Cellular Energetics

The totality of an organism’s chemical reactions

The sequence of enzyme-catalyzed reactions that begin with a specific molecule and end with a product (each step is catalyzed by a specific enzyme)

Pathway that releases energy by breaking down complex molecules into simpler compounds

Pathway that consumes energy to build complex molecules from simpler ones (also known as biosynthetic pathways)

The capacity to cause change

Energy can be transferred and transformed, but it cannot be created or destroyed (also called the principle of conservation of energy)

Every energy transfer or transformation increases the entropy of the universe

A measure of molecular disorder

Reaction that has a net release of free energy and is spontaneous (ΔG is negative)

Reaction that absorbs free energy from it’s surroundings and is nonspontaneous (ΔG is positive)

• Chemical

• Transport

• Mechanical

Endergonic reactions by phosphorylation, transferring a phosphate group to another molecule, such as a reactant

The phosphorylated intermediate

ATP hydrolysis which leads to a change in protein’s shape and often its ability to bind to other molecules

A chemical agent that speeds up a reaction without being consumes by the reaction

A macromolecule that acts as a catalyst (most enzymes are proteins)

The energy required to start a reaction by breaking bonds in the reactant molecules

By reducing the activation energy, thereby increasing the rate of reaction

The reactant molecule on which an enzyme acts

The enzyme and substrate bound together

The region of an enzyme to which the substrate binds

An enzyme's shape and conformation changing over time in response to substrate binding

By weak interactions like hydrogen bonds

By

• Orienting substrates correctly

• Straining substrate bonds

• Providing a favorable microenvironment

• Covalently bonding to the substrate

By increasing the substrate concentration

When all enzyme molecules in a solution are bonded with substrate

By adding more enzyme

• General environmental factors, such as temperature and pH

• Chemicals that specifically influence the enzyme

An inhibitor that binds to the active site of an enzyme and prevents the substrate from binding

An inhibitor that binds to an alternate site on the enzyme, causing the active site to change shape and become less effective

By weak interactions

By covalent bonds

When a regulatory molecule binds to a protein at one site and affects the protein’s function at another site (can either stimulate or inhibit an enzyme’s activity)

When the end product of a metabolic pathway shuts down the pathway (prevents a cell from wasting chemical resources by synthesizing more product than is needed)

The process that converts solar energy into chemical energy

Organisms that sustain themselves without eating anything derived from other organisms

Organisms that obtain their organic material from other organisms

In the leaves

Microscopic pores on leaves where CO2 and O2 can exit