Afunctional group that is acidic and part of the amino acid backbone:

COOH (carboxyl group)

Explanation:

The amino acid backbone is common/ primary to all amino acids and the R-group is what makes each amino acid unique. The alpha-carbon is central and is connected to the amino group (NH3+), Carboxylic acid group (COOH), Hydrogen (H) which form the backbone and the R-group which differs in each amino acid.

one is through turgidity. this occurs before ground tissue ( collenchyma

and sclerenchyma cells) become well

developed to give structural support to the plant as it grows bigger. the xylem

tissue (composed of rigid tissue) of the young

plant render this support and also maintaining osmotic turgidity of the surrounding

plant cells.