Energy
The capacity to do work
Chemical work
Making and breaking of chemical bonds; it enables cells and organisms to grow, maintain a suitable internal environment, and store information needed for reproduction and other activities
Transport work
This enables cells to move ions, molecules, and larger particles through the cell membrane and through the membranes of organelles in the cell
Concentration gradient
A difference in the concentration of a substance between two places
Mechanical work
Used for movement; at the cellular level, movement includes organelles moving around in a cell, cells changing shape, and cilia and flagella beating. Most mechanical work is mediated by motor proteins that make up certain intracellular fibers and filament
Kinetic energy
The energy of motion
Potential energy
Stored energy that has the ability to do work
First law of thermodynamics
The total amount of energy in the universe is constant
Second law of thermodynamics
Natural spontaneous processes move from a state of order (nonrandomness) to a condition of randomness or disorder
Entropy
A condition of randomness or disorder
Bioenergetics
The study of energy flow through biological systems
Chemical reaction
A substance undergoes a chemical change to become a different substance by breaking existent covalent bonds or making new bonds
Reactants
A reaction begins with one or more molecules
Products
A reaction ends with one or more molecules
Reaction rate
The speed with which a reaction takes place
Free energy
The potential energy stored in the chemical bonds of a molecule
Activation energy
a. The energy required to initiate a reaction and b. The initial input of energy required to bring reactants into a position that allows them to react with one another
Exergonic reaction
Chemical reaction that releases energy
Endergonic reaction
A reaction that requires a net input of energy from an outside source
Reversible reaction
A chemical reaction that can proceed in both directions
Irreversible reaction
If a chemical reaction proceeds in one direction but not the other
Isozymes
Related forms of a single enzyme
Electrophoresis
A technique used to determine which enzymes are present in a tissue sample
Coenzymes
Organic cofactors for enzymes; they do not alter the enzyme's binding site as inorganic cofactors do
Vitamin
Nutrient needed in small amounts to serve as a cofactor or coenzyme
Phosphorylation
Addition of a phosphate group to a molecule
Oxidation-reduction reaction
Involves the transfer of electrons or proton (H+) between chemicals
Dehydration reaction
Reaction in which two molecules combine into one, losing water in the process
Hydrolysis reaction
Reaction in which large molecules are broken into smaller ones by addition of water
Addition reaction
Reaction in which a functional group is added to one or more of the substrates
Subtraction reaction
Reaction in which a functional group is removed from one or more of the substrates
Exchange reaction
Reaction in which functional groups are exchanged between or among substrates
Kinase
An enzyme that adds a phosphate group to the substrate
Deamination
Removal of an amino group from a molecule
Amination
Addition of an amino group to a molecule
Transamination
Transfer of an amino group from one molecule to another
Metabolism
All the chemical reactions in the body
Catabolism
Reactions that release energy and result in the breakdown of large biomolecules
Anabolism
Metabolic pathways that require a net input of energy and that synthesize small molecules into larger ones
Kilocalorie
Amount of energy needed to raise the temperature of 1 liter of water by 1 degree C
Feedback inhibition
The end product of a metabolic pathway acts as an inhibitory modulator of the pathway
Glycolysis
Metabolic pathway that converts glucose to pyruvate (aerobic) or lactic acid (anaerobic)
Citric acid cycle
Key metabolic pathway of aerobic respiration
Gene
A region of DNA that contains all the information needed to make a functional piece of mRNA
Transcription
Transfer of information coded in DNA into mRNA
tRNA
Serves as the physical link between mRNA and the amino acid sequence of proteins; tRNA carried an amino acid to the ribosome as directed by the codon in the mRNA
Translation
The assembly of amino acids into a protein chain from mRNA
Transcription factors
Regulatory proteins that bind to DNA and alter gene expression
Alternative splicing
The processing of mRNA to make different proteins from a single strand of DNA
Anticodon
The tRNA base triplet that pairs with the mRNA codon for an amino acid
Signal sequence
Initial segment of a newly-made protein that directs the protein to the proper organelle for processing, packaging, and delivery
Endergonic reaction
Exergonic reaction
Enzymes
increase rate of chemical reactions
Anaerobic metabolism
C6H12O6--> 2C3H5O3- + 2H+
0 NADH
anaerobic metabolism
2 ATP
anaerobic metabolsm
Glycolysis
1 Glucose to 2 Pyruvate
Aerobic metabolism
C6H12O6 + 6O2 --> 6 CO2 + 6H2O
2 NADH
Glycolysis
2 ATP
Glycolysis
6 NADH
Citric acid cycle
2 FADH2
citric acid cycle
2 ATP
citric acid cycle
4 CO2
citric acid cycle
NADH, FADH2, and O2
electron transport chain uses 6 ___, 2 ___, and 6 ___.
26-28 ATP
electron transport chain
6 H2O
aerobic metabolism
30-32 ATP
aerobic metabolism
6 CO2
aerobic metabolism
Adenosine triphosphate (ATP)
nucleotide containing three high-energy phosphate bonds that can provide energy to do work
Nicotinamide adenine dinucleotide (NAD+)
a coenzyme that picks up high energy electrons and shuttles them to the electron transport chain
Pyruvate
end product of anaerobic breakdown of glucose
Acetyl CoA
a derivative of pyruvate combines with a coenzyme, required to begin the citric acid cycle
Electron transport chain
a series of mitochondrial proteins that transfer electron energy to ATP and require oxygen
Citric acid cycle
a series of enzymatic reactions that begins with the input of 2 carbon units that occurs in the mitochondrion of a cell
Catabolic
One pathway that produced ATP starts with glucose. When glucose enters a cell, it is broken down via successive steps. Along the way, some ATP is produced directly. With regard to the breakdown of glucose, this is is an example of ___ pathways.