AP Biology Chapter 8 (Campbell and Reece) Flashcards

7732663726	The living cell	- a miniature factory where thousands of reactions occur -Converts energy in many ways	0
7732663727	metabolism	-an emergent property of life that arises from interactions between molecules with the cell -transforms matter and energy, subject to the laws of thermodynamics	1
7732663728	metabolic pathway steps	- begin with a specific molecule and end with a product - each catalyzed by a specific enzyme	2
7732663729	Catabolic pathways	-Break down complex molecules into simpler compounds -Release energy	3
7732663730	Anabolic pathways	-Build complicated molecules from simpler ones -Consume energy	4
7732663731	Energy	-the capacity to cause change -Exists in various forms -can be converted	5
7732663732	Kinetic energy	energy associated with motion	6
7732663733	Potential energy	-stored in the location of matter -chemical energy stored in molecular structure	7
7732663734	Thermodynamics	the study of energy transformations	8
7732663735	First Law of Thermodynamics	-Energy can be transferred and transformed -Energy cannot be created or destroyed	9
7732663736	Second Law of Thermodynamics	-Spontaneous changes that do not require outside energy increase the entropy, or disorder, of the universe	10
7732663737	Living systems	-Increase the entropy of the universe -Use energy to maintain order	11
7732663738	What does the free- energy change of a reaction tell us?	whether the reaction occurs spontaneously	12
7732663739	Free-Energy Change, ∆G	energy that can do work under cellular conditions	13
7732663740	change in free energy	related directly to the enthalpy change (∆H) and the change in entropy	14
7732663741	Free Energy, Stability, and Equilibrium	-Organisms live at the expense of free energy -During a spontaneous change --Free energy decreases and the stability of a system increases	15
7732663742	maximum stability	The system is at equilibrium	16
7732663743	exergonic reaction	a net release of free energy and is spontaneous	17
7732663744	endergonic reaction	absorbs free energy from its surroundings and is nonspontaneous	18
7732663745	Equilibrium and Metabolism	Reactions in a closed system -Eventually reach equilibrium	19
7732663746	Cells in our body	Experience a constant flow of materials in and out, preventing metabolic pathways from reaching equilibrium	20
7732663747	ATP powers what and how?	ATP powers cellular work by coupling exergonic reactions to endergonic reactions	21
7732663748	three main kinds of cell work	powered by the hydrolysis of ATP -Mechanical -Transport -Chemical	22
7732663749	Mechanical work	the beating of cilia, thr contraction od muscle cells and the movement of chromosomes during cellular reproduction	23
7732663750	Transport work	pumping of substances across membranes	24
7732663751	Chemical cell work	the pushing of endergonic reactions	25
7732663752	Structure and Hydrolysis of ATP	Energy is released from ATP ATP hydrolysis -Can be coupled to other reactions	26
7732663753	ATP		27
7732663754	How ATP Works	By phosphorylation, transferring a phosphate to other molecules	28
7732663755	Regeneration of ATP	Catabolic pathways drive the regeneration of ATP from ADP and phosphate	29
7732663756	What do enzymes speed up? How?	Enzymes speed up metabolic reactions by lowering energy barriers	30
7732663757	catalyst	chemical agent that speeds up a reaction without being consumed by the reaction	31
7732663758	enzyme	catalytic protein	32
7732663759	The Activation Barrier	Every chemical reaction between molecules involves both bond breaking and bond forming	33
7732663760	example of a chemical reaction	hydrolysis	34
7732663761	activation energy (EA)	amount of energy needed to push the reactants over an energy barrier hill so that the "downhill" part of the reaction can begin	35
7732663762	How Enzymes Lower the EA Barrier	An enzyme catalyzes reactions -By lowering the EA barrier	36
7732663763	Substrate Specificity of Enzymes	substrate -the reactant an enzyme acts on enzyme -Binds to its substrate, forming an enzyme- substrate complex	37
7732663764	The active site	region on the enzyme where the substrate binds	38
7732663765	Catalysis in the Enzyme's Active Site	In an enzymatic reaction -The substrate binds to the active site	39
7732663766	catalytic cycle of an enzyme		40
7732663767	The active site can lower an EA barrier by	-Orienting substrates correctly -Straining substrate bonds -Providing a favorable microenvironment -Covalently bonding to the substrate	41
7732663768	activity of an enzyme	affected by general environmental factors	42
7732663769	Effects of Temperature and pH	Each enzyme -Has an optimal temperature in which it can function	43
7732663770	Cofactors	nonprotein enzyme helpers	44
7732663771	Coenzymes	-Are organic cofactors	45
7732663772	Enzyme Inhibitors	inhibit the action of specific enzymes	46
7732663773	Noncompetitive inhibitors	-Bind to another part of an enzyme, changing the function	47
7732663774	Regulation of enzyme activity helps control . . .		48
7732663775	Allosteric regulation		49
7732663776	A cell's metabolic pathways . . .	Must be tightly regulated	50
7732663777	Allosteric Activation and Inhibition	Many enzymes are allosterically regulated They change shape when regulatory molecules bind to specific sites, affecting function	51
7732663778	Cooperativity	a form of allosteric regulation that can amplify enzyme activity	52
7732663779	feedback inhibition	end product of a metabolic pathway shuts down the pathway	53
7732663780	Within the cell, enzymes may be . . .	-Grouped into complexes -Incorporated into membranes -Contained inside organelles	54