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a) A small diagram of the cell highlighting the nucleus and endoplasmic reticulum. The nucleus is a large sphere in the cell and the endoplasmic reticulum is a series of webbed membranes just outside the nucleus. B) A micrograph showing these same structures. Outside the nuclear envelope are many lines labeled rough endoplasmic reticulum. A smaller set of lines is labeled mitochondrion overlaying part of the RER.
The rough endoplasmic reticulum is studded with ribosomes for the synthesis of membrane proteins (which give it its rough appearance).

Golgi apparatus

The Golgi apparatus was discovered within the endomembrane system in 1898 by Italian scientist Camillo Golgi (1843–1926), who developed a novel staining technique that showed stacked membrane structures within the cells of Plasmodium , the causative agent of malaria. The Golgi apparatus is composed of a series of membranous disks called dictyosomes, each having a single lipid bilayer, that are stacked together ( [link] ).

Enzymes in the Golgi apparatus modify lipids and proteins transported from the ER to the Golgi, often adding carbohydrate components to them, producing glycolipids, glycoproteins, or proteoglycans. Glycolipids and glycoproteins are often inserted into the plasma membrane and are important for signal recognition by other cells or infectious particles. Different types of cells can be distinguished from one another by the structure and arrangement of the glycolipids and glycoproteins contained in their plasma membranes. These glycolipids and glycoproteins commonly also serve as cell surface receptors.

Transport vesicles leaving the ER fuse with a Golgi apparatus on its receiving, or cis , face. The proteins are processed within the Golgi apparatus, and then additional transport vesicles containing the modified proteins and lipids pinch off from the Golgi apparatus on its outgoing, or trans , face. These outgoing vesicles move to and fuse with the plasma membrane or the membrane of other organelles.

Exocytosis is the process by which secretory vesicles (spherical membranous sacs) release their contents to the cell’s exterior ( [link] ). All cells have constitutive secretory pathways in which secretory vesicles transport soluble proteins that are released from the cell continually (constitutively). Certain specialized cells also have regulated secretory pathways , which are used to store soluble proteins in secretory vesicles. Regulated secretion involves substances that are only released in response to certain events or signals. For example, certain cells of the human immune system (e.g., mast cells) secrete histamine in response to the presence of foreign objects or pathogens in the body. Histamine is a compound that triggers various mechanisms used by the immune system to eliminate pathogens.

A small diagram of the cell outlining the Golgi complex which is a series of stacked membranes in the cell. A more detailed diagram shows the stacked membranes labeled cisternae and the inner regions of the stacks labeled lumen. Small spheres on the top are show transport vesicles from ER fuse with the cis face of the golgi. Small spheres on the bottom show newly formed secretory vesicles emerging from the trans face of the golgi. A micrograph shows the golgi in the cell as a stack of lines forming a semi-circle.
A transmission electron micrograph (left) of a Golgi apparatus in a white blood cell. The illustration (right) shows the cup-shaped, stacked disks and several transport vesicles. The Golgi apparatus modifies lipids and proteins, producing glycolipids and glycoproteins, respectively, which are commonly inserted into the plasma membrane.

Lysosomes

In the 1960s, Belgian scientist Christian de Duve (1917–2013) discovered lysosomes , membrane-bound organelles of the endomembrane system that contain digestive enzymes. Certain types of eukaryotic cells use lysosomes to break down various particles, such as food, damaged organelles or cellular debris, microorganisms, or immune complexes. Compartmentalization of the digestive enzymes within the lysosome allows the cell to efficiently digest matter without harming the cytoplasmic components of the cell.

Questions & Answers

what type of widal test
sobhit Reply
Explain Mould
Chinenye Reply
Explain mycoses and it's classification
Chinenye
why do we have hiccups?
Manisha Reply
shakey diaphragm
Curlisse
The antibody binding site is formed primarily by:
Asalla Reply
How many types of MICROORGANISMS do we have?
Hope Reply
Hello friends
Hope
What's pathogenesity
Usman Reply
something that causes disease
Anietie
who is the father of microbiology?
Hope
no it is not it also dealt withe fermentation techniques, downstream processing of isolated products etc
Ramchandra Reply
hy
Abdul
hy
Roshan
you from
Abdul
I'm from Bangalore, India
Shanu
in banglore
Prabhat
what group is Indian
Abdul
I'm from pune
Vitthal
ok
Abdul
Why scientists is not studies the drungs or vaccines of a virus, based on common characterstics of virus as living and non-living organisms?
demisew
what are the examples of viruses and their causing agent
kolawole Reply
coronavirus in the family of Coronaviridae and the causing agent is common cold where it spread easily compared to hot region.you can correct me if I am wrong.
nyakaraitta
👍
Puja
what
nkechi
okay there are major 3 groups (1.Enterovirus=poliovirus, cocksakievirus A&B,echovirus,endovirus etc causing poliomyelities,meningitis, fever,respiratory disease, acute hemorrhagic conjunctivitis, 2.Hepatitis virus- infectious hepatitis , 3.Rotavius incl.coronavius =vomiting, diarrhoea and common co
nyakaraitta
isthe another virus are coronaviridae
anuush
Hai Puja
Shanu
g
Abdul
corona virus is not dangerous but not care is very dangerous..............
Abdul
👍
Puja
he means if we take care we will not be infected
abel
yeah
Abdul
for the question thing first let's classify viruses then it would be easier to deal with zem
abel
Where you all from?
Shanu
Pakistan
Abdul
what are five elements that are needed for bacteria to grow?
Florence
proper acidity (ph)
Abdi-fatah
salt level
Abdi-fatah
Temperature
Bejide
osmotic pressure,oxygen,light
abel
but zey are not only five n we can classify zem as physical and chemical
abel
air in hydrogen and carbon and niterogin
Abdul
1. Possible complications and outcomes for cutaneous anthrax:
Firoj Reply
chlamydia can it be viral disease?
nyakaraitta Reply
noh
Vitthal
what is microbiology
Sohel Reply
is the study of tiny organisms with the use of microscopes
Bejide
Is the study of microorganisms
Usman
is the biological science of identification and charaterization of micro organisms surrounding the environment
Jojo
what are the major groups of archae bacteria
Brian Reply
methanogens, halophiles, thermophiles
Mahalakshmi
Right, mali
vivek
yeah!!
Mahalakshmi
yes
nyakaraitta
right
Jojo
how can get information
Raage Reply
how i study microbiology
Raage
By Reading About It
Rajat
quickest form
Raage
why do our brain needs glucose?
Bijay Reply
b/c our brain works glucose as the other body use insulin
Cabdi
of course why do hairs obtain nutrients yet there is no blood?
nyakaraitta
can I get a diagram of paramicium
nyakaraitta
what is the meaning of the term microbiology
Mary Reply
 study of all living organisms that are too small to be visible with the naked eye.
Nnamdi
yahh it right
Stavan
wow lovely
Psalm
Well said.
Shanu
study of microscopic organism like protozoa, bacteria, fungi, algea ,viruses betc
Dr
what are the career opportunities in microbiology
Anietie

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Source:  OpenStax, Microbiology. OpenStax CNX. Nov 01, 2016 Download for free at http://cnx.org/content/col12087/1.4
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