Question

How are glucose molecules transported into a cell?

Answer 1

cells in intestine absorbes glucose . a glucose molecule is large so it cannot pass through cell membrane via simple diffusion . instead facilitated diffusion and two types of active transport are there

facilitated diffusion is a passive transport mechanism in which carrier proteins shuttle molecules across the cell membrane without energy expenditure .molecules transfer from higher to lower concentration . rbc use facilitated diffusion to absorb glucose

the cells along intestine use active transport mechanism .primary active transport need atp to pump glucose in to the cell either with or against the concentration gradient .the transport proteins are known as atpase enzymes

secondary active transport is another method by which cell import glucose .in this a transmembrane protein known as symporter imports 2 sodium ions for every glucose molecule it imports .this method doesnot use atp ,but relies upon the higher concentration gradient of sodium outside the cell relative to inside .it is used in heart ,kidney ,brain ,small intestine and other organs .here the positively charged sodium ions provide electrochemical energy to import glucose with or against the concentration gradient