Energy and Metabolism (Chapter 6) Flashcards
The significant properties by which we define life are
Order, growth, reproduction, responsiveness, and internal regulation.
The significant properties by which we define life requires a constant supply of
energy
bioenergetics
the analysis of how energy powers the activities of living systems.
1.What is Thermodynamics? 2.What does the term mean?
- A branch of chemistry concerned with energy changes. 2. “Heat changes”
The study of transformations of energy, using heat as the most convenient form of measurement of energy.
Thermodynamics.
Energy
The capacity to do work.
Energy exists in two states, which are:
1) Kinetic energy 2) potential energy
Kinetic energy
energy in motion
potential energy
stored energy; energy that is not being used, but could be.
Objects that are not actively moving but have the capacity to do so possess what form of energy?
potential energy Example: A boulder at a hilltop; or a child sitting at the top of a slide
Stored potential energy is released as what form of energy?
Kinetic Energy Ex: Child going down a slide.
Name 6 forms of energy
mechanical heat sound electric light radioactive
What form of energy is the most convenient way of measuring energy?
Heat
Unit of heat most commonly employed in biology
kilocalorie (kcal)
1 kilocalorie =
1000 calories
1 calorie =
the amount of heat required to raise the temperature of water one degree Celsius.
1 joule =
0.239 calories
What provides energy for living systems?
the sun
Energy flows into the biological world from t
the sun
Plants, algae, and certain bacteria capture energy through
photosynthesis
What occurs in photosynthesis?
- Energy is absorbed form sunlight. 2. Energy absorbed is used to combine small molecules (water + carbon dioxide) 3. Carbon is converted from inorganic to organic form. 4. Energy from sunlight is stored as potential energy in the covalent bonds between atoms in sugar molecules.
Breaking bonds between atoms requires
energy
During a chemical reaction, the energy stored in chemical bonds can be used to make what?
new bonds
When is an atom or molecule said to be oxidized?
when electrons are lost
Oxidation (process)
Loss of an electron by an atom or molecule.
What is the most common electron acceptor in biological systems?
Oxygen
When is an atom or molecule said to be reduced?
when electrons are gained
Reduction (process)
gain of electrons by an atom or molecule
What form of a molecule has the higher level of energy, the reduced form or the oxidized form?
reduced form
Oxidation-reduction, or redox reaction
A type of paired reaction in living systems in which electrons are lost (oxidation) by one atom and gained by another atom (reduction) ** oxidation and reduction always take place together.
True or False All activities of organisms– growing, running, thinking, singing, reading, involves changes in energy.
true
The first law of thermodynamics states that
The total amount of energy in the universe remains constant; as energy cannot be created or destroyed, it can only change from one form to another (potential to kinetic).
What is heat? Heat is a form of what type of energy?
- A measure of the random motion of molecules, the greater the heat the greater the motion. 2. Kinetic energy
During the conversion of chemical potential energy stored in some molecules, some of the energy dissipates into the environment as
heat
Heat can be harnessed to do work only when there is a
heat gradient; that is, a temperature difference between two areas.
Is heat energy capable of doing the work of cells?
no; cells are to small to maintain significant internal temperature differences.
What type of reaction do cells rely on for energy?
chemical reaction
Second Law of Thermodynamics states that
disorder in the universe, aka entropy is continuously increasing in the universe as energy changes occur … so disorder is more likely than order.