MICROBIO pro-euk and bacterial structure Flashcards
prokaryotes came from the word
“pro - before” and “karyon - nucleus, nut or kernel”
organisms that do not contain true nucleus and membrane-bound organelles
prokaryotes
the functions of prokaryotes takes place in
cytoplasm or cytoplasmic membrane
components of prokaryotes
cell wall
plasma membrane
cytoplasm
dna
ribosomes
capsule
flagella
fimbriae
rigid structure that contains as peptidoglycan
cell wall
cell wall is also referred to as
murein layer
provides an extra layer of protection, helps the cell maintain its shape, and prevents dehydration
murein layer
outer covering that seprates the cells interior from its surrounding environment
plasma membrane
consists of a jelly-like cytosol indisde the cell, plus the cellular structures suspended in it
cytoplasm
the genetic material of the cell
DNA
molecular machines that synthesize protein
Ribosomes
sticky and helps the cell attach to surfaces in its environment
Capsule
whip-like structures that acts as rotary motors to help bacteria move
Flagella
numerous, hair-like structures that are used for attachment to host cells and other surfaces
Fimbriae
organisms whose cells have a nucleus enclosed w/n membranes, unlike prokaryotes, which have no membrane-bound organelles.
eukaryotes
parts of euk.cell
plasma membrane
cytoplasm
nucleus
chromosomes
nucleolus
ribosomes
mitochondria
peroxisomes
lysosomes
a phospholipid bilayer with embedded proteins
that separates the internal contents of the cell from its surrounding
environment. The plasma membrane controls the passage of organic
molecules, ions, water, and oxygen into and out of the cell. Wastes (such
as carbon dioxide and ammonia) also leave the cell by passing through
the plasma membrane, usually with some help of protein transporters.
plasma membrane
refers to the entire region of a cell between
the plasma membrane and the nuclear envelope. It is
composed of organelles suspended in the gel-like cytosol,
the cytoskeleton, and various chemicals (see figure
below). Even though the cytoplasm consists of 70 to 80
percent water, it nevertheless has a semisolid
consistency. It is crowded in there. Proteins, simple
sugars, polysaccharides, amino acids, nucleic acids,
fatty acids, ions and many other water-soluble
molecules are all competing for space and water.
cytoplasm
is the most prominent organelle in a cell when viewed
through a microscope. The nucleus (plural = nuclei) houses the
cell’s DNA.
nucleus
are structures within the nucleus that are
made up of DNA, the hereditary material.
chromosomes
A darkly staining area within the nucleus called
the nucleolus (plural = nucleoli) aggregates the ribosomal RNA
with associated proteins to assemble the ribosomal subunits
that are then transported out to the cytoplasm through the
pores in the nuclear envelope.
nucleolus
are the cellular structures responsible for
protein synthesis.
ribosomes
are often called
the “powerhouses” or “energy factories” of a cell because
they are the primary site of metabolic respiration in
eukaryotes.
mitochondria
terminal electron is oxygen
aerobic respiration
a compound other than oxygen
is the terminal receptor
anaerobic respiration
are small, round organelles enclosed by
single membranes. These organelles carry out redox
reactions that oxidize and break down fatty acids and
amino acids. They also help to detoxify many toxins that
may enter the body.
peroxisomes
are sometimes called the cell’s “garbage
disposal”. Enzymes within the lysosomes aid the
breakdown of proteins, polysaccharides, lipids, nucleic
acids, and even “worn-out” organelles.
lysosomes
structure of bacteria
smaller and simpler in structure than eukaryotic cells, with no recognizable organelles.
first seen by
Anton Van Leeuwenhoek
3 categories of bacterial cell structure
internal structure, cell envelope, external structures
consists of the cytopasm, nucleoid, bacterial chromosome, plasmid, ribosomes and storage granules
internal structure
cell membrane, peptidoglycan cell wall or an outer lipid membrane (found only in gram (-) cells)
cell envelope
flagella, fimbriae, sex pilus and glycocalyx considered as appendages and coverings.
external structure
lies within the plasma membrane, gel-like matrix and is relatively featureless by electron microscope - although small granules can be seen.
Cytoplasm
composition of cytoplasm
water, enzyme, nutrients, wastes and gases.
cell structures in cytoplasm
ribosomes, chromosome, plasmid
function for the cell of cytoplasm
growth, metabolism and replication
region of cytoplasm where the chromosomal DNA is located and where the strands of DNA are found
nucleoid
small extra-chromosomal DNA which contains genes for antibiotic resistance or virulence
plasmid
size and number of plasmid
1-200 kb ; 1-700 copies
