Metabolism

Question 1

What is a Signal Transduction Pathway

Answer 1

Interaction between Receptor Proteins in Plasma Membrane and Proteins/Aminoacids

Question 2

How do Proteins act once they interact with the intended molecule

Answer 2

Activation of Proteins (Secondary messengers) inside the cell

Question 3

Example of G-coupled Pathway hormones

Answer 3

Glucagon , adrenalin and PTH

Question 4

What happens when a Gs protein is activated

Answer 4

Stimulation of Adenyl Cyclase which increases cAMP and activates PKA = Transcription Factor

Question 5

What is Metabolism

Answer 5

All biochemical reactions occuring in the organism

Question 6

Main functions of Metabolic Pathways

Answer 6

1. Formation of ATP
2. Creation of structural biomolecules
3. Elimination of waste molecules

Question 7

What is a biochemical pathway

Answer 7

Sequence of reactions required to convert one REACTANT molecule to a PRODUCT

Question 8

What are the 2 main mechanism of Regulation in biochemical pathways

Answer 8

1. Allosteric inhibition
2. Feedback Inhibition

Question 9

What is Allosteric Inhibition

Answer 9

Biomolecule which interact with enzyme (at a different site) and either Activates or Deactivates it

Question 10

What is feedback inhibition

Answer 10

The PRODUCT of an enzyme inhibits enzyme’s function

Question 11

What is an enzyme

Answer 11

Protein which catalyze or facilitate biochemical reactions

Question 12

Molecule that can be used to switch on or off a metabolic pathway

Answer 12

Enzyme

Question 13

What are enzyme kinetics

Answer 13

How Enzyme catalyzed reactions are affected by various conditions (eg: Inhibitors)

Question 14

The Rate of Reaction (Vo) depends on

Answer 14

1. Concentration of Reactant/Substrate [S)
2. Max reaction rate of an enzyme (Vmax)
3. Michaelis constant of the enzyme (KM)

Question 15

Michaelis-Menten equation is used to

Answer 15

Calculate the rate of reaction

Question 16

Michaelis-Menten equation is

Answer 16

Vo= [ (Vmax) x [S] ] / [KM + [S] ]

Question 17

What is a Linewaver-Burk Plot

Answer 17

Representation of the inverse of Michaelis-Menten equation

Question 18

Linewaver-Burk Plot is used to

Answer 18

1. Calculate KM and Vmax of enzymes
2. Identify the presence of Activators or Inhibitors

Question 19

The point in Linewaver-Burk Plot where the Y axis is crossed represents

Answer 19

1/ Vmax

Question 20

The point in Linewaver-Burk Plot where the X axis is crossed represents

Answer 20

1/ KM

Question 21

The X and Y axis in Linewaver-Burk Plot represents

Answer 21

X = [S]
Y = [Vmax]

Question 22

Michaelis Constant property

Answer 22

The velocity reaction is half the Vmax when MK and [S] are numerically equal

Question 23

How does a Competitive inhibitor affects Linewaver-Burk Plot

Answer 23

1/KM = Changes (Increases)

1/Vmax = Same

Question 24

How does a Uncompetitive inhibitor affects Linewaver-Burk Plot

Answer 24

1/KM = Decreases

1/Vmax = Decreases

Question 25

Less KM means

Answer 25

More affinity

Question 26

Competitive inhibitor can be reversed by

Answer 26

Increasing substrate [S]

Question 27

Why does KM decreases in Uncompetitive inhibitor

Answer 27

Increases affinity for the Substrate. But Inhibits complex Enzyme-Substrate. Cannot go back and cannot form product

Question 28

How does a Non-Competitive inhibitor affects Linewaver-Burk Plot

Answer 28

KM = Same Vmax = Decreases

Question 29

The only inhibition that can be reversed by increasing substrate is

Answer 29

Competitive inhibitor.