Endoplasm and ectoplasm, Biology

Assignment Help:

Endoplasm and Ectoplasm

Under the light microscope, we can find two regions in the-cytoplasm .of the amoeba;

  1.  The central region, the endoplasm which is fluid like sol and
  2. The ectoplasm, the region of the cytoplasm just beneath the plasma membrane, which is gel-like.

In the phase contrast microscope, we can see that the endoplasm contains abundant particles and membranous organellae, found in constant random motion, indicating their freedom of movement in the sol region of the cytoplasm. Ectoplasm contains a three-dimensional network of cross-linked actin fibres, and all other organelle are excluded from the region. This gel region apparently decides the shape of the pseudopodium and may transmit tension from the regions of cellular contraction to the sites of contact with the substratum. It is believed that the ectoplasm contains non-cross-linked actin filaments and probably myosin filaments also.

As a pseudopodium elongates and the sol-like endoplasm streams into it, the region of the endoplasm near the tip of the pseudopodium apparently transforms into - gel-like ectoplasm. Simultaneously, the ectoplasm elsewhere in the cell transforms into sol-like endoplasm, probably by an uncrossing of linking actin fibres. Proteins such as actin, fimbrin and fodrin are involved in the sol-to-gel transition. They cross-link actin filaments and bundle them to each other. Cross linking of actin filaments produces a network confining the movement of individual actin molecules and results in the semisolid gel state.


Related Discussions:- Endoplasm and ectoplasm

Glomerular filtrate in comparison to the blood, Q. What is the major transf...

Q. What is the major transformation presented by the glomerular filtrate in comparison to the blood? Glomerular filtrate is the name given to the plasma after it has entered th

What is dextrin, Dextrin  Polymers of D-glucose, formed due to partial ...

Dextrin  Polymers of D-glucose, formed due to partial  hydrolysis of starch by enzymes.

Reproduction, site of fertilistion in human

site of fertilistion in human

The exine layer, The Exine Layer It consists of two layers, inner (nex...

The Exine Layer It consists of two layers, inner (nexine) which is continuous and an outer (sexine) the sculptured one. The outer layer has ornamentations comprising rod-like

Explain the stages of alzheimer''s disease, Explain the Stages of alzheimer...

Explain the Stages of alzheimer's disease? Stage I - There is an increased forgetfulness, anxiety and depression. Associated nutrition related changes include difficulty in

Explain gametophyte, "In these autotrophs, sporophyte is the dominant gener...

"In these autotrophs, sporophyte is the dominant generation. Gametophyte is also photosynthetic and not dependent on sporophyte for nutrition."  These autotrophs are:  a.  P

What do you mean by amphibians of the plant world, Q. Why can the bryophyte...

Q. Why can the bryophytes be considered the "amphibians of the plant world"? Like adult amphibians, the bryophytes live in the terrestrial environment but they depend on water

Nutrition - autotrophic nutrition, AUTOTROPHI C NUTRITION Pr...

AUTOTROPHI C NUTRITION Preparation of organic food from the inorganic materials in the living body. May be photoautrophic, e.g. Euglena virdisima. May be chemo

Describe the functionality of implant material, Functionality of implant ma...

Functionality of implant material It should take maximum advantage of available bone and permit the maximum amount of forces to be transmitted through the implant within physio

What is the significance of spicules, What is the significance of Spicules?...

What is the significance of Spicules? Any needlelike structure. This term is very often thought of in conjunction with sponges and refers to needlelike structures produced by s

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd