Bios 2210 Exam 1 study guide
What is a protist?
Eukaryote that cannot be classified as an animal, plant, fungi, or bacteria
What are the Enterobacteriacea?
a group of short, Gram-negative, facultative anaerobic rods that are found in the intestinal tract of various mammals, including human
What are phototrophic bacteria?
acquire the energy for anabolism by absorbing light with pigments located in thylakoids
What is a micrograph or microphotograph?
a photograph or digital image taken through a microscope or similar device to show a magnified image of an object
What is a protozoan?
a single-celled microscopic animal of a group of phyla of the kingdom Protista, such as an amoeba, flagellate, ciliate, or sporozoan.
What is a hydrogen bond?
a weak bond between two partially charged atoms
What is selective permeability?
ability of a membrane to regulate passage of materials into and out of the cell
What molecular structure was discovered in the 1950s and who was involved? What is the field of study called molecular biology?
double helix: James watson and Francis crick.. genetics
Where are microbes?
everywhere
How are disaccharides held together?
glycosidic bonds
cell arrangement
grouping of individual cells
What is a fatty acid?
hydrocarbon chain with a carboxyl group at one end
What are fungi? And molds? Are they photosynthetic? Are they eukaryotes?
organisms that eats organic material, Molds are microscopic fungi that live on plant or animal matter, no, eukaryotic
Why does a cell "shrink" when the medium or solution it is in has a higher solute concentration than the cell itself? What is this called?
osmosis, changing concentrain
What are helminths?
parasitic worms
What is tonicity?
the ability of a surrounding solution to cause a cell to gain or lose water
What is biochemistry
the application of chemistry to the study of biological processes at the cellular and molecular level
Microbiota?
the term for the microbes that are normally present in and on the human body; usually beneficial
Describe the unique cell characteristics of Archaea.
their ability to live in extremely hot or chemically aggressive environments
What is a redox reaction?
transfer of one or more electrons from one reactant to another
What does the term strepto- mean?
twisted chain
Are Bacteria and Archaea both prokaryotes?
yes
Are Lactobacillus spp. And Streptococcus spp. Gram positive?
yes
Are bacteria found in air, soil, and water?
yes
Is glucose a monosaccharide? How many carbons does it have?
yes, 6 carbons
Typical size of bacteria
1-5 micrometers um
Typical size of virus?
10-100 nanometers
Give an example of a slightly acidic pH?
6
What is a prokaryote?
A cell without a nucleus
What is a polar covalent bond?
A covalent bond in which electrons are not shared equally
polymer
A long molecule consisting of many similar or identical monomers linked together.
What are the types and main groups of microbes?
Viruses, Bacteria, Archaea, Fungi, and Protists.
Describe Proteobacteria in terms of their cell wall srtucutre?
All "Proteobacteria" are Gram-negative (though some may stain Gram-positive or Gram-variable in practice), with an outer membrane mainly composed of lipopolysaccharides. Many move about using flagella, but some are nonmotile or rely on bacterial gliding.
Prokaryotic
An organism whose cells do not have an enclosed nucleus, such as bacteria.
endosymbiotic theory
Ancestors of mitochondria and plastids was prokaryotes that came to live in a host cell.
Microbes
Any microscopic organism. Mainly bacteria, protists, some fungi, and even some tiny multi-cellular organisms.
Eukaryotic
Cell with a nucleus (surrounded by its own membrane) and other internal organelles.
binomial nomenclature
Classification system in which each species is assigned a two-part scientific name
What is gram staining?
Gram staining is a procedure by which bacteria can be classified by the ability of the cell wall to absorb a crystal violet dye, followed by a red safranin counterstain.
Gram positive bacteria, why do they stain dark purple and how are they different from Gram negative bacteria?
Gram-positive bacteria have a thick mesh-like cell wall made of peptidoglycan (50-90% of cell envelope), and as a result are stained purple by crystal violet, whereas gram-negative bacteria have a thinner layer (10% of cell envelope), so do not retain the purple stain and are counter-stained pink by safranin.
Do any eukaryotes have cell walls?
In eukaryotes, vertebrates don't have a cell wall but plants do.
How do microscopes work?
Most microscopes use lenses to magnify the image of an object by focusing light or electrons
What was discovered in 1940s that changed the practice of medicine? Who was well known for this discovery?
Penicillian: Alexander Fleming
What are flatworms?
Platyhelminthes
What is the difference between SEM and TEM ?
SEMs are used to examine the surface of specimens and produce a 3D image. TEMs are used to examine the internal ultrastructure of cells.
What is cell morphology?
The cell shape, arrangement, structures (ex. Endospores, flagella, etc.)
phlogeny
The evolutionary history of a species or group of related species
How are the cell structures different in prokaryotes vs. eukaryotes?
The primary distinction between these two types of organisms is that eukaryotic cells have a membrane-bound nucleus and prokaryotic cells do not
Taxonomy
The scientific study of how living things are classified
Describe the shape and arrangement of the cells of Staphylococcus aureus.
They grow in clusters, pairs and occasionally in short chains.
Microbiome?
all of the microorganisms that live in a particular environment, such as a human body
What is the subunit of proteins?
amino acids
Define magnification and how to calculate total magnification when using a compound microscope ( like you would use in lab )
amount or degree of visual enlargement of an observed object : 2x,4x,10x times original 10
Define virus, are they prokaryotes or eukaryotes, why not?
an infective agent that typically consists of a nucleic acid molecule in a protein coat, is too small to be seen by light microscopy, and is able to multiply only within the living cells of a host. neither not living
What are the main groups of eukaryotes?
animals, plants, fungi, protists
What is the important role of Streptomyces?
antibiotics
What is yeast?
any unicellular fungus that reproduces vegetatively by budding or fission, including forms such as candida that can cause disease.
Colonial morphology?
appearance of colonial growth on agar media such as color, density, consistency, surface texture, shape, and size.
Why do we know much less about Archaea species when compared to Bacteria species?
archaea are less abundant and harder to find
What are some shapes of bacteria ?
bacillus (rod) coccus (spherical) spirillum (spiral) vibrio (curved rod)
How are microbes classified?
basis of cell structure, cellular metabolism, or on differences in cell components such as DNA, fatty acids, pigments, antigens, and quinones
What is a peptide bond?
bond between two amino acids
cellular & acellular
cellular is of, relating to, consisting of, or resembling a cell or cells while acellular is not composed of cells; not cellular
What is the function of proteins in the cell?
cellular machines for cellular signaling, catalyzing chemicals, molecular transportation
Modern day tree of life- Woese and Fox....and what is 16S rRNA?
cellular morphology and genomic similarities (16srRNA used)
What is electron microscopy?
it provides detailed images of cells and its parts. Electrons are absorbed, deflected or transmitted on the density of the structures of the specimen
Cholesterol, found in animal tissues, where in human cells?
liver
What cell structures are found in eukaryotic cells and not prokaryotic cells?
mitochondria
Endosymbiotic theory and its supporting evidence?
mitochoondria
organic molecules
molecules that contain carbon
What is chemotaxis?
movement of a motile cell or organism, or part of one, in a direction corresponding to a gradient of increasing or decreasing concentration of a particular substance.
Cyanobacteria? Are they eukaryotic or prokaryotic?
prokaryotic
Where are proteins made in the cell?
ribosomes
What are nematodes?
roundworms
Compare the magnification capability of SEM vs Compound light microscopy like bright field.
sem 100,000x, light 1000x
Can you recognize images taken from an SEM compared to a TEM?
sem looks 3d, tem looks 2d
What are examples of polysaccharides?
starch, glycogen, cellulose, chitin