provide structural support, collagen
- as surface receptors (signals)
- as carries, carry molecules across the membrane
what are the factors that affect protein shape?
- pH
- temp
- salt concertation
- changing these variables alters the activity/function of a protein
- if a protein’s shape is altered so severely that the protein no longer functions, the protein is said to be denatured
what are cells?
cells are essentially well organized assemblages of macromolecules with many common features shared among diverse types of cells, such as bacteria, mammals, plants, and fungi
cenitmeter
10^-2 meter
milimeter
10^-3 meter
micrometer
10^-6 meter
nanometer
10^-9 meter
angstrom
10^-10 meter
light microscopy microscopes
- bright-field
- dark-field
- phase-contrast
- fluorescence
what are the types of electron microscopes?
TEM and SEM
what are the uses for wet mounts?
- for living organisms
- used for observing motility
what is smear prepartation used for?
- dead cells
- stains of dead cells
what are simple stains used for? what are the types of dyes?
- simple stains are used showing morphology, size, and arrangement
- positive and negative
positive staining
uses basic dye that binds to the specimen
negative staining
uses acidic dye that binds to the background
basic dyes
-have positively charged groups, bind to negatively charged molecules such as nucleic acids, many proteins, and the surfaces of bacterial and archaeal cells
acidic dyes
-in their ionized form, have a negative charge and bind to positively charged cell structures
what are the examples of differential staining?
- gram stain
- acid-fast stain
- structural stains
what are microorganisms?
organisms that are too small to be seen with the unaided eye
what includes microbes?
bacteria, fungi, protozoa, microscopic algae, and viruses
what are the jobs of microorganisms?
- decompose waste and generate oxygen by photosynthesis
- produce fermented food
- produce industrial products such as acids and alcohols, and biofules
how many cells is an adult human composed of? bacterial cells?
- 30 trillion body cells
- 40 trillion bacterial cells
what is the microbiome?
- a group of microbes that live stably on/in the human body
- help to maintain good health
- can prevent growth of pathogenic microbes
- may help train immune system to discriminate threats
how are microbiota aquired?
- begin as newborns
- may colonize the body indefinitely or be fleeting
- normal microbiota prevent growth of pathogens and produce growth factors for vitamins B and K
the human microbiome project
- begin in 2007
- goal of determining the makeup of typical microbiota of various areas of the body
- secondary goal of understanding the relationship between changes in microbiome and human disease
the national microbiome initiative (NMI)
- begin in 2016
- explores the role microbes play in different ecosystems
biotechnology
is the use of microbes for practical applications, such as producing foods and chemicals
recombinant DNA technology
enables bacteria and fungi to produce a variety of proteins, vaccines, and enzymes
- missing or deflective genes in human cells can be replaces in gene therapy
- genetically modified bacteria are used to protect crops from insects and from freezing
