Bioenergetics Organisms must continually exchange and in order

Bioenergetics • Organisms must continually exchange ______ and _______ in order to _____, reproduce, and maintain __________.

Metabolism The inset in this figure shows the first two steps in the catabolic pathway that breaks down glucose in cellular respiration.

• Metabolic pathways can be catabolic or anabolic • Catabolic pathways • Anabolic pathways

_______ pathways are exergonic

• Anabolic pathways are _________

• Is this reaction endergonic or exergonic?

• The released energy from _______ pathways can be used to drive _________ reactions • Ex) the catabolism of ______ in cellular respiration can be used to drive the synthesis of DNA during DNA replication

Photosynthesis vs cellular respiration • Which is which? • Delta G = -686 kcal/mol • Delta G = + 686 kcal / mol.

Practice • Sucrose + H 2 O glucose + fructose G= 7. 0 • Glycerol + fatty acid monoglyceride +H 2 O • Amino acid + amino acid dipeptide 1. 2. 3. 4. G = 17 Name/describe each of the reactions above Give a (+) or (– )in front of G Label as endergonic or exergonic Label as spontaneous or nonspontaneous G = 3. 5

• ATP • Why is this molecule the energy currency of the cell?

What type of reaction is occurring

• ATP is a renewable resource that is continually regenerated by adding a phosphate group to _____. – The energy to support renewal comes from ___________ in the cell. – In a working muscle cell the entire pool of ATP is recycled once each minute, over 10 million ATP consumed and regenerated per second per cell. • Regeneration, an endergonic process, requires an investment of energy: delta G = 7. 3 kcal/mol.

Spontaneous or nonspontaneous?

Spontaneous or nonspontaneous?

• The 1 st law of thermodynamics – • The 2 nd law of thermodynamics -

• 2. A. 3. Organisms must exchange matter with their environment to grow, reproduce and maintain organization. • Molecules and atoms from the environment are necessary to build new molecules. – Carbon moves from the environment to organisms where it is used to build carbohydrates, lipids, proteins, and nucleic acids. Carbon is used in storage compounds and cell formation in all organisms. – Nitrogen moves from the environment to organisms where it is used in building proteins and nucleic acids. Phosphorus moves from the environment to organisms where it is used in nucleic acids and certain lipids.

Nitrogen cycle

Phosphorus cycle

The “life” of a carbon atom • Carbon dioxide glucose carbon dioxide glucose starch glucose in animal glycogen glucose carbon dioxide glucose (either a triglyceride, amino acid, structural polysaccharide, nucleotide, etc) • Diagram the processes that are transferring the carbon to different molecules – Name the system (biotic or abiotic) that the atom is in – Label the process and describe (catabolic/anabolic; reason why it is occurring)