Tutor profile: Aashka M.

What is the difference between Gram-Negative and Gram-Positive bacteria?

Gram-negative bacteria have a very thin (single-layer) peptidoglycan layer, however, the Gram-positive bacteria have a thicker (multilayer) peptidoglycan layer. Furthermore, Gram-negative bacteria have an outer membrane whereas the Gram-positive does not.

What is Gibbs Free Energy?

Gibbs Free Energy is the energy associated with a chemical reaction that can be used to do work. The free energy of a system is the sum of its enthalpy (H) plus the product of the temperature (Kelvin) and the entropy (S) of the system: ∆G= ∆H-T∆S

What are NMDA Glutamate Receptors?

Glutamate is one of the main excitatory neurotransmitters found in the human central nervous system (CNS). A special type of glutamate receptor (GluR) is known as N-methyl-D-aspartate (NMDA) glutamate receptors, they are involved in mechanisms of synaptic plasticity in the mammalian brain and are important for learning and memory. There are two types of glutamate receptors: ionotropic and metabotropic. NMDA Glutamate receptors are a type of inotropic receptors. the other type being non-NMDA receptors consisting of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and kainate. AMPA and NMDA share the same tetrameric structure. However, NMDA receptors require two ligands (glutamate and glycine) and have a magnesium ion blocking the pore that needs to be removed by depolarisation so that other ions can pass through, as seen in Diagram 1. A few other properties found in NMDA Glutamate receptors are that it is permeable to calcium ions and its activation can be both, ligand-gated or voltage-dependent. Of the three receptors- NMDA, AMPA, and KA- NMDA receptors have been studied most thoroughly and frequently recognized for being involved in diseases related to the CNS. The constant overactivation of NMDA GluRs can cause excitotoxicity- a form of neurodegeneration. Several studies have been done that suggest that NMDA GluRs play a very important role when it comes to causing neurological diseases such as epilepsy.