Metabolism: Energy, Thermodynamics, ATP, Electron Carriers, Enzymes, and Regulation

A set of fill-in-the-blank flashcards covering key concepts from metabolism, energy units, thermodynamics, ATP, electron carriers, enzymes, and their regulation.

The SI unit of energy is __.

Joule (J)

One calorie equals approximately __ joules.

4.184

In nutrition, the unit kcal stands for the __.

kilocalorie

One joule is equal to approximately __ cal.

0.239

Energy associated with position is __ energy.

potential

Energy associated with motion is __ energy.

kinetic

Energy stored in chemical bonds is __ energy.

chemical

The 1st Law of Thermodynamics states that energy cannot be .

created or destroyed

The measure of disorder is called __.

entropy

Free energy is denoted by the symbol __.

G

H = G + TS expresses enthalpy equals free energy plus __.

TS (temperature × entropy)

G = H − TS expresses free energy equals enthalpy minus __.

TS (temperature × entropy)

The change in free energy for a reaction is __.

ΔG = Gfinal − Ginitial

An exergonic reaction has ΔG < 0 and is __.

exergonic (spontaneous)

An endergonic reaction requires energy and is __.

endergonic (non-spontaneous)

Metabolism is the sum of all chemical reactions that take place in a __.

organism

A metabolic pathway is a series of interconnected biochemical reactions occurring within a __.

cell

Catabolism is the process of breaking down molecules to release energy; its ΔG is __.

negative

Anabolism is building up molecules and is __ (requires energy).

endergonic

In redox reactions, the species that donates electrons is the __ agent.

reducing

In redox reactions, the species that accepts electrons is the __ agent.

oxidizing

The oxidized form of NAD is __.

NAD+

The reduced form of NADP+ is __.

NADPH

The reduced form of FAD is __.

FADH2

ATP is the energy __ of the cell.

currency

Hydrolysis of ATP yields ADP + Pi + __.

energy

ATP is composed of adenine, ribose, and three __.

phosphate groups

The steps in the ATP cycle are ATP hydrolysis, energy coupling, and regeneration of __.

ATP

One type of work powered by ATP is __ work.

mechanical

The release of Pi and ADP causes a conformational change in motor proteins called the __ (power stroke).

power stroke

Transport work is powered by ATP to drive __ transport.

active

Chemical work involves biosynthesis of macromolecules such as proteins and __.

nucleic acids

In cellular respiration, energy from catabolism is used to regenerate __ from ADP and Pi.

ATP

NAD+, NADP+, and FAD are examples of __ carriers.

electron

The oxidized form of NAD+ is __.

NAD+

The reduced form of NADP+ is __.

NADPH

The reduced form of FAD is __.

FADH2

An enzyme is a biological __ that speeds up chemical reactions without being consumed.

catalyst

The region of the enzyme where the substrate binds is the __.

active site

The process by which the enzyme lowers the activation energy is called __.

catalysis