-
_________ is the process where fungus covert the energy stored in certain organic molecules to light.
Bioluminescence
-
The totality of an organisms chemical reactions is called __________
Metabolism
-
_________ is an emergent proerty of life that arises from interactions between molecules within the orderly environment of the cell.
Metabolism
-
A _______ begins with a specific molecule, which is then altered in a series of defined steps, resulting in a certain product. Each step is catalyzed by a specific enzyme.
A catabolic pathway
-
A pathway that releases energy by breaking down complex molecules to simpler compounds
Catabolic pathway
-
__________ consume energy to build complicated colecules from simpler ones (also called biosynthetic pathways
Anabolic pathways
-
Energy is
the capacity to cause change.
-
Energy can be associated with the relative motion of objects, this energy is called
kinetic energy
-
Stored energy is called
potential energy
-
Energy that is available for release in a chemical reaction is called
chemical energy
-
The portion of a system's energy that can perfrom work when temperature and pressure are uniform throughout the system of a cell is called
Free energy AG
-
Based on their freep-energy changes, chemical changes can either be
exergonic (energy outward), or endergonic (energy inward)
-
An ________ proceeds with a net release of free energy
exergonic reaction
-
An _________ is one that absorbs free energy frm its surroundings
endergonic reaction
-
Exergonic reactions are coupled with endergonic reaction by
ATP
-
A cell does 3 main kinds of work:
- Chemical work
- Transport work
- Mechanical work
-
The pushing of endergonic reaction is known as
chemical work
-
The pumping of substances across membranes against the direction of spontaneous movement is known as
transport work
-
The beating of cilia is an example of
mechanical work
-
The bonds between the phosphate groups of ATP can be broken by
hydrolysis
-
The free energy required to phosphorylate ADP comes from
exergonic breakdown reactions (catabolism) in the cell
-
An _______ is a macromolecule that acts as a _________, a chemical agent that speeds up a reaction without being consumed by the reaction
enzyme, catalyst
-
the initial investment of energy for starting a reaction-the energy required to contort the molecules so the bonds can break is
Activation energy (free energy of activation) (EA)
-
An enzyme catalyzes a reaction by
lowering the EA barrier, enabling the reactant molecules to absorb enough energy to reach the transition state even at moderate temperatures.
-
The reactant an enzyme acts on is called its
substrate
-
When an enzyme binds to its substrate it forms an
enzyme substrate complex
-
While enzyme and substrate are joined
the catabolic action of the enzyme converts the substrate to products of the reaction
-
Where the enzyme molecule binds to the substrate is called the
active site
-
The substrate is held into place by
weak bonds, such as hydrogen and ionic bonds
-
An enzymes activity-how efficiently it functions- is effected by
general environmental factors, such as temperature and pH
-
The rate of an enzymatic reaction can increase with
increased temperature because substrates collide with active sites more frequently when the molecules move rapidly.
-
The optimal pH for most enzymes falls in the range of
pH 6-8
-
Nonprotein helper for catalytic activity that may be hound tightly to the enzyme or loosely and reversibly to the substrate are called
cofactors
-
If the cofactor is an organic molecule, it is more specifically called a
coenzyme
-
An inhibitor that reduces the productivity of an enzyme by blocking substrates from entering active sites are called
Competitive inhibitors
-
____________________ do not directly compete with the substrate but bind to a different part of the enzyme changing its shape
Noncompetitive inhibitors
-
any case in which a protein function at one site is affected by the binding of a regulatory molecule to a seperate site. It may result in either inhibition or stimulation of an enzyme's activity
is Allosteric regulation
-
When ATP allosterically inhibits an ezyme in an ATP-generating pathway, the result is
feedback inhibition
-
Energy flows into an ecosystem as ________ and ultimately leaves as _______
Sunlight, heat
-
Catabolic pathways
yield energy by oxidizing organic fuels
-
Catabolic pathways are ______________ that release stored energy by breaking down complex molecules.
Metabolic pathways
-
_________________-- is a partial degredation of sugars that occurs without the use of oxygen
Fermentation
-
The most prevavent and efficient catabolic pathway is __________ in which oxygen is consumed as a reactant along with the organic fuel
aerobic respiration
-
________________ doesn't use oxygen
anaerobic respiration
-
When there is an electron transfer in a chemical reaction it is a
redox reaction
-
In a redox reaction, the loss of electrons from one substance to another is
oxidation
-
The addition of electronsto another substance in a chemical reaction is known as
reduction
-
An electron shuttle in a chemical reaction is
NAD+
-
Cellular respiration uses an ____________________ to break the fall of electrons to oxygen into several energy releasing steps.
Electron transport chain
-
The 3 stages of cellular respiration are
- Glycolysis
- The citric acid cycle (Krebs cycle)
- Oxidative phosphorylation: electron transport chain and chemiosmosis
-
Glycolysis occurs in the ____________________, it begins the degredation process by breaking _________ into two molecules of a compound called __________
cytoplasm, glucose, pyruvate
-
Upon entering the _________________ via active transport, pyruvate is converted to a compound called _______________-
mitochondrion, Acetyl CoA
-
The _______________________ takes place in the mitochondrial matrix of eukaryotes or in the ________ of prokaryotes, it completes the breakdown of glucose by oxidizing a derivitive of pyruvate to carbin dioxide.
Citric acid cycle (Krebs cycle)
-
When ATP is made by direct trannsfer of a phosphate group from an organic substrate to ADP by an enzyme it is called
Substrate-level phosphorylation
-
The ________________ is a collection of molecules embedded in the inner membrane of the mitochondrion
electron transport chain
-
Populating the inner membrane of the mitochondrion are many copies of a protein complex called ______________ the enzyme that actually makes ATP from ADP
ATP synthesis
-
Two types of fermention are
Alchol fermentation and lactic acid fermentation
-
In alcohol fermention _______________ is converted to ethanol in two steps: the first step releases carbon dioxide and converted to acetaldehyde. In the second step acetaldehyde is reduced by the supply of _______ needed for the continuation of glycolysis
pyruvate, NAD+
-
During ________ pyruvate is reduced by NADH to form lactate as an end product with no release of CO2
lactic acid fermention
-
Self-feeders are called
autotrophs
-
Organisms that live on compounds produced by other organisms are called
heterotrophs
-
Photosynthesis converts
light energy to the energy of food
-
The sites of photosynthesis in plants are
chloroplasts
-
The dense fluid within the chloroplasts is called
stroma
-
The chloroplast splits ___________ into _______________
hydrogen, water
-
Photosynthesis involves
redox reactions
-
Photosynthesis requires energy, therefore it is
endergonic
-
The 2 stages of photsynthesis are
- light reactions
- the Calvin cycle
-
Light reactions convert
light to chemical energy
-
The Calvin cycle makes
sugar
-
A ____________ is composed of a a protein complex called a ___________ surrounded by a several light-harvesting complexes
photosystem, reaction center complex
-
Each ____________ consists of various pigment molecules bound to proteins
light harvesting complex
-
Photosystem I and photosystem II populate the
thylakoid membrane
-
The Calvin Cycle uses ______ and ___ to convert CO2 to _______
ATP, NADPH, sugar
-
The Calvin cycle is anabolic it
consumes energy
-
_______ enters the Calvin Cycle in the from of CO2 and leaves in the form of ___________
Carbon, sugar
-
The Calvin Cycle spends _____ as an energy source and consumes ______ as reducing power for adding high energy electrons to make sugar
ATP, NADPH
-
3 Phases of the Calvin Cycle are
- Carbon Fixation
- Reduction
- Regeneration of CO2 acceptor
-
The process by which a signal on a cells surface is converted to a specific cellular resoponse is a series of steps called
a signal transduction pathway
-
both plant cells and animal cells have _______________ that allow molecules to pass between adjacent cells
cell junction
-
Two cells in an animal cell may communicate by interaction between molecules on their surfaces this is called
cell to cell recognition
-
The three stages of cell signalling are
- Reception
- Transduction
- Response
-
_______________- is the target cell's detection of a signaling molecule coming from outside the cell
Reception
-
______________ (the second stage of cell signaling) is the binding of the signaling molecule which changes the receptor protein in some way
Transduction
-
___________ The third stage of cell signaling where the transduced signal triggers a cpecific cellular ____________
Response, response
-
A molecule that specifically binds to another molecule is called a
ligand
-
Intracellular receptor proteins are found in either the _______ or the ___ of target cells
cyoplasm, nucleus
-
A _________________ is a plasma receptor that works with the help of a _________, a protein that binds the energy rich molecule GTP.
G-protein-couples receptor, G Protein
-
___________________ belong to a major class of plasma membrane receptors characgterized by having enzymatic activity.
Receptor tyrosine kinases
-
A _________ is an enzyme that catalyzes the transfer of phosphate groups
kinase
-
A ________________ is a type of membrane receptor containing a region that can act as a "gate" when the receptor changes shape
ligand-gated ion channel
-
The binding of a specific signaling molecule to a receptor on the plasma membrane triggers the first step in the chain of molecular interactions called
the signal transduction pathway
-
_______________ and ___________________-- of proteins is a widespread cellular mechanism for regulating protein activity.
Phosphorylation, adephosphorylation
-
The general name for an enzyme that transfers phosphate groups from ATP to a protein is
protein kinase
-
Important in the phosphorylation cascade are the _________________, enzymes that can rapidly remove phosphate groups from proteins, a process called _________________.
Protein phosphateses, dephosphorylaiton
-
Many signaling pathways also involve small, nonprotein, water-soluble molecules or ions called
second messengers
-
Binding epinephrine to the plasma membrane of a live cell elevates the cytosolic concentration of a compound called
cyclic adenosine monphosphate (cycle AMP or cAMP)
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