BIO Flashcards
defined as the ability to do work or bring about a change, allowing organisms to carry out different life processes, including growth, development, metabolism, and reproduction
Energy
energy of motion
Kinetic energy
- is a stored energy whose capacity to accomplish work is not being used at the moment.
- is in the form of chemical energy stored in the chemical bonds of biomolecules.
potential energy
First law of thermodynamics
law of conservation of energy
energy cannot be created nor destroyed, but it can be changed from one form to another.
first law of thermodynamics
it states that energy cannot be changed from one form to another without a loss of usable energy. When cells oxidize food molecules to drive chemical reactions, heat is also released into the surroundings
second law of thermodynamics
- used to indicate the relative amount of disorganization.
- measures randomness
entropy
the common energy currency of cells
Adenosine triphosphate or ATP
ATP is synthesized through three mechanisms:
- substrate-level phosphorylation
- oxidative phosphorylation
- photophosphorylation.
Adenosine triphosphate is a nucleotide composed of
- nitrogen-containing base adenine
- five-carbon sugar ribose
- three phosphate groups.
begin with reactants whose covalent bonds contain more potential energy than those in products. The reaction releases to the surroundings an amount of energy equal to the difference in potential energy between the reactants and the products. An example of this is the oxidation of glucose molecules to release energy.
Exergonic reactions
requires net input of energy and yield products that are rich in potential energy. An endergonic reaction starts with reactants that contain relatively little potential energy. Energy is absorbed from the surroundings as the reaction occurs, so the products of an endergonic reaction contain more chemical energy than the reactants did. A biological example of an endothermic reaction is photosynthesis.
Endergonic reactions
it is composed of organic molecules such as carbohydrates, proteins, and fat, which can be broken down to liberate energy.
chemical energy
When a person walks, he or she converts chemical energy into
mechanical energy
type of kinetic energy associated with the random movement of atoms or molecules.
thermal energy
The thermal energy that is transferred from one object to another is called
heat
Forms of energy
- Mechanical
- Chemical
- Kinetic
- Potential
- Thermal
a portion of the solar energy absorbed by the plant becomes heat when glucose is utilized during
respiration
the process in which cells obtain energy by breaking down food molecules
respiration
TRUE or FALSE: The more disordered a system is, the higher is its
entropy
TRUE
TRUE or FALSE: Some cells can make glucose out of carbon dioxide and water, and all cells can actively move ions to one side of the membrane.
TRUE
TRUE or FALSE: the entropy of the universe as a whole, including that of the sun itself, is continuously decreasing.
FALSE, it’s continuously increasing
TRUE or FALSE: The more active an organism is, the greater is its demand for ATP molecules.
TRUE
TRUE or FALSE: Only 45% of all the free energy stored in the bonds of glucose is
transformed into ATP; the rest is lost as heat.
FALSE, 39% only
The energy released from … is used to drive biochemical functions.
ATP
What’s the charge of the three phosphate groups?
negative
the bonds connecting the phosphate groups can readily be broken by
hydrolysis
phosphate transfer is called
phosphorylation
hydrolysis is what kind of reaction
exergonic reaction
two ways to synthesize ATP
- Kinase
- ATP Synthase
mediated by a group of enzymes
Kinases
is the process of producing ATP by combining ADP and a phosphate group from a phosphorylated molecule instead of an inorganic phosphate.
Substrate-level phosphorylation
is an ATP synthesizing mechanism that utilizes the energy derived from the transfer of electrons in an electron transport system to combine ADP and inorganic phosphate
Oxidative phosphorylation
The third mechanism of ATP synthesis is found only in
photosynthetic cells
- is a process that is similar
to oxidative phosphorylation in several ways - driven by the proton motive force generated during the flow of electrons in the light reaction stage.
photophosphorylation
oxidative phosphorylation, the energy comes from electrons produced by the
oxidation of biological molecules
The protons flow through the
ATP synthase enzyme complex
Cells have two major ways to couple ATP hydrolysis to an energy-requiring reaction—ATP is used to
- energize a reactant
- change the shape of a reactant
TRUE or FALSE: The negatively charged phosphate causes the protein to undergo a change in shape that allows it to interact with and move the ion across the membrane.
TRUE
are energy-releasing processes where the reactants have greater energy than the products.
Exergonic reactions
are energy-releasing processes where the reactants
have less energy than the products
Endergonic reactions
ATP functions as an
energy carrier
When a phosphate group is transferred from ATP to another molecule, energy is transferred along with the phosphate through a process called
phosphorylation
has only two phosphate groups
adenosine diphosphate or ADP
is the portion that provides energy for cellular work.
triphosphate tail of ATP
ATP energizes other molecules in cells by transferring phosphate groups to those molecules. This transfer of phosphate groups helps cells perform
mechanical, transport, and
chemical functions
TRUE or FALSE: The cells of our body spend energy continuously, and cells are lucky to evolve with ATP,
which is considered to be a renewable resource.
TRUE
TRUE or FALSE: Adenosine diphosphate is more stable and has lower potential energy than ATP
TRUE
are a mechanism of cells to utilize the energy released from ATP hydrolysis to drive other processes.
coupled reactions
endergonic; the energy requirement is represented by a
positive Gibbs free energy
exergonic; the energy requirement is represented by a
negative Gibbs free energy
a German chemist, discovered the adenosine triphosphate.
Karl Lohmann
chemically synthesized the
ATP
Alexander Todd
showed that ATP is a bearer of chemical energy in the cell
Fritz Lipmann
