Intro to Metabolism

What is metabolism

sum of all chemical reactions in the body

What are metabolic pathways

A metabolic pathway is a linked series of chemical reactions occurring within a cell. The reactants, products, and intermediates of an enzymatic reaction are known as metabolites, which are modified by a sequence of chemical reactions catalyzed by enzymes.

What is the difference between kinetic and potential energy

Kinetic energy is energy in action, while potential energy is stored energy.

What is thermal energy

kinetic energy associated with the random movement of atoms or molecules

What is chemical energy

potential energy available for release in a chemical reaction

What is the first law of thermodynaimcs

The energy in the universe is constant. Energy can be transfered and transformed, but it cannot be created or destroyed

What is the second law of thermodynamics

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

What is entropy

measure of molecular disorder, or randomness

What is meant by a spontaneous reaction

a process that occurs without an overall input of energy; energetically favorable

What is meant by a nonspontaneous reaction

not energetically favorable, so you need to put energy in to make it happen

How do entropy and a spontaneous reaction relate

When entropy is higher, the reaction is spontaneous. Meaning order decreased and disorder increased

How does entropy and nonspontaneous reaction relate

When entropy is less, the reaction is nonspontaneous. Order increases and disorder decreases

What is the balancing order within living systems? How do they break down matter

Cells created balanced structures from less organized materials. (monomers - polymers - amino acids - polypeptides). They breakdown matter through metabolism

What is free energy (G)

measure of energy capable of doing work. Free energy is a measure of a systems stability. Unstable systems (higher G) will try to become stable (lower G)

How does the change in free energy relate to if the reaction occured spontaneously or not

If the change in G is negative, the reaction will occur spontaneously. If the change in G is zero or positive, the reaction will occur nonspontaneously

WHat is the relationship between free energy and exergonic reactions

An exergonic reaction occurs with a net release of free energy to the surroundings. It has a negative chnage in G, being spontaneous

What is the relationship between free energy and endergonic reactions

An endergonic reaction abosrbs free energy from the surroundings. It has a positive change in G, being nonspontaneous

What are the three main kinds of cellular work

chemical work, transport work, mechanical work

How do cells obtain energy to do cellular work

energy coupling; the use of an exergonic process to drive an endergonic one

How does ATP perform cellular work

ATP forms cellular work by phosphorylation, or transferring a phosphate group to make molecules more reactive

How is ATP regenerized

Energy is released when the terminal phospophate bond is broken. The energy comes from the chemical change to a state of lower free energy in the products.

Where does ATP regeneration come from

ATP is regenerated by the addition of a phosphate group to adenosine diphosphate (ADP)

What is the energy released from ATP breakdown used for

Cellular functions; The ATP cycle couples energy-yielding porcesses to energy-consuming ones

What are the functions of enzymes in biological systems

What is a catabolic reaction

Breaks down larger molecules into smaller molecules; relases energy

What is an anabolic reaction

Builds larger molecules from smaller molecules; requires ATP

What is a catalyst

substance that speeds up the rate of a chemical reaction

Why is the investment of activation energy necessary to initiate a spontaneous reaction

Without the addition of energy, the reactions would occur too slowly to have an impact

How do molecules reach a transition state

The molecule must abosrbs energy from its surroundings. they become unstable when enough energy is absorbed

How is activation energy affected by enzymes

Enzymes lower the activation energy

How does enzyme structure determine enzyme specififty

The reactant that an anzyme acts on is called the enzyme's substrate. The enzyme binds to its substarte forming an enzyme-substrate complex. Each enzyme catalyzes a specific reaction and can recognize its specififc substrate among even closely related compounds

What is the induced-fit model of enzyme function

enzyme slightly changes shape to interact with substrate

How does temperature, pH, asmotic pressure, cofactors, and enzyme inhibitors affect enzyme activity

Changes in these will cause the enzyme/protein to denature and not be able to function how it is supposed to

What does the regulation of metabolic pathways rely on

Cells regulate metabolic pathways by switching on or off genes that encode for specific enzymes, or by regulating the activing of existing enzymes

What are cofactors

nonprotein enzyme helpers

What are coenzymes

organic cofactors

What is a competitive inhibitor

a molecule that competes with the substrate to bind in the active site of an enzyme.

What is a noncompetitive inhibitor

A molecule that binds to an allosteric site and prevents the proper functioning of an enzyme