Unit 9 Physical, Chemical, and Energy Changes in Digestion
Physical digestion
is mechanical digestion which is the breaking, crushing, and mashing of
food.
It causes a physical change, which is a change in size, shape, and color
Chemical digestion
large molecules of food are broken down into smaller molecules in
order to pass into the bloodstream
Causes a chemical change (a new substance is formed) as a result of:
Interaction of food with bile
Reaction of food with hydrochloric acid HCl
Enzymes breaking down starches
Cellular Respiration
the process of breaking down foods to produce energy rich ATP
molecules
Occurs in the mitochondria of eukaryotic cells
Sugar, protein, and fat molecules are broken down into smaller
molecules.
Chemical bonds are broken, energy is released.
Organic Compound
is a chemical compound that contains carbon atoms
Common elements in organic compounds include:
Types
Proteins
Hydrogen
phosphorus
chlorine
Oxygen
sulfur
nitrogen
proteins, carbohydrates, lipids, nucleic acids
ALL proteins are composed of carbons, hydrogen, and nitrogen
Proteins are made up of smaller molecules called amino acids
Proteins are needed for growth, repair, transport, and digestion
Carbohydrates
molecules including sugars, starches, and fibers are made up of carbon,
hydrogen and oxygen
Carbohydrates release more energy because they have more bonds
Lipids
includes fats, oils, waxes, and phospholipids and contain carbon,
hydrogen, and oxygen
Lipids carry information between cells
They are energy stores
Phospholipids form cells walls and cell membranes
Nucleic acids
large organic molecules that determine the genetic traits of an
organism. Small units are called nucleotides
Nucleotides are made up of carbon, hydrogen, oxygen, and nitrogen
and compose DNA and RNA
Energy
Kinetic
energy of motion in an object or organism
The amount of kinetic energy depends on mass and speed
Potential
is the energy an object or organism has due to its position, condition, or
chemical composition.
When an organism is able to move but is resting or still it has potential
energy
Chemical energy
is the energy stored in the bonds of molecules
It is a form of potential energy
Released when the bonds in food molecules are broken
Example
Electrical Energy
muscle cells break up glycogen to provide the energy needed to move
energy that results from the position or motion of charged particles
Form of kinetic energy
Example
Sound Energy
messages sent through the nervous system are a form of electrical
energy
for of kinetic energy
The vibration of particles generates sound energy
Example
Thermal Energy
when you talk your vocal cords vibrate causing air molecules to vibrate
(kinetic energy transformation)
is the total kinetic energy of all the atoms and molecules in an organism
Thermal energy is generated as particles move around
Faster moving particles create more thermal energy