How to make section heading case sensitive in this?

Question

    \documentclass[a4paper,12pt,reqno, two side]{amsart}
    \usepackage{amsmath}
    \usepackage{amsfonts}
    \usepackage{amssymb}
    \usepackage{amsthm}
    \usepackage{color}
    \usepackage{ifpdf}
    \usepackage{array}
    
    \usepackage{url}
    \usepackage{graphicx}
    \usepackage{float}
    \usepackage{multirow,bigdelim}
    
    \usepackage{hyperref}% http://ctan.org/pkg/hyperref
    \usepackage{cleveref}% http://ctan.org/pkg/cleveref
    \usepackage{lipsum}% http://ctan.org/pkg/lipsum
    \usepackage{chngcntr}% http://ctan.org/pkg/lipsum
    
    \usepackage{epstopdf} 
    \def\numset#1{{\\mathbb #1}}
    
    
    
    
    
    
    \theoremstyle{plain}
    \newtheorem{Th}{Theorem}[section]
    \newtheorem{Lemma}[Th]{Lemma}
    \newtheorem{Cor}[Th]{Corollary}
    \newtheorem{Prop}[Th]{Proposition}
    
    \theoremstyle{definition}
    \newtheorem{Def}[Th]{Definition}
    \newtheorem{Conj}[Th]{Conjecture}
    \newtheorem{Rem}[Th]{Remark}
    \newtheorem{?}[Th]{Problem}
    \newtheorem{Ex}[Th]{Example}
    
    \newcommand{\im}{\operatorname{im}}
    \newcommand{\Hom}{{\rm{Hom}}}
    \newcommand{\diam}{{\rm{diam}}}
    \newcommand{\ovl}{\overline}
   
    
    \newcommand\blfootnote[1]{%
      \begingroup
      \renewcommand\thefootnote{}\footnote{#1}%
      \addtocounter{footnote}{-1}%
      \endgroup
    }
    
    \begin{document}

\title{BLABLA}

\author{Bhasth}
\author{Da}


\address{Uni\\ Department of Mathematics \\ 11}
\email{a.com}
\address{Sri  \\ i \\ 1107}
\email{ds.com}



\begin{abstract} The 
\end{abstract}

\keywords{to}



\subjclass[2010]{Pri0.}

\maketitle

\section{Make this case sensitive} 
\lipsum

\end{document}

EDIT- I want section heading appear as "Make this case sensitive" and not as "MAKE THIS CASE SENSITIVE"

Answer 1

Before \begin{document}, add the following lines:

\makeatletter
\renewcommand\section{%
   \@startsection{section}{1}\z@{.7\linespacing\@plus\linespacing}%
   {.5\linespacing}{\normalfont\centering}}
\makeatother

\documentclass[a4paper,12pt,reqno, two side]{amsart}
\usepackage{lipsum}
\makeatletter
\renewcommand\section{%
   \@startsection{section}{1}\z@{.7\linespacing\@plus\linespacing}%
   {.5\linespacing}{\normalfont\centering}}
\makeatother
    
\begin{document}

\title{BLABLA}

\author{Bhasth}
\author{Da}

\address{Uni\\ Department of Mathematics \\ 11}
\email{a.com}
\address{Sri  \\ i \\ 1107}
\email{ds.com}

\begin{abstract} The 
\end{abstract}

\keywords{to}

\subjclass[2010]{Pri0.}

\maketitle

\section{Make this case sensitive} 
\lipsum

\end{document}