What is the zipper model?

What is the zipper model?

The zipper model of translational control: a small upstream ORF is the switch that controls structural remodeling of an mRNA leader. Cell. 2003 May 16;113(4):519-31. doi: 10.1016/s0092-8674(03)00345-3.

What is molecular zipper?

It is a simple statistical physics model of the formation or unraveling of a long chain of links (often used as a toy model for DNA). Part of the reason that the zipper problem is so popular in homework assignments is that it has a great balance of interesting physics with relatively simple calculations.

What is the name of the zipper enzyme in DNA replication?

Helicase – Enzyme that untwists & opens DNA molecule (like a zipper).

What holds the teeth of the DNA zipper together?

2) The two chains of nucleotides in a DNA molecule are held together by hydrogen bonds between the bases. In DNA, cytosine forms three hydrogen bonds with guanine, and thymine forms two hydrogen bonds with adenine. 3) Complementary base pairing produces a long, two-stranded molecule that is often compared to a zipper.

What are primes in DNA?

Each end of DNA molecule has a number. One end is referred to as 5′ (five prime) and the other end is referred to as 3′ (three prime). The 5′ and 3′ designations refer to the number of carbon atom in a deoxyribose sugar molecule to which a phosphate group bonds.

How does DNA hold information?

DNA stores biological information in sequences of four bases of nucleic acid — adenine (A), thymine (T), cytosine (C) and guanine (G) — which are strung along ribbons of sugar- phosphate molecules in the shape of a double helix.

What is the zipper theory in biology?

Phagocytosis is the fundamental cellular process by which eukaryotic cells bind and engulf particles by their cell membrane. Particle engulfment involves particle recognition by cell-surface receptors, signaling and remodeling of the actin cytoskeleton to guide the membrane around the particle in a zipper-like fashion.

Why is prime used in DNA?

The prime mark is there to distinguish the carbons of the sugar from the carbons of the nucleic acid/base (which are labeled without a prime). A deoxyribose with its labeled carbon atoms.

How is DNA adapted to its function?

DNA winds into a double helix, with hydrogen bonding between the bases of each strand like the rungs of a ladder. This structure enables DNA to coil so that the long molecule is compact and lots of information can be stored in a small space.

What is the partition function for a single-ended zipper?

This is surprisingly easy for our single-ended zipper. Recall that a partition function is defined by the following sum: In the expression above, s denotes a particular state, E s is the energy of the state s, k is Boltzman’s constant, and T is the temperature of the system.

What is the opening of the zipper in DNA replication?

Opening of zipper: Unwinding of DNA and formation of 2 replication forks. DNA topoisomerase II (a.k.a DNA gyrase in prokaryotes) removes positive supercoils ahead of advancing replication. Topoisomerase I nicks DNA, relieving torsional tension of the replicating helix. Topoisomerase II introduces the double strand break to avoid DNA tangle.

Is DNA a zipper or a zipper?

Prokaryotic DNA as a zipper with single slider (single origin of replication) and Eukaryotic DNA as a zipper with two sliders (multiple origin of replication). Complementary teeth pair: Complementary base pairs attached by hydrogen bonds

What is the zipper problem in physics?

Physics students the world over encounter the zipper problem at some point in their studies. It is a simple statistical physics model of the formation or unraveling of a long chain of links (often used as a toy model for DNA ).