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Flashcards in Chapter 7 Deck (49):
1

Energy

Capacity to do work

2

Name the states of energy

Kinetic energy


Potential energy

3

Energy in motion

Kinetic energy

4

Stored energy

Potential energy

5

Name 5 forms of energy

H.E.L.M R


Heat
Electric
Light
Mechanical
Radioactivity

6

How is heat measured?

In kilocalories

7

1 calorie =

The amount of heat needed to raise the temperature of water by 1 degree Celsius

8

1 kilo calorie =

1,000 calories

9

1st Law of thermodynamics

Energy cannot be created or destroyed

Energy can only be converted from one form to another

Concerns amount of energy in the universe

10

2nd Law of thermodynamics

Order is more likely than disorder

Concerns the transformation of potential energy into heat or molecular motion

Entropy is always increasing

11

Entropy

Disorder in the universe

12

Thermodynamics

Branch of chemistry that deals with energy changes, or "heat changes"

13

Potential energy stored in chemical bonds can be transferred from one molecule to another by way of ____________

Electrons.

14

Oxidation

Loss of electrons

15

Reduction

Gain of electrons

16

What is the most common electron acceptor?

Oxygen

17

Reduced form of a molecule has a higher ______________ than the oxidized form

Level of energy

18

Breaks the chemical bonds that hold atoms together

Energy

19

Heat energy

Increases atomic motion

Makes it easier for atoms to pull apart

20

Free energy

Energy available to do work or break and form other chemical bonds

Denoted as the symbol G (Gibbs free energy)

21

Enthalpy

Energy contained in a molecules chemical bonds

22

G = H - (TS)

What does each letter represent?

G = Free energy

H = Enthalpy

T= temperature

S= entropy

23


What creates changes in free energy: G= H-(TS) ?

Chemical reactions

24

A) Reduces
B) Increases

1) Chemical bonding _________ disorder.

2) Heat ________ disorder.

1) A

2) B

25

G = H - (TS)

When is G positive?

When products contain more free energy than reactants

Energy is supplied

26

G = H- (TS)

When is G negative?

When reactants contain more free energy than products

Energy is released

27

Endergonic reaction

G= H-(TS)

G is positive (products of the reaction contains more free energy than reactants)

Inward energy


28

Exergonic reaction

G=H-(TS)

G is negative (reactants of the reaction contain more free energy than the products)

Outward energy

29

The transfer of energy in chemical reactions can be described as either __________ or _____________

Endergonic (inward)

Exergonic (outward)

30

Most reactions require _______ to get started

Energy

31

Activation energy

Extra energy needed to get a reaction initiated or started

Destabilizes chemical bonds

Used in endergonic and exergonic reactions

Large amounts of activation energy can slow down reactions

32

Catalyst

Substance that lowers activation energy

Does not alter proportion of reactant

33

The chief energy "currency" of cells, powers almost every energy requiring process in cells.

ATP

34

Describe ATP structure :

Adenine

Ribose (5-carbon sugar)

3 phosphates

35

Where does ATP store energy?

Bonds between phosphates

36

Describe Phosphates :

Highly negative

Repel each other (phosphates)

Require a lot of energy to keep phosphates bound to each other

Releases a lot of energy when bond between phosphates is broken

37

When the bond between phosphates is broken ATP converts to __________, therefore energy has been ___________


(T/F) This reaction is not reversible?

ADP + P(i)

Released

False. Reaction is reservable.

38

What makes ATP an effective energy donor?

Instability

39

Is ATP a good long term energy storage molecule?

No. It is unstable (instability)

40

What fuels the production of ATP from ADP + Pi?

The energy released from an exergonic reaction

41

ATP hydrolysis

The energy released when ATP is broken down to ADP

Fuels endergonic reactions

42

Enzymes

Molecules that catalyze reactions in living cells

Most are proteins

Lower activation energy required for reaction not changes or consumed by the reaction

Interact with substrates

43

What enables an enzyme to stabilize a temporary association between substrates

Unique 3- dimensional shape

44

Substrate

Molecule that will undergo a reaction

45

Active site

Region of the enzyme that binds to the substrate

46

Binding of an enzyme to a substrate causes the enzyme to

Change shape= producing a better induced fit between the molecules

47

Bringing 2 substrates together in the correct orientation causes an enzyme to

Lower its activation energy required for new bonds to form

48

T/F

Not all enzymes are proteins.

True

49

Ribozymes

RNA with enzymatic abilities.