Chapter 8: Metabolism Flashcards Preview

Bio 93: Exam 2 > Chapter 8: Metabolism > Flashcards

Flashcards in Chapter 8: Metabolism Deck (25)
Loading flashcards...
1

Name the two types of reactions

Catabolic - breakdown pathways, releases energy

Anabolic - biosynthetic pathways, requires energy

2

CHE & ADE

Catabolic
Hydrolysis
Exergonic

Anabolic
Dehydration
Endergonic

3

What is Potential Energy?

Stored energy waiting to be used

4

What is Kinetic Energy?

Energy that an object has because of its movement

5

First law of thermodynamics

Energy cannot be created nor destroyed

6

Second law of thermodynamics

Energy transformations are not 100% efficient

7

Which do you think contains the most potential energy?
A. Glucose
B. Sucrose
C. A phospholipid
D. A triacylglycerol

D. It has more bonds, therefore it's more efficient to store a lot of energy.

8

Exergonic reactions ________ energy.

release

9

In terms of spontaneity, exergonic reactions are ________.

Spontaneous

10

Endergonic reactions ______ energy.

require

11

In terms of spontaneity, endergonic reactions are __________.

Non spontaneous

12

Which of the following is an endergonic reaction?

A. Synthesis of a polypeptide from amino acids
B. Diffusion of oxygen molecules across a plasma membrane
C. Digestion of starch into its component glucose molecules
D. Formation of hydrogen bonds between water molecules

A. Synthesis of a polypeptide is dehydration, which is endergonic.

13

What is energy coupling?

1. Energy transferred from catabolic -> anabolic

2. Energy transferred from exergonic -> endergonic

14

How do you make sure energy is not lost during a transfer?

Through the energy carrier, ATP.

15

Where is energy stored in ATP?

In the covalent bonds between the phosphates

16

When ATP is hydrolysized, the energy release powers an __________ reaction.

Endergonic

17

What are enzymes?

- catalysts that speed a reaction
- not consumed by the reaction
- are reusable
- many of them are proteins

Ending in -ase

18

In terms of Activation Energy, exergonic reactions have _____ energy overall than when they started.

less

19

In terms of Activation Energy, endergonic reactions have _____ energy overall than when they started.

more

20

Enzymes _______ the activation energy.

lower

21

True or False

Enzymes decrease the energy of the products to make endergonic reactions exergonic reactions.

False. Enzymes do not change the energy of products or reactants.

22

Explain the 5 steps of how enzymes do their work.

1. Substrates enter the active site.
2. Substrates are held in the active site due to their shape.
3. Substrates undergo intermolecular forces in the substrate complex and are converted into products.
4. The products (substrates) now have a different shape and are released.
5. The active site is now available for new substrates.

23

Inhibitors

What is normal binding?

When the substrate goes directly to the active site of an enzyme without any interference.

24

Inhibitors

What is competitive inhibition?

When a competing substrate goes into the active site and the original substrate doesn't bind.

25

Inhibitors

What is noncompetitive inhibition?

When a noncompetitive inhibitor binds to a different active site on the same enzyme. This changes the shape of the active site for the original substrate and it cannot bind.