lecture one Flashcards
what is the definition of biology?
its the study of life, and various forms of life exist in the form of an organism
what is an assembly of molecules functioning as a stable whole that exhibit life “organization”
an organism
life can by divided into 3 domains, what are they?
bacteria, archaea, and eukarya
describe a multicellular organism
multicellular- activities of life are divided among many specialized cells (plants and animals)
cells are the basic structure and functional unit of all living organisms, all cells are composed of one or more cells, and if a cell is broken the property of like is lost
cell theory
why are cells small
- cells have a finite life span
- simple logistics
- cell metabolic demands
why do cells need to keep distances short
cells rely on simple diffusion to move molecules towards a gradient of concentration
why do cells require a larger surface area
develop convoluted/ branchy surface morphologies
what is a microscopy
technique for producing visible images of objects that are two small for the human eye
what are the three types of microscopy
-optical microscopy(light microscope)
-electron microscopy
-fluorescent
resolution
ability if a microscope to distinguish between two objects as being separate
magnification
ratio of the object as viewed to its real size
why are cells so small?
explained by surface area to volume ratio.
differential interference contrast
uses prisms to generate interference patterns for contrast and gives 3-d appearance
confocal fluorescense microscope
increases contrast by capturing thin slices of specimen
what are the two types of electron microscopy
transmission electron microscopy-
scanning electron microscopy-
describe a unicellular organism
a unicellular-independent organism capable of carrying out all activities necessary for life (all bacteria)
what is finite life(cells small)
easily repaired when broken down
what is simple logistics (cell small)
specialized cells easily replaced without disruption
what are cells metabolic demands
due to many chemical reactions taking place
what is an optical microscope
- uses visible light and a system of lenses to magnify images of small samples
what is an electron microscope
- uses electrons to illuminate specimen
fluorescent microscope
uses light produced by fluorophores in samples, yielding a more detailed image
what is the surface area to volume ratio
indicates how much surface area is available compared to how big the cell is. If the surface area to volume ratio is small, the cell is very big
