Question

What is the difference between a glycosidic linkage and a peptide linkage? 

Answer 1

 The linkage between two monosaccharide units through oxygen atom iscalled glycosidic linkage. 

whereas peptide linkage in an amide formed between -COOH group and - NH₂ group.
\[\ce{H2N-CH2-COOH +
\begin{array}{c}H2N-CH-COOH\\\ce{|}\\\ce{CH3}\end{array}
->[-H2O]}
\begin{array}{c}\ce{H2N-CH2 \overset{Peptide linkage}{-CO-NH\bond{-}}CH-COOH}\\
\ce{\phantom{------}|}\\
\ce{\phantom{-------}CH3} \end{array}\]