Energy, Cellular Respiration, and Homeostasis Review

A comprehensive set of practice questions covering energy laws, cellular respiration pathways, redox reactions, and homeostatic thermoregulation mechanisms.

What is the difference between potential energy and kinetic energy?

Potential energy is stored energy due to position or structure, while kinetic energy is the energy associated with objects in motion.

What are the two laws of thermodynamics?

The First Law states that energy cannot be created or destroyed, only transformed; the Second Law states that every energy transfer increases the entropy of the universe.

How do exergonic and endergonic reactions differ?

Exergonic reactions release energy and occur spontaneously, while endergonic reactions require an input of energy to proceed.

Is cellular respiration considered an exergonic or endergonic process?

Cellular respiration is considered an exergonic process because it releases energy from the breakdown of glucose.

What are $ATP$ and $ADP$, and what is their relationship?

$ATP$ (Adenosine Triphosphate) is the primary energy currency of the cell; when it loses a phosphate group to release energy, it becomes $ADP$ (Adenosine Diphosphate).

Definition of Phosphorylation

The process of adding a phosphate group to a molecule, often used to store energy or activate proteins.

What is the difference between oxidation and reduction?

Oxidation is the loss of electrons from a substance, while reduction is the addition of electrons to a substance.

What are Redox reactions?

Chemical reactions that involve the transfer of electrons between two species, consisting of both an oxidation and a reduction component.

What is the role of electron carriers like $NAD^+$ and $FADH$?

They act as coenzymes that pick up electrons during the early stages of cellular respiration and transport them to the electron transport chain.

What are the primary steps of cellular respiration?

The steps include Glycolysis, the Krebs cycle (Citric Acid Cycle), and the electron transport chain.

What is the function of the electron transport chain?

To use high-energy electrons from carriers to create a proton gradient that powers the synthesis of $ATP$.

What is chemiosmosis?

The process in which the movement of protons down their electrochemical gradient across a membrane is used to drive cellular work, such as the synthesis of $ATP$.

What is the final electron acceptor at the end of the electron transport chain?

Oxygen ($O_2$) is the final electron acceptor.

Which pathways of cellular respiration are aerobic and which are anaerobic?

The Krebs cycle and electron transport chain are aerobic (require oxygen), while Glycolysis can function in anaerobic conditions; fermentation is an anaerobic pathway.

What is fermentation and what are its two main types?

Fermentation is an anaerobic process for breaking down glucose; the two types are lactic acid fermentation and alcoholic fermentation.

What is the difference between regulators and conformers in the context of homeostasis?

Regulators use internal mechanisms to control internal change in the face of external fluctuation, while conformers allow their internal condition to change in accordance with external changes.

Define endothermic and ectothermic thermoregulatory strategies.

Endothermic animals generate heat by metabolism to maintain body temperature, whereas ectothermic animals gain heat from external sources.

Define poikilothermic and homeothermic strategies.

Poikilothermic animals have body temperatures that vary with the environment, while homeothermic animals maintain a relatively constant body temperature.

How does a negative feedback loop maintain homeostasis?

It works by detecting a change in a variable (like body temperature or blood glucose) and triggering a response that counteracts that change to return the system to its set point.

What are the four types of heat gain or loss?

Conduction, convection, radiation, and evaporation.

What is the process of counter-current heat exchange?

A mechanism where heat is transferred between fluids flowing in opposite directions (such as blood in adjacent arteries and veins) to reduce heat loss to the environment.