Cellular Respiration Flashcards
where is energy stored?
Energy used by organisms is stored in organic compounds
what is energy defined as?
the ability to cause change.
what is chemical energy and where is it stored?
Chemical energy is potential energy that is released by a chemical reaction.
Chemical energy is stored in bonds that join atoms.
what happens to organic compounds when energy is needed? what does ATP store?
When energy is needed, the bonds of organic compounds are broken and energy is released and stored in adenosine triphosphate molecules (ATP).
ATP stores readily usable energy.
what is ATP?
Universal carrier of energy for organisms.
Immediately usable chemical energy that is needed for survival.
what does ATP contain? What happens when it breaks?
The molecule contains two high energy bonds between the inorganic phosphate groups.
These bonds are easily broken to form a small packet of energy
The amount of “packets” used depends on the energy requirements of the cell.
When ATP gives up its energy, it splits into a molecule of ADP (adenosine diphosphate) and a molecule of phosphate.
This process is reversible using energy from the breakdown of glucose during cellular respiration.
what is cellular respiration?
The process by which organisms transform chemical energy from organic compounds into ATP is cellular respiration.
how do cells obtain most of their energy?
Cells obtain most of their energy for making ATP by breaking apart glucose, lipids and proteins.
how is chemical energy released from glucose? What is formed?
The chemical energy from glucose is released in a series of steps that involve enzymes, so that energy is released in many small packets. Each energy packet can be used to produce an ATP molecule from ADP.
The breakdown of glucose molecules results in carbon dioxide, water and energy being formed.
what percentage of energy from glucose is stored in bonds of ATP?
Of the chemical energy released form glucose, 40% is converted to energy stored in the bonds of ATP during aerobic respiration. The rest is lost as heat.
what are the two stages of cellular respiration?
Cellular respiration can be divided into two stages. Glycolysis and aerobic respiration if oxygen is present or aerobic respiration if it is absent.
If there is insufficient oxygen, anaerobic respiration will occur but aerobic respiration will also happen, using all available O2.
what is glycolysis? what does it involve? Where does it occur and does it need oxygen?
First stage of cellular respiration.
It involves the splitting of lysis of glucose into two pyruvate molecules.
This occurs in the cytosol and is anaerobic (does not need oxygen).
how much ATP is needed in glycolysis and what is the net gain?
Glycolysis uses two ATP molecules in breaking down one glucose molecule but it produces four more so their is a net gain of two.
what affects what happens after glycolysis?
What happens after glycolysis depends on whether or not their is oxygen.
when does aerobic respiration take place? where? what happens?
When oxygen is available.
Occurs in the mitochondria and uses ADP.
Pyruvate molecules are broken down to produce carbon dioxide, water and ATP.
