WCU\Microbiology 290 Chapter 3 WCU
– Study Guide & Key Concepts real
exam!!!
Friedrich Wöhler (1800-1882)
The idea that organic chemicals could come only from living organisms had to be abandoned in 1828.
synthesized an organic molecule, urea, using only inorganic reactants in his laboratory
we know that all living things contain?
both organic and inorganic chemicals
many organic chemicals can be made from?
inorganic chemicals by laboratory processes.
Biologists agree that all living things share at least four processes of life
growth, reproduction, responsiveness, and metabolism.
Growth.
Living things can grow; that is, they can increase in size
Reproduction
Organisms normally have the ability to reproduce themselves. Reproduction means that they increase in
number, producing more organisms organized like themselves. Reproduction may be accomplished
asexually (alone) or sexually with gametes (sex cells). Note that reproduction is an increase in number,
whereas growth is an increase in size. Growth and reproduction often occur simultaneously.
Responsiveness
All living things respond to their environment. They have the ability to change themselves in reaction to
changing conditions around or within them. Many organisms also have the ability to move toward or
away from environmental stimuli—a response called taxis.
Metabolism
Metabolism can be defined as the ability of organisms to take in nutrients from outside themselves and
use the nutrients in a series of controlled chemical reactions to provide the energy and structures
needed to grow, reproduce, and be responsive. Metabolism is a unique process of living things;
, nonliving things cannot metabolize. Cells store metabolic energy in the chemical bonds of adenosine
triphosphate (ă-den′ō-sēn trī-fos′fāt), or ATP
In the 1800s, two German biologists, Theodor Schwann (1810-1882) and Matthias Schleiden (1804-
1881), developed the theory
that all living things are composed of cells.
Cells
are living entities, surrounded by a membrane, that are capable of growing, reproducing, responding,
and metabolizing
The smallest living things are
single-celled microorganisms
what are the different kinds of cells?
Free-living, independent organisms;
others live together in colonies or form the bodies of multicellular organisms
Do cells exist in multiple sizes?
Various sizes
from the smallest bacteria to bird eggs, which are the largest of cells.
What are all cells described as?
Prokaryotes and Eukaryotes
Scientists categorize organisms based on shared characteristics into groups called
taxa
What are the two Taxa
domain archaea and domain bacteria
What do domain Archaea and domain Bacteria—consist of?
organisms that are prokaryotic, but "prokaryote" is not itself a taxon
Prokaryotes
The distinctive feature of prokaryotes is that they can read their DNA genetic code and simultaneously
make proteins.
typical one doesn't have a membrane surrounding its genetic material meaning no nucleus. "before
nucleus" greek.
what did the electron microscope reveal about prokaryotes?
typically lack various types of internal structures bound with membranes that are present in eukaryotic
cells.