123. Which one of the following will NOT change upon adding an enzyme to a chemical reaction or
changing the concentration of reactants or products?
A. ∆𝐺°
B. 𝐾𝑒𝑞
C. ∆𝐺
A. A, B
B. B, C
C. A, B, C
D. Only A

Detailed Explanation:

Enzymes are biological catalysts that accelerate chemical reactions by lowering the activation energy, without altering the reaction’s fundamental thermodynamic properties.

Let’s break down the choices:

1. ΔG° (Standard Gibbs Free Energy Change):

   • It is a constant for a given reaction under standard conditions.

   • It is based on the intrinsic energy difference between reactants and products.

   • Unaffected by enzymes or concentrations.

2. Keq (Equilibrium Constant):

   • Depends solely on the relative energy levels of reactants and products.

   • Enzymes do not change Keq; they only help the system reach equilibrium faster.

3. ΔG (Actual Gibbs Free Energy Change):

   • Varies with the concentration of reactants and products.

   • Can change if concentrations change, but not by the enzyme alone.

Therefore:

• ΔG° and Keq are constants for a reaction.

• ΔG changes with concentration.

✅ Correct Answer:

A. A, B

Title: Understanding Embryonic Stem Cells: Defining Pluripotency

Slug: pluripotent-embryonic-stem-cells-explained

Meta Description: Learn what makes embryonic stem cells pluripotent and how they differ from other stem cell types like multipotent or unipotent cells in their differentiation potential.

Key Phrase: pluripotent embryonic stem cells

Detailed Explanation:

Embryonic stem cells derived from the inner cell mass of the blastocyst are called pluripotent stem cells. These cells can:

• Differentiate into any cell type of the three embryonic germ layers:

  • Ectoderm (e.g., skin, neurons)

  • Mesoderm (e.g., muscle, blood)

  • Endoderm (e.g., liver, pancreas)

They cannot form extra-embryonic tissues like the placenta—this distinguishes them from totipotent cells, such as a zygote.

Comparison:

• Multipotent: Can become a limited range of cells (e.g., hematopoietic stem cells).

• Oligopotent: Even more restricted differentiation (e.g., lymphoid or myeloid cells).

• Unipotent: Can form only one cell type (e.g., muscle stem cells).

✅ Correct Answer:

A. Pluripotent stem cells