- Messages
- 66
- Reaction score
- 2
- Points
- 16
can someone please explain the pregnancy test kit?
We are currently struggling to cover the operational costs of Xtremepapers, as a result we might have to shut this website down. Please donate if we have helped you and help make a difference in other students' lives!
Click here to Donate Now (View Announcement)
Examples of how energy is used in the transmission of nerve impulses- the activity of the sidium potassium pumpUsing examples outline the need for energy in living organisms.
I'm not sure what to write..
Asalamulalikum can anyone explain that what is the role of Potassium channels and Calcium ions during the secretion of Insulin ?
CAN ANYONE EXPLAIN
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s12_qp_13.pdf Q2
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w11_qp_11.pdf Q14 Q24
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s11_qp_11.pdf Q5 Q6 Q14
THANK YOU
1) We know that along food chains, the biomass decreases (roughly 10% is transferred to the next trophic level)CAN ANYONE EXPLAIN
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s12_qp_13.pdf Q2
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w11_qp_11.pdf Q14 Q24
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s11_qp_11.pdf Q5 Q6 Q14
THANK YOU
So basically K+ channels in the plasma membrane of the beta cells first open causing K+ to diffuse out.
Which then causes the inside of the cell to be -70mV to compared to the outside.
If glucose levels are high, glucose enters the beta cells.
THe glucose is then phosphorylated then metabolised to produce ATP.
The presence of extra ATP causes K+ channels to close hence K+ cannot diffuse out of the membrane anymore making it -30mV.
Ca2+ channels are normally closed.
They open in response to the change in membrane potential.
Ca2+ move into the cell. Ca2+ then causes vesicles to release insulin by exocytosis
Could anyone PLEASE give me an explanation or help me understand the electron transportchain in respiration?
Firstly the ETC chain takes place on the inner membranes of the mitochondria. here are a few steps:Could anyone PLEASE give me an explanation or help me understand the electron transportchain in respiration?
can someone please explain the pregnancy test kit?
What the ETC does is that it splits hydrogen brought by the reduced NAD and FAD's into a proton (H+) and an electron. This electron has energy so it goes through an electron transfer chain all the way giving up energy. This energy is used to pump H+ into the intermembranal space of the mitochondrion. As the H+ concentration in the space increases it tends to flow out back into the mitochondrial matrix by diffusion. The H+ do so by passing through ATPase molecules. When H+ pass the ATPase molecules gain energy to combine ADP+P to form ATP. The H+ is then accepted by oxygen and thats why you need oxygen to respire and hence produce ATP and hence be able to eat, walk and talk.
Firstly the ETC chain takes place on the inner membranes of the mitochondria. here are a few steps:
1) at the beginning of the ETC the reduced NAD and reduced FAD (which are products of the previous stages of aerobic respiration) split, and give H+ ions and electrons. they are oxidized and regenerated for use in the other steps
2) The electrons are picked up by ELECTRON CARRIERS which are part of the electron transport chain (usually cytochrome molecules act as the electron carriers) these carriers pass the electrons down the chain
3) the electrons when split have high energies, as they pass down the chain they release some of their energy. This energy is used to pump out H+ ions from the mitochondrial matrix into the intermembrane space
4) These electrons are finally accepted by oxygen molecules. These oxygen molecules, along with H+ ions and the electrons from the chain combine to form a water molecule.
5) Now the concentration of H+ ions in the intermembrane space is higher than the matrix inside. So an electrochemical gradient is set up, H+ ions move down this concentration gradient via special transporter proteins on the inner membrane which have ATP synthase (enzyme) as part of their structure. 3 H+ ions produce one ATP molecule as they pass through this protein, this process is known as chemiosmosis...
hope that helps, good luck
What do we need to know for bio tech? do we need to remember the fermeter ? like labelling aswell as functions?
hey guys what is the difference between embro, foetus, and zygote? And in section b where we have to answer 1 question. Whenever i answer those questions my answers are not very long but they do contain all the points in the markscheme. Like if they give a space of 3 pages my answer to a come in half page or a little more and the answer to b is also a half page or can be less. So, will my marks be deducted if i write short answers like this? plzz help ty
can anyone explain how does superovulation occur?? what hormones and drugs are used and what are their effects? how does it allow many follicles to form?
They are similar. A zygote forms after fertilization. A zygote becomes an embryo which becomes a fetus.
An embryo is a multicellular diploid eukaryote in its earliest stage of development.
In organisms that reproduce sexually, once a sperm fertilizes an egg cell, the result is a cell called the zygote that has all the DNA of two parents.
A fetus (or foetus, or fœtus) is a developing mammal or other viviparous vertebrate, after the embryonic stage and before birth.
This is the very basic explanation.
For electrophoresis in chem , PCR is used after restriction enzyme but in biology text book ( the green book)it is used before restriction enzyme.... what should i beleive ?
For almost 10 years, the site XtremePapers has been trying very hard to serve its users.
However, we are now struggling to cover its operational costs due to unforeseen circumstances. If we helped you in any way, kindly contribute and be the part of this effort. No act of kindness, no matter how small, is ever wasted.
Click here to Donate Now