Energy is
the capacity to do work
Potential Energy
The general term that describes energy stored in chemical bonds
entropy, energy
According to the second law of thermodynamics: The amount of ___ in living systems increases without the input of ___.
Transfer energy
Chemical reactions in a living system function to
Synthesis, energonic
The ___ of glycogen from many glucose molecules is an ___ reaction
Activation energy is
The energy required to bring molecules into a postion where they can interact
There are small changes in the net free energy from substrate to product
A reversible reaction is one where...
Isozymes
Are enzymes with slightly different structure that catalyze the same reaction
Lowering the activation energy of a reaction
Enzymes increase reaction rate by
There is no net change in the amount of substrates or products
When a chemical reaction is in equilibrium...
Coenzymes
Organic molecules that act as receptors/carriers for the cleaved portion of the substrate
Modulators
The activity of an enzyme is changed by environmental factors such as temperature or pH; these factors are referred to as
phosphorylation; kinase
The addition of a phosphate group to a substrate is called ___. The enzyme that catalyzes this reaction is referred to as a ___.
Addition, subtraction, and exchange reactions
Phosphate groups may be transferred from one molecule to another during
Denature
When an enzyme's activity is destroyed by heat or a change in pH
The active site
A competitive inhibitor binds to
A region of the enzyme other than the active site
An allosteric modulator binds to
Transferase
An enzyme that transfers chemical groups among substrates
Ligase
An enzyme that joins two substrates using energy
Hydrolase
An enzyme that adds or subtracts water molecules
Kinase
An enzyme that transfers phosphates from ATP to a substrate molecule
Oxidized
A molecule that loses electrons during a reaction
active sites of enzymes
The ___ are regions of an enzyme that are involved in bringing substrates together
Saturation
When an enzyme is working as fast as it can because its active site is continually refilled with substrate
Gain of electron
Results in a REDUCED molecule
End-product inhibition
The process whereby increasing amounts of product reduce activity of the enzyme
DNA
When energy is released during catabolism, it is temporarily trapped in high energy bonds or electrons of certain compounds. Which of the following is NOT associated with carrying energy?
ATP,
DNA,
NADH,
FADH2,
or NADPH
Compartmentation
Grouping related enzymes into specific organelles
Aerobic metabolism of glucose
Requires oxygen and produces more ATP per glucose than anaerobic pathways
Cytoplasm, mitochondria
The reactions of glycolysis occur in the cell's ___; the reactions of the citric acid cycle occur in the ___.
Oxygen
In the aerobic metabolism of glucose, ___ acts as the final electron acceptor.
The chemiosmotic theory
The explanation for how ATP bonds are actually formed during oxidative phosphorylation is
2.5
For each NADH molecule that moves through the electron transport system, what is the potential yield of ATP molecules?
1.5
What is the potential yield of ATP molecules for each FADH2 molecule entering the electron transport system?
The NADH molecules produced during glycolysis are in the cytoplasm; occasionally, electrons are carried by the lower energy FADH2 instead of NADH.
Why is there a range of 30-32 ATP molecules produced from one glucose molecule?
Glucose, amino acids, and fatty acids
Can serve as substrates for ATP production
Kinetic, ATP
ATP synthase transfers the ___ energy of the H+ ions to the high-energy phosphate bond of ___.
transamination
Removing an amine group from one molecule and binding it to a different molecule
Transcription
The process of forming mRNA is
tRNA
After forming a complex with the ribosome, mRNA interacts with a third molecule. This molecule is
Start, promoter region
The TAC sequence of DNA is the ___ of a coding sequence that is preceded by the ___ that regulates transcription.
Gene
All of the triplet codes needed to produce exactly one functional piece of RNA are found in one
Proteins
Information stored in the nucleus is translated into
Nucleus
Transcription occurs in the ___ of the cell
RNA polymerases
The enzymes that synthesize mRNA from the start codon
Induced, transcription factors
To activate a regulated gene, the formation of mRNA is ___ by the binding of ___ to the promoter
Intron, alternative splicing
Once synthesized, the ___ of mRNA are removed through ___, which results in the formation of the coding sequence of a protein.
Anticodon
The tRNA molecule contains the three-base sequence called the
Cytoplasm
In the absence of a signal sequence, a newly synthesized protein localizes to the
Ubiquitin
Following post-translational modification, any misfolded protein will be destroyed by
Ligase
Representative Enzyme for Synthetase
Oxidoreductase
Representative Enzyme for Dehydrogenase
Hydrolase
Representative Enzyme for Dehydratase
Hydrolase
Representative Enzyme for Lipase
Transferase
Representative Enzyme for Kinase
Lyase
Representative Enzyme for Aminase
Lyase
Representative Enzyme for Deaminase
Potential
A molecule positioned on the high-concentration side of a concentration gradient stores ___ energy.
Reversible reaction
A chemical reaction that can proceed in both directions
Endergonic
Chemical reactions that require an input of energy are said to be ___.
Covalent
Metabolic intermediates use ___ bonds to transfer energy to the high-energy bonds of ATP, NADH, FADH2, or NADPH
Enzymes
The rates of chemical reactions that occur in the human body are controlled by a particular type of protein called ___.
Key intermediate
A certain molecule that participates in more than one biochemical pathway and acts as a branch point for channeling substrate in one direction or another is called a ___.
Reaction rate
___ describes how much product is generated or substrate destroyed within a period of time.
Oxygen
The availability of ___ determines if pyruvate continues into the citric acid cycle.
Glucose-6-phosphate, ATP
Glucose is phosphorylated to ___ with a phosphate from ___.
ATP to ADP
The activity of metabolic pathways is influenced by the ratio of ___.
Phosphorylation
In the process of ___ a phosphate group is attached to a molecule.
NADH, mitochondria
___ generated in the ___ enter the electron transport system to generate 2.5 ATP molecules.
Potential energy, intermembrane space
Energy released by electrons moving through the electron transport system is stored as ___ by H+ ions concentrated in the ___.
Inner mitochondrial membrane, cytochromes
The electron transport system is located in the ___ and includes enzymes and iron-containing proteins known as ___ .
Anticodon
During the synthesis of proteins, amino acids are assembled in the proper sequence because the tRNA molecules that bring them to the ribosomes have an ___ that is complementary to a specific codon in the mRNA.
Transcription; nucleus, translation
mRNA is created in a process called ___. It then leaves the ___ and enters the cytosol to direct ___, the assembly of amino acids into protein.
tRNA
Amino acids are carried to the ribosomes to be incorporated into polypeptide chains by ___.
RNA polymerase, magnesium
The enzyme ___ and ___ ions are required for the synthesis of mRNA.
mRNA
A molecule of ___ consists of all the codons needed to produce a specific polypeptide chain at the ribosome.
rRNA
Ribosomes are composed of protein and ___.
Single
RNA is usually ___ stranded.
Small interfering, micro
Two types of RNA block translation of mRNA. They are ___ RNA and ___ RNA.
Constitutively active
Genes that are always being expressed in a cell involve promoters that are ___.
Promoter, induce, repress
Transcription factors are proteins whose binding to the ___ region for a gene can ___ (increase) or ___ (decrease) expression of that gene.
Exon
The ___ is the portion of the mRNA that contains the coding sequence of the gene.
Dehydration synthesis
The peptide bond formed between amino acids occurs as a consequence of ____.
Molecular chaperones
Proteins folding can take place spontaneously or with ___.
Exergonic chemical reaction
Releases energy as the reaction progresses.
The enzyme would not be able to function
How would the lack of a required cofactor for an enzyme affect that enzyme's function?
Damaged cells release enzymes into the blood that can be detected
Enzymes are often useful as diagnostic tools how?
Adding more substrate molecules
The rate of product formation by an enzyme-catalyzed reaction would be increased by
Either increase or decrease depending upon enzyme properties
Changes in environmental pH or temperature will cause the reaction rate for an enzyme to
Changing the concentration of an enzyme
Cells normally regulate the rate of an enzymatic reaction by
Ribonuclease activity and siRNA concentration
Increasing ___ will decrease the amount of mRNA transcript within a cell for a constitutively active gene
Accumulate inside the cell
In order to slow generation of product from a particular biochemical pathway within a cell, the intermediates formed by that pathway...
Pyruvate
What is a key intermediate of glucose catabolism to the citric acid cycle?
2 ATP and 0 NADH
The net energy yield for the anaerobic metabolism of one glucose molecule is
Requires the vitamin pantothenic acid for its conversion to acetyl CoA
Inside the matrix of the mitochondria, pyruvate...
During anaerobic glycolysis
NADH is produced from each reaction described except one. Identify the exception:
During aerobic glycolysis,
During the conversion of pyruvate to acetyl CoA,
During the citric acid cycle,
or During anaerobic glycolysis
In the mitochondria due to the electron transport system, ATP
Oxidative phosphorylation occurs ___; the beneficial end product is ___.
ATP synthase
The protein in the mitochondria that captures the kinetic energy of moving H+ ions and converts it to the stored energy of ATP is called ____.
The oxygen is combined with hydrogen to form water
What happens to the oxygen that is metabolized within the mitochondria?
Isoenzymes are produced from a single gene.
What is the result of alternative splicing of mRNA?
UAG
Transcription of the DNA triplet sequence ATC yields ___.
GUA
Transcription of the DNA triplet sequence CAT will bind to the tRNA bearing ___.
Serves as a guide for mRNA synthesis
The template strand of DNA...
Inducers
During starvation, steroid hormones trigger the transcription of genes for lipid metabolism in their target cells. This would be an example of control by ___.
Form proteins
If the enzyme RNA polymerase was completely inhibited within a cell, it could not...
DNA, promoter, where to bind to the DNA
Regulatory-protein transcription factors bind to ___ and activate ___, which tells the RNA polymerase ___.
Coenzymes
Vitamins are precursors for ___.
Properties of Living organisms
Acquire, transform, store, and use energy.
Sense and respond to internal and external environments.
Maintain Homeostasis.
Store, use, and transmit information.
Reproduce, develop, grow, and die.
Chemical work
making and breaking chemical bonds
Transport work
useful for creating concentration gradients, moving ions, molecules, and larger particles
Mechanical work
moving organelles, changing shape, beating flagella and cilia, and contracting muscles
Exergonic Reaction
ATP + H20 --> ADP + Pi + H+ + Energy
Endergonic Reaction
Glucose --> Glycogen
Activation Energy
Coupled reactions acquire...