U3L1: Intro to Metabolism

Question 1

What is metabolism?

Answer 1

All the chemical rxns in a cell/organism that are needed for life processes.

Question 2

What is energy?

Answer 2

Energy is the ability to do work.

Question 3

What is the first law of thermodynamics?

Answer 3

Energy cannot be created or destroyed, only transferred or transformed.
EX: a caribou eats plants (chem energy) and converts it to other forms of energy (mechanical energy to move)

Question 4

What is the second law of thermodynamics?

Answer 4

During a energy transfer, entropy (disorder) increases because useful energy becomes unusable.
EX: A runner converts only 40% of the energy into a useful form. The rest is unused and given off as thermal energy (body heat).

Question 5

What is entropy?

Answer 5

It is the number of possible arrangements a system can have (how many ways can you rearranging its insides while keeping its outwardly state unchanged).

Question 6

What happens when you release energy from ATP?

Answer 6

Produces ADP + pi

Question 7

What happens when you add energy to ADP + Pi?

Answer 7

Produces ATP

Question 8

What are spontaneous changes?

Answer 8

A change that begins will continue on its own and doesn’t require a continuous supply of energy.

Question 9

What are endergonic rxns?

Answer 9

rxns that do not occur spontaneously. Energy is needed to initiate the reaction EX: converting CO2 and water into glucose and O2 gas

Question 10

What are exergonic rxns?

Answer 10

rxns that happen spontaneously and release free energy
EX: burning of wood: cellulose in tree contain a lot of potential energy and burning wood releases free energy

Question 11

What is free energy?

Answer 11

Energy that is able to do useful work; the energy that is not lost and does work after an energy transfer.

Question 12

In an endergonic rxn…

Answer 12

Free energy is gained (reactants have less free energy than products)

Question 13

In an exergonic rxn…

Answer 13

Free energy is released (products have less free energy than reactants)

Question 14

What are anabolic reactions?

Answer 14

they are enzyme-catalyzed rxns where simpler molecules form complex molecules (require energy to form bonds and are reduction rxns)

Question 15

What are catabolic reactions?

Answer 15

they are enzyme-catalyzed rxns where a larger molecule breakdown into simpler molecules (ATP is produced, usually oxidation rxns)

Question 16

What is energy coupling?

Answer 16

The transfer of energy from one reaction to another in order to drive the second reaction

Question 17

What is the equation for cellular respiration?

Answer 17

C6H12O6 + 6O2 → 6CO2 + 6H2O + energy!

Question 18

What are reduction rxns?

Answer 18

gain of electrons or hydrogen –> require energy (occurs simultaneously and have higher energy lvl then the oxidized)

Question 19

What are oxidation rxns?

Answer 19

lose of electrons or hydrogen –> release energy (occurs simultaneously)

Question 20

What is an electron carrier?

Answer 20

a compound that picks up electrons from energy-rich compounds and gives them to low-energy compounds
EX: NAD+

Question 21

Explain LEOGER

Answer 21

When a compound accepts an electron it becomes reduced. When a compound loses an electron it becomes oxidized.

Question 22

Electron Carriers in Respiration

Answer 22

NAD+: nicotinamide adenine dinucleotide—-> reduced NADH+ provides source of energy to drive ATP synthesis

FAD+: flavin adenine dinucleotide
—->reduced FADH2