Role of ATP and NAD

H2.2.8 Syllabus Objectives Explain the role of ATP and describe how it is formed from ADP + P Explain the role of NADP+ in trapping and transferring electrons and hydrogen ions in cell activities

Energy Carriers ATP, NADP+ and NAD+ play a vital role in trapping and transferring energy in cellular activities

ADP and ATP ADP is an abbreviation for Adenosine Diphosphate this is a molecule found in the cells of all organisms It is made of the base adenine, a 5 carbon sugar called ribose and 2 phosphate groups ADP is a low energy molecule

ADP and ATP If another phosphate is added to ADP it forms ATP (Adenosine Triphosphate) Extra energy is also added as there is an extra bond between the last two phosphate groups Addition of a phosphate like this is called Phosphorylation ATP is rich in energy and stores this energy carrying it around in the cell

ADP and ATP ATP cannot store energy for very long it breaks down releasing energy and converting back to ADP Most cells release energy from ATP 10 million times every second! This energy is used for cellular reactions

Learning Check What do ADP and ATP stand for? What base is found in ATP and ADP? What sugar is found in ATP and ADP? Which is a higher energy molecule? How does ADP become ATP? This process is called p How is the energy in ATP released?

NADP+ and NADPH NADP+ is a low energy molecule involved in photosynthesis NADP+ can combine with 2 high energy electrons and a proton to form NADPH NADPH is a very high energy molecule It’s energy is used to form glucose in photosynthesis

NADP+ and NAD NAD+ is used in respiration It can combine with 2 high energy electrons and a proton to form NADH which is very high in energy Remember P for photosynthesis, NADP+ is used in photosynthesis NAD+ in respiration

Both NADH and NADPH release energy and protons when they break down into NAD+ and NADP+ These electrons, protons and energy are used by cells

Learning Check Is NADP+ used in photosynthesis or respiration? What combines with NAD+ and NADP+ to form NADH and NADPH? What do NADH and NADPH provide for reactions in cells? How do they provide these things?

END