Test 2

The branch of chemistry concerned with energy changes

The capacity to do work

Energy of motion

Stored energy

An atom or molecule that loses an electron

An atom or molecule that gains an electron is said to be reduced

Play a key role in the flow of energy through biological systems; always take place together, because every electron that is lost by one atom is gained by another atom

Concerns the amount of energy in the universe

A measure of the random motion of molecules (and therefore a measure of one form of kinetic energy)

Concerns the transformation of potential energy into hear, or random molecular motion

The disorder in the universe

Amount of energy actually available to break and subsequently form other chemical bonds; the energy available to do work in any system

Energy contained in a molecule's chemical bonds

Any reaction that requires an input of energy

Reactions release the excess free energy as heat; "outward energy"

Numeric value of the equilibrium

The extra energy needed to destabilize existing chemical bonds and initiate a chemical reaction

The process of influencing chemical bonds in a way that lowers the activation energy needed to initiate a reaction

The chief "currency" all cells use for their energy transactions is the nucleotide ___________________________.

In most reactions involving ATP, only the outermost high-energy phosphate bond is hydrolyzed, cleaving off the phosphate group on the end

Can be created by hydrolysis of pyrophosphate

Both of the two terminal phosphates can be hydrolyzed to release energy

The molecules that will undergo the reaction

Vertebrate red blood cells overcome this problem by employing an enzyme within their cytoplasm

Most enzymes are globular proteins with one or more pockets or clefs

Substrates bind to the enzyme at these active sites

A way that enzymes form associations by carrying out reaction sequences; Often several enzymes catalyzing different steps of a sequence of reactions are associated with one another in noncovalently bonded assemblies

Some ribozymes have folded structures and catalyze reactions on themselves

Ribozymes act on other molecules without being changed themselves

The rate of an enzyme-catalyzed reaction also increases with temperature, but only up to a point

A substance that binds to an enzyme and decreases its activity

The end product of a biochemical pathway acts as an inhibitor of an early reaction in the pathway

Compete with the substrate for the same active state occupying the active site and thus preventing substrates from binding

Many enzymes can exist in either an active or inactive conformation

Bind to the enzyme in a location other than the active site, changing the shape of the enzyme and making it unable to bind to the substrate

Most noncompetitive inhibitors bind to a specific portion of the enzyme

A substance that binds to an allosteric site and reduces enzyme activity

Binds to allosteric sites to keep an enzyme in it's active configuration, thereby increasing enzyme activity

Enzyme function is often assisted by additional chemical components

When the cofactor is a nonprotein organic molecule

Living chemistry, the total of all chemical reactions carried out by an organism

Chemical reactions that expend energy to build up molecules

Reactions that harvest energy by breaking down molecules

Reactions in a cell occur in sequences

A form of photosynthesis that does not produce oxygen; Found in four different bacterial groups: purple bacteria, green sulfur bacteria, green nonsulfer bacteria, and heliobacteria

A form of photosynthesis that does produce oxygen; Found in cyanobacteria, seven groups of algae, and essentially all land plants

The first two stages of photosynthesis require light and are commonly called:

The third state, the formation of organic molecules from CO₂; takes place via a cyclic series of reactions

As long as ATP and NADPH are available, the carbon fixation reactions can occur either in the presence or in the absence of light. These reactions are called ________________________.

The internal membrane of chloroplasts; A continuous phospholipid bilayer organized into flattened sacs that are found stacked on one another in columns

Flattened sacs that are found stacked on one another in columns

Photosynthetic pigments for capturing light energy along with the machinery to make ATP

Connections between grana are _______________.

A semiliquid substance that surrounds the thylakoid membrane system

In the thylakoid membrane, photosynthetic pigments are clustered together to form ___________________, which show distinct organization within the thylakoid

H⁺ ions and electrons generated by the splitting of water were used to convert CO₂ into organic matter in a process called __________________.

Molecules that absorb light energy in the visible range

A particle of light; acts like a discrete bundle of energy

A beam of light is able to remove electrons from certain molecules, creating an electrical current; Occurs when photons transfer energy to electrons

The range and efficiency of photons it is capable of absorbing

The main photosynthetic pigment in plants and cyanobacteria and the only pigment that can act directly to convert light energy to chemical energy

Complements and adds to the light absorption of chlorophyll a

Secondary light-absorbing pigments

Pigments contain a complex ring structure with alternating single and double bonds

The relative effectiveness of different wavelengths of light in promoting photosynthesis

Consist of carbon rings linked to chains with alternating single and double bonds

Accessory pigments found in cyanobacteria and some algae; composed of proteins attached to a tetrapyrrole group

a light-harvesting complex; captures photons from sunlight and channels than to the reaction center chlorophylls

A transmembrane protein-pigment complex

A photon of light is captured by a pigment; Excites an electron within the pigment

The excitation energy is transferred to the reaction center which transfers an energetic electron to an acceptor molecule, initiating electron transport

The excited electrons are shuttled along a series of electron carrier molecules embedded within the photosynthetic membrane

The protons that accumulate on one side of the membrane now flow back across the membrane through ATP synthase where chemiosmotic synthesis of ATP takes place, just as it does in aerobic respiration

An absorption peak of 700 nm, so its reaction center pigment is called P₇₀₀₊

Has an absorption peak of 680 nm, so its reaction center pigment is called P₆₀₀₊

Two photosystems are connected by a complex of electron carriers

The path of electrons is not a circle--the electrons ejected from the photosystems do not return to them, but rather end up in NADPH

Can by explained a mechanism involving two photosystem absorbs preferentially in the red, the other in the far-red

Illustrates the two electron-energizing steps, one catalyzed by each photosystem

The primary electron acceptor for the light-energized electrons leaving photosystem II

The reduced quinone passes the excited electron pair to a proton pump called

A small, copper-containing protein that carries the electron pair to photosystem I

Electrons are passed to an iron-sulfur protein

The cycle of reactions that allow carbon fixation

Because the first intermediate of the cycle, phosphoglycerate, contains three carbon atoms this process is called

Energy-rich 5-carbon sugar

A large, 16-subunit enzyme found in the chloroplast stroma

O₂ is incorporated into RuBP, which undergoes additional reactions that actually release CO₂

Plants that fix carbon using only C₃ photosynthesis

The capture of CO₂ occurs in one cell and the decarboxylation occurs in an adjacent cell

Perform both reactions in the same cell, but capture CO₂ using PEP carboxylase at night, then decarboxylase during the day

Plants, algae, and some bacteria harvest the energy of sunlight through photosynthesis, converting radient energy into chemical energy. These organisms, along with a few others that use chemical energy in a similar way, are called _____________.

All other organisms live on the organic compounds autotrophs produce, using them as food.

Where energy is harvested; the oxidation of organic compounds to extract energy from chemical bonds.

The electrons lost are accompanied by protons, so that what is really lost is a hydrogen atom, nut just an electron

An enzyme catalyzes a redox reaction involving an energy-rich substrate molecule, with the help of a cofactor, ___________.

High-energy electrons from the initial chemical bonds have lost much of their energy, and these depleted electrons are transferred to a final electron acceptor. When this acceptor is oxygen, the process is called _________________.

High-energy electrons from the initial chemical bonds have lost much of their energy, and these depleted electrons are transferred to a final electron acceptor. When the acceptor is an inorganic molecule other than oxygen, the process is called ________________.

High-energy electrons from the initial chemical bonds have lost much of their energy, and these depleted electrons are transferred to a final electron acceptor. When the acceptor is an organic molecule, the process is called _______________.

Located in the mitochondrial inner membrane; electrons are passed to another set of electron carriers

The initial breakdown of glucose

Protein kinases that are regulated by cyclin binding and its phosphorylation state

The phase in which the cell synthesizes a replica of it's genome

The normal number of chromosomes in a cell reflecting the equal contribution from both parents

The overall process of genome duplication, segregation, and division of cellular contents

A dislike structure that functions as an attachment site for microtubules to separate chromatids

The two replicas of a single chromosome held together at their centromeres by cohesion proteins

The protein that forms microtubules, which cells extensively synthesize in G₂

The region on the chromosome where two sister chromatids are held together and the kinetochore forms

The phase in the cell cycle during which mitochondria and other organelles replicate

The phase in mitosis when chromosomes are clustered at opposite poles and the spindle apparatus disappears

A resting state that cells often enter before resuming cell division

The first stage of mitosis in which the chromosomes condense and the spindle apparatus is assembled

A domain of chromatin in which the genes are being actively expressed

The phase in the cell cycle when the cytoplasm divides creating two daughter cells

The mitotic phase in which chromosomes are pulled to opposite poles and the spindle poles move apart

A radial array of microtubules extended from the centrioles toward the nearby plasma membrane

The complex of DNA wrapped around histone proteins that look like beads on a string

A pair of microtubule-organizing centers replicated in G₂ to produce one for each pole of the cell

The particular array of chromosomes an individual organism possesses

The mitotic phase in which all of the chromosomes are aligned at the equator of the cell

The phase in the cell cycle in which the spindle apparatus assembles and sister chromatids move apart

The process used by bacteria to duplicate genetic information and segregate it into two daughter cells

A domain of chromatin in which the genes are not actively expressed

One complete set of chromosomes necessary to define an organism

The portion of the cell cycle between cell divisions consisting of G_1, S, G₂ together

Mutations in these genes have dominate, gain-of-function effects leading to cancer

The space between the daughter cells in plants that is filled with pectins

When both copies of this type of gene lose function, there is a loss of control of cell proliferation

Trigger intracellular signaling systems and can override cellular controls that inhibit cell division

Genes that can, when introduced into a cell, cause it to become a cancer cell

An expanding membrane portion in plants that grows outward and fuses with the plasma membrane

Marks the securing protein for degradation by the proteosome

A division formed at the midpoint of a bacterial call facilitated by the FtsZ protein assembling there

Regulatory proteins that are required to activate Cdks

Composed of both cyclin and a kinase and acts as a positive regulator of cell cycle progression in frogs

Each of the maternal and paternal copies of the came chromosome in a pair

Proteins that have an overall positive charge that promote and guide the coiling of DNA

The primary growth phase of the cell encompassing the major portion of the cell cycle

The cells that will eventually undergo meiosis to produce gametes

Sites of contact between homologous chromosomes that are produced as a result of crossing over

The number of chromosomes found in gametes (eggs or sperm)

Gametes that contain an improper number of chromosomes and can lead to spontaneous abortion

The failure of chromosomes to move to opposite poles in either meiotic division

The different possible combinations of maternal and paternal chromosomes in gametes

An elaborate structure consisting of homologues closely paired with a lattice of proteins between them

Structures thought to contain the enzymatic machinery necessary to break and rejoin chromatids

The process by which two haploid gametes fuse to form a new diploid cell

Phase of meiosis in which homologous chromosomes align and kinetochore microtubules attach to each

Segregate to opposite poles during the meiosis II to produce four haploid cells

A specialized reduction division that produces cells with half the normal number of chromosomes

Division, beginning without DNA replication, that resembles mitosis and produces four haploid cells

A process unique to meiosis in which homologues exchange chromosomal material

The nonreproductive cells found in embryos and mature individuals

Somatic cells

The imaginary plane along which homologous chromosomes align in metaphase I

Cells (egg or sperm) resulting from a meiotic division of germ-line cells, specialized for sexual reproduction

Phase of meiosis in which homologous cluster at the poles of the cells and the nuclear envelope reforms

The initial reduction division in which homologous chromosomes are segregated to two daughter cells

A single cell with a diploid number of chromosomes resulting from the fusion of an egg and a sperm

Reproductive life cycle that involves an alternation between haploid and diploid cells, or organisms

The process whereby homologous chromosomes find each other and become closely associated

Phase of meiosis in which the chromosomes begin to condense and the microtubule spindle begins to form

Two sets of chromosomes present in the somatic cells of adult individuals

Meiosis in which there is no recombination, but the homologous chromosomes still divide accurately

One of the two copies of a chromosome, each derived from one parent, found in diploid cell

Phase of meiosis when chiasmata and broken as spindle fibers shorten and homologous pairs are pulled apart