Metabolism

Question 1

Metabolism

Answer 1

Sum of all the chemical reactions that occurs within a living cell/tissue/organism

Question 2

Use of metabolism

Answer 2

used to build or break down chemical to make other chemicals
used to liberate or store energy used to do cellular/ organismal function

Question 3

Metabolite

Answer 3

Different molecules in a pathway

Question 4

Advantages of multi-step pathways

Answer 4

multiple points help to control how fast the reactions occur
Ability to divert ‘pathway intermediates’ to other pathways to do things
changes to metabolism through evolution

Question 5

1st Law of thermodynamics

Answer 5

Energy cannot be created or destroyed. energy can only be transformed/converted

Question 6

2nd of thermodynamics

Answer 6

Changes in Entropy can never be negative. As more of enrgy is transformes, more of it is watsed (lost as thermal energy)

Question 7

Free Energy (G)

Answer 7

The amount of energy in ‘the system’ available to do useful work
final state -initial state

Question 8

The reactants have G (initial state)
The products have G(final state)
True/ False

Answer 8

True

Question 9

what happens when the reactants have more free energy than the products

Answer 9

G will be less than zero
These reactions are exergonic = energy releasing. exothermic (negative)
it took LESS energy to break the bonds in reactants compared to the energy released when the bonds are formed
These reactions are spontaneous, not necessarily instantaneous (all at once)

Question 10

when bonds form, does it take energy or release energy?

Answer 10

when bonds are formed it releases energy

Question 11

when bonds break, does it take energy or release energy?

Answer 11

when bonds break, it takes energy

Question 12

what happens when the reactants have less free energy than the products

Answer 12

G will be greater than zero
Endergonic = energy consuming. endothermic(positive)
it takes MORE energy to break the bonds in reactants compared to the energy released
when the bonds were formed in the products.

Question 13

Why does ATP take less energy to break?

Answer 13

This is because of the electronegativities of the close oxygen, they want to move away from each other. ATP is easier to break

Question 14

Exergonic reactions can be coupled with those that are endergonic?
True/False

Answer 14

True

Question 15

Transition State

Answer 15

This is an unstable configuration

Question 16

Activation Energy

Answer 16

The minimum amount of energy required to reach the transition state and result in a chemical reaction

Question 17

What do enzymes do

Answer 17

Enzymes speed up the rate of reactions (without being consumed) by lowering the activation energy.
Lowering activation energy means making the bonds easier to break.
G is unaffected by enzyme

Question 18

what are substrates

Answer 18

Reactant molecules

Question 19

what are catalysts

Answer 19

substance that increases the rate of a chemical reaction without itself undergoing permanent changes
enzymes are catalyst

Question 20

Induced-fit model

Answer 20

Theory that the active site and the substrate are not perfect matches for each other

Question 21

step by step process of induced-fit model

Answer 21

1. Substrates enter the active site; Enzymes changes the shape so its’ active site can fit the substrate
2. Substrates are held in active site by weak bonds like hydrogen and ionic
3. Substrates are converted to products
4. Products are released
5. Active site is available for two new substrate molecule

Question 22

What are ways for enzymes catalyst to speed up reactions?

Answer 22

a. Holding two substrates close together in the right orientation
b. Stressing substrate bonds through movement of the protein
c. ‘microenvironment’ of the active site speeds up reaction
d. Some amino acids directly participate in reactions

Question 23

what happens when the 3d shape of a protein is altered

Answer 23

When the 3d shape of a protein is altered, the protein stops working (Denaturation - protein unfolding)

Question 24

What can denature a protein?

Answer 24

A. Increased Temperature (speed up a reaction until the protein denatures)
differences in #of hydrogen bonds
# of disulfide bridges
B. pH
Affecting the # of ionic bonds with the protein

Question 25

Types of substrate-enzyme binding

Answer 25

Normal
Competitive Inhibition
Non-Competitive Inhibition

Question 26

Competitive Inhibition

Answer 26

the inhibitor molecule deceives the enzymes by resembling the original substrate. It binds to the active site, so the original substrate can’t bind. This makes the reaction slower or stop

Question 27

Non-competitive Inhibition

Answer 27

The inhibitor molecule binds elsewhere on the enzyme and changes its shape. The original substrate cannot bind because the active site is changes. An example is feedback inhibition. stops reaction maybe*

Question 28

Allosteric Activation

Answer 28

A regulatory molecule(not substrate) binds to a regulatory site(sides)which stabilized the active site

Question 29

Allosteric Inactivation Site

Answer 29

A regulatory molecule(not substrate) that binds to a regulatory site (sides) which stabilizes the inactive site

Question 30

Cooperativity

Answer 30

when a substrate binds one unit (inside), which stabilizes the active site on the other unit