Facilitated Diffusion

-
What is facilitated diffusion? In membrane, there are protein channels (pores) that allow polar molecules (soluble in water but not soluble in lipids) to move through them. The molecules that move through these channels never come into contact with the hydrophobic layer or the membrane's polar surface because these channels provide a continuous pathway for molecules that are moving through them. In this type of diffusion, like simple diffusion, no energy is consumed. Large and polar molecules require help to pass through the membrane. This help is done by a type of protein called carrier (transport) protein . To pass through the membrane, a molecules binds (temporarily) with carries protein in lipid bilayer and is transported from an area of higher concentration to an area of lower concentration.  Related topics: Simple Diffusion
Post a Comment

What is development?gonads-fertilization-embryology

-

What is development?

 DEVELOPMENT  is a process by which a multicellular organism arises through mitotic division of a single cell-the fertilized egg or zygote and produces the whole body. The study of development is known as developmental biology. The whole development process is studied under different fields.

Gonads are the sex organs that produce gametes that are the foundation of development. In human, male has one pair of gonads outside the body. Male gonads are called testes(sing. Testis) and female also has a pair of gonads inside the abdomen gonads are called ovaries(sing. ovary).

Gametes are the sex cells. Female gamete is called an egg and male gamete is called a sperm

Fertilization (See Fertilization) is a process  in which an egg from female is fused with a sperm from male. Now the egg is called fertilized egg or zygote.


 Embryo/Embryology

 is the early development stage of multicellular organisms that begins just after the egg is fertilized. In developmental biology, the development of embryo is called embryogenesis. The study of animal development has traditionally been called as embryology.

Each day we replace more than a gram of our skin cells(the older cells being sloughed off as we move) by mitosis, and our bone marrow sustains the development of millions of new red blood cells every minute of our lives.

 

Comments

Post a Comment

Popular posts from this blog

Types of wetland-The Knowledge

-
Image
Types of wetlands There are five recognized types of wetlands.(See Wetland ) 1.Marine These are coastal wetlands including coastal lagoons,rocky shores,and coral reefs. Marine wetland 2.Estuarine It include deltas,tidal marshes,and mangrove swamps. Estuarine wetland   3.Lacustrine These wetlands are associated with lakes. Lacustrine wetland   4.Riverine These wetlands are found along rivers and streams. Riverine wetland   5.Palustrine These wetlands lack following water,”marshy”,marshes,swamps and bogs. Palustrine wetland   (See  Impoetance of wetland )  
Read more

Bacillary white diarrhea in poultry

-
Image
 For Urdu Click [ HERE ] Bacillary white diarrhea This disease is also known as pullorum disease as the bacterium named as Salmonella pullorum that causes this disease. It is fatal septicemia in young chicks. •Causes White diarrhea/pullorum disease is caused by bacterium“Salmonella pullorum” •Clinical signs Its symptoms include: Somnolence Weakness Loss of appetite Chalky white diarrhrea Stained greenish brown in and around vent •Treatment Following medication should be done to cure this disease. Enrofloxacin Parental injections Oral liquids Supportive therapy   Bumble foot/Pododermatitis in poultry
Read more

Definition of polyspermy/Fast block anf slow block polyspermy-The Knowledge

-
POLYSPERM Polyspermy refers to the egg that has been fertilized by more than one sperm. Types of polyspermy There are two types of polyspermy. 1.Fast block to polyspermy 2.Slow block to polyspermy Fast block to Polyspermy The Fast block polyspermy is achieved by changing the electric potential of the egg plasma membrane. This membrane provides a selective barrier between the egg cytoplasm and the outside environment, and the ionic concentration of the egg differs greatly from that of its surroundings. This concentration difference is especially significant for sodium and potassium ions. Seawater has a particularly high sodium ion concentration, whereas the egg cytoplasm contains relatively little sodium. The reverse is the case with potassium ions. Slow block to polyspermy The eggs of sea urchins (and many other animals) have a second mechanism to ensure that multiple sperm do not enter the egg cytoplasm. The fast block to polyspermy is transient , since the membrane pot
Read more