Objective 5:

1.  They are mechanical and chemical.
http://wiki.answers.com/Q/What_are_the_two_parts_of_digestion&isLookUp=1
2.  Mechanical digestion is when you hve to do something to digest your food for yourself like chewing but chemical digestion is when a chemical called hydrochloric acid breaks down your food. http://wiki.answers.com/Q/What_is_the_difference_between_mechanical_digestion_and_chemical_digestion#ixzz16btmgJUm
3.  This means they can't do mechanical digestions so the chemical digestion has to work harder.
4.  mounth=7pH, stomach acid=1.5pH, small intestine=7
http://wiki.answers.com/Q/What_is_the_ph_in_your_mouth&isLookUp=1
http://wiki.answers.com/Q/What_is_the_pH_of_the_stomach
http://wiki.answers.com/Q/What_is_the_Ph_of_the_small_intestine&isLookUp=1
5.  The different enzymes work better at different pHs.
http://wiki.answers.com/Q/How_is_pH_important_during_digestion&alreadyAsked=1&rtitle=Why_are_pH_variations_in_different_parts_of_the_digestive_system_important_to_the_process_of_digestion&isLookUp=1