Unit 2 - Metabolism and energy

Question 1

What is life

Answer 1

a constant flow of energy and organisms capture energy and use it for work

Question 2

Metabolism

Answer 2

is the sum of all chemical rxn in a cell or organism

Question 3

What is energy

Answer 3

the ability to do work (transfer of energy from one place to another) called thermodynamics
1) kinetic
2) potential energy

Question 4

Kinetic

Answer 4

energy of motion (electrical)

Question 5

Potenital energy

Answer 5

stored energy and is dependent on objects location or chemical structure (gravitational)

Question 6

Metabolism

Answer 6

all chemical process
1) catabolic
2) anabolic

Question 7

Catabolic rxn

Answer 7

energy is released + complex mol r broken down to simpler mol
ie. cellular respiration
Glucose + oxygen = carbon dioxide + water + energy

Question 8

Anabolic rxn

Answer 8

energy is absorbed + simpler mol combine to build mol more complex
ie. protein synthesis
amino acid + amino acid = protein + water

Question 9

active or catabolic
a) protein synthesis
b) digestion
c) DNA synthesis
d) photosynthesis
3) cellular respiration

Answer 9

a) anabolic
b) catabolic
c) anabolic
d) anabolic
e) catabolic

Question 10

First law of thermodynamics

Answer 10

“energy cannot be created or destroyed but converted into another form”
ie. ingests food

Question 11

First low of thermodynamics pt 2

Answer 11

during cellular respiration, the energy in the bonds of glucose is released and is transformed into new mol, motion, and heat energy

Question 12

Second law of thermodynamics

Answer 12

“in every energy transfer or conversion, some of the useful energy is the system bc unusable and increases the entropy of the universe
-never = 100%
-conversion to heat fate of chemical energy

Question 13

Entropy

Answer 13

is a measure of the amt of randomness disorder in a system

Question 14

example of second law of thermodynamics

Answer 14

cleaning your room is highly ordered (low entropy). Eventually your room bc messy (high entropy) therefore u need to clean it (lots of energy)
work=total energy-heat

Question 15

Catabolic rxn

Answer 15

always increases entropy

Question 16

chemical rnx entropy increase when

Answer 16

• solids react from liquids or gaeses
  -liquids react to form gasesous products
• the total number of product mol is greater than the total number of reactant mols

Question 17

an arm raised increase or decrease in entropy

Answer 17

decrease bc potential energy is increased

Question 18

a cell divides increase or decrease in entropy

Answer 18

increase as the system is bc more random of the cells free energy used in cell division.

Question 19

Free energy

Answer 19

the amt of energy that can do useful work, not a not deltG = H -TS

Question 20

delta G =
H =
T =
S =
TS =

Answer 20

delta G= energy available to do work
H = enthalpy of total energy
T = temperature in K
S = entropy
TS = energy not available to do work

Question 21

Heat of Reaction

Answer 21

is calc by the difference in bond enrgies (energy consumed when bonds break - energy released when bond form)
delta G = Gfinal state - Ginital state

Question 22

Definition of Free Energy

Answer 22

-spontaneous process
- concept of free energy provides a criterion for measuring spontaneity

Question 23

Enthalpy definition

Answer 23

a measure of the total potential energy expressed as a heat reaction (delta H)

Question 24

Free energy in depth

Answer 24

• decrease in E gives up energy and an increase in E contributes to spontaneity of a process
• higher temp enhances effect of an entrophy change

Question 25

delta G < 0
Delta G > 0
Delta G = 0

Answer 25

<0 spontaneous, exergonic rxn.
>0 not a spontaneous endergonic rxn
=0 reaction at equilibrium

Question 26

Types of rxn

Answer 26

Exergonic vs endergonic

Question 27

Exergonic rxn

Answer 27

chemical rxn that releases free energy; the product have less free energy.
- decrease gibbs free energy
- increase in stability
- spontaneous
- downhill, moving towards equilibrium
- give off energy

Question 28

Endergonic rxn

Answer 28

a chemical reaction that absorbs free energy the products have more free energy than the reactant
- decrease stability
- not spontaneous
-movement away from equilibrim
-anabolic

Question 29

Exergonin rxn fuels Endergoninc rxn

Answer 29

ie. you build muscle by + amino acids together to make muscle fibres (needs energy). you have just eaten a healthy snack filled w nutrients and your digesting it as we speake (releasing energy)

Question 30

Coupled Rxn

Answer 30

the transfer of energy from one rxn to another in order to drive secondrxn
- exergonic rxn release free energy therefore can proceed spontaneously
- endergonic rxn need a supply of free energy and cannot procced on their own.

Question 31

If the activation energy of a reaction is 1250kj/mol and the energy released by the formation of products in the rxn is 1186kj/mol what type of rxn has taken place

Answer 31

exergonic bc there is less enrgy in the products; delta G is -

Question 32

is an anabolic rxn more likely to be exergonic or endergonic

Answer 32

endergonic

Question 33

would this type of rxnhave a + or - value for delta G

Answer 33

positive delta G

Question 34

How is the melting of ice is an increase in entropy

Answer 34

ice is organized into a tight lattice of water mol w intermolecular hydrogen bonding. when ice melts, the water mols r randomly moving over one another in the liquid state and r less organized hence an increase in entropy