Langbahn Team – Weltmeisterschaft

Talk:Active transport

F-ATPase

I'm not sure if I understand why F-ATPases (ATP synthases) are active transporters. Here they are listed as number 2 in the "Types of primary active transporters". Active transporters are by definition proteins that create a gradient by using ATP. ATP synthases do the exact opposite, they synthesize ATP by using a gradient. I'm not an expert on this topic, maybe I'm missing something. Also, this is the first time I'm in Wikipedias "Talk" section. I think I'm doing it wrong. — Preceding unsigned comment added by ScienceEel (talk • contribs) 21:34, 20 June 2020 (UTC)[reply]

Untitled

ACTIVE TRANSPORT

Not sure how to put it but perhaps a why section, where in biology is this actually useful/used? arrived at this page from Bladderwort

it is vital to the nervous system of all animals. this is probably talked about in the neuron article (etc): neurons require a resting membrane potential of about -70mV which is largely established by active transport of K+ and Na+ across the membrane. every 3 Na+ exported out is replaced by 2 K+ imported. this imbalance causes the negative membrane potential. This potential causes a fast influx of Na+ (due to ELECTRIC and chemcial potentials) when the Na+ channels (passive) are opened by a stimulus. This can cause depolarisations (i.e. a neuron firing).

active transport is also used in the kidneys to regain most of the materials lost in the filtrate so it is not lost in the urine (e.g. glucose is taken up by secondary active transport, at a rate of nearly 100% except in diabetics).

You could write in a little about primary active and secondary active transport: primary active transport uses the energy in ATP to move stuff, secondary active transport uses electrochemical differences and coupling I think. There are already seperate articles for these, but a mention and link in this article would be nice.

ABC transporter

I can't find any reference to it, but the sodium pump should really be an example of a ABC-transporter. Does anyone know?--Gak (talk) 15:17, 13 November 2008 (UTC)[reply]


Active transport is moved by energy.

How does this help you? —Preceding unsigned comment added by 67.173.81.104 (talk) 04:23, 27 January 2009 (UTC)[reply]

Cholesterol-rich lipid membranes

The lipid rafts supporting active transports and other transmembrane activities have cholesterol present almosts 1:1 with sphyngomyelin lipids. Why do text books keep ignoring the huge importance of cholesterol mediation in this area? It is a relatively new paradigm shift in lipid rafts (12 years old) but incredibly important to today's students surely!Glynwiki (talk) 07:09, 22 June 2009 (UTC)[reply]

References needed

Currently there are no references. Earlier versions such as[1] have had references. I'm not sure if they were removed for legitimate reasons or not. —dv82matt 06:04, 10 January 2010 (UTC)[reply]

"Against concentration gradient"

I think there is a mistake in the article, here I write, why I think it is a mistake.

Diffusion, which is a form of passive transport, works against the concentration gradient, because gradient of the concentration points in the direction from lower concentrations to higher concentrations. (See a definition of the gradient.) Diffusion moves particles from areas with higher concentrations to lower concentrations, therefore it moves particles against the concentration gradient. Therefore, active transposrt, unlike the passive pransport, moves the particles in the direction of the concentration gradient, not against it. Or is there some different definition of gradient, which is used in biology? --Irigi (talk) 14:05, 10 February 2010 (UTC)[reply]

Merger proposal

This page Primary active transport, Secondary active transport and Co-transport are all small pages covering smiler content that are sub categories of Active transport. — Preceding unsigned comment added by Jasoninkid (talk • contribs) 01:50, 17 September 2011 (UTC) If there are no objections I will start the merge by coupling the other articles in to this one and later create the redirects.Jasoninkid (talk) 20:40, 19 September 2011 (UTC) I've added primary and Secondary active transport although it needs a quit a bit of smoothing out. Jasoninkid (talk) 21:22, 19 September 2011 (UTC)[reply]

active transport: requires energy, goes against concentration gradient(low to high)... there short sweet and to the point! — Preceding unsigned comment added by 75.139.88.25 (talk) 15:17, 15 October 2011 (UTC)[reply]

Merging: nope.avi .... easier to find when separate — Preceding unsigned comment added by 71.83.233.123 (talk) 19:42, 20 November 2011 (UTC)[reply]

Merging: perhaps include the co-transport section as a subsection of Active Transport, but it is definitely easier to leave the Co-Transport page as its own page for purposes of finding it. — Preceding unsigned comment added by 122.105.140.100 (talk) 09:25, 6 April 2013 (UTC)[reply]

Energy

I have edited the introduction, because previously it said that passive transport does not use any kind of energy. This is not true. Passive transport relies on the kinetic energy of the substance that is being transported. This kinetic energy is what causes it to move around and (by random chance) cross the membrane. The difference is that active transport actually uses the cell's energy (ATP or electrochemical gradient) to pump the substance across the membrane. Famedog (talk) 10:15, 1 November 2012 (UTC)[reply]

Is cotransport active transport at all?

I query the utility of the term "secondary active transport" as a description of cotransport. It seems to me that there is a clear distinction between active transport where the energy comes from the immediate hydrolysis of ATP and which stops the moment you poison the pump, and passive transport where the energy comes from an electrochemical gradient, and which will persist after poisoning the pump until the gradient runs down. If we start talking about secondary active transport then we muddy the water fairly comprehensively. Very many biological gradients ultimately require metabolic energy for their maintenance, and in so far as that is the case, transport systems using these gradients become "secondary active transport" and passive transport dissappears from the scene.

As an obvious example, the Na and K flow during a nerve impulse depends on the gradient established by the Na/K ATPase (classic active transport), but as far as I know nobody ever describes the action potential as a "secondary active transport" process. In fact most neuroscience teachers rather strongly emphasise that the ion flow is indeed a passive process.

I'd like to canvas opinion on this topic rather than diving in and editing directly. Any thoughts?

Wjheitler (talk) 10:49, 27 November 2013 (UTC)[reply]

Assessment comment

The comment(s) below were originally left at Talk:Active transport/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

rated top as high school level/SAT biology content - tameeria 14:17, 17 February 2007 (UTC)[reply]


Hi there,

Looks like this article has been vandalized. Could somebody restore it ? —Preceding unsigned comment added by 67.69.138.67 (talk) 16:24, 27 November 2007 (UTC)[reply]

Last edited at 16:26, 27 November 2007 (UTC). Substituted at 06:38, 29 April 2016 (UTC)

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Split

Now that there is enough written for primary and secondary transport (which should rather be named cotransport or electrochemical potential-driven transport), can we split these two concepts again? They are completely different. --SCIdude (talk) 13:58, 4 September 2019 (UTC)[reply]

how is active transport possible since it contradicts the second law of thermodynamics

Wiki Education assignment: CHEM 378 - Biochemistry Lab - spring 2023

This article was the subject of a Wiki Education Foundation-supported course assignment, between 30 January 2023 and 20 May 2023. Further details are available on the course page. Student editor(s): Mynameiskeyshawnsmith (article contribs). Peer reviewers: Dosunodos212.

— Assignment last updated by Dosunodos212 (talk) 23:43, 15 May 2023 (UTC)[reply]

Quelle: http://en.wikipedia.org/wiki/Talk:Active_transport