exam 2 module 6 Energy of Life Flashcards
energy
a) potential energy(chemical energy)- stored energy available to do work.
1. energy bar
2. chemical bonds in sugar molecule
For example, a bicyclist at the top of a hill illustrates potential energy, as does the compression of a spring.
b) kinetic energy- the energy of motion. Any moving object contains kinetic energy.
1. light
2. sound waves
3. moving objects, such as molecules,
4. Contracting muscles
example- The bicyclist moving down the hill, Light and sound waves also have kinetic energy
energy
a) potential energy(chemical energy)- stored energy available to do work.
For example, a bicyclist at the top of a hill illustrates potential energy, as does the compression of a spring.
b) kinetic energy- the energy of motion. Any moving object contains kinetic energy.
example- The bicyclist moving down the hill, Light and sound waves also have kinetic energy
thermodynamics defintion
study of energy transformation.
thermodynamics
a) the first law of thermodynamics- law of energy conservation. It states that energy cannot be created or destroyed, just converted to one form or another.
b) the second law of thermodynamics- all energy transformations are inefficient because every reaction loses some energy as heat. (heat energy) is lost at each step. Heat energy is disordered, which means it cannot be used or converted back to a useful form of energy.
c) entropy- measure of the amount of disorder, or randomness, in a system. Every time energy is converted to one form or another, entropy increases. In general, the more disordered a system is, the higher its entropy.
metabolic reactions
a) endergonic reactions- requires the input of energy to proceed (end- or endo- means “put into”). The products of an endergonic reaction contain more energy than the reactants. Typically, endergonic reactions build up complex molecules from simpler components.
b) exergonic reactions-releases energy (ex- or exo- means “out of”). The products of an exergonic reaction contain less energy than the reactants. Such reactions break large, complex molecules into their smaller, simpler components.
ATP( energy “currency.”)
a) ATP structure (triphosphate, adenine, ribose)( its a PICTURE)
b) exergonic hydrolysis of ATP- adenosine diphosphate (ADP, in which only two phosphate groups are attached to ribose), the freed phosphate group, and a burst of energy.
c) Coupled reactions release and store energy in ATP- one reaction provides the energy that drives the other.
For example, ATP synthesis occurs when energy released from exergonic reactions is used to add a phosphate (P) to ADP (figure 4.9a). Cells also couple the hydrolysis of ATP to drive endergonic reactions. The energy released during ATP hydrolysis can be used to power endergonic reactions (figure 4.9b).
i) phosphorylating- A cell uses ATP as an energy source by phosphorylating (transferring a phosphate group to) another molecule
Adenosine triphosphate (ATP)
all cells use ATP in many chemical reactions to do different kinds of work.
Examples of jobs that require ATP include muscle contractions, transporting substances across the membrane, moving chromosomes during cell division, and synthesizing the large molecules that make up cells.
ATP short-term energy storage
Organisms require huge amounts of ATP. A typical human cell uses the equivalent of 2 billion ATP molecules a minute just to stay alive.
What are the main parts of an ATP molecule?
ATP is a nucleotide consisting or ribose, a nitrogenous base, and three phosphate groups.
How does ATP hydrolysis supply energy for cellular functions?
Hydrolysis of ATP breaks the unstable bonds between the second and third phosphate group, releasing energy. The reaction is coupled to cellular reactions that require energy input.
Describe the relationship among endergonic reactions, ATP hydrolysis, and cellular respiration.
the ATP that is produced in cellular respiration can undergo hydrolysis, releasing energy that can be used to drive endergonic reactions.
