Iaa stimulates cell enlargement, Biology

Assignment Help:

IAA Stimulates Cell Enlargement

Cell wall contains layer of cellulose fibrils and are normally quite rigid. Thus for a cell to grow, there must be a mechanism for relaxing the cellulose fibrils. IAA releases the cross linking bands which hold the micro fibrils together. Auxin is thought to cause the walls to become plastic and them osmotic water intake causes the cell to swell like a balloon. American physiologist P.M. Ray has observed that IAA effect on elongation begins after a lag period of only 8-12 minutes, in tissues as coleoptiles. Recently it has been found that with certain auxins or even with IAA itself when used under correct conditions, the lag period can be reduced to 1 minute or less.

These effects are now considered to be as a result of activisation of proton pumps in membrane that pump protons in cell wall and cause a rise in acidity. Acidification loosens bonds in cell wall and cell wall plasticity increases. This rapid response is followed by activation of m-RNA translated into enzymes that catalyze synthesis of cellulose and other cell wall materials which cause the strengthening of elongated cell wall completing the cell elongation.


Related Discussions:- Iaa stimulates cell enlargement

What is constipation, Q. What is Constipation? Constipation is irregula...

Q. What is Constipation? Constipation is irregular, infrequent or difficult passage of faeces. It is the most common physiological disorder of the alimentary tract. It is chara

Explain adverse effects of ketoconazole, Explain Adverse Effects of ketocon...

Explain Adverse Effects of ketoconazole Anorexia, nausea and vomiting are common with higher doses (>400 mg/day) of ketoconazole; taking the drug with food or at bedtime may i

Define the activation of an agonist during movement, Explain the relationsh...

Explain the relationship between an agonist muscle and its antagonist as it relates to positional control, functional movement and neuromuscular activation. For example, how the th

Explain the term protoderm, Explain the term Protoderm? The protoderm ...

Explain the term Protoderm? The protoderm is one of the so-called "primary tissues" because it is formed first during germination and subsequent plant growth. The protoderm g

Modes of nitrate reductase and nitrite reductase, Modes of NO - 3 reducti...

Modes of NO - 3 reduction Accordingly, there are the following three basic modes of NO - 3 reduction. Directly dependent upon photosynthesis as in cyanobacter

Phenotypic classes, 1. A pure-breeding black, smooth guinea pig was mated t...

1. A pure-breeding black, smooth guinea pig was mated to a pure-breeding white, rough female. They produced several litters, and eventually, five males and twenty females resulted

Name the foods to avoid in soft diet, Name the Foods to avoid  in soft die...

Name the Foods to avoid  in soft diet include: Fried foods and nuts, rich pastries and desserts, Raw  vegetables, Heavily spiced foods, Gas-forming vegetables, S

Aortic allograft -biological valves, Aortic Allograft (Homograft) :  ...

Aortic Allograft (Homograft) :  In the earlier years fresh antibiotic preserved aortic allografts were tried. As the shelf life is limited, availability of all sizes at all t

45, What grade did you get in biology?

What grade did you get in biology?

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