Chapter 6,7 Enzymes And Metabolism

Question 1

Metabolism

Answer 1

Sum total of all chemical reactions that occur within a living organism

Question 2

Chemical reaction

Answer 2

Process in which one or more substance are changed to other substances
Reaction is reservable
ATP can drive a reaction in a desired direction
Catalysts can be used to speed up the rate of reaction

Question 3

Energy

Answer 3

The ability to promote change

Question 4

Kinetic energy

Answer 4

Associated with movement

Question 5

Potential energy

Answer 5

Energy that a substance possesses because of its structure or location
Glucose - it can potentially be oxidized to CO2 and water

Question 6

Thermodynamics

Answer 6

Study of energy interconversions

Question 7

First Law of thermodynamics

Answer 7

Energy cannot be created or destroyed

Question 8

Second law of thermodynamics

Answer 8

Transfers of energy, or transformation of energy, increases the entropy of a system

Question 9

Gibbs free energy

Answer 9

H = G+ TS

Question 10

Spontaneous Reactions

Answer 10

Occurs with out an additional input of energy
The change in free energy (G) that occurs as a result of a chemical reaction can be used to determine if a reaction is spontaneous

Question 11

Evaluating free energy change

Answer 11

G < 0 negative free energy

G > 0 positive free energy

Question 12

Exergonic

Answer 12

Releases free energy spontaneous

Question 13

Endergonic

Answer 13

Requires addition of free energy from the environment

Does not proceed spontaneously

Question 14

Cellular respiration

Glycolysis

Answer 14

Involves the breakdown of glucose

Can occur in the presence of oxygen equals aerobic, or in the absence of oxygen equals an anaerobic

10 steps can be grouped into three phases
Energy investment, cleavage, energy liberation

Yields 2 NADH and 4 ATP , 2 Pyruvate
Happens in cytosol

Question 15

Phases of glycolysis

1. Energy investment

Answer 15

2 ATP hydrolyzed

Phosphates from these ATP are used to convert the glucose to fructose - 1,6 bisphosphate over three sequential reactions

Question 16

Phases of glycolysis

2. Cleavage

Answer 16

Fructose 1,6 bisphosphate (6C) is cleaved into two molecules of glyceraldehyde -3- phosphate (3 carbon each)

Question 17

Three phases of glycolysis

3. Energy liberation

Answer 17

Two glyceraldehyde -3-phosphate molecules are broken down into two Pyruvate molecules

Produces 2 NADH and 4ATP

Question 18

Breakdown of Pyruvate

Answer 18

In eukaryotes, Pyruvate is transported to the mitochondria matrix

Broken down by the enzyme complex called pyruvate dehydrogenase

Question 19

For each Pyruvate

Answer 19

One molecule of CO2 is removed

Remaining Acetyl group is attached to coenzyme to create acetyl CoA
NADH is made

Question 20

Citric Acid Cycle

Metabolic cycle

Answer 20

Particular molecules enter the cycle while others leave

Question 21

Citric acid cycle

Answer 21

Acetyl group is removed from Acetyl CoA and attached to oxaloacetate (4C) to form citrate (6C)

Series of 8 steps produces 2 CO2, 3NADH, 1FADH2, 1 GTP (used to make 1 ATP)
Oxaloacetate is regenerated and starts the cycle again of Acetyl CoA is available

Question 22

Oxidative Phosphorylation

Answer 22

6 CO2, 4ATP, 10 NADH AND 2FADH2
Turn oxidative phosphorylation, high energy electrons are removed from NADH and FADH2 to make more ATP by phosphorylation of ADP
Typically requires oxygen

Question 23

Electron Transport Chain

Answer 23

A group of protein complexes and small organic molecules embedded in the inner mitochondrial membrane

Accept and release electrons
Transfers are redox reactions

Question 24

Oxygen

Answer 24

The electron transport chain is also called the respiratory chain

Oxygen that we breathe is used in the process as the final electron acceptor
In the last step, electrons are transferred from cytochrome oxidase to molecular oxygen

Question 25

H+ electrochemical Gradient

Answer 25

Electrons travelling along the electron transport chain release free energy
Some of this free energy is captured by H+ pumps and is used to pump H+ out of the mitochondrial matrix and in the inter-membrane space
H+ is higher pursue the matrix

Question 26

Electron transfers

Answer 26

Electrons on NADH and FADH2 have a high amount potential energy
As electrons travel to acceptors of higher electronegativity, free energy is released
Some of release energy it’s hard enough to pump hydrogen plus across to enter mitochondrial membrane

Question 27

ATP Synthase

Answer 27

The hydrogen plus electrochemical gradient is a source of potential energy
The lipid bilayer is relatively impermeable to hydrogen plus, but had to jump class can pass through ATP synthase
The free energy released is hardest by the enzyme ATP synthase to make ATP from ADP and PI

Question 28

Chemiosmosis

Answer 28

Chemicals in the days of ATP by pushing hydrogen plus across a membrane

ATP synthase