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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Biology => Topic started by: billiondrag on March 07, 2012, 08:14:33 pm

Title: 3 quick questions about detergent
Post by: billiondrag on March 07, 2012, 08:14:33 pm

What exactly does detergent do to the cell membrane? How does this affect the functions of the cell membrane? Is detergent more destructive to a cell membrane than vinegar?

I didnt do Unit 1 and I am still finding it hard to grasp the basics(the cell membrane). Any help would be greatly appreciated.

Thanks =)

Title: Re: 3 quick questions about detergent
Post by: Starlight on March 07, 2012, 10:21:23 pm

Here's some links that'll help :)

http://www.studyzones.com/questionzone/answer/83987x1402/effect-of-detergent-on-beetroot-cell-membrane

http://uk.answers.yahoo.com/question/index?qid=20110131121301AALtvYT

http://en.wikipedia.org/wiki/Cell_disruption#Detergent_methods 'see detergent methods section'

http://www.piercenet.com/browse.cfm?fldID=5558F7E4-5056-8A76-4E55-4F3977738B63

if anyone could shed light on the vinegar aspect though

Title: Re: 3 quick questions about detergent
Post by: billiondrag on March 08, 2012, 04:50:29 pm

thanks so much.

Checking out those links now.

Title: Re: 3 quick questions about detergent
Post by: Shenz0r on March 08, 2012, 07:30:18 pm

Detergent will destroy the membrane much more than vinegar, and that's why the detergent leaks out more pigment from the beetroot slices in the detergent solution.

Detergent is an amphiphatic substance, meaning that it has hydrophobic (non-polar, electrons are shared equally) and hydrophilic (polar, electrons are shared unequally) ends. This means that it is an ideal surfactant and it is capable of reducing surface tension. When the detergent solution comes into contact with the plasma membrane, it forms micelles (little globules of fat formed from the hydrophobic fatty acids of the phospholipid bi-layer) and thus tears apart the plasma membrane. As substances can only diffuse through the membrane when gaps are created in the membrane (because of the fluidity of the membrane), a lot of pigment will leak out of the membrane due to the bigger gaps in the membrane, and a lot more substances can diffuse into the cell.

The vinegar solution is acidic and contains more hydrogen ions than hydroxide ions. Thus, amino acids will tend to donate or accept protons in order to stabilise pH levels in the cell. Since the amino acids have changed their structure, this leads to a change in intermolecular bonding between amino acids, in particularly, hydrophobic interactions and hydrogen bonds. As a result, the secondary and tertiary structure will change and the protein will denature (because it's changed shape, it cannot no longer carry out its specific function). Pigment will leak out of the cell as a result BUT the phospholipids in the plasma membrane are not affected, thus no bigger gaps are created in the membrane and less pigment leaks out.

*Your SAC answers do not need to be this long

Title: Re: 3 quick questions about detergent
Post by: billiondrag on March 08, 2012, 07:53:10 pm

Thank you i was getting a bit confused about what micelles were  :)

Title: Re: 3 quick questions about detergent
Post by: Daenerys Targaryen on March 08, 2012, 08:36:33 pm

isnt the detergent just used to create bubbles? lol thats what i was told