Terms - Biothermodynamics

Question 1

Cofactors

Answer 1

Can be described as non-protein molecules that assist enzymes.

They include two classes: Organic (coenzyme, Ex: Vitamins) and Inorganic (metal ions, ex: Iorn, magnesium)

Question 2

Ribozyme

Answer 2

RNA that functions as an enzyme

Question 3

Enzymes

Answer 3

Described as unique molecules, most of which (not all enzymes are proteins) are proteins that catalyze biochemical reactions
- substrate specific
- pH and temp vary
- unique combination of amino acid monomer unit

Question 4

prosthetic group

Answer 4

• When a cofactor is covalently bound to an enzyme
• Are organic or inorganic non-protein molecules that are found tightly to a protein to facilitate its functions

Question 5

anabolic

Answer 5

• small molecules are assembled into large ones
• energy is required

Question 6

catabolic

Answer 6

• large molecules are broken down into small ones
• energy is released

Question 7

metabolism

Answer 7

Can be described as all the chemical processes that occur within the human body known to sustain life

Question 8

Cooperativity

Answer 8

as a phenomenon that occurs where an enzyme becomes more receptive to additional substrate molecules after one substrate molecule binds to the active site
- an example: Hemoglobin

Question 9

Hemoglobin

Answer 9

is a quaternary protein with 4 subunits that each contain an active site for binding of a single oxygen

Question 10

catalysts

Answer 10

such as an enzyme accelerate the rate of the overall reaction by lowering the activation energy

Question 11

Km

Answer 11

• known as Michaelis constant and represents the substrate concentration at which the rate of reaction is half of the max velocity of the enzyme or Vmax.
• when Km is elevated, it will result in worse substrate binding
• when Km is lowered, it will result in better substrate binding

Question 12

Active site

Answer 12

• When a substrate binds to an enzyme at the location known as an active site
• it does so by using the induced fit approach

Question 13

Activation energy with enzyme or without enzyme

Answer 13

Enzymes have a lower activation energy than when there is no enzyme. (higher activation energy)

Question 14

Activation energy

Answer 14

can be described as the “hill” a reaction must climb to move forward
- where the role of ATP comes into play (ATP is a common source of activation energy

Question 15

ATP

Answer 15

is formed via phosphorylation
- ADP and phosphate come together using energy from an energy-rich molecule like glucose

Question 16

allosteric enzyme

Answer 16

Contain both an active site for the substrate and an allosteric site for the binding of an allosteric effector (activator or inhibitor)

Question 17

competitive inhibition

Answer 17

occurs when a substance mimics a substrate and inhibits the enzyme by binding at the active site

• increasing substrate concentration will overcome the effect of competitive inhibition
• Vmax: Same
• Km: different

Question 17

non-competitive inhibitor

Answer 17

molecule binds to the allosteric site of the enzyme, preventing the substrate form binding to the active site and thus, decreasing the maximal rate or Vmax of the reaction

• Vmax: Different
• Km: same

Question 18

Pepsin

Answer 18

is an enzyme responsible for protein digestion. When active pepsin cleaves proteins via breaking bonds in order to form smaller polypeptides
- inactive form is known as pepsinogen

Question 19

vmax

Answer 19

represents its maximal velocity of an enzyme