Energy & metabolism Flashcards Preview

BIO 110 > Energy & metabolism > Flashcards

Flashcards in Energy & metabolism Deck (46)
Loading flashcards...
1
Q

How is energy from sunlight stored?

A

-Stored as potential energy in covalent bonds between atoms in the sugar molecules

2
Q

How is the strength of the covalent bond measured?

A

-By the amount of energy that’s required to break it

3
Q

What happens to the energy stored in chemical bonds during a chemical reaction?

A

-The energy is used to make new bonds

4
Q

What is it called when an atom LOSES an electron?

A

-Oxidation bc oxygen is the most common electron receptor in biological systems

5
Q

What is called when an atom GAINS an electron?

A

-Reduction= the reduced form of a molecule has HIGHER energy that oxidation form

6
Q

What are Redox Reactions?

A
  • When oxidation & reduction take place together

- Play a key role in the flow of energy in biological systems

7
Q

What is Energy defined as?

A

-The ability to do work

8
Q

What does the First Law of Thermodynamics state?

A
  • Energy cannot be created nor destroyed, it can ONLY change from one form to another
  • The total amount of energy in the world remains constant
9
Q

What is Heat?

A
  • Energy that dissipates into the environment

- A Measure of the random motion of molecules

10
Q

How does Energy flow in the biological world?

A

-In one one direction w/ new energy from the sun constantly entering the system to replace the energy that’s been dissipated into heat

11
Q

What is a heat gradient?

A

-The temperature difference between 2 areas

12
Q

How can heat be harnessed to do work?

A
  • ONLY when there is a heat gradient present

- But CAN’T work in cells bc they’re too small so cells must rely on chemical reactions for energy

13
Q

How does the energy available to do work decreases?

A

-It decreases due to the increasing loss of being turned into heat

14
Q

What is the 2nd Law of Thermodynamics?

A
  • States that disorder (entropy) is constantly increasing= you CAN’T keep all the useful energy which is why perpetual motion is impossible
  • ONLY low to high entropy NEVER high to low entropy
15
Q

What is Entropy?

A
  • The disorder in the universe

- Low quality, unusable energy

16
Q

What is Truely High Entropy?

A

-The entropy state would NOT be distinct

think of different paint colors mixing together to create a different color

17
Q

What is Low Entropy?

A

-The entropy state would be MORE distinct= can see a more clear separation
(can see the green and the blue before making purple)

18
Q

what are the equations expressing the 1st & 2nd law are limited to?

A

-ONLY applies to ISOLATED systems bc biological systems are open systems

19
Q

What’s the difference between the 1st & 2nd law regulations?

A
  • The 1st law regulates the AMOUNT of energy

- The 2nd law regulates the DISTRIBUTION of energy & mass

20
Q

What type of energy makes it easier to pull atoms apart?

A

-Heat energy bc it increases atomic motion

21
Q

What influence does Heat vs Chemical bonding have on a molecule?

A
  • Chemical Bonding REDUCES disorder

- Heat INCREASES disorder

22
Q

What is Free Energy?

A
  • High quality & useful energy BUT always being converted into low quality, unusable energy (entropy)
  • Predicts the outcomes of reactions of any systems (open or closed)
23
Q

What is the Equation for free energy (delta G)

A

Delta G= Delta H- TdeltaS

24
Q

Using the Free energy equation, What does it mean when Delta G is Positive?

A
  • The products have MORE free energy than reactants=Endergonic
  • NOT spontaneous bc they require an INPUT of energy
25
Q

Using the Free Energy equation, what does it mean when Delta G is negative?

A

-Spontaneous reaction= Exergonic

26
Q

Because chemical reactions are reversible, an Exergonix reaction will be…..

A

-Endergonic in reverse

27
Q

What role doe the Equilibrium Constant play when thinking about free energy changes?

A
  • An Exergonic reaction has an equilibrium FAVORING the PRODUCTS
  • An Endergonic reaction has an equilibrium FAVORING the REACTANTS
28
Q

What must happen BEFORE new chemical bonds can form?

A

-Existing bonds MUST be broken which requires an energy input

29
Q

What is Activation energy?

A

-The extra energy needed to stabilize existing chemical bonds & initiate a chemical reaction

30
Q

What does the rate of an Exergonic reaction depend on?

A

-Activation energy required for reaction to begin

31
Q

Reactions with larger activation energies….

A

-Tend to proceed SLOWER bc fewer molecules succeed getting over the initial energy hurdle

32
Q

What are 3 ways to increase the rate of reactions?

A
  • Increasing the energy of reacting molecules
  • Lowering activation energy
  • Use a catalyst to lower the activation energy
33
Q

What’s the difference between Catalysis & a Catalyst?

A
  • Catalysis is the process of influencing chemical bonds in a way that lowers the activation energy needed to initiate a reaction
  • A Catalyst is the substance that gets this process done
34
Q

How does a Catalyst work?

A
  • They exert their action by affecting an intermediate stage in the reaction= Transition stage
  • Then they stabilize this= lowers activation energy
  • They DO NOT violate the laws of thermodynamics
35
Q

What is the direction of a chemical reaction determined by?

A

-SOLEY by the difference in free energy between reactancts & products

36
Q

What is the chief currency of energy?

A

-ATP (Adenosine Triphosphate)

37
Q

What is ATP used for?

A
  • Building blocks for RNA molecules

- Drive endergonic processes bc it can provide most of the energy a cell needs

38
Q

What 3 components make up ATP?

A
  • 5 carbon sugar (ribose)= framework for the other 2 subunits to attach to
  • 2 nitrogen carbon rings = weakly attracted to hydrogen ions= weak base
  • 3 phosphates
39
Q

How does ATP store energy & how does it get transferred to another molecule?

A
  • Key lies in the phosphate groups bc they’re super negatively charged= have low activation energy & easily broken by hydrolysis
  • The hydrolysis of the outermost high energy bond of ATP results in negative delta G which is energy that’s able to produce work= AD plus inorganic Pi
  • The liberated phosphate group then temporarily attaches to an immidiate molecule
40
Q

What makes ATP a poor long term energy storage molecule?

A

-the inability of its phosphate bonds

41
Q

How do cells use ATP cyclically?

A
  • Since cells only have seconds worth of ATP
  • Cells use Exergonic reactions to provide energy to synthesize ATP from ADP+ Pi
  • Then they use hydolysis of ATP to provide energy to drive Endogernic processes
42
Q

How does the shape of an Enzyme help lower the activation energy of reactions?

A
  • Since it’s a 3D shape, it can stabilize a temporary association between substrates
  • By bringing 2 substrates together in the correct orientation or stressing chemical specific bonds, it lowers the activation energy required for new bonds to form
  • Enzymes can be reused & only a small amount is needed it won’t be changed/consumed
43
Q

What do the Enzymes of a cell determine by facilitating specific chemical reactions?

A

-Can determine the course of metabolism (collection of all chemical reactions in a cell)

44
Q

What are Enzymes?

A
  • 3D globular proteins w/ one or more pockets= active sites

- Since they’re not ridgid they can induce a better fit when the subtrate comes into the active sites

45
Q

What is Enzyme-Substrate Complex?

A

-Substrates binding to the enzyme at their active sites (pockets)

46
Q

What are the 5 steps for Catalysis to occur within the Enzyme-Substrate Complex?

A
  • Substrate molecule must first fit into the active site
  • Then amino acid side groups of the enzyme end up very close to certain bonds of substrate
  • The amino acid side group interact chemically w/ substrate by stressing or distorting specific bond to lower activation energy needed to break it
  • After bonds are broken/ new bonds form, substrates are converted into products
  • Then these products dissociate from the enzyme