Metabolism: Energy and Enzymes, Metabolism and Energy

Kinetic energy

The energy of motion

Potential energy

Energy stored due to an object's position or arrangement

chemical energy

A form of potential energy that is stored in chemical bonds between atoms.

mechanical energy

The amount of work an object can do based on its potential and kinetic energy.

first law of thermodynamics

Energy can be transferred and transformed, but it cannot be created or destroyed.

second law of thermodynamics

Every energy transfer or transformation increases the entropy of the universe.

heat

Every time energy is transferred in an ecosystem, some of the energy is lost as ___________________

energy efficiency

The percentage of energy put into a system that does useful work

entropy

(thermodynamics) a thermodynamic quantity representing the amount of energy in a system that is no longer available for doing mechanical work (heat)

metabolism

All of the chemical reactions that occur within an organism

reactants

A starting material in a chemical reaction

products

Ending materials in a chemical reaction.

free energy

energy available to do work

exergonic reaction

A spontaneous chemical reaction in which there is a net release of free energy.

endergonic reaction

A chemical reaction that requires energy input(heat, light, or electricity) in order to proceed.

spontaneous reaction

A reaction that will proceed or occur on its own without an input of energy from its surroundings.

phosphorylation

the transfer of a phosphate group to a molecule

transport work

Enables cells to move ions, molecules, and larger particles through the cell membrane and through the membranes of organelles in the cell. Particularly useful for creating concentration gradients.

mechanical work

energy needed to contract molecules, beat flagella, etc

ribozyme

a type of RNA that can act as an enzyme

metabolic pathway

Begins with a specific molecule, which is then altered in a series of defined steps, resulting in a certain product.

substrates

The material or substance on which an enzyme acts.

enzyme-substrate complex

Formed by the temporary binding of enzyme and reactants enables the collisions to be more effective and lowers the activation energy of the reaction

Active site

The specific portion of an enzyme that attaches to the substrate by means of weak chemical bonds.

synthesis

Combining of small molecules or substances into larger, more complex ones

degradation

Substrate is broken down into smaller parts

Induced fit

Brings chemical groups of the active site into positions that enhance their ability to catalyze the chemical reaction.

Energy of activation

The amount of energy required to start a reaction. Enzymes work by diminishing the activation energy needed for a reaction to go to completion.

denaturation

A process in which a protein unravels, losing its specific structure and hence function; can be caused by changes in pH or salt concentration or by high temperature.

Enzyme cofactors

molecules or ions required for normal enzyme function

Coenzymes

vitamins that assist in the normal functioning of enzymes

enzyme inhibition

occurs when an active enzyme is prevented from binding to a substrate by an inhibitor

oxidation

The loss of electrons

reduction

Gaining electrons

Redox reaction

Another name for an oxidation-reduction reaction

Mitochondria

An organelle in eukaryotic cells that serves as the site of cellular respiration; uses oxygen to break down organic molecules and synthesize ATP

cellular respiration

Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen. Glucose is oxidized to carbon dioxide.

The 2 groups that chemical processes in cells.

Catabolic and Anabolic

Breaking down processes are degradative processes are called _____________ processes are net energy ___________ processes.

catabolic; releasing.

Building up processes are synthetic processes are called ______________ processes are net energy _____________ processes.

anabolic; storing.

Oxidation reactions __________ energy.

release

Reduction reactions _____________ energy

absorb

Oxidation and Reduction reactions occur together:

Energy __________ (oxidation) must be ____________ (reduction)

Energy _____________ (reduction) must have __ _______________ (oxidation)

released; absorbed; absorbed; a source

Hydrogen bonds indicate....

the level of reduction.

Energy is needed to ________ molecules together

bring or collide

Effective Collision

When molecules collide in the proper orientation during a reaction

Energy may come from....

the reacting ________ or ____________________

the _____________________

breaking chemical __________ and ____________ them to make a new chemical bond.

atoms; molecules; environment; bonds; linking

_____________ energy is the amount of energy required to bring __ potentially _________ molecules into the __________ ________________ for the desire ___________________ to occur.

Activation; 2; reactive; proper orientation; reaction

If the activation energy is too high, the higher the chances....

the reaction will not occur.

Another way of describing enzymes as ____________.

facilitators

Enzymes can be worn out due to .....

the 2nd Law of Thermodynamics

Enzymes ________ activation energy by bringing the reacting molecules into the proper _________________ for the desired reaction.

reduce; orientation

Enzyme attachment can cause 4 actions:

turn the enzyme _______ or ________

or ___________ or ______________ enzyme activity.

on; off; increase; decrease

The _______ ______ is where the substrates bind with the enzyme, thus causing the ______________ to occur

active site; reaction

The substrate binding into the active site is an example of ...

proper orientation

Two factors can affect enzymes:

temperature and pH

After 40 degrees C, the starts to slowly ____________ and ____________ the activation energy, thus slow the process of ___________ products.

denature; oxidize; producing