Basic microbiology Flashcards
What are the 3 domains of life?
bacteria archaea eukarya
Define a bacteria
a member of a large group of unicellular microorganisms which have cell walls but lack organelles and an organized nucleus, including some that can cause disease.
Define archaea
microorganisms which are similar to bacteria in size and simplicity of structure but radically different in molecular organization. They are now believed to constitute an ancient group which is intermediate between the bacteria and eukaryotes.
Define Eukaryote
an organism consisting of a cell or cells in which the genetic material is DNA in the form of chromosomes contained within a distinct nucleus. Eukaryotes include all living organisms other than the eubacteria and archaea.
any cell or organism that possesses a clearly defined nucleus
What is a eukaryote and example
eukarya
Eukaryotic cells have the nucleus enclosed within the nuclear membrane. The cell has mitochondria. Flagella and cilia are the locomotory organs in a eukaryotic cell. A cell wall is the outermost layer of the eukaryotic cells.
What structures define a prokaryote?
lack a membrane-bound nucleus to hold their chromosomes. Instead, the chromosome of a prokaryote is found in a part of the cytoplasm called a nucleoid. Prokaryotes generally have a single circular chromosome that occupies a region of the cytoplasm called a nucleoid.
Example of a prokaryote
bacteria and archaea
Compare a prokaryote and eukaryote
Prokaryotes are always unicellular, while eukaryotes are often multi-celled organisms. Additionally, eukaryotic cells are more than 100 to 10,000 times larger than prokaryotic cells and are much more complex. The DNA in eukaryotes is stored within the nucleus, while DNA is stored in the cytoplasm of prokaryotes.
Is this a prokaryote or eukaryote?
Eukaryote
eukaryotic cell
Is this a prokaryote or eukaryote?
Prokaryote
prokaryotic cell
What are microbial causes of infection?
bacteria
viruses
fungi
parasites
prions
Define a bacteria
Bacteria are tiny, single-celled living organisms. There are millions of different types of bacteria. Many can be found in and on your body and are beneficial to you. These bacteria make up your microbiome, which keeps your body healthy. Other bacteria can make you sick.
a member of a large group of unicellular microorganisms which have cell walls but lack organelles and an organized nucleus, including some that can cause disease.
Define a virus
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.
A virus is an infectious microbe consisting of a segment of nucleic acid (either DNA or RNA) surrounded by a protein coat. A virus cannot replicate alone; instead, it must infect cells and use components of the host cell to make copies of itself.
Define a fungi
any of a group of spore-producing organisms feeding on organic matter, including moulds, yeast, mushrooms, and toadstools.
Define a prion
A prion is a type of protein that can trigger normal proteins in the brain to fold abnormally. Prion diseases can affect both humans and animals and are sometimes spread to humans by infected meat products.
The prion mode of action is very different to bacteria and viruses as they are simply proteins, devoid of any genetic material.
Define a parasite
an organism that lives in or on an organism of another species (its host) and benefits by deriving nutrients at the other’s expense.
A parasite is an organism that lives on or in a host organism and gets its food from or at the expense of its host.
List bacteria, viruses, fungi, parasites and prions according to size
parasites
fungi
bacteria
viruses
prions
