Microbioogy Chapter 3 word bank

Acid-fast bacteria

Fast" in this sense means "firmly attached" (Dyes that are fast do not run out of cloth when it is washed)
Acid fast bacteria have cell walls that contain long chain waxy molecules these are water proof and help prevent the cells drying out.This means th

Active transport

the movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy.

Capsule

Function of Glycocalyx (3): AKA? Adherence & protect from environment. (drying, chemicals, etc)
Possibly may provide nutrients
AKA: Slime layer or capsule
well-definied polysaccharide or protein layer that is usually rather slimy that closely surrounds so

Chromatin

Mass of genetic material composed of DNA and proteins that condense to form chromosomes during eukaryotic cell division. Chromatin is located in the nucleus of a cell.
DNA + Proteins = Chromatin
What are the three major components of chromatin? DNA, histo

Cilia

________ act as micro-levers transmitting vibrations to the sensory-receptor cells.

Concentration gradient

the gradual difference in the concentration of solutes in a solution between two regions. In biology, a gradient results from an unequal distribution of ions across the cell membrane. When this happens, solutes move along a concentration gradient. This ki

Conjugation pili (sex)

fine filamentous projections (pili) on the surface of a bacterium that are important in conjugation. Often seem to be coded for by plasmids that confer conjugative potential on the host, in the case of the f plasmid, the f pili are 8-9nm diameter and seve

Cytoplasm

The cytoplasm (of both eukaryotes and prokaryotes) is where the functions for cell expansion, growth, metabolism, and replication are carried out.
In eukaryotic cells, the cytoplasm is that part of the cell between the cell membrane and the nuclear envelo

Diffusion

The passive movement of molecules or particles along a concentration gradient, or from regions of higher to regions of lower concentration.

Endocytosis

A process in which cell takes in materials from the outside by engulfing and fusing them with its plasma membrane.
There are two types of endocytosis, called phagocytosis, which literally means cell-eating, and pinocytosis, which literally means cell-drin

Endoplasmic reticulum

There are two kinds of ER: the RER, or the rough endoplasmic reticulum, and the SER, or the smooth endoplasmic reticulum.
The RER bears many ribosomes on its outer surface giving it a rough appearance; hence, its name. Since RER has ribosomes attached to

Endotoxin

heat stable polysaccharide like toxin bound to a bacterial cell. The term is used more specifically to refer to lipopolysaccharide (LPS) of the outer membrane of gram-negative bacteria. There are three parts to the molecule, the lipid a (six fatty acid ch

Eukaryotic cells

Cells of or derived from eukaryote characterized by having a distinct, membrane-bound nucleus.

Exocytosis

When materials leave the cell by the membrane "spitting it out

Facilitated diffusion

Transport of substances across a biological membrane from an area of higher concentration to an area of lower concentration by means of a carrier molecule. Since the substances move along the direction of their concentration gradients, energy is not requi

Fimbriae

(1) (microbiology) A short, filamentous projection on a bacterial cell, used not for motility but for adhering to other bacterial cell (especially for mating) or to animal cells.

Flagella

a long, thin, cellular appendage capable of rotation and responsible for swimming motility in prokaryotic cells
What parts does a flagella consists of? -Hook
-Filament
-Basal Body

Fluid mosaic model

The plasma membrane is described to be fluid because of its hydrophobic integral components such as lipids and membrane proteins that move laterally or sideways throughout the membrane. That means the membrane is not solid, but more like a 'fluid'.
The me

Glycocalyx

(1) The outer layer usually made up of bound polysaccharides on the cell surface and superficial layer of unbound proteoglycans and glycoproteins
(2) Sugar coat surrounding the cell wall of bacterium, as bacterial capsule or slime layer in various bacteri

Golgi body

Structure: composed of membrane-bound stacks known as cisternae
Functions: involved in glycosylation (i.e. adding carbohydrate to a protein), packaging of molecules like proteins into vesicles for secretion, transport of lipids around the cell, and the cr

Gram-negative cell wall

(Science: microbiology) a common class of bacteria normally found in the gastrointestinal tract that can be responsible for disease in man (sepsis).
bacteria are considered to be gram-negative because of their characteristic staining properties under the

Gram-positive cell wall

(Science: microbiology) bacteria that retain the stain or that are resistant to decolourisation by alcohol during grams method of staining.
this is a primary characteristic of bacteria whose cell wall is composed of a thick layer of peptidologlycan contai

Hypertonic

Of or pertaining to a solution (e.g. extracelllular fluid) with higher solute concentration compared with another. (see: hypotonic, isotonic). For example, if the extracellular fluid has greater amounts of solutes than the cytoplasm, the extracellular flu

Hypotonic

3. refers to a solution with a comparatively lower concentration of solutes compared to another

Inclusions

2. (Science: chemical) a foreign substance, either liquid or solid, usually of minute size, inclosed in the mass of a mineral.

Isotonic

Pertaining to a solution that has the same tonicity as some other solution with which it is compared. For example, blood serum is isotonic to a physiologic salt solution. Solutions that have same tonicity will result in no net flow of water across the cel

Lipopolysaccharide (LPS)

Lipopolysaccharide is commonly found as major constituent of the cell walls of certain bacteria, particularly the gram-negative strains, whose function is to help stabilize the overall membrane structure and to protect it from certain chemicals.
It is hig

Lysosome

Organelles containing a large range of digestive enzymes used primarily for digestion and removal of excess or worn-out organelles, food particles, and engulfed viruses or bacteria.
Their specific functions include digestion of macromolecules from phagocy

Mitochondria

They produce large amounts of energy through oxidative phosphorylation of organic molecules during cellular respiration. That is, they are capable of using glucose and oxygen to produce energy (and releasing carbon dioxide and water in the process) for us

Mycolic acid

Does the gram stain work on mycobacteria? Why or why not? Mycobacteria stain poorly with gram stain! They have MYCOLIC ACIDS (long fatty acids) in their cell wall that give the bacteria a "waxy" covering making them relatively impermeable.

N-acetyl glucosamine

An acetylated amino sugar that is an important moiety of glycoproteins. NAG

N-acetyl muramic acid

NAM

Nuclear envelope

The double-layered membrane that envelopes the nucleus of a eukaryotic cell, separating the contents of the nucleus from the (cytoplasm).
It is made up of two layers, each composed of a lipid bilayer. It is perforated with holes, called nuclear pores, to

Nuclear pores

Any of the many perforations on the nucleus as a result of the assembly of nucleoporins that span the nuclear envelope
Supplement:
Nuclear pores pertain to the numerous openings in the [nuclear envelope]]. They are octagonal in shape owing to the assembly

Nucleoid / Nuclear region

The portion within a prokaryotic cell where the genetic material is to be found.
In contrast to eukaryotes with a nucleus, prokaryotes have a nucleoid where the genetic material can be found. The nucleoid is different from the nucleus of the eukaryotes in

Nucleolus

The round granular structure within the nucleus of a cell, and composed of protein and RNA.
Nucleolus is involved with ribosomal RNA synthesis and formation of ribosomes in eukaryotes.

Nucleus

(biology) The large, membrane-bounded organelle that contains the genetic material, in the form of multiple linear DNA molecules organized into structures called chromosomes.
In biology, the major functions of nucleus are to maintain the integrity of DNA

Organelles

Literally, the term means "little organs". As the body is composed of various organs, the cell, too, has "little organs" that perform special functions. They are membrane-bound compartments or structures of a cell.
A eukaryotic cell contains many organell

Osmosis

1. Diffusion of a solvent (usually water molecules) through a semipermeable membrane from an area of low solute concentration to an area of high solute concentration.

Outer spore coat

A dormant, reproductive cell formed by certain organisms. It is thick-walled and highly resistant to survive under unfavorable conditions so that when conditions revert to being suitable it gives rise to a new individual.
Some of the spore-producing organ

Peptidoglycan

(1) A glycan (a polysaccharide) attached to short cross-linked oligopeptides in the cell wall of eubacteria
(2) A crystal lattice structure in the bacterial cell wall that is made up of linear chains of alternating amino sugars, namely N-acetylglucosamine

Periplasmic space

The periplasm is found in gram-negative bacteria and is the space in between the cytoplasmic and outer membranes. (Many feel a periplasm is also present in gram-positive bacteria in between the cytoplasmic membrane and the peptidoglycan.) The periplasm is

Peroxisomes

They have a single membrane that contains digestive enzymes for breaking down toxic materials in the cell.
Peroxisomes hold on to enzymes that require oxygen (oxidative enzymes)
Peroxisomes absorb nutrients that the cell has acquired. They are very well k

Phagocytosis

The process of engulfing and ingestion of particles by the cell or a phagocyte (e.g. macrophage) to form a phagosome (or food vacuole), which in turn fuse with lysosome and become phagolysosome where the engulfed material is eventually digested or degrade

Phospholipid bilayer

This arrangement of phospholipids in bilayer is used to describe the cell membranes of many animal and plant cells. The two layers of phospholipids are arranged in a way that their hydrophobic tails are projecting to the interior whereas their hydrophilic

Phototaxis

A direct response in response to the presence of light in organism, where a positive effect sees the organism move towards the light and a negative one away from the light.

Plasmids (p. 199 & 200)

A linear or circular double-stranded DNA that is capable of replicating independently of the chromosomal DNA.
Certain plasmids are able to insert themselves into the chromosomes particularly in regions where there is a common sequence of nucleotides. Henc

Prokaryotic cells

(1) The cell of a prokaryote, i.e. an organism whose cell generally lacks a true nucleus.

Ribosomes

A minute particle composed of protein and ribonucleic acid (RNA) that serves as the site of protein synthesis.
Ribosomes of prokaryotes (e.g. bacteria) are smaller than most of the ribosomes of eukaryotes (e.g. plants and animals). However, the plastids a

Selectively permeable

A feature and a function of the plasma membrane that is essential to maintain homeostasis by regulating the passage of some substances while preventing others from entering the cell.
The plasma membrane is capable of being selectively permeable because of

Slime layer

An irregular, diffuse, unorganized form of glycocalyx in bacterial cells, comprised mostly of exopolysaccharides, glycoproteins, and glycolipids, and renders protection from dessication, loss of nutrients, and chemical insult (e.g. antimicrobial action)
B

Techoic acid

Acts as rebar in the cell wall
In bacteria, the cell wall is composed of peptidoglycan, and is essential to the survival of many bacteria. Bacteria have been classified into Gram-positive and Gram-negative based on the structure of the cell wall. Gram-pos

Vacuole / Vesicle

Vacuole: A membrane-bound vesicle found in the cytoplasm of a cell whose function includes intracellular secretion, excretion, storage, and digestion.
It can be found in animal and plant cells, and it can be especially conspicuous in plant cells.
Vesicle: