TLS Online TPP Program

#Id: 7583


Negative membrane potential may allow calcium channels to be opened and permit calcium to enter the sperm. 


#Unit 5. Developmental Biology #Fertilization #Part B Pointers
More Pointers
TLS Online TPP Program

#Id: 7711

#Unit 1. Molecules and their Interaction Relevant to Biology

                                                                 α-Turn

Contains hydrophilic amino acids and protrudes outside the protein surface like a hook.

Consists of 5 amino acids, generally termed as i, i+1, i+2, i+3 and i+4

H-bond is seen between i and i+4 (First and Fifth residue)

The conformation of i+1, i+2 and i+3 are crucial and on the basis of this, they are classified into

9 groups

TLS Online TPP Program

#Id: 7712

#Unit 1. Molecules and their Interaction Relevant to Biology

                                                γ-Turn


Consists of 3 amino acids, generally termed as i, i + 1 and i + 2

H-bond is seen between i and i + 2 (First and Third residue)

The conformation of i + 1 is crucial and on the basis of this, they are classified into 2 groups

The dihedral angles of residue i + 1 are (70, -60) and (-70, 60) of the classical and inverse gamma turns

TLS Online TPP Program

#Id: 7713

#Unit 1. Molecules and their Interaction Relevant to Biology

                                                        𝝅-Turn

Consists of 6 amino acids, generally termed as i, i + 1 , i + 2 i + 3 i + 4 and i + 5

H-bond is seen between i and i + 5 (First and sixth residue)

TLS Online TPP Program

#Id: 8443

#Unit 1. Molecules and their Interaction Relevant to Biology

The 310 helix has 3 residues per tum and contains 10 atoms between the hydrogen bond donor and acceptor, hence its name.

TLS Online TPP Program

#Id: 8444

#Unit 1. Molecules and their Interaction Relevant to Biology

Both the pi helix and the 310 helix occur rarely and usually only at the ends of a helices or as single-tum helices. They are not energetically favorable, since the backbone atoms are too tightly packed in the 310 helix and so loosely packed in the n helix that there is a hole through the middle. 
Only in the a helix are the backbone atoms properly packed to provide a stable structure.

TLS Online TPP Program

#Id: 8445

#Unit 1. Molecules and their Interaction Relevant to Biology

Right-handed helical conformation has 3.6 residues per turn and 1.5A/aa.