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Describe the first three levels of protein structure and the interactions which stabilise them.

Primary structure - sequence of amino acids in a polypeptide chain, amino acids joined by peptide bonds. Secondary structure - folding of the polypeptide chain into regular structures such as alpha-helices a...
JC
Answered by Joe C. • Biology tutor
3686 Views

What are the steps contained in action potential production?

The first step of the production of an action potential is a stimulus, which is a signal that excites the cell membrane causing Na+ ion channels to open. These channels are called voltage gated ion channels ...
MM
Answered by Megan M. • Biology tutor
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Explain why the pancreas is described as both an endocrine and an exocrine organ.

This question requires you to know the difference between endocrine and exocrine glands, as well as knowing the basic functions of the pancreas. Endocrine = secretes directly into the blood stream(usually ho...
WM
Answered by William M. • Biology tutor
9501 Views

Give one piece of evidence that supports the theory that mitochondria evolved from prokaryotic cells.

Mitochondria contain 70S ribosomes (as opposed to 80S which would be found in other eukaryotic organelles) the same as prokaryotic cells. They also have their own DNA (mtDNA) which is separate from the DNA o...
LE
Answered by Lucy E A. • Biology tutor
8218 Views

Colour blindness is a recessive trait caused by an error in the X chromosome. A couple without color blindness are expecting their second child. Their first child was born colour blind. What is the probability of their second child being colour blind?

Colour blindness is recessive, which implies that the child needs to have both chromosomes carrying the genetic error to be born with this condition. We know this is linked to the sex chromosome X so we will...
SR
Answered by Sabela R. • Biology tutor
4162 Views