lecture 2 Flashcards
Archaea
One of two taxonomic prokaryotic domains having archaeal rRNA sequences
Bacteria
One of the two taxonomic prokaryotic domains, Bacteria are prokaryotic microorganisms typically having cell walls of peptidoglycan.
Cells
A fundamental part of the living system,
cells are the smallest collection of matter that perform all activities required for life.
Allorganisms are made up of cells.
chloroplasts
An organelle found in plants and photosynthetic protists (eukaryotic
organism that is not an animal, plant or fungi). Absorbing sunlight for use in photosynthesis.
Chromatin
The complex of DNA and proteins making up eukaryotic chromosomes.
When the cell is not dividing, chromatin exists in
its dispersed form, as a mass of very long, thin fibres that are not visible with a light microscope.
DNA
Deoxyribonucleic Acid: A nucleic acid molecule, composed of two chains which form a double stranded helix, each chain is made up of four chemical building blocks called nucleotides.
DNA carries the genetic instructions for all cellular processes (growth, development, function and reproduction). See also
nucleotides.
domain
A taxonomic category above the kingdom level. The three
domains of life are Archaea, Bacteria and Eukarya.
Electrochemical
gradient
The diffusion gradient of an ion, which is affected by both the concentration difference of an ion across a membrane (a chemical force) and the ion’s tendency to move relative to the membrane potential (an electrical force).
Endosymbiosis
A relationship between two species in which one organism lives inside the cell or cells of another organism.
Endosymbiont
theory
The theory that mitochondria and plastids, including chloroplasts,
originated as prokaryotic cells engulfed by a host cell. The
engulfed cell and its host cell then evolved into a single organism.
See also endosymbiosis.
eukarya
The domain that includes all eukaryotic organisms.
eukaryotes
An organism with a membrane-enclosed nucleus and organelles.
Typical size range 10-100 mm.
fungi
Eukaryotic organisms that have cell walls and obtain food from other organisms.
Ion channel
A transmembrane protein channel that allows a specific ion to diffuse across the membrane down its concentration or electrochemical gradient.
ligand
A molecule that binds specifically to another molecule, usually a larger one.
microscopy
A technical field of using microscopes to view objects that cannot be seen by the naked eye
