The Vital Question 1 Flashcards
endosymbiosis
a mutual relationship (usually a trade of metabolic substances) between two cells, in which on partner physically lives inside the other. “Lynn Margulis talked about endosymbiosis - the same types of trade, but now so intimate that some collaborating cells physically live inside their host cell like the traders who sold from within the temple.” endo - greek prefix meaning “within, inner, absorbing, or containing” symbiosis - living together is what “symbiosis” is all about; the word came to us, via German and New Latin, from the Greek symbiōsis, meaning “state of living together.” “Symbiōsis,” in turn, traces to “symbios” (“living together”), a combination of syn-, meaning “with,” and bios, meaning “life.”
nanomachines
a microscopic machine constructed by the use of nanotechnology. “Proteins are assembled on remarkable nanomachines found in all cells, called ribosomes.” (7)
ribosomes
protein-building ‘factories’ found in all cells, which convert the RNA code-script (copied from DNA) into a protein with the correct sequence of amino acid building blocks. “Proteins are assembled on remarkable nanomachines found in all cells, called ribosomes.” (7) MD - think of ribs as a good source of protein. think of amino acids being the salts that are delivered to the ribs by waiter (transfer RNA) according to the menu (messenger RNA - codescript copied from DNA). When enough salts (amino acids) are delivered, patron eats and you have a protein.
amino acids
one of 20 distinct molecular building blocks that are linked together in a chain to form a protein (often containing hundreds of amino acids) Amino acids are organic compounds that combine to form proteins. Amino acids and proteins are the building blocks of life. When proteins are digested or broken down, amino acids are left. The human body uses amino acids to make proteins to help the body: Break down food Grow Repair body tissue Perform many other body functions “They draw in ‘tickertape’ code-script that encodes a protein, and translate its sequence precisely, letter by letter, into the protein itself. To do so, they recruit all the building blocks (amino acids) needed, and link them together into a long chain, their order specified by the code-script.” (8)
arcane
known or knowable only to a few people : secret arcane rites an arcane ritual; broadly : mysterious, obscure arcane explanations arcane technical details “But at the arcane level of their genes and biochemistry, the gulf between bacteria and archea is as great as that between bacteria and eukaryotes (us).” (8) (13) MD
archaea (sing. archaeon)
one of the three great domains of life, the other two being the bacteria and eukaryotes (such as ourselves); archaea are prokaryotes, lacking a nucleus to store their DNA, and most other elaborate structures found in complex eukaryotes. (10) MD - how are bacteria and archaea different. Which came first?
proticity
electrical current generated by a flow of protons (instead of a flow of electrons). “Essentially all living cells power themselves through the flow of protons (positively charged hydrogen atoms), in what amounts to a kind of electricity - proticity - with protons in place of electrons. The energy we gain from burning food in respiration is used to pump protons across a membrane, forming a reservoir on one side of the membrane. The flow of protons back from this reservoir can be used to power work in the same way as a turbine in a hydroelectric dam.” (13) MD - proton and electricity + picture of the proton gradient
phagocytosis
The physical engulfing of one cell by another, swallowing it up into a ‘food’ vacuole to be digested internally. Osmotrophy is the external digestion of food, followed by absorption of small compounds, as practised by fungi. “Some cells such as amoebae make their living by physically engulfing other cells, a process called phagocytosis. Some are photosynthetic, Others, such as fungi, digest their food externally - osmotrophy.” (32) Etymology - Greek phago- “eating, devouring” (see -phagous) + -cyte (cyto- of a cell or cells) MD - think of a fag (cigarette) becoming engulffed by a cigarette carton
osmotrophy
the external digestion of food, followed by absorption of small compounds, as practised by fungi. “Some cells such as amoebae make their living by physically engulfing other cells, a process called phagocytosis. Some are photosynthetic, Others, such as fungi, digest their food externally - osmotrophy.” (32)
metabolism
the processes by which a living organism uses food to obtain energy and build tissue and disposes of waste material “the set of life-sustaining reactions within living cells.” MD -
polypeptide
A polypeptide is a compound of amino acids that contains ten or more amino acids. If there are more than fifty amino acids, this is now considered a protein. MD -
protein
A chain of amino acids linked together in a precise order specified by the sequence of DNA letters in a gene; a polypeptide is a shorter chain of amino acids, whose order need not be specified.
amino acid
one 20 distinct molecular building blocks that are linked together in a chain to from a protein (often containing hundreds of amino acids.)
RNA
ribonucleic acid: a close cousin of DNA, but with two tiny chemical alterations that transform its structure and properties (has a ribose sugar instead of a deoxyribose sugar, RNA nucleotides have a uracil base instead of thymine.) RNA is found in three main forms: messenger RNA (a code-script copied from DNA); transfer RNA (which delivers amino acids according to the genetic code); and ribosomal RNA (which acts as ‘machine parts’ in ribosomes).
peptide
A peptide is another name for protein, but is not considered a protein because of its size. A peptide is a compound that consists of two or more amino acids. When an amino acid would react to another amino group, it would link to such group, creating a peptide bond. So when you talk about the main link of protein structure, a peptide bond unites such structure.
