Topic 6- Metabolism

Question 1

What is metabolism?

Answer 1

Chemical reactions that take place in a cell that are catalyzed by an enzyme

Question 2

Catabolic vs. Anabolic pathways

Answer 2

Catabolic breaks molecules into smaller pieces which releases energy when you break the bonds
Anabolic builds complex proteins from smaller pieces which requires an energy input.

Question 3

What are the 2 laws of thermodynamics?

Answer 3

1. Energy can be transferred but not created or destroyed?
2. Energy will move to a more random state. aka increased entropy which means you will lose a small amount of energy in a reaction.

Question 3

Describe ATP and how it work

Answer 3

Adenosine Triphosphate. To get energy you break off the bond between the third phosphate creating ADP and a stray phosphate.

Question 4

What are the types of chemical reactions?

Answer 4

1. Exergonic- Releases energy. Reactants have a high level of energy while the products have a low level of energy. Catabolic pathways = exergonic.
2. Endergonic- requires energy for reaction. Reactants have a lo level of energy while products have a high level. Anabolic = endergonic.

Question 5

Describe Activation Energy.

Answer 5

Before every Reaction you need a additional energy to destabilize existing bonds before a reaction can take place.

Question 6

What is a enzyme? Describe how it works?

Answer 6

A protein whose job it is to speed up chemical reactions by reducing the amount of activation energy needed.

Reactants called substrates enter the active site and are held there by weak bonds.
The enzyme then does something to reduce the activation energy, the products are released.

Question 7

How do enzymes react to heat and pH?

Answer 7

When heated up it begins vibrating so fast it falls apart
When it cools down it slows down so much that it becomes in effective
When the pH is not what it is used to, the influx of hydrogen or hydroxide ions disrupts the hydrogen bonds holding the protein together.

Question 8

What are the different type of enzyme inhibitors and how do they work?

Answer 8

Competitive inhibitors- they bind at the active site, stopping the substrate from getting there. They get less effective as the substrate concentration increases.

Non competitive inhibitors- Binds to the allosteric site which distorts the proteins shape which prevents the substrate from bindings

Question 9

Describe feedback inhibition.

Answer 9

When the end product of the metabolic pathway inhibits a earlier enzyme in the path making it self regulating which is very efficient.