Download - Energy
Energy
Energy
Energy can be described as the ability to do work
Energy that is stored in organic molecules is known as chemical energy Glucose
the energy living organisms use to do work is called free energy
without a constant source of energy, living systems would not survive
Three kinds of work:
Chemical constructing and breaking down large complex
molecules▪ proteins and nucleic acids
Transport the movement and concentration of materials▪ Materials and nutrients required for building complex
molecules, and growth of cellular structures
Mechanical includes movement such as muscle contractions.
Obtaining Energy
Autotrophs use the sun’s energy to convert carbon
dioxide and water into food in the form of carbohydrates
green plants that make their own food through the process of photosynthesis
Obtaining Energy
Heterotrophs Must take in food that is already made food comes from plants or other animals
that have eaten plants break the chemical bonds in large food
molecules and release energy through the process of cellular respiration▪ Autotrophs also undergo cellular respiration
Energy Storage - ATP
the carrier of energy is the molecule adenosine triphosphate or ATP
there are 3 components to the ATP molecule:
Cellular Respiration
breakdown of glucose (C6H12O6) in the presence of oxygen (O2) to produce cellular energy (ATP) C6H12O6 + 6O2 -->6 CO2 + 6H2O + 38 ATP
3 Main Parts to the reaction…
Cellular Respiration
Glycolysis: occurs in the cytoplasm, converts glucose to
pyruvic acid an anaerobic process - O2 is not required
pyruvic acid diffuses into the mitochondrion Citric Acid or Krebs Cycle
occurs in the mitochondria an aerobic process; only occurs in the
presence of O2
Releases CO2 as a product
Cellular Respiration
Electron Transport System: Actual production of ATP molecules, 6 H2O are formed when the electrons
unite with O2* at the end of electron transport chain.
* Note: This is the function of oxygen in living organisms!
Release of Energy
Energy is released when ATP loses the endmost phosphate group Results in adenosine diphosphate (ADP)
If energy is not immediately needed phosphate groups are re-attached
The energy in an ATP molecule is stored in the bonds between the phosphate groups