Bioenergetics

Question 1

What are the four forms of energy?

Answer 1

Chemical

Electrical

Mechanical

Heat

Question 2

What is chemical energy?

Answer 2

Energy stored in bonds of chemical compound.

Question 3

What is electrical energy?

Answer 3

Energy resulting from flow of electric charge.

Question 4

What is mechanical energy?

Answer 4

The sum of kinetic and potential energy.

ORGANIZED MOTION

Question 5

What is heat energy? (aka molecular kinetic energy)

Answer 5

RANDOM atomic-molecular motion

The more heat you have the more kinetic energy you have.

Question 6

What is free energy (G)?

Answer 6

The total amount of energy available to break and form other chemical bonds.

The energy available to do work in a system.

Question 7

What is an endergonic reaction?

Answer 7

A reaction in which the energy of the products is greater than the energy of the reactants.

Energy must be supplied.

Delta G is positive

Ex. Photosynthesis

Question 8

What is an exergonic reaction?

Answer 8

A reaction in which the energy of the products is lower than the energy of the reactants.

Energy is released.

SPONTANEOUS

Delta G is negative

ex. Cellular Respiration

Question 9

What are the two ways the rate of a reaction can be increased?

Answer 9

Heating

A Catalyst

Question 10

What three things make up and ATP?

Answer 10

3 phosphate groups

Ribose

Adenine

Question 11

What is a calorie?

Answer 11

The heat required to change the temperature of one gram of substance by one degree Celsius

Question 12

How many protons and electrons are donated to NAD+ when it’s reduced?

Answer 12

1 proton

2 (high energy) electrons

Question 13

How is ATP made?

Answer 13

Cellular respiration

Question 14

What are the three stages of cellular respiration?

Where do they occur?

Answer 14

Glycolysis
- cytosol

Citric Acid Cycle
- mitochondrial matrix

Oxidative Phosphorylation
- inner mitochondrial membrane

Question 15

What are the products of glycolysis?

Answer 15

Net 2 ATP

2 NADH

2 Pyruvate

Question 16

What is the gist of the citric acid cycle?

Answer 16

A pyruvate enters the mitochondrial matrix. 1 carbon is removed and CO2 exits the cycle. A hydrogen is transferred to NADH and exits the cycle.

The remaining combines to form Acetyl-CoA.

This enters the citric acid cycle by binding to oxaloacetate.

The cycle continues until oxaloacetate is reformed.

Question 17

What is the key purpose of the citric acid cycle?

Answer 17

Hydrogens are bumped off and used for entry into the electron transport chain.

Also, high energy electron carriers are produced (NADH and FADH2)

Question 18

What are the products of ONE TURN of the citric acid cycle?

Answer 18

3 - NADH

1 - FADH2

2 - CO2

1 - ATP

Question 19

What is the final electron acceptor in the electron transport chain?

Answer 19

Molecular oxygen (that we breathe in)

O2- and H+ combine to make H2O

Question 20

What are the two purposes of the long chain of electron carriers in the electron transport chain?

Answer 20

The high energy electrons release energy as they move through the chain. This energy is used to transport H+ across the inner membrane.

Also, by removing the energy, the oxygen can accept the electron, which drives the reactions. If The energy was still too high, the oxygen wouldn’t be able to bind to it.

Question 21

How does ATP synthase work?

Answer 21

ATP synthase operates by creating a channel through which hydrogen can go down its concentration gradient back into the mitochondrial matrix. The energy released in doing so is used by ATP synthase to bind ADP to Pi

Question 22

What is the net yield of cellular respiration?

Answer 22

2 ATP from glycolysis

2 ATP from the Citric Acid Cycle

34 ATP from oxidative phosphorylation

MINUS 2 ATP for shuttling NADH across mitochondrial membrane

= TOTAL ABOUT 36 ATP

Question 23

How many ATP molecules are made in prokaryotes v eukaryotes?

Answer 23

Eukaryotes = 36 ATP

Prokaryotes = 38 ATP